GASTRO: BOARDS AND BEYOND Flashcards
(1210 cards)
1
Q
What condition is characterized by endometrial cancer, colon cancer, and a family history of endometrial and ovarian cancer?
A
Lynch syndrome (hereditary nonpolyposis colorectal cancer).
1
Q
What is the “3-2-1 Rule” in relation to Lynch syndrome?
A
Requires 3 or more Lynch-associated cancers (2 of whom are first-degree relatives) over 2 or more generations, with at least 1 person affected by age 50.
2
Q
What type of genetic inheritance pattern does Lynch syndrome follow?
A
Autosomal dominant.
3
Q
What is the underlying cause of Lynch syndrome?
A
A DNA mismatch repair gene defect leading to microsatellite instability.
4
Q
How does Lynch syndrome affect the development of cancer?
A
It causes dysplasia in multiple organs that becomes malignant faster than typical lesions.
5
Q
At what age do patients with Lynch syndrome typically develop cancers compared to the general population?
A
Patients develop cancers at a much younger age than would typically occur.
6
Q
What role do genetic counseling and screening play in managing Lynch syndrome?
A
They are crucial for early detection and prevention strategies in affected individuals and families.
7
Q
What gene mutation is associated with familial adenomatous polyposis (FAP)
A
Mutations in the APC gene.
8
Q
What is the primary cancer risk associated with familial adenomatous polyposis?
A
Increased risk of colorectal cancer.
9
Q
Why is “polyposis” included in the name familial adenomatous polyposis?
A
Because the APC gene leads to the development of multiple colonic polyps.
10
Q
Does familial adenomatous polyposis increase the risk of breast or ovarian cancers?
A
No, it does not increase the risk of breast or ovarian cancers
11
Q
How many colon polyps do patients with familial adenomatous polyposis typically develop?
A
Patients can develop hundreds to thousands of colon polyps.
12
Q
At what age do patients with familial adenomatous polyposis typically start developing polyps?
A
Often by adolescence.
13
Q
What is Gardner’s syndrome?
A
An autosomal dominant condition characterized by adenomatous polyposis and soft-tissue tumors.
14
Q
Which gene mutation is responsible for Gardner’s syndrome?
A
APC gene mutation on chromosome 5.
15
Q
How many colonic polyps do patients with Gardner’s syndrome typically develop?
A
Hundreds of colonic polyps.
16
Q
What is the malignancy potential of the colonic polyps in Gardner’s syndrome?
A
Although benign, they have a strong malignancy potential.
17
Q
What is the risk of developing colorectal cancer for patients with Gardner’s syndrome or familial adenomatous polyposis (FAP) by age 50?
A
100% chance if the colon is not removed.
18
Q
What are some extra-colonic features associated with Gardner’s syndrome?
A
Osteomas, congenital hypertrophy of retinal pigment epithelium (CHRPE), and epidermoid cysts.
19
Q
Where do osteomas commonly develop in patients with Gardner’s syndrome?
A
In the mandible.
20
Q
Where do epidermoid cysts typically occur in Gardner’s syndrome?
A
In locations such as the face, scalp, and extremities.
21
Q
How does classic familial adenomatous polyposis (FAP) differ from Gardner’s syndrome?
A
FAP is restricted to the colon and does not involve the development of epidermoid cysts, fibromas, or osteomas.
22
Q
What common genetic mutation is found in both Gardner’s syndrome and familial adenomatous polyposis (FAP)?
A
APC gene mutation.
23
Q
Why are the terms Gardner’s syndrome and FAP sometimes used interchangeably?
A
Because some FAP patients have limited extra-colonic features similar to those in Gardner’s syndrome.
24
In a patient with osteomas and cysts, which syndrome is the more accurate diagnosis: Gardner’s syndrome or classic FAP?
Gardner’s syndrome is the better answer.
25
Is a variant of Lynch syndrome (hereditary non-polyposis colorectal cancer) with sebaceous skin tumors.
Muir-Torre syndrome
26
Is a variant of familial adenomatous polyposis with malignant central nervous system tumors.
Turcot’s syndrome
27
What is juvenile polyposis syndrome (JPS)?
An autosomal dominant condition involving numerous hamartomatous polyps in the GI tract, primarily in the colon and rectum.
28
What types of polyps are most commonly found in JPS?
Hyperplastic, adenomatous, and hamartomatous polyps.
29
At what age can polyps in JPS begin to develop?
As early as the first decade of life.
30
What does the term “juvenile” refer to in juvenile polyposis syndrome?
It refers to the histological characterization of the polyps, not the age of the patient.
31
What is the most common clinical manifestation of JPS?
Rectal bleeding
32
What are some other symptoms that can occur in JPS?
Prolapsing polyps, pain, diarrhea, and iron-deficiency anemia
33
What is the risk of colorectal cancer in patients with JPS by age 35?
About 20%, increasing to 68% by age 60.
34
What is the lifetime risk of gastric cancer in patients with JPS?
20% to 30%
35
What is required for a clinical diagnosis of JPS?
At least one of the following:
- Five or more juvenile polyps in the colorectum
- Multiple juvenile polyps throughout the GI tract
- Any number of juvenile polyps in someone with a known family history of the disease.
36
How is JPS managed?
Routine screening for colorectal cancer with colonoscopy and gastric cancer with upper endoscopy.
37
Is an autosomal dominant syndrome associated with hamartomatous polyps of the GI tract, mucosal hyperpigmentation, and increased risk of cancer. Although this patient has hamartomatous lesions of the GI tract, he does not have the pigmented macules seen in more than 95% of PJS.
Peutz-Jeghers syndrome (PJS)
38
What is a common site for distant metastases of colon cancer?
The liver.
39
Why does colon cancer commonly metastasize to the liver?
Because of the portal venous drainage from the intestinal tract to the liver.
40
Besides the liver, what are other potential sites of metastasis for colon cancer?
The lungs and peritoneum.
41
How do most carcinomas, including colonic adenocarcinoma, primarily spread?
Via lymphatics.
42
What are the alternative routes of metastasis for colon cancer?
Through the bloodstream (hematogenous spread via the portal system), direct extension of the tumor, and seeding of peritoneal fluid.
43
What are the most common sites of metastasis for colon cancer?
Regional lymph nodes, the liver, lungs, and the peritoneum.
44
Intraperitoneal seeding refers to the spread of tumors via intraperitoneal fluid. Ovarian tumors in women often spread through this mechanism. Colon cancer can spread via intraperitoneal seeding. When it does, lesions appear on the outside of the liver, since this is the area in contact with intraperitoneal fluid. In addition to the exterior of the liver, seeding from colon cancer often leads to abdominal lesions in specific areas with stasis of peritoneal fluid (normally this fluid moves with position and bearing down). These include
The pouch of Douglas, the right lower quadrant mesentery, and the peritoneum of the sigmoid colon.
45
Develops in the setting of cirrhosis and chronic infection by hepatitis B or C.
A primary liver cancer or hepatocellular carcinoma
46
Occurs in immunocompromised patients (e.g., recipients of solid organ transplants, allogeneic hematopoietic cell transplants, etc.).
Systemic or invasive aspergillosis
47
What is the progression of mutations in colon cancer called?
The adenoma-carcinoma sequence (chromosomal instability pathway).
48
Which gene is the first to mutate in the adenoma-carcinoma sequence?
The APC gene (a tumor suppressor gene).
49
What is the significance of a mutation in the KRAS gene?
It is a proto-oncogene mutation found in the majority of hyperplastic colon polyps and is essential for neoplastic progression.
50
What is the third mutation that cells acquire to become malignant in colon cancer?
A mutation in the p53 gene (another tumor suppressor gene).
51
What does the presence of all three mutations (APC, KRAS, p53) indicate?
The cells are malignant.
52
How does familial adenomatous polyposis (FAP) affect the adenoma-carcinoma sequence?
n FAP, germline mutations in the APC gene are inherited, leading to numerous polyps due to the mutation being present from the start.
53
What characterizes a sporadic polyp in colon cancer?
A negative family history for colon cancer and no inherited gene mutations.
54
What deficiency is this woman experiencing in the context of carcinoid syndrome?
Niacin deficiency
55
What symptoms are associated with elevated serotonin levels in carcinoid syndrome?
Flushing, palpitations, abdominal pain, and diarrhea
56
What is the precursor molecule to serotonin?
Tryptophan
57
How much of tryptophan is normally utilized for serotonin production?
About 1%
58
In carcinoid syndrome, what percentage of tryptophan may be used for serotonin synthesis?
Up to 70%
59
What deficiency can result from the increased use of tryptophan for serotonin synthesis?
Tryptophan deficiency
60
How is niacin (vitamin B3) produced in the body?
From tryptophan
61
What are the primary symptoms of Sjögren’s syndrome?
Dry mouth (xerostomia) and dry eyes (xerophthalmia).
62
How does diminished saliva production affect oral health in Sjögren’s syndrome?
It frequently leads to an increased risk of dental caries (cavities).
63
What is the mechanism of action of pilocarpine in treating Sjögren’s syndrome?
Pilocarpine stimulates muscarinic receptors (M1, M2, M3) to increase oral and ophthalmic secretions.
64
Why is pilocarpine often intolerable for many patients?
Its nonselective action on muscarinic receptors causes cholinergic side effects.
65
What are some common cholinergic side effects of pilocarpine?
Sweating, urinary frequency, diarrhea, bradycardia, nausea, weakness, flushing, and hypotension.
66
What eye effect is caused by pilocarpine?
Miosis (pupillary constriction).
67
Anticholinergic drugs include atropine and scopolamine. Some side effects include:
Hypertension, constipation, urinary retention and mydriasis.
68
What is the most common type of salivary gland tumor?
Pleomorphic adenomas.
69
Where are pleomorphic adenomas typically located?
In the superficial lobes of the parotid glands.
70
Are pleomorphic adenomas benign or malignant?
They are usually benign, but they can undergo malignant transformation.
71
What is a potential complication of pleomorphic adenomas regarding facial anatomy?
They can invade the facial nerve.
72
Why are pleomorphic adenomas described as “biphasic”?
They contain glandular epithelial cells surrounded by supportive stroma.
73
What types of supportive tissue can be found in pleomorphic adenomas?
Cartilage, hyaline, or bone.
74
What term is sometimes used to describe the composition of pleomorphic adenomas?
"Chondromyxoid," due to the presence of cartilage (chondroid tissue) and mucous cells (myxoid tissue).
75
What is a common issue associated with the surgical removal of pleomorphic adenomas?
Local recurrence.
76
What are Type I branchial cleft cysts, and where do they form?
They are cavities near the parotid gland caused by incomplete regression of ectodermal structures in the embryo.
77
What is the most common malignant salivary gland tumor?
Mucoepidermoid carcinoma.
78
What cell types are found in mucoepidermoid carcinoma?
A mixture of mucin-producing columnar cells and epidermoid cells.
79
What viral infection is caused by paramyxovirus and characterized by bilateral parotid gland swelling?
Mumps.
80
What would be seen on biopsy in a case of mumps?
A lymphocytic infiltrate consistent with viral infection.
81
What type of tumors are Warthin’s tumors, and are they benign or malignant?
Warthin’s tumors are benign salivary gland tumors.
82
What is the histological characteristic of Warthin’s tumors?
Fluid-filled cysts surrounded by lymphoid infiltrates.
83
What are Warthin’s tumors also known as?
Papillary cystadenoma lymphomatosum.
84
What is the second most common type of salivary gland tumor?
Warthin’s tumors.
85
Where do Warthin’s tumors almost always occur?
In the parotid glands.
86
Why should both parotid glands be examined in clinical practice?
Because Warthin’s tumors can be multifocal and bilateral.
87
In which gender do Warthin’s tumors occur more commonly?
Males
88
How much more likely are smokers to develop Warthin’s tumors?
Smokers are 8 times more likely to develop this tumor.
89
What are the histological features of Warthin’s tumors?
They are composed of fluid-filled cystic spaces lined with epithelial cells and dense lymphoid infiltrates, sometimes forming germinal centers.
90
Is the most common salivary gland malignancy in adults. It is composed of a variable mixture of squamous, mucus-secreting, and intermediate cells.The cystic appearance of this man’s tumor is not consistent with mucoepidermoid carcinoma.
Mucoepidermoid carcinoma
91
Represent 60% of parotid tumors and present as painless, slow-growing, discrete masses. Histologically, pleomorphic adenomas are called “biphasic,” because they contain glandular epithelial cells surrounded by stroma (supportive tissue) with cartilage, hyaline, or bone. The tumor is sometimes described as “chondromyxoid,” because it contains cartilage (chondroid tissue) and mucous cells (myxoid tissue).
Pleomorphic adenomas
92
Are rare and aggressive salivary tumors that occur in older men and have distant metastases at the time of presentation.
Small-cell carcinomas
93
Adenoid cystic carcinoma (ACC) is a locally aggressive tumor with three growth patterns: ?. This tumor is more common in the submandibular, sublingual, and minor salivary glands. ACC is not associated with smoking.
Tubular, cribriform, and solid.
94
What is the most common malignant salivary gland tumor in all age groups?
Mucoepidermoid carcinoma.
95
What types of cells compose mucoepidermoid carcinoma?
Variable mixtures of squamous, mucus-secreting, and intermediate cells
96
How do low-grade mucoepidermoid carcinoma lesions typically appear histologically?
They are cystic and have a higher percentage of squamous and mucus-producing cells than intermediate cells.
97
How do high-grade mucoepidermoid carcinoma lesions differ from low-grade lesions?
High-grade lesions are more solid, have more squamous and intermediate cells, show signs of anaplasia in the squamous component, and contain fewer mucus-producing cells.
98
What percentage of all salivary gland tumors do mucoepidermoid carcinomas represent?
Approximately 15%.
99
Where do mucoepidermoid carcinomas typically occur?
In the parotid glands or minor salivary glands.
100
What are some potential complications of mucoepidermoid carcinoma?
They can invade the facial nerve and present with pain and paralysis.
101
What is Meckel’s diverticulum a remnant of?
The embryonic vitelline duct (or yolk stalk).
102
What is a diverticulum?
An outpouching of the intestines.
103
In which part of the intestine does Meckel’s diverticulum occur?
In the small intestine.
104
What type of tissue can be found in Meckel’s diverticulum?
Gastric mucosa (or, rarely, pancreatic tissue).
105
What do the parietal cells in the gastric mucosa of Meckel’s diverticulum produce?
Acid.
106
How can gastric mucosa in Meckel’s diverticulum lead to complications?
It may cause ulceration in the adjacent small bowel, resulting in bleeding.
107
What is the "rule of twos" regarding Meckel’s diverticulum?
It occurs in about 2% of the population, is about 2 inches long, found about 2 feet from the ileocecal valve, 2% of patients develop complications, and has a male-to-female ratio of 2:1.
108
Lymphocytes are found in ? of the intestines. These cells are not responsible for the bleeding in Meckel’s diverticulum.
Peyer's patches
109
Chief cells are found in the stomach and produce ? for digestion of proteins.
pepsin
110
Are glandular cells present in epithelial coatings of the mucous membranes of the respiratory tract and the digestive system. These cells produce mucus to protect the digestive or respiratory tubes.
Goblet cells
111
Are found in the jejunum and duodenum. They release secretin when stimulated by a fall in pH to 4 or below in the small intestinal lumen. Secretin increases the secretion of bicarbonate (HCO3-) from the pancreas.
S cells
112
What findings during pregnancy are consistent with Down syndrome (trisomy 21)?
Elevated serum β-HCG concentrations and fetal nuchal translucency detected on ultrasound.
113
What is duodenal atresia?
A complete obstruction of the duodenum by an atretic (closed) lumen.
114
What is duodenal stenosis?
A narrowed duodenal lumen that causes partial obstruction, allowing some bile and intestinal contents to flow.
115
How do duodenal atresia and stenosis commonly present in newborns?
With bilious vomiting due to backup of intestinal contents.
116
What classic sign is seen on an abdominal X-ray for duodenal atresia?
The "double-bubble" sign, showing a pocket of air before and after the duodenum.
117
What is the initial treatment for duodenal atresia or stenosis?
Nasogastric decompression and fluids, followed by surgical intervention.
118
Jejunal atresia involves a failure of the jejunum to canalize. This can be indistinguishable from duodenal atresia with abdominal distension and bilious vomiting. The ? on x-ray is classically associated with jejunal atresia. In addition, duodenal stenosis is more likely in a baby with Down syndrome.
“triple bubble” sign
119
Is a condition that affects premature infants. The intestinal wall develops necrosis, and symptoms start within 2 weeks of birth including fever, vomiting, and diarrhea with abdominal distension.
Necrotizing enterocolitis
120
Is characterized by narrowing of the lumen of the pylorus due to smooth muscle hypertrophy. Babies present with nonbilious vomiting after eating, and a palpable mass in the right upper quadrant classically described as “olive-shaped.”
Pyloric stenosis
121
Result from a failure of the trachea to completely separate from the esophagus, leaving a connection between these structures. This results in aspiration of stomach contents into the lungs when infants attempt to feed.
Tracheoesophageal fistulas
122
What is duodenal atresia?
A congenital failure of the duodenum in the small intestine to canalize.
123
What are the clinical features of duodenal atresia?
Distension of the stomach with bilious vomiting.
124
What does the "double bubble" sign indicate on X-ray?
A blind loop of the duodenum and gastric dilatation associated with duodenal atresia.
125
How common is duodenal atresia?
It occurs in about 1 in every 5,000 to 10,000 live births.
126
What percentage of infants with duodenal atresia have Down syndrome?
20% to 40%.
127
What condition can result from any process that disrupts swallowing in the womb?
Polyhydramnios (excess amniotic fluid).
128
How can pregnancy be affected by a fetus with duodenal atresia?
It is often complicated by polyhydramnios due to disrupted swallowing.
129
Is a life-threatening complication of pregnancy. It occurs in the 3rd trimester with abrupt onset of painful vaginal bleeding. Abruption is not associated with duodenal atresia.
Placental abruption
130
Is a complication of pregnancy that leads to hypertension, proteinuria, edema, and seizures. This is not associated with duodenal atresia.
Eclampsia
131
In placenta previa, the placenta attaches to the lower uterus over the cervix. ? can be life-threatening in this situation. Placenta previa is not associated with duodenal atresia.
Vaginal delivery
132
How is amniotic fluid produced and removed?
It is produced by fetal kidneys (fetal urine) and removed by fetal swallowing and intestinal absorption.
133
What can cause excess amniotic fluid?
Increases in urinary excretion or impaired swallowing/digestion.
134
What physical changes might a woman with polyhydramnios experience?
A rapidly expanding abdomen.
135
What is the amniotic fluid index (AFI)?
The sum of the measurement of the maximal depth of the amniotic fluid pocket in all four quadrants of the abdomen.
136
Which condition is specifically associated with polyhydramnios?
Esophageal atresia.
137
What occurs in esophageal atresia?
The esophagus ends in a blind pouch, preventing appropriate swallowing of amniotic fluid by the fetus.
138
Refers to poor growth of a fetus during pregnancy. It can be caused by poor maternal nutrition or lack of adequate oxygen supply to the fetus. It is associated with oligohydramnios (decreased amniotic fluid).
Intrauterine growth restriction
139
Refers to pulmonary hypoplasia and limb abnormalities that occur in the fetus due to oligohydramnios (decreased amniotic fluid). The amniotic fluid index is low in oligohydramnios.
Potter’s syndrome
140
Pulmonary agenesis
It is associated with oligohydramnios.
141
Is the failure of one or both kidneys to form. The absence of normal fetal renal function causes oligohydramnios.
Renal agenesis
142
What is malrotation?
A condition where the cecum is positioned in the right mid- to upper quadrant instead of the right lower quadrant due to improper rotation of the midgut during development.
143
What causes volvulus in the context of malrotation?
The twisting of the intestines around the mesentery due to abnormal positioning during peristalsis.
144
What symptoms may develop in a baby with malrotation and volvulus?
Bilious emesis (vomiting) and abdominal pain.
145
Is an abdominal X-ray reliable for diagnosing malrotation with volvulus?
No, it is often unreliable and can be normal.
146
What is the test of choice for diagnosing malrotation with volvulus?
Upper GI contrast study with fluoroscopy.
147
What is the primary treatment for malrotation with volvulus?
Surgical intervention.
148
Is characterized by absence or underdevelopment of the bile ducts. This leads to biliary obstruction with jaundice, dark urine, and acholic stools.
Biliary atresia
149
Why is reflux of stomach contents common in neonates?
The lower esophageal sphincter is not completely developed.
150
How is regurgitation in neonates typically characterized?
It is effortless and without vomiting, often referred to as “happy spitters.”
151
When does regurgitation usually occur in neonates?
Typically occurs more than 10 minutes after feeding
152
Is bilious vomiting common in neonates with reflux?
No, bilious vomiting does not occur in these cases.
153
In atresia, there is no lumen for intestinal flow. This leads to vomitting shortly after the baby first begins to feed. The fact that this baby was feeding normally during his first week of life makes intestinal obstruction from atresia
Very unlikely.
154
The pylorus is the opening of the stomach into the duodenum. Pyloric stenosis is characterized by narrowing of the lumen of the pylorus due to smooth muscle hypertrophy. Babies present with ? after eating, and a palpable mass in the right upper quadrant, classically described as “olive-shaped.”
Non-bilious vomiting
155
What is a hiatal hernia?
A protrusion of the stomach through the diaphragm and into the thoracic cavity.
156
What causes hiatal hernias?
Progressive disruption of the gastroesophageal junction (GEJ) over time.
157
Where does the gastroesophageal junction (GEJ) normally reside?
Below the diaphragm.
158
What happens to the hiatal tunnel in patients with a hiatal hernia?
It widens, allowing the GEJ to slide upward.
159
What happens to the phrenoesophageal membrane in hiatal hernias?
It becomes lax, failing to tether the esophagus to the diaphragm.
160
What are the two main types of hiatal hernias?
Sliding (type I) and paraesophageal (type II, III, and IV) hernias.
161
Which type of hiatal hernia is the most common?
Sliding hernias (90 percent).
162
Can hiatal hernias be asymptomatic?
Yes, they may be asymptomatic.
163
What are common clinical features of hiatal hernias?
Symptoms of gastroesophageal reflux disease (GERD) such as pain after eating, regurgitation, and dysphagia.
164
What can a chest x-ray show in large sliding hiatal hernias?
A retrocardiac mass with an air-fluid level, indicating gastric cardia protrusion into the thoracic cavity.
165
What is achalasia?
A condition characterized by increased tone of the lower esophageal sphincter (LES), making it difficult to relax.
166
What causes the increased tone of the LES in achalasia?
Absence of inhibitory innervation to the LES, such as that seen in Chagas disease.
167
Where is Chagas disease common?
South America.
168
What are common symptoms of achalasia?
Progressive dysphagia, regurgitation, and aspiration of undigested food.
169
How might a patient with achalasia present in terms of x-ray findings?
Evidence of a hiatal hernia may be present alongside classic symptoms.
170
What is gastroparesis?
A condition characterized by delayed emptying of gastric contents.
171
What is a common cause of gastroparesis?
Many cases are idiopathic, but it can be associated with diabetes.
172
What are common symptoms of gastroparesis?
Early satiety, nausea, abdominal pain, bloating, and weight loss.
173
How might a patient with gastroparesis present in relation to hiatal hernia?
They may have classic hiatal hernia symptoms and evidence of a hiatal hernia on x-ray.
174
What are mediastinal lymphomas?
They are a type of lymphoma that can present as a mediastinal mass.
175
What is an important consideration in the differential diagnosis of a mediastinal mass?
Mediastinal lymphomas are part of the differential diagnosis.
176
What findings indicate that a patient does not have a mediastinal mass?
A chest X-ray showing no mediastinal mass.
177
What systemic symptoms do patients with lymphoma commonly present with?
Fevers, weight loss, and night sweats.
178
Do symptoms of GERD typically occur in mediastinal lymphoma?
No, symptoms of GERD generally do not occur in mediastinal lymphoma.
179
Zenker’s diverticulum is an outpouching of the mucosa and submucosa between the cricopharyngeus muscle and lower inferior constrictor muscles. This creates an outpouching in the pharynx. Zencker’s diverticulum is characterized by
Transient dysphagia, pulmonary aspiration, foul breath, and appearance of a neck mass.
180
What is congenital diaphragmatic hernia (CDH)?
A condition where abdominal contents pass into the thoracic cavity through a hole in the diaphragm.
181
What characteristic appearance does a baby with CDH often have at birth?
A "scaphoid-shaped" (curved inward) abdomen due to abdominal contents in the chest.
182
Why does herniation of abdominal contents occur more often on the left side in CDH?
The liver provides relative protection of the diaphragm on the right side.
183
What complication can result from intestinal structures herniating into the chest cavity?
Pulmonary hypoplasia due to lack of space for normal lung development.
184
What is believed to cause congenital diaphragmatic hernia?
Defective formation of the pleuroperitoneal membranes, which separate the thoracic and peritoneal cavities.
185
How is CDH often diagnosed in modern medicine?
By ultrasound during pregnancy.
186
What findings on a chest X-ray indicate CDH?
Air- or fluid-filled structures in the thorax due to herniation of bowel.
187
What is the primary treatment for congenital diaphragmatic hernia?
Surgery to reposition the abdominal organs and seal the diaphragm.
188
What factors influence the prognosis of CDH?
The degree of organ hypoplasia, especially pulmonary hypoplasia.
189
What are foregut defects?
Congenital abnormalities of the upper GI tract, including various malformations.
190
Name some congenital abnormalities caused by foregut defects
Esophageal atresia and stenosis, pyloric stenosis, atresia of the gallbladder and bile ducts, liver malformations, and pancreatic malformations.
191
What results from the persistence of the second pharyngeal cleft or pouch?
A branchial fistula, which is an abnormal tract on the side of the neck and in the pharynx.
192
What causes tracheoesophageal fistulas?
Incomplete separation of the esophagus and trachea by the tracheoesophageal septum during week 4 of development.
193
What is esophageal atresia?
A congenital condition where the esophagus ends in a blind pouch and does not connect to the stomach.
194
What is pyloric stenosis?
A condition where the pylorus (the opening from the stomach to the duodenum) is narrowed, causing obstruction.
195
What is a femoral hernia?
A herniation of bowel through the femoral ring.
196
What causes the femoral ring to widen and weaken?
Aging, injury, or frequent exposure to high intra-abdominal pressure (e.g., from constipation).
197
Where is a femoral hernia typically located?
Under the inguinal ligament, producing a mass or bulge.
198
How can a femoral hernia be identified during an examination?
By a line drawn between the anterior superior iliac spine and the pubis.
199
In which population is femoral hernia more common?
In woman's
200
What is an indirect inguinal hernia?
A type of hernia where bowel herniates above the inguinal ligament.
201
202
In which population do indirect inguinal hernias most commonly occur?
Males
203
Where does the bowel herniate in an indirect inguinal hernia?
Laterally in relation to the inferior epigastric vessels and into the scrotum.
204
What causes indirect inguinal hernias?
Patency of the processus vaginalis.
205
How can indirect inguinal hernias be distinguished from direct inguinal hernias?
Indirect hernias occur lateral to the inferior epigastric vessels, while direct hernias occur medial to them.
206
What is a direct inguinal hernia?
A type of hernia that passes through the inguinal triangle above the inguinal ligament.
207
Where is a direct inguinal hernia located in relation to the inferior epigastric vessels?
Medially in relation to the inferior epigastric vessels.
208
In which population are direct inguinal hernias more common?
Older men
209
What causes direct inguinal hernias?
Weakness of the inguinal canal floor.
210
How can direct inguinal hernias be distinguished from indirect inguinal hernias?
Direct hernias occur medial to the inferior epigastric vessels, while indirect hernias occur lateral to them.
211
Occurs when a portion of the intestines is pushed through the umbilical opening in the abdominal wall. Umbilical hernias may occur from the persistence of the umbilical fibromuscular ring in newborns or as a consequence of increased intra-abdominal pressure due to many different causes in adults (obesity, pregnancy, etc.).
An umbilical hernia
212
The classic imaging finding of a sliding hiatal hernia is ?. This is indicated by the short white arrow above, which points to the GEJ, located above the diaphragm (long white arrow).
An hourglass sign (also called “collar sign”).
213
What are esophageal varices?
Dilated veins in the esophagus caused by portal hypertension, leading to gastrointestinal bleeding in patients with cirrhosis.
214
What complication of cirrhosis leads to the formation of esophageal varices?
Portal hypertension.
215
What is Boerhaave’s syndrome?
Effort ruptures of the esophagus due to increased intraesophageal pressure relative to intrathoracic pressure.
216
What are common causes of Boerhaave’s syndrome?
Straining and vomiting.
217
What are clinical features of Boerhaave’s syndrome?
Retrosternal chest pain, dyspnea, and subcutaneous emphysema.
218
What is achalasia?
The failure of the lower esophageal sphincter (LES) to relax due to the absence of ganglion cells in the esophagus.
219
What are clinical features of achalasia?
Dysphagia, regurgitation, food aspiration, and inflammation of the esophageal myenteric plexus.
220
What is eosinophilic esophagitis (EoE)?
An inflammatory condition of the esophagus causing dysphagia, especially in individuals with allergies or asthma.
221
What are common clinical features of eosinophilic esophagitis?
Dysphagia, vomiting, abdominal pain, and food impaction.
222
How is eosinophilic esophagitis diagnosed?
Diagnosis is made via histologic findings, as endoscopic findings are not always present.
223
What factors are involved in the pathogenesis of eosinophilic esophagitis?
Genetic, environmental, and host immune system factors.
224
What are common symptoms of GERD?
Heartburn, hoarseness, sore throat, regurgitation, and cough.
225
What occurs in a sliding hiatal hernia?
The gastroesophageal junction (GEJ) slides to a position above the diaphragm.
226
What characterizes a paraesophageal hiatal hernia?
The gastric fundus herniates upward into the thorax next to the esophagus, while the GEJ may remain in its usual position.
227
Through what structure does the gastric fundus herniate in a paraesophageal hiatal hernia?
Through a defect in the phrenoesophageal membrane.
228
What is the function of the phrenoesophageal membrane?
It is a connective tissue structure that anchors the esophagus to the esophageal hiatus in the diaphragm.
229
In the sliding or type I hiatal hernia, the gastric cardia protrudes above the diaphragm. In a paraesophogeal hernia,
The cardia (the point where the esophagus enters the stomach) remains below the diaphragm
230
What characterizes a direct inguinal hernia?
Protrusion of abdominal contents into Hesselbach's triangle.
231
What are the borders of Hesselbach's triangle?
Medially by the rectus abdominis, laterally by the inferior epigastric artery, and inferiorly by the inguinal ligament.
232
What is the most common type of inguinal hernia?
Indirect inguinal hernias, occurring in both men and women.
233
How does an indirect inguinal hernia occur in males?
The processus vaginalis fails to close, allowing a loop of bowel to enter the scrotum via the inguinal canal.
234
What is the processus vaginalis?
An embryonic outpouching of the parietal peritoneum that descends with the testes into the scrotum.
235
What happens to the processus vaginalis normally after descent of the testes?
It closes, preventing any connection to the abdomen.
236
What forms the tunica vaginalis in males?
Some tissue from the processus vaginalis that remains surrounding the testes.
237
Where do indirect inguinal hernias pass in relation to the inferior epigastric vessels?
Laterally to the inferior epigastric vessels and through both the deep and superficial inguinal rings.
238
What are potential complications of groin hernias?
Trapping of herniated intestine, bowel obstruction, and bowel ischemia.
239
What does tenderness on exam suggest in a patient with a hernia?
It may indicate a strangulated hernia, which requires immediate surgery.
240
How is the pathogenesis of an indirect inguinal hernia similar to that of a hydrocele?
Both conditions involve fluid or contents entering the incompletely closed processus vaginalis.
241
Is a superficial, subcutaneous connective tissue layer of the scrotum. The dartos muscle within the dartos fascia assists with scrotal elevation.
Dartos fascia
242
Is a connective tissue structure in the midline of the abdomen through which umbilical hernias may protrude.
Linda alba
243
What is the external spermatic fascia?
The outermost layer of fascia that covers the spermatic cord.
244
From which muscle is the external spermatic fascia derived?
It is derived from the external oblique muscle and its aponeurosis.
245
What is the internal spermatic fascia?
The innermost layer of fascia that covers the spermatic cord.
246
From which fascia is the internal spermatic fascia derived?
It is derived from the transversalis fascia.
247
What is the significance of the spermatic fascia?
It provides protection and support to the spermatic cord structures, including blood vessels and nerves.
248
What is Hirschsprung’s disease?
A condition caused by failure of neural crest cell migration to the intestinal wall, leading to aganglionosis.
249
What does "aganglionosis" mean?
A lack of neurons in the colon wall, specifically in Auerbach's plexus and Meissner's plexus.
250
What plexuses are absent in patients with Hirschsprung’s disease?
Both the myenteric (Auerbach's) plexus and the submucosal (Meissner's) plexus.
251
How does the absence of innervation affect intestinal function in Hirschsprung's disease?
It causes a “functional” blockage due to lost intestinal motility.
252
What can be seen on a barium study in patients with Hirschsprung's disease?
Recto-sigmoid narrowing with proximally distended bowel loops.
253
How can Hirschsprung's disease be differentiated from functional constipation?
Presence of a tight anal sphincter and an empty rectum.
254
What is the typical presentation of Hirschsprung's disease?
Chronic constipation.
255
When is Hirschsprung’s disease usually diagnosed?
Most patients are diagnosed in the neonatal period, but milder cases may be diagnosed later in infancy or childhood.
256
What are the crypts of Lieberkühn?
Glandular structures in the mucosal layer of the small intestine that contain goblet cells.
257
What are goblet cells responsible for?
They produce mucus, which helps lubricate and protect the intestinal lining.
258
What can a biopsy showing crypt abscess indicate?
It can be seen in ulcerative colitis but would not explain findings in Hirschsprung’s disease.
259
What are the components of the mucosa?
The epithelium (including the basement membrane), lamina propria, and muscularis mucosae
260
What are Peyer’s patches?
Masses of lymphatic tissue found in the lamina propria and submucosa of the ileum.
261
What is the primary function of Peyer’s patches?
They play a role in the immune response by monitoring intestinal bacteria and preventing the growth of pathogenic bacteria.
262
What is Hirschsprung’s disease?
A congenital disorder where neural crest cells fail to migrate to the intestinal wall, causing a functional blockage due to lack of innervation.
Chronic constipation and failure to pass meconium.
263
What two disorders should be considered in a case of failure to pass meconium?
Hirschsprung’s disease and cystic fibrosis.
264
What is the gold standard for diagnosing Hirschsprung’s disease?
A deep rectal suction biopsy.
265
What does a biopsy in Hirschsprung’s disease reveal?
Lack of ganglion cells (aganglionosis) in the colon wall.
266
What is the treatment for Hirschsprung’s disease?
Surgical resection of the aganglionic portions of the colon.
267
Are commonly associated with Crohn’s disease, which does not present in neonates.
Granulomas and transmural ulcers
268
What is observed in biopsy specimens from patients with Hirschsprung’s disease?
Absence of ganglion cells and hypertrophy of nerve fibers.
269
Where do the hypertrophied nerve fibers in Hirschsprung’s disease derive from?
Autonomic and sensory nerves outside the affected area.
270
Why do nerve fibers show hypertrophy in Hirschsprung’s disease?
As a compensatory response to the absence of ganglion cells, as these nerves attempt to integrate with the aganglionic segment.
271
Is the classic finding in celiac disease
Numerous lymphocytes with villous atrophy
272
Is characterized by transmural intestinal ganglioneuromas, a rare benign tumor of neural crest cells.
Multiple endocrine neoplasia type 2B (MEN 2B)
273
What is achalasia?
A disorder of esophageal motility characterized by an inability to relax the lower esophageal sphincter (LES).
274
What causes achalasia?
Damage to ganglion cells in the myenteric plexus (Auerbach’s plexus).
275
Where are the ganglion cells that are affected in achalasia located?
Between the inner circular and outer longitudinal layers of the muscularis propria of the esophagus.
276
What is the consequence of the loss of esophageal motility in achalasia?
Dysphagia for both solids and liquids due to the requirement of peristalsis for swallowing.
277
What does the inability to relax the LES lead to in achalasia?
Dilatation of the esophageal wall.
278
What is the classic radiological finding associated with achalasia on a barium swallow study?
The “bird beak” sign.
279
What are G cells?
Gastrin-producing cells located in the stomach and duodenum.
280
In which conditions might gastrin concentrations be elevated?
Zollinger-Ellison syndrome and autoimmune gastritis.
281
What do parietal cells in the stomach produce?
Hydrochloric acid (HCl) and intrinsic factor.
282
What can intrinsic factor deficiency lead to?
Pernicious anemia.
283
What is the underlying issue in achalasia related to the lower esophageal sphincter?
An inability of the smooth muscle to relax, but it is not the muscle cells themselves that are damaged.
284
What are common clinical findings in cirrhotic liver disease?
Jaundice, abdominal pain, and hematemesis from bleeding varices.
285
What structures are contained within the hepatoduodenal ligament?
The hepatic artery, the portal vein, and the common bile duct.
286
Why is lymphadenopathy common in patients with end-stage liver disease?
It usually results from lymphatic hyperplasia.
287
Where is the hepatic bile duct located?
Inferior to the liver and superior to the gallbladder.
288
Is the hepatic bile duct contained within the hepatoduodenal ligament?
No, it is not contained within the hepatoduodenal ligament.
289
Why is the gallbladder less likely to be compressed by lymphadenopathy of the hepatoduodenal ligament?
Because it is not contained within the hepatoduodenal ligament.
290
What is the remnant of the umbilical vein called?
The ligamentum teres of the liver.
291
Where is the ligamentum teres located?
At the free end of the falciform ligament, and it is not contained within the hepatoduodenal ligament.
292
What is Superior Mesenteric Artery (SMA) syndrome?
A condition characterized by compression of the third portion of the duodenum between the aorta and the superior mesenteric artery.
293
What can lead to the development of SMA syndrome?
Significant weight loss, which causes loss of mesenteric fat.
294
What are common clinical manifestations of SMA syndrome?
Postprandial epigastric pain, early satiety, and occasionally bowel obstruction.
295
How does SMA syndrome cause duodenal obstruction?
The compression of the duodenum leads to intermittent obstruction.
296
Hypertrophy of the gastric pylorus causes ?. This is a congenital anomaly that presents in infants with projectile vomiting.
Pyloric stenosis
297
Meissner’s plexus is located in the ? of the intestines. It is involved in the pathogenesis of Hirschsprung’s disease, a disorder of the colon that occurs predominantly in young children.
Submucosal layer
298
What two arteries supply blood to the large colon?
The superior mesenteric artery (SMA) and the inferior mesenteric artery (IMA).
299
Where is the watershed region located in the colon?
At the splenic flexure.
300
Why does the watershed area become vulnerable to ischemia during shock?
Because under-perfusion occurs, reducing blood flow through the sparse collateral circulation.
301
What are the primary clinical features of ischemic colitis?
Severe abdominal pain and the passage of blood and mucus from the rectum.
302
What radiographic findings may be seen in ischemic colitis?
Thumb-printing and dilation of the bowel proximal to the area of ischemia.
303
Is predominantly supplied by the superior mesenteric artery and does not lie within the watershed region. Hypotension does not easily cause ischemia in this segment of the colon.
The ascending colon
304
What arteries supply blood to the rectum?
The internal iliac artery and the inferior mesenteric artery.
305
Why is the rectum infrequently involved in colonic ischemia?
Due to its dual blood supply from the internal iliac artery and the inferior mesenteric artery.
306
What symptoms are associated with upper gastrointestinal bleeding?
Hematemesis (vomiting blood) or melena (black, tarry stools), but not bright red blood from the rectum.
307
What is a classic finding in acute mesenteric ischemia?
Pain that is out of proportion to the physical examination.
308
What might a patient with acute mesenteric ischemia report about their abdominal pain?
Severe abdominal pain (e.g., "10/10") despite only mild tenderness on examination.
309
What is a common finding in patients with bowel ischemia?
Blood in the stool.
310
What laboratory findings might be present in a patient with acute mesenteric ischemia?
Elevated white blood cell count and elevated lactate.
311
In patients with atrial fibrillation, what is a likely cause of acute mesenteric ischemia?
Formation of a clot in the left atrium that embolizes to the bowel.
312
Which vessel is most commonly involved in acute mesenteric ischemia?
The superior mesenteric artery.
313
What are colonic diverticula?
Outpouchings of the bowel wall that form at natural areas of weakness in the muscular layer.
314
Are diverticula usually symptomatic?
No, they are generally asymptomatic unless complications develop.
315
What complications can arise from diverticula?
Inflammation (diverticulitis), perforation, or bleeding.
316
What is diverticulitis?
Inflammation of the diverticula, which can lead to symptoms such as abdominal pain, fever, and changes in bowel habits.
317
What is diverticulitis?
A complication of diverticular disease (diverticulosis) characterized by inflammation of the diverticula. Largely asymptomatic, but may become symptomatic due to inflammation or complications.
318
What complications can arise from diverticulitis?
Abscess, bleeding, obstruction, and perforation.
319
What are common symptoms of diverticulitis?
Constipation and left lower quadrant pain.
320
What type of granulomas are associated with Crohn’s disease?
Noncaseating granulomas.
321
What is Crohn’s disease?
A form of inflammatory bowel disease (IBD) that can affect any part of the gastrointestinal tract.
322
What is the most common symptom of Crohn’s disease?
Recurrent diarrhea (which may or may not be bloody).
323
Can Crohn’s disease cause symptoms other than diarrhea?
Yes, it can also cause abdominal pain, weight loss, and fatigue, among others.
324
Perforation of the colon is characterized by acute abdominal pain and systemic inflammatory response. Abdominal examination shows
Rebound tenderness, guarding, and abdominal distention
325
What is the Pringle maneuver?
A surgical technique involving the placement of a vascular clamp across the hepatoduodenal ligament.
326
What does the Pringle maneuver accomplish?
It interrupts blood flow to the liver through the hepatic artery and portal vein.
327
If bleeding continues after the Pringle maneuver, what are the likely sources of blood loss?
The inferior vena cava or the hepatic vein.
328
When is the Pringle maneuver typically used?
During liver surgery or trauma to assess the source of bleeding
329
What condition is suggested by a baby's anal dimple and inability to pass meconium in the first 24 hours?
Imperforate anus
330
What should children born with an imperforate anus be evaluated for?
Vertebral and renal abnormalities
331
What does the VACTERL association stand for?
Vertebral anomalies, Anal atresia, Cardiac defects, Tracheoesophageal fistula/Esophageal atresia, Renal and Radial anomalies, and Limb defects.
332
What are common cardiac abnormalities associated with the VACTERL association?
Ventricular septal defect, atrial septal defect, and tetralogy of Fallot.
333
What are other common findings in the VACTERL association besides anal atresia?
Tracheoesophageal fistulas and renal agenesis.
334
What is holoprosencephaly?
A failure of the brain to divide into two hemispheres.
335
In what genetic condition is holoprosencephaly most commonly seen?
Trisomy 13 (Patau’s syndrome), occurring in about 50% of cases
336
What sequence is typically associated with pulmonary hypoplasia?
Potter’s sequence.
337
What are the key features of Potter’s sequence?
Pulmonary hypoplasia, clubbed feet, and cranial abnormalities.
338
What are the key features of Potter’s sequence?
Pulmonary hypoplasia, clubbed feet, and cranial abnormalities.
339
What does the pectinate line mark?
The transition from the rectum to the anus.
340
What type of epithelium is found above the pectinate line?
Columnar epithelium, similar to that of the digestive tract.
341
Which arteries supply blood to the tissues above the pectinate line?
The superior and middle rectal arteries.
342
How are hemorrhoids occurring above the pectinate line classified?
Internal hemorrhoids.
343
Are internal hemorrhoids usually painful?
No, they are generally not painful but are prone to bleeding.
344
Where does lymph drainage above the pectinate line flow to?
The internal iliac lymph nodes.
345
Which lymph nodes receive drainage from below the pectinate line?
The superficial inguinal lymph nodes.
346
Why is the pectinate line clinically significant in terms of lymphatic drainage?
It marks the division between different lymphatic drainage pathways and associated lymph nodes.
347
What type of innervation do tissues below the pectinate line have?
Somatic innervation.
348
What type of innervation do tissues above the pectinate line have?
Visceral innervation.
349
Are lesions below the pectinate line typically painful?
Yes, pain is common in lesions below the pectinate line.
350
Are hemorrhoids arising below the pectinate line generally painful or prone to bleeding?
They are generally painful and less prone to bleeding.
351
What artery supplies blood to tissues below the pectinate line?
The inferior rectal artery.
352
What artery provides blood supply to tissues above the pectinate line?
The superior rectal artery.
353
What are hemorrhoids?
Vascular structures that drain blood into the venous system.
354
What can cause engorgement and bleeding of hemorrhoids?
Any cause of venous hypertension.
355
How does pregnancy contribute to the development of hemorrhoids?
The growing fetus compresses the inferior vena cava, raising venous pressure.
356
What type of hemorrhoids are commonly associated with painful rectal bleeding during pregnancy?
External hemorrhoids.
357
Why are hemorrhoids a common problem among pregnant women?
Due to increased venous pressure from compression of the inferior vena cava.
358
How can disorders of coagulation affect pregnancy?
They may increase the risk of bleeding during pregnancy and delivery.
359
Which disorders are examples of coagulation disorders?
Hemophilia and von Willebrand’s disease.
360
Do coagulation disorders typically present as isolated hemorrhoidal bleeding during pregnancy?
No, they do not commonly present as isolated hemorrhoidal bleeding.
361
What is a common complication of pregnancy related to hemorrhoids?
Painful rectal bleeding, especially from external hemorrhoids.
362
What are gallstones, and what symptoms do they typically cause?
Gallstones can produce right upper quadrant pain, especially after fatty meals.
363
What structures are found in the portal triad of the liver lobule?
Bile duct, portal vein, and hepatic artery.
364
How does the size of the bile ducts compare to the portal veins and hepatic arteries in the portal triad?
Bile ducts are smaller than portal veins and usually larger than hepatic arterial branches.
365
What is pancreas divisum?
A developmental anomaly characterized by two pancreatic ducts (a dorsal and a ventral duct) instead of a single duct.
366
From which embryonic structure does the pancreas develop?
The pancreas derives from the foregut.
367
Which other structures also develop from the foregut?
Esophagus, stomach, liver, gallbladder, and the upper portion of the duodenum.
368
What percentage of embryos develop pancreas divisum?
Approximately 10%.
369
What causes pancreas divisum?
Fusion failure of the dorsal and ventral pancreatic ducts.
370
Are most individuals with pancreas divisum symptomatic or asymptomatic?
Most individuals are asymptomatic, but some may develop pancreatitis.
371
The hindgut gives rise to the
Distal one-third of the transverse colon, the descending colon, and the rectum.
372
The intermediate mesoderm gives rise to the
Kidneys, lower urinary tract, and reproductive system.
373
The midgut gives rise to the
Distal duodenum, jejunum, ileum, ascending colon, and proximal two-thirds of the transverse colon.
374
Normally disappears before birth but may persist as an anomaly called Meckel's diverticulum.
The yolk sac
375
What is annular pancreas?
A rare congenital anomaly where pancreatic tissue surrounds the duodenum, leading to potential obstruction.
376
What are common symptoms of annular pancreas in infants?
Nonbilious vomiting and poor weight gain.
377
What is the estimated prevalence of annular pancreas?
Approximately 5 to 15 per 100,000 births.
378
How does the pancreas normally develop?
From two outpouchings of the duodenum called the ventral and dorsal buds.
379
What does the dorsal bud of the pancreas become?
The tail and body of the pancreas.
380
What does the ventral bud of the pancreas become?
The head and uncinate process of the pancreas.
381
What typically happens during normal gut rotation regarding the pancreatic buds?
The ventral bud passes behind the duodenum to fuse with the dorsal bud.
382
What percentage of patients with annular pancreas are asymptomatic?
About two-thirds (or approximately 66%).
383
What complications can arise from annular pancreas?
Impaired flow through the duodenum due to constriction by pancreatic tissue.
384
How does the pancreatic duct connect to the digestive system?
The pancreatic duct joins the pancreas to the common bile duct.
385
What complication can arise from obstruction of the pancreatic duct in patients with annular pancreas?
Obstruction can lead to fibrosis and potentially result in pancreatitis.
386
Does the obstruction of the pancreatic duct describe the embryological cause of annular pancreas?
No, obstruction of the pancreatic duct is a complication, not the embryological cause of the condition.
387
What potential impact does fibrosis have in patients with annular pancreas?
Fibrosis can obstruct the pancreatic duct, leading to pancreatitis.
388
What is Zone 3 of the liver also known as?
The centrilobular zone.
389
What major function occurs in Zone 3 of the liver?
Drug metabolism, including the metabolism of cytochrome P-450 drugs.
390
Which drugs are metabolized in Zone 3 of the liver?
Phenytoin, macrolides, rifampin, warfarin, and others.
391
Why is the oxygen content lower in Zone 3 compared to Zones 1 and 2?
Because Zone 3 is farthest from the hepatic artery.
392
What is the significance of the lower oxygen content in Zone 3?
It affects the metabolic processes and susceptibility to injury in this area.
393
What are the five structures included in the portal triad?
The proper hepatic artery, the hepatic portal vein, the bile ductules, lymphatic vessels, and a branch of the vagus nerve.
394
What is the function of the proper hepatic artery within the portal triad?
It supplies oxygenated blood to the liver.
395
What role does the hepatic portal vein play in the portal triad?
It carries nutrient-rich blood from the gastrointestinal tract to the liver.
396
What is the function of the bile ductules in the portal triad?
They collect bile produced by the liver and transport it to larger bile ducts.
397
What is the role of the vagus nerve branch in the portal triad?
It provides autonomic innervation to the liver, influencing various functions.
398
What is a gastrinoma?
A gastrin-secreting tumor usually found in the pancreas or duodenum.
399
What does gastrin do?
It stimulates the release of gastric acid from parietal cells in the stomach.
400
What are common symptoms of gastrinoma?
Abdominal pain from peptic ulcers, diarrhea (either watery or fatty), and high-volume gastric secretions.
401
How does gastrin affect pancreatic enzymes?
Gastrin creates a low-pH environment that can inactivate pancreatic enzymes.
402
In which patients should gastrinoma be suspected?
In patients with multiple peptic ulcers, especially those refractory to standard therapy.
403
What is the first step in evaluating a suspected gastrinoma?
Measurement of serum gastrin levels.
404
What are the normal serum gastrin levels?
0 to 100 pg/mL.
405
What serum gastrin level indicates a gastrinoma?
Levels greater than 1,000 pg/mL.
406
What is the primary function of cholecystokinin (CCK)?
CCK stimulates contraction of the gallbladder and promotes the release of digestive enzymes from the pancreas.
407
Would elevated cholecystokinin explain symptoms of gastrinoma?
No, elevated CCK levels would not explain the clinical presentation of a gastrinoma.
408
What role does secretin play in digestion?
Secretin increases bicarbonate release from the pancreas, neutralizing gastric acid in the duodenum.
409
How is secretin used in the diagnosis of gastrinomas?
In gastrinomas, secretin injection causes a paradoxical increase in gastrin release, aiding in diagnosis.
410
What is the function of somatostatin in the gastrointestinal system?
Somatostatin inhibits the release of many gastrointestinal hormones and reduces gastric acid secretion.
411
What symptoms are associated with VIPomas?
VIPomas cause watery diarrhea, hypokalemia, and achlorhydria.
412
What is the effect of vasoactive intestinal peptide (VIP)?
VIP stimulates pancreatic bicarbonate and fluid secretion, among other functions.
413
What condition can lead to elevated levels of gastrin?
Gastrinomas, which are gastrin-secreting tumors.
414
What is a somatostatinoma?
A rare pancreatic tumor that secretes excess somatostatin, inhibiting the secretion of other gastrointestinal hormones.
415
Which cells produce somatostatin?
Delta cells (D cells) in the pancreas and intestines.
416
What are the effects of excess somatostatin in the body?
It inhibits the release of secretin, insulin, cholecystokinin, and gastrin, leading to achlorhydria, gallstones, steatorrhea, and hyperglycemia.
417
What is achlorhydria?
A condition characterized by a lack of hydrochloric acid in the gastric secretions, resulting in a high gastric pH.
418
What laboratory findings may be associated with cholestasis in somatostatinoma?
Elevated alkaline phosphatase and bilirubin levels.
419
What symptoms can arise from a somatostatinoma?
Symptoms include steatorrhea (greasy stools), hyperglycemia, abdominal pain, and weight loss.
420
How is somatostatinoma diagnosed?
Diagnosis is made by identifying elevated fasting plasma somatostatin levels.
421
What genetic condition is associated with somatostatinomas?
Multiple endocrine neoplasia type 1 (MEN 1), which is characterized by pituitary adenoma, parathyroid adenoma, and pancreatic tumors.
422
What are the "3 P's" of MEN 1?
Pituitary adenoma, parathyroid adenoma, and pancreatic tumors.
423
Why can recognizing somatostatinoma be challenging?
Its key features, such as steatorrhea and hyperglycemia, overlap with conditions like chronic pancreatitis, requiring careful clinical evaluation.
424
What condition do gastrinomas cause?
Zollinger-Ellison syndrome, characterized by excessive gastrin production leading to peptic ulcers.
425
What are the typical symptoms of a gastrinoma?
Abdominal pain and watery diarrhea, often accompanied by multiple or refractory peptic ulcers.
426
Do gastrinomas cause hyperglycemia?
No, hyperglycemia does not occur with gastrinomas.
427
What is a glucagonoma?
A tumor of the pancreatic alpha cells that leads to hyperglycemia, necrolytic migratory erythema, and weight loss.
428
What symptoms are associated with glucagonomas?
Hyperglycemia/diabetes, necrolytic migratory erythema, and weight loss. Steatorrhea does not occur.
429
What do insulinomas produce?
Excess insulin, leading to hypoglycemia that is relieved by glucose administration.
430
What is a VIPoma?
A tumor that secretes vasoactive intestinal peptide (VIP), causing WDHA syndrome (watery diarrhea, hypokalemia, achlorhydria)
431
What are the symptoms of WDHA syndrome caused by VIPomas?
Watery diarrhea, hypokalemia, and achlorhydria; the diarrhea is not steatorrhea.
432
Does hyperglycemia occur with VIPomas?
No, hyperglycemia does not occur with VIPomas.
433
What is Zollinger-Ellison syndrome (ZES)?
A disorder characterized by gastrin-producing tumors that lead to increased gastric acid production, resulting in ulcers.
434
What causes the abdominal pain in ZES?
Abdominal pain is caused by peptic ulcers due to excessive gastric acid.
435
What types of diarrhea are associated with ZES?
Diarrhea may be watery (from high-volume gastric secretions) or fatty (from steatorrhea due to inactivated pancreatic enzymes).
436
Where are gastrin-secreting tumors typically located in ZES?
Tumors may be found in the duodenum or pancreas.
437
How is Zollinger-Ellison syndrome treated?
It is treated with proton pump inhibitors (PPIs) like omeprazole, which decrease gastric acid secretion.
438
What is the mechanism of action of proton pump inhibitors?
PPIs inhibit the H+/K+ ATPase on the luminal surface of parietal cells, reducing gastric acid secretion.
439
Acinar cells in the pancreas produce enzymes that enter the duodenum to assist in the digestion of food.
Ductal cells of the pancreas line the pancreatic ducts. They produce bicarbonate-rich pancreatic juice in response to secretin.
440
? of the duodenum and jejunum produce cholecystokinin. This hormone increases pancreatic secretions and causes gallbladder contraction.
I cells
441
Are found in the duodenum. They produce the hormone secretin, which increases pancreatic bicarbonate secretion and decreases gastric acid secretion.
S cells
442
What is pernicious anemia?
An autoimmune disorder caused by the destruction of gastric parietal cells, leading to vitamin B12 deficiency.
443
What do parietal cells produce that is essential for vitamin B12 absorption?
Intrinsic factor.
444
What are the typical laboratory findings in B12 deficiency due to pernicious anemia?
Macrocytic anemia (low hemoglobin and hematocrit, high MCV).
445
What are common symptoms of pernicious anemia?
Fatigue, neurologic dysfunction, and difficulty walking due to loss of proprioception.
446
How does pernicious anemia affect gastric acid production?
Parietal cell atrophy leads to decreased gastric acid production.
447
What happens to serum gastrin levels in pernicious anemia?
Serum gastrin levels rise (hypergastrinemia) due to decreased acid production.
448
What histological finding might be seen on gastric biopsy in pernicious anemia?
Hyperplasia of G cells
449
What is a VIPoma?
A rare tumor of the non-beta islet cells of the pancreas that produces vasoactive intestinal peptide (VIP).
450
What are the primary symptoms of VIPoma?
Profuse watery diarrhea (10 or more times per day) resembling cholera, non-anion gap acidosis, and hypokalemia.
451
How does VIP contribute to diarrhea in VIPoma patients?
VIP stimulates pancreatic bicarbonate secretion, leading to watery diarrhea
452
What electrolyte imbalances are commonly seen in VIPoma?
Hypokalemia due to loss of potassium in the stool and acidosis due to loss of bicarbonate.
453
What clinical signs might indicate volume depletion in a VIPoma patient?
Tachycardia and dry mucous membranes.
454
What type of acidosis is typically associated with VIPoma?
Non-anion gap metabolic acidosis.
455
Typically presents with weight loss, hyperglycemia, and necrolytic migratory erythema, a papular rash of the face, perineum, and extremities.
Glucagonoma
456
Common clinical features of an ? include hypoglycemia, leading to confusion, altered mental status, palpitations, sweating, and tremulousness. About one-fifth of patients will experience weight gain.
Insulinoma
457
What LFT patterns are typically seen in acute hepatitis C infection?
Elevated AST and ALT levels, with AST typically being less than or equal to ALT, and Alk Phos levels often normal.
458
What are the common liver function tests (LFTs) mentioned?
AST (aspartate aminotransferase), ALT (alanine aminotransferase), Alk Phos (alkaline phosphatase).
459
In chronic hepatitis C, what are the expected LFT findings?
Mild to moderate elevations in AST and ALT, with Alk Phos usually normal.
460
What is a common mode of transmission for hepatitis C virus (HCV)
Exposure often occurs through dirty needles among IV drug users and at tattoo parlors.
461
What percentage of initial hepatitis C infections progress to chronic liver disease?
Greater than 90%.
462
What are the potential outcomes of chronic hepatitis C infection?
Scarring of the liver (fibrosis) and cirrhosis.
463
In chronic HCV, how do the levels of AST and ALT compare to alkaline phosphatase?
AST and ALT are elevated relative to alkaline phosphatase.
464
In all forms of viral hepatitis, which enzyme is typically elevated more, AST or ALT?
ALT is usually elevated to a greater degree than AST.
465
How does the AST
ratio differ in alcoholic hepatitis compared to viral hepatitis?
In alcoholic hepatitis, AST is usually greater than ALT (AST ratio > 1.5), whereas in viral hepatitis, ALT is typically greater than AST.
466
What are the expected serum levels of AST and ALT in chronic hepatitis C?
Usually less than 500 U/L.
467
What are alkaline phosphatase levels typically like in chronic hepatitis C?
Alkaline phosphatase levels are often within normal limits.
468
What is intrahepatic cholestasis of pregnancy (ICP) also known as?
Pruritus gravidarum.
469
During which trimester does ICP typically occur?
In the second or third trimester of pregnancy.
470
What causes ICP?
High levels of estrogen and progesterone during pregnancy, which decrease bile flow in the liver.
471
What is the hallmark symptom of ICP?
Pruritus (itching) of the skin.
472
What leads to the pruritus experienced in ICP?
Elevated bile acids in the bloodstream.
473
Can jaundice occur in cases of ICP?
Yes, jaundice may rarely develop in cases of severe cholestasis.
474
Is ICP a permanent or reversible condition?
It is a reversible form of cholestasis.
475
What is the effect of ICP on bile flow?
It leads to a lack of bile flow (cholestasis) in the liver.
476
In a patient with itching in absence of a rash, think of ?. This is seen in pruritus gravidarum as well as other biliary disorders, such as primary biliary cholangitis.
Cholestasis
477
What does the absence of urine urobilinogen suggest?
It indicates that bile (including bilirubin) is not reaching the intestines due to hepatic or biliary obstruction.
478
Conjugated hyperbilirubinemia: How elevated are the liver enzymes (AST and ALT) in this case?
They are twice the upper limit of normal.
479
Conjugated hyperbilirubinemia: How does alkaline phosphatase compare to AST and ALT in this patient?
Alkaline phosphatase is elevated to a much greater degree than AST and ALT.
480
What is the term for the pattern of liver test abnormalities characterized by greater alkaline phosphatase elevation?
Cholestatic pattern.
481
In which conditions is the cholestatic pattern typically seen?
It is seen in cases of biliary obstruction.
482
What are the typical liver enzyme levels (AST, ALT, alkaline phosphatase) in a patient with cholestatic liver disease?
AST and ALT are moderately elevated, while alkaline phosphatase is significantly elevated.
483
What type of bilirubin is released in extravascular hemolysis?
Unconjugated bilirubin.
484
What are the typical AST and ALT levels in isolated hemolysis?
They are normal.
485
What is the primary mechanism of bilirubin release in extravascular hemolysis?
It occurs when red blood cells are broken down outside of the blood vessels, typically in the spleen and liver.
486
How does the absence of unconjugated hyperbilirubinemia help differentiate between hemolytic anemia and other conditions?
It indicates that the hemolysis is not the primary issue, as hemolysis typically leads to increased unconjugated bilirubin.
487
What types of inherited liver diseases are associated with unconjugated bilirubinemia?
Crigler-Najjar syndrome and Gilbert’s syndrome.
488
What are the liver function test results (AST and ALT) in patients with Crigler-Najjar and Gilbert’s syndromes?
Liver function tests (AST and ALT) are normal.
489
What are common disorders that lead to marked elevations of AST and ALT (greater than 1,000)?
Acute hepatitis B, acute hepatitis A, acetaminophen toxicity, and ischemic liver disease (shock liver).
490
What is primary biliary cholangitis (PBC)?
An autoimmune condition causing destruction of intrahepatic bile ducts, leading to intrahepatic cholestasis.
491
In which demographic is PBC most commonly seen?
Women in their 40s or 50s.
492
What are common symptoms of PBC?
Fatigue and pruritus (itching).
493
What does serum liver testing typically show in PBC?
Marked elevation of alkaline phosphatase (2 to 4 times the upper limit of normal) with normal or mildly elevated AST and ALT.
494
What other autoimmune diseases are commonly associated with PBC?
Sjögren’s syndrome.
495
What percentage of PBC patients may experience Raynaud’s phenomenon?
About 5% to 15%.
496
What causes bile salt deposition in the skin?
Cholestasis.
497
What are the major bile acids mentioned in relation to PBC?
Chenodeoxycholic acid and cholic acid.
498
What happens to serum alkaline phosphatase levels in cholestasis?
They rise in the setting of impaired bile flow.
499
In primary biliary cholangitis (PBC), how does alkaline phosphatase behave?
Alkaline phosphatase levels rise significantly.
500
Histamine is produced by
Mast cells, basophils, neutrophils, and platelets.
501
The end product of heme catabolism, gives the brown color to human feces.
Stercobilin
502
Where does most lipid reabsorption occur in the gastrointestinal tract?
In the jejunum.
503
What percentage of bile acids are reabsorbed in the terminal ileum?
95%.
504
What is bile primarily composed of?
Cholesterol and bile acids.
505
What can lead to gallstone formation?
Disruption in bile composition, including decreased availability of bile acids.
506
How can surgical resection or Crohn's disease affect gallstone formation?
They interfere with the absorption of bile acids in the terminal ileum, leading to gallstones.
507
What happens to bile when there is a loss of bile salts?
The liver has fewer bile salts to add to new bile, resulting in bile that becomes overloaded with cholesterol.
508
What type of gallstones can form as a result of bile overload with cholesterol?
Cholesterol gallstones.
509
Folate is absorbed in the
Jejunum
510
May cause microcytic anemia. However, iron is absorbed in the duodenum.
Iron deficiency
511
Is absorbed in the duodenum and jejunum.
Vitamin B2 (riboflavin)
512
Of note, vitamin B12 absorption occurs in the ileum and will be impaired following ileal resection.
Ileal resection.
513
What digestive issue may develop after ileal resection?
Diarrhea due to fat malabsorption and steatorrhea.
514
How does diarrhea from ileal resection affect potassium levels?
It can cause hypokalemia, as potassium is lost in the stool.
515
What are the physiological consequences of ileal failure?
Loss of bile salts leading to gallstones, fat malabsorption, loss of vitamin B12 absorption, and decreased fluid absorption.
516
What vitamin absorption is affected by ileal resection?
Vitamin B12 absorption.
517
What happens to fluid absorption after ileal resection?
There is decreased fluid absorption.
518
It is high yield to know the physiologic consequences of ileal failure that occur after surgery or in Crohn’s disease. These include
Loss of bile salts leading to gallstones and fat malabsorption, loss of vitamin B12 absorption, and decreased fluid absorption
519
How can elevated serum bilirubin (hyperbilirubinemia) be categorized?
Unconjugated (>85% of total), conjugated (>50% of total), or mixed (20% to 50% conjugated).
520
What is the normal distribution of serum bilirubin?
About 75% unconjugated and about 25% conjugated.
521
What typically causes mixed bilirubin elevations?
Primary liver diseases (e.g., hepatitis).
522
What are the main causes of unconjugated hyperbilirubinemia?
Hemolysis, drugs impairing the conjugation process, and inherited disorders (e.g., Gilbert’s syndrome, Crigler-Najjar syndrome).
523
What indicates that this man has unconjugated hyperbilirubinemia?
No evidence of hemolysis and no medications, suggesting an inherited disorder.
524
What enzyme is involved in conjugating unconjugated bilirubin?
Glucuronyl transferase.
525
What is the effect of Gilbert’s syndrome on bilirubin levels?
It leads to unconjugated hyperbilirubinemia due to decreased glucuronyl transferase activity (about 30% of normal).
526
Under what conditions might jaundice develop in a patient with Gilbert’s syndrome?
Stressors like fasting, febrile illness, heavy physical exertion, or menses.
527
How is Gilbert’s syndrome diagnosed?
Based on mild unconjugated hyperbilirubinemia in the absence of liver disease or hemolysis.
528
Is treatment necessary for Gilbert’s syndrome?
Usually not necessary.
529
What occurs in Crigler-Najjar syndrome regarding glucuronyl transferase activity?
There is a complete absence of glucuronyl transferase activity.
530
What is the consequence of the absence of glucuronyl transferase in Crigler-Najjar syndrome?
A complete inability to conjugate bilirubin, leading to markedly elevated unconjugated bilirubin.
531
In any case of unconjugated hyperbilirubinemia, what should be included in the differential diagnosis?
Hemolysis.
532
What findings suggest the absence of hemolysis in this patient?
A normal peripheral blood smear and normal markers of hemolysis (LDH, haptoglobin).
533
What describes the pathophysiology of Dubin-Johnson syndrome?
A defect in the excretion of bilirubin, causing elevated conjugated bilirubin.
534
What is the pathophysiology of Rotor’s syndrome?
Defective storage of bilirubin, characterized by conjugated hyperbilirubinemia.
535
What is Crigler-Najjar syndrome?
A rare autosomal recessive condition caused by the absence of glucuronyl transferase activity in the liver. Lack of conjugation of bilirubin and high levels of unconjugated bilirubin.
536
When does Crigler-Najjar syndrome typically appear?
In the first few days of life.
537
What serious condition can result from elevated bilirubin in Crigler-Najjar syndrome?
Kernicterus, a form of brain damage associated with elevated bilirubin.
538
What are the typical liver function test results in Crigler-Najjar syndrome?
Usually normal.
539
What treatments are used for Crigler-Najjar syndrome?
Exchange transfusion and phototherapy while awaiting liver transplantation.
540
How does newborn jaundice differ from adult jaundice?
Newborn jaundice has a unique differential diagnosis, with most cases being benign “physiologic” unconjugated hyperbilirubinemia.
541
When does physiologic jaundice typically develop in newborns?
1 to 2 days after birth.
542
What indicates that jaundice in a newborn is usually pathological?
Jaundice occurring within the first 24 hours of life.
543
What serum bilirubin level in a newborn is always considered pathologic?
Greater than 17 mg/dL.
544
Aside from Crigler-Najjar syndrome, what are other causes of early jaundice in newborns?
Congenital infections (syphilis, cytomegalovirus, rubella, toxoplasmosis), sepsis, and other causes.
545
What leads to physiologic jaundice in full-term babies at birth?
Increased bilirubin production and decreased ability to excrete bilirubin.
546
When do bilirubin levels typically peak in newborns with physiologic jaundice?
About 4 days after birth.
547
What is the usual peak bilirubin level in physiologic jaundice?
About 5 to 6 mg/dL.
548
How does physiologic jaundice usually resolve?
Most cases resolve without intervention, but some may require phototherapy.
549
How can breast-fed newborns experience an exaggerated form of physiologic jaundice?
Inadequate food and water intake can delay meconium passage, reducing bilirubin excretion.
550
What is the effect of decreased oral intake in breast-fed newborns on bilirubin levels?
It may lead to mild dehydration, concentrating serum bilirubin.
551
What condition can arise from Rh incompatibility between an Rh-negative mother and Rh-positive fetus?
Hemolytic disease of the newborn (HDN), which can manifest as jaundice.
552
What test would be positive in cases of Rh incompatibility, indicating hemolysis?
A positive Coombs test.
553
How can Rh-negative mothers avoid hemolytic disease of the newborn?
By receiving Rhesus antibodies during pregnancy.
554
Why can the normal levels of haptoglobin and the fact that this is the first pregnancy exclude the diagnosis of Rh incompatibility?
These findings suggest there is no hemolysis occurring.
555
What is Dubin-Johnson syndrome?
An autosomal recessive condition characterized by mild jaundice and elevated bilirubin due to impaired transfer of conjugated bilirubin into bile ducts.
556
When can Dubin-Johnson syndrome present?
It can present shortly after birth or after an inciting incident, such as the use of oral contraceptives or during pregnancy.
557
How do sex steroids in oral contraceptives affect patients with Dubin-Johnson syndrome?
They can reduce hepatic excretory function, transforming mild hyperbilirubinemia into jaundice in susceptible patients.
558
What laboratory results are typical in Dubin-Johnson syndrome?
An increase in conjugated bilirubin without elevation of liver enzymes like ALT and AST.
559
What physical exam finding may be present in Dubin-Johnson syndrome?
Hepatomegaly.
560
What macroscopic liver change is associated with Dubin-Johnson syndrome?
A black discoloration of the liver from the accumulation of bilirubin.
561
What is the classic laboratory profile of alcoholic hepatitis?
An AST to ALT ratio usually >2.
562
In alcoholic hepatitis, what is the typical AST level?
AST is usually about 500 U/L and almost never greater than 1000 U/L.
563
What other liver enzyme may be elevated in alcoholic hepatitis?
Gamma-glutamyl transpeptidase (GGT) concentrations may be elevated up to 8 to 10 times normal.
564
What symptoms might patients with alcoholic hepatitis present with?
Patients are often asymptomatic but may present with jaundice and hepatomegaly.
565
In which population does alcoholic hepatitis typically occur?
In chronic alcohol users after heavy alcohol consumption.
566
What are the potential consequences of acetaminophen overdose?
Liver tenderness and jaundice.
567
What is a hallmark laboratory finding in acetaminophen toxicity?
Markedly elevated levels of plasma aminotransferases (AST and ALT usually both > 1,000 IU/L)
568
What severe complication can arise from acetaminophen toxicity?
Fulminant liver failure and a rising prothrombin time (PT).
569
What are other classic causes of marked elevation of AST and ALT?
Ischemic/shock liver and acute hepatitis A or B.
570
What is ascending cholangitis?
An infection of the biliary tree occurring in the setting of biliary obstruction.
571
What laboratory finding is typical in ascending cholangitis?
Elevated alkaline phosphatase concentrations.
572
What is non-alcoholic steatohepatitis (NASH)?
Fat accumulation in the liver not caused by alcohol consumption, often associated with obesity.
573
How are AST and ALT levels typically affected in NASH?
Elevated 2 to 5 times the upper limit of normal, with an AST to ALT ratio usually less than 1.
574
What are the typical AST and ALT levels in acute hepatitis B?
Marked elevations of 1,000 to 2,000 IU/L.
575
Often present with isolated hyperbilirubinemia in the absence of other liver test abnormalities.
Inborn errors of bilirubin metabolism
576
What are the key differential diagnoses for conjugated hyperbilirubinemia?
Biliary obstruction, liver disease, or an inherited disorder of bilirubin metabolism.
577
What findings would exclude biliary obstruction or liver disease in this case?
Normal liver enzymes and alkaline phosphatase.
578
Family history is significant for a “liver problem” disease in the baby’s grandmother. Given the family history, which two syndromes are most likely in this baby?
Dubin-Johnson syndrome or Rotor’s syndrome.
579
What causes Dubin-Johnson syndrome?
Defective liver excretion of conjugated bilirubin.
580
What is the mechanism of Rotor’s syndrome?
Defective hepatic storage of conjugated bilirubin leads to leakage of bilirubin into the plasma, causing hyperbilirubinemia.
581
What characterizes Arias’s syndrome (Crigler-Najjar syndrome type 2)?
An autosomal recessive disorder with unconjugated hyperbilirubinemia, jaundice, and serum bilirubin ranging from 6 to 20 mg/dL.
582
What is the UDP-glucuronosyltransferase activity in children with Arias’s syndrome?
Less than 10% of normal.
583
What characterizes Crigler-Najjar syndrome type I?
An autosomal recessive disorder with severe unconjugated hyperbilirubinemia and serum bilirubin ranging from 18 to 44 mg/dL.
584
What is the UDP-glucuronosyltransferase activity in children with Crigler-Najjar syndrome type I?
Absence of UDP-glucuronosyltransferase activity.
585
What is primary biliary cholangitis?
A chronic biliary disorder characterized by selective destruction of biliary epithelial cells of small and medium-sized hepatic ducts.
586
Who is primarily affected by primary biliary cholangitis?
Mainly women between 30 and 65 years.
587
What is kernicterus?
A form of permanent brain damage from exposure to high levels of bilirubin.
588
What are some symptoms of kernicterus?
Abnormal movements, sensorineural hearing loss, and gaze abnormalities.
589
What is a characteristic feature of kernicterus related to brain structures?
Yellow staining of central nervous system structures due to hyperbilirubinemia.
590
Which specific areas of the brain are affected by kernicterus?
Basal ganglia, hippocampus, lateral thalamic nucleus, geniculate bodies of the thalamus, and some brainstem nuclei.
591
Why are the basal ganglia significant in kernicterus?
They are involved in motor coordination, which explains the involuntary movements observed in affected children.
592
What are the common symptoms of acute pancreatitis?
Severe upper abdominal pain, nausea, and vomiting.
593
When do serum levels of pancreatic enzymes (amylase and lipase) typically elevate after the onset of acute pancreatitis symptoms?
Within 4 to 8 hours.
594
What is the function of pancreatic amylase?
To cleave starch into smaller polysaccharides at the internal 1 to 4 alpha linkage during digestion.
595
What are the main sources of amylase in humans?
The pancreas and salivary glands, with small quantities found in other tissues.
596
Is an enzyme synthesized in the pancreas and secreted into the small intestine. This enzyme hydrolyzes (adds water to) proteins, leading to protein breakdown.
Carboxypeptidase
597
The main function of pancreatic lipase is to
Hydrolyze triglycerides into glycerol and free fatty acids.
598
Is made in the stomach and breaks down proteins into smaller peptides. Is most efficient in cleaving peptide bonds between hydrophobic and aromatic amino acids such as phenylalanine, tryptophan, and tyrosine.
Pepsin i
599
Catalyzes the hydrolysis of peptide bonds in the duodenum, breaking down proteins into smaller peptides. Trypsin cleaves peptide chains mainly at the carboxyl side of the amino acids lysine and arginine.
Trypsin
600
What is the hallmark symptom of acute pancreatitis?
Upper abdominal pain, often radiating to the back, with associated nausea and vomiting.
601
What is trypsin and how is it activated?
Trypsin is an enzyme derived from the inactive precursor trypsinogen, activated by enteropeptidase (enterokinase) in the duodenum.
602
In acute pancreatitis, where does trypsin activation occur?
n the pancreas itself, leading to auto-digestion of pancreatic tissue.
603
What is believed to be the initiating event of acute pancreatitis?
The activation of trypsin within the pancreas.
604
What happens once trypsin is activated in acute pancreatitis?
It can activate other pancreatic enzymes, leading to a cascade of enzyme activity and causing acute pancreatitis.
605
What is the function of amylase?
Amylase breaks down long-chain carbohydrates.
606
Why is amylase significant in the context of pancreatitis?
It is an important marker for pancreatitis, indicating pancreatic inflammation.
607
What are transaminase enzymes?
Enzymes, such as aspartate transaminase (AST), that play a role in amino acid metabolism.
608
What is the function of elastase?
Elastase is an enzyme that degrades elastic fibers.
609
Where is pancreatic elastase produced?
In the acinar cells of the pancreas.
610
How is pancreatic elastase activated?
It is initially produced as an inactive zymogen and later activated in the duodenum by trypsin.
611
What gastric pH level stimulates secretin release?
A gastric pH below 4.5.
612
Where is secretin released from?
Duodenal S cells into the bloodstream.
613
What is the major function of secretin?
It is the major stimulus for pancreatic HCO3- (bicarbonate) secretion.
614
When do plasma secretin levels rise?
After a meal.
615
How do plasma secretin levels correlate with bicarbonate secretion?
Plasma secretin levels rise and correlate with increased HCO3- secretion.
616
Inhibits the release of other gastrointestinal hormones (gastrin, secretin). It is not a major stimulus for pancreatic bicarbonate secretion.
Somatostatin
617
Is the major stimulus for the release of pancreatic enzymes. Also stimulates the gallbladder. Alone has a weak effect on pancreatic fluid and bicarbonate secretion. It can potentiate (increase) the effects of secretin.
Cholecystokinin (CCK)
618
Can stimulate pancreatic bicarbonate release but has only a small effect, much smaller than secretin.
The vagus nerve
619
What do lipases catalyze?
The breakdown of lipids.
620
What is the role of pancreatic lipases?
They convert triglycerides into glycerol and fatty acids.
621
Increases glycogenolysis and relaxes the smooth muscle of the stomach and gallbladder.
VIP
622
Zollinger-Ellison syndrome due to a gastrin-producing tumor (gastrinoma). These tumors occur in the duodenum or pancreas, and secrete gastrin. Gastrin is a hormone normally secreted by G cells that stimulates secretion of gastric acid from parietal cells. Excess gastric acid leads to ulcers. The main clinical features of Zollinger-Ellison disease are
peptic ulcers, diarrhea, weight loss, and abdominal pain. The majority (80%) of gastrinomas occur sporadically. About 20% are linked with multiple endocrine neoplasia type 1 (MEN 1) syndrome.
623
What are some indications for proton pump inhibitors (PPIs) like omeprazole?
Treatment of peptic ulcer disease, gastroesophageal reflux disease (GERD), and Zollinger-Ellison syndrome.
624
How do PPIs block gastric acid secretion?
By inhibiting the hydrogen-potassium ATPase pump on the luminal surface of the parietal cell membrane.
625
What happens to gastrin levels when PPIs are used?
Gastrin levels increase as a compensatory response to decreased stomach acid production.
626
What role does carbonic anhydrase play in gastric acid secretion?
It generates gastric acid in parietal cells.
627
How does PPI therapy affect carbonic anhydrase activity?
The activity of carbonic anhydrase decreases in patients taking PPIs who cannot secrete acid normally.
628
What effect does histamine binding to H2 receptors have on cAMP levels?
It increases intracellular cyclic adenosine monophosphate (cAMP) levels.
628
Where do histamine molecules bind in the stomach?
To H2 receptors located on acid-secreting gastric parietal cells.
629
How does cyclic AMP affect gastric acid secretion?
It activates the hydrogen-potassium pump, leading to the release of hydrogen ions into the stomach.
630
What is the mechanism of action of ranitidine?
Ranitidine is an H2 receptor antagonist that competitively inhibits H2 receptors, reducing acid secretion.
631
What happens to intracellular cAMP levels when ranitidine blocks histamine activity?
There is a fall in intracellular cAMP levels.
632
Is a membrane-associated enzyme that cleaves phospholipids. It is a second messenger for several G-protein associated receptors including those for acetylcholine and gastrin.
Phospholipase C (PLC)
633
Is a lipid second messenger that is converted to inositol triphosphate (IP3) by PLC. This second messenger system is associated with receptors for acetylcholine and gastrin.
Phosphatidylinositol 4,5-bisphosphate (PIP2)
634
The main function of ? is to mobilize Ca2+ from storage organelles. Calcium then regulates other processes. This is part of the PLC-IP3 system associated with acetylcholine and gastrin.
IP3
635
What is aluminum hydroxide commonly used for?
Relief of gastroesophageal reflux disease (GERD) symptoms.
636
How does aluminum hydroxide neutralize stomach acid?
By forming aluminum chloride and water.
637
What is a common adverse reaction to aluminum hydroxide?
Constipation, Hypophosphatemia.
638
Why does aluminum hydroxide cause constipation?
It decreases gastrointestinal motility.
639
How does aluminum hydroxide lead to hypophosphatemia?
By binding phosphate in the gut.
640
What can hypophosphatemia lead to?
Muscle weakness.
641
How does sodium bicarbonate neutralize acid?
It forms salt, water, and carbon dioxide.
642
What side effects can result from the formation of carbon dioxide when using sodium bicarbonate?
Bloating and belching.
643
What can absorption of bicarbonate lead to?
Alkalosis.
644
What can the formation of salt from sodium bicarbonate lead to?
Fluid retention.
645
How does magnesium hydroxide neutralize acid?
By forming magnesium chloride and water.
646
What is a common side effect of magnesium hydroxide?
Diarrhea.
647
What can excessive use of magnesium hydroxide lead to?
Hypermagnesemia, which can cause bradycardia, hypotension, and death.
648
What is famotidine classified as?
A histamine 2 (H2) blocker.
649
How does famotidine work?
By blocking histamine receptors in parietal cells.
650
What are common side effects of famotidine?
Generally well tolerated; rare confusion in the elderly, elevation of AST and ALT, and cardiac arrhythmias.
651
What is omeprazole classified as?
A proton pump inhibitor (PPI).
652
How does omeprazole work?
By inhibiting the hydrogen-potassium pump in parietal cells.
653
What are some long-term adverse reactions of omeprazole?
Increased risk of Clostridioides difficile infection, pneumonia, osteopenia, and decreased levels of calcium, magnesium, iron, and B12.
654
What rare side effect can omeprazole cause?
Constipation.
655
What side effects can occur after administering metoclopramide?
Restlessness and dystonia (spasms).
656
What type of side effects are caused by metoclopramide?
Extrapyramidal side effects.
657
How does metoclopramide function pharmacologically?
It is a dopamine (D2) receptor antagonist.
658
What area of the brain does metoclopramide primarily affect to decrease nausea and vomiting?
The chemoreceptor trigger zone in the central nervous system.
659
What movement symptoms can metoclopramide induce due to altered dopamine activity?
Restlessness, akathisia, dystonia, and rarely tardive dyskinesia.
660
What is tardive dyskinesia and how is it related to metoclopramide?
A movement disorder that can occur with long-term use of metoclopramide.
661
How does metoclopramide affect the seizure threshold?
It lowers the seizure threshold and should be avoided in patients with epilepsy.
662
What type of medication is ondansetron?
A 5-hydroxytryptamine (5-HT3) receptor antagonist.
663
Where are 5-HT3 receptors located?
In the vomiting center of the medulla and in the vagal and spinal nerves of the GI tract.
664
What effect does ondansetron have when it blocks 5-HT3 receptors?
Relief of nausea.
665
What are common side effects of ondansetron?
Headache and constipation.
666
What is lactulose primarily used for?
Treatment of constipation.
667
How does lactulose benefit patients with hepatic encephalopathy?
It promotes the excretion of ammonia via the GI tract.
668
What is the function of calcium carbonate?
It is an antacid that neutralizes stomach acid by forming calcium chloride.
669
What side effects can result from calcium carbonate use?
Bloating and belching due to carbon dioxide formation, as well as constipation from calcium ingestion.
670
What is sodium polystyrene sulfonate primarily used for?
Management of hyperkalemia by binding and excreting potassium through the GI tract.
671
What type of laxative is sodium polystyrene sulfonate?
An osmotic laxative.
672
What are magnesium hydroxide and magnesium citrate used for?
Management of constipation as osmotic laxatives.
673
What is polyethylene glycol commonly used for?
As an osmotic laxative for bowel preparation prior to colonoscopy.
674
What is the classic presentation of ulcerative colitis?
Bloody diarrhea.
675
How does diarrhea in Crohn's disease differ from that in ulcerative colitis?
While diarrhea and gastrointestinal bleeding can occur in Crohn's disease, grossly bloody stools are rare; usually, only microscopic amounts of blood are detected.
676
What serum antibody is strongly associated with ulcerative colitis?
Elevated levels of serum p-ANCA antibodies.
677
What is pyoderma gangrenosum?
A painful skin lesion characterized by ulceration and necrosis, common in ulcerative colitis.
678
Name some extraintestinal manifestations of ulcerative colitis.
Primary sclerosing cholangitis, ankylosing spondylitis, and uveitis.
679
What are pseudopolyps in the context of ulcerative colitis?
Masses of scar tissue that project into the intestinal lumen, developing from the healing of colonic ulcerations.
680
Are pseudopolyps more common in ulcerative colitis or Crohn's disease?
Pseudopolyps are a common manifestation of ulcerative colitis.
681
Is an abnormal connection between two body structures. Intestinal fistula formation is common in Crohn’s disease. Examples of fistulas in Crohn’s disease include connections between the intestines and anus (perianal), abdomen, or bladder (enterovesical). Treatment is usually with surgery.
A fistula
682
Is a feature of long-standing Crohn’s disease. Inflammation leads to excess fat deposition within the mesentery. This can lead to extension of the mesentery around the entire surface of the bowel. Other pathological features of Crohn’s disease include stricture formation and transmural inflammation
Creeping fat
683
Are a common extraintestinal manifestation of Crohn’s disease, specifically due to involvement of the terminal ileum. Patients with Crohn’s disease often have malabsorption of fat due to small bowel inflammation. Free fat in the gut binds calcium. Normally, calcium binds oxalate in the gut, limiting oxalate absorption. When less calcium is available due to fat malabsorption, oxalate absorption increases. This leads to increased urinary oxalate excretion and increases the risk of kidney stones.
Calcium oxalate kidney stones
684
Are a pathological hallmark of Crohn’s disease.
Non-caseating granulomas
685
What are classic symptoms of ulcerative colitis?
Abdominal pain and bloody diarrhea
686
What is the "lead pipe" appearance in ulcerative colitis?
The distal colon shows smooth intestinal walls lacking the normal haustra indentations.
687
What type of antibodies are often elevated in ulcerative colitis?
Perinuclear antineutrophil cytoplasmic antibodies (p-ANCA).
688
What is the sensitivity and specificity of p-ANCA for ulcerative colitis?
55% sensitivity and 88% specificity.
689
What characterizes toxic megacolon?
Abrupt onset of colon inflammation and dilation without obstruction (non-obstructive dilation).
690
How can toxic megacolon be differentiated from other causes of colon dilation?
Toxic megacolon is associated with systemic toxicity (fever, tachycardia) in addition to colon dilation.
691
In which other conditions might you see dilated bowel without obstruction?
Hirschsprung’s disease, impaired gastrointestinal motility, and chronic constipation.
692
Are found in patients with granulomatosis with polyangiitis.
Cytoplasmic antineutrophil cytoplasmic antibodies (c-ANCA)
693
Are found in patients with Crohn’s disease with a 55% sensitivity and 92% specificity.
Anti-Saccharomyces cerevisiae antibodies (ASCA)
694
Are elevated in patients with autoimmune hepatitis.A
Anti-smooth muscle antibodies
695
Are elevated in patients with primary biliary cholangitis.
Anti-mitochondrial antibodies
696
What are common clinical findings in Crohn's disease?
Abdominal pain and diarrhea.
697
What portions of the GI tract can Crohn's disease affect?
Any portion from "mouth to anus," but most commonly the ileum.
698
What symptoms may occur with ileal involvement in Crohn's disease?
Fat malabsorption leading to steatorrhea (greasy, foul-smelling stools) and right lower quadrant abdominal pain.
699
What are common extraintestinal features of Crohn's disease?
Erythema nodosum, migratory polyarthritis, ankylosing spondylitis, kidney stones, and uveitis.
700
What pathologic features are associated with Crohn's disease?
Transmural, non-caseating granulomatous inflammation, skip lesions, cobblestone mucosa, fistula disease, strictures, and creeping fat.
701
What type of immune response is associated with Crohn's disease?
Th1 cell-mediated response.
702
How does the immune response in Crohn's disease differ from that in ulcerative colitis?
Ulcerative colitis is associated with a Th2 cell-mediated response.
703
Smoking improves outcomes in ? for unclear reasons. In Crohn’s disease, smoking is associated with worsened outcomes.
ulcerative colitis
704
Crypt abscesses caused by neutrophil inflammation are a hallmark pathological feature of ulcerative colitis.
Crypt abscesses caused by neutrophil inflammation
705
Ulcerative colitis always involves the
Rectum
706
Crohn’s disease most commonly involves the
Ileum
707
How does sulfasalazine work in the treatment of ulcerative colitis?
It is split by bacteria in the colon into sulfapyridine and 5-aminosalicylic acid (5-ASA), with 5-ASA being the active component that limits inflammation.
708
What are common side effects of sulfasalazine?
Nausea, vomiting, hypersensitivity, and oligospermia in men.
709
Is the oligospermia caused by sulfasalazine reversible?
Yes, it is reversible with drug cessation.
710
What is the role of methotrexate in treating inflammatory bowel disease?
It inhibits folate metabolism.
711
What side effect is associated with methotrexate?
Megaloblastic anemia.
712
What is infliximab and its use in inflammatory bowel disease?
Infliximab is an antibody that binds tumor necrosis factor alpha (TNF-alpha) and is used to treat inflammatory bowel disease, rheumatoid arthritis, ankylosing spondylitis, and psoriasis.
713
What are some adverse effects of infliximab?
Increased risk of infection, including tuberculosis.
714
What is prednisone commonly used for in inflammatory bowel disease?
It is used as an anti-inflammatory medication.
715
What are some side effects of prednisone?
Cushing’s-like syndrome, gastritis, skin thinning, poor wound healing, hyperglycemia, and lipodystrophy.
716
What condition is indicated by abdominal pain, distension, and failure to pass stools or flatus?
Small bowel obstruction.
717
What is the most common cause of mechanical small bowel obstruction in adults?
Abdominal adhesions (fibrous scar tissue) following surgery, such as appendectomy.
718
What are the initial treatment steps for small bowel obstruction?
Bowel rest and intestinal decompression via placement of a nasogastric tube.
719
When is surgery indicated for small bowel obstruction?
If symptoms are severe or do not resolve with conservative treatment.
720
What is the second most common cause of mechanical small bowel obstruction?
Hernias, often seen at the umbilicus or inguinal regions.
721
How does intestinal malignancy relate to small bowel obstruction?
It is a rare cause and typically requires surgical removal of the affected area.
722
What characterizes intussusception?
"Telescoping" of the intestine, where one segment folds into another, leading to obstruction and ischemia.
723
What are the classic symptoms of intussusception?
Abdominal pain, obstruction, and potentially “currant jelly stool.”
724
What are common underlying causes of intussusception in children?
Meckel’s diverticulum and lymphoid hyperplasia due to viral infections.
725
What is volvulus, and where is it commonly located?
Twisting of the intestines, commonly occurring at the sigmoid colon or cecum.
726
What are classic imaging findings of sigmoid volvulus?
A dilated sigmoid colon and an airless rectum.
727
In which population is volvulus most commonly seen?
The elderly population, typically around age 70.
728
What condition is characterized by a lack of movement in the intestines?
Ileus.
729
What imaging findings are typical in ileus?
Diffuse dilation of the small bowel with air-fluid levels.
730
What is the most common etiology of ileus?
Recent abdominal surgery or medications, particularly opioids.
731
How do opioids contribute to the development of ileus?
They slow down intestinal motility, leading to decreased movement and potential constipation.
732
What are stool softeners often prescribed alongside opioid pain medications?
To limit constipation and prevent ileus.
733
What role does inflammation play in ileus?
Inflammation (e.g., from inflammatory bowel disease, appendicitis, diverticulitis) can impair the muscular function of the intestine.
734
How is the ileus typically affected in cases of inflammation?
It is often isolated to the affected segment of bowel.
735
Why is inflammation less likely in this patient, despite potential causes of ileus?
The patient has normal vital signs and no fever.
736
Are small bowel tumors common causes of ileus?
No, they are rare causes of ileus and obstruction.
737
Is intussusception common in adults?
No, it is rare but can lead to ileus involving the affected segment of the bowel.
738
What is the most common cause of mechanical small bowel obstruction in adults?
Adhesions, but they are unlikely if there is no history of abdominal surgery.
739
What is Hirschsprung’s disease?
A congenital disorder characterized by abnormal colonic peristalsis due to the absence of ganglion cells in the colon.
740
What causes Hirschsprung’s disease?
Failure of neural crest cells to migrate to the colon, leading to absence of nerve cells in Meissner’s and Auerbach’s plexuses.
741
What are common symptoms of Hirschsprung’s disease?
Failure to pass meconium, abdominal distension, bilious emesis, and absence of stool on digital rectal examination.
742
What does barium imaging reveal in Hirschsprung’s disease?
A "transition zone" that is cone-shaped, with proximal bowel being dilated and distal bowel being narrow and compressed.
743
How is Hirschsprung’s disease definitively diagnosed?
Through a rectal suction biopsy that demonstrates the absence of ganglion cells.
744
What is the treatment for Hirschsprung’s disease?
Resection of the affected colon and rectum.
745
Why is abdominal ultrasound important in children?
It does not expose them to harmful radiation and can diagnose various abdominal conditions.
746
Why is a CT scan used cautiously in younger patients?
Due to the radiation exposure involved.
747
What imaging technique is not useful for diagnosing Hirschsprung’s disease?
Upper endoscopy, as it affects the colon and rectum.
748
What is a technetium-99m scan useful for?
Diagnosing Meckel’s diverticulum, characterized by ectopic gastric and pancreatic tissue in the small intestine.
749
What is the classic physical exam finding in Hirschsprung’s disease?
Absence of stool on digital rectal examination.
750
What is the likely diagnosis for a woman presenting with cystitis and pneumaturia?
Cystitis with pneumaturia, likely due to a colovesical fistula.
751
What is a colovesical fistula?
An abnormal connection between the colon and bladder, often caused by diverticulitis.
752
How does a colovesical fistula develop after diverticulitis?
Inflammation leads to adhesion of the diverticulum to the bladder wall, and necrosis can create an opening allowing air and stool to enter the bladder.
753
What are the common symptoms of cystitis?
Dysuria, urgency, frequency, and pneumaturia (air in the urine).
754
What is the definitive management for a colovesical fistula?
Surgery to remove the affected colon segment and repair the bladder
755
What is a common complication of acute diverticulitis?
Abscess formation, often presenting with persistent symptoms despite antibiotic treatment.
756
What clinical features indicate perforation of the colon due to diverticulitis?
Severe abdominal pain, rebound tenderness, fever, chills, leukocytosis, and often hemodynamic instability.
757
What symptoms can occur if diverticulitis leads to bowel obstruction?
Nausea, vomiting, abdominal distension, and obstipation.
758
When is lower gastrointestinal bleeding most common in diverticular disease?
Significant bleeding generally occurs in the absence of acute diverticulitis.
759
What are the key features of diverticulitis?
Symptoms include abdominal pain, fever, changes in bowel habits, and potentially complications like abscesses or perforation.
760
What is the primary characteristic of irritable bowel syndrome (IBS)?
IBS is defined as a functional bowel disorder characterized by chronic abdominal pain and altered bowel habits with no structural cause
761
How frequently must abdominal pain occur for a diagnosis of IBS?
Abdominal pain must occur at least 3 days per month over the last three months.
762
What additional features are required for the diagnosis of IBS?
Improvement of pain with defecation, change in stool frequency, or onset of symptoms associated with change in stool appearance.
763
What types of bowel habits can IBS involve?
IBS can involve diarrhea, constipation, or both.
764
In which demographic is IBS slightly more common?
IBS has a slightly higher incidence among women.
765
What are telangiectasias, and in which condition can they be found?
Telangiectasias are dilated submucosal capillaries with flattened endothelia, commonly seen in hereditary hemorrhagic telangiectasia.
766
What complications can arise from telangiectasias in the gastrointestinal tract?
They can lead to gastrointestinal bleeding and iron deficiency anemia.
767
What are common causes of duodenal ulcers?
Duodenal ulcers can occur due to Helicobacter pylori infection or Zollinger-Ellison syndrome (ZES).
768
How does abdominal pain typically present in patients with duodenal ulcers?
Abdominal pain is worse at night and improved with eating.
769
What is the role of Brunner’s glands in the duodenum?
Brunner’s glands produce alkaline fluid in response to acidified conditions, often hypertrophying in cases of peptic ulcer disease.
770
What is KRAS, and where is it located?
KRAS is a GTPase proto-oncogene located on the short arm of chromosome 12.
771
What is the consequence of a mutation in KRAS?
A point mutation in KRAS leads to increased expression and uncontrolled cellular division, resulting in dysplasia.
772
Which malignancies are commonly associated with KRAS mutations?
KRAS mutations are implicated in pancreatic, lung, and colonic adenocarcinomas.
773
What is BCR-ABL, and what condition is it associated with?
BCR-ABL is a mutated tyrosine kinase inhibitor associated with chronic myeloid leukemia (CML) and acute lymphoblastic leukemia (ALL).
774
Which malignancy is primarily associated with mutations in the BRAF gene?
BRAF mutations are primarily associated with melanoma.
775
What other malignancies can BRAF mutations be implicated in?
BRAF mutations are also associated with non-Hodgkin’s lymphoma and papillary thyroid cancer.
776
What is the MYC proto-oncogene, and with which cancer is its amplification associated?
MYC is a transcription factor, and its amplification is associated with small cell lung cancer.
777
What syndromes are associated with mutations in the RET oncogene?
The RET oncogene is associated with multiple endocrine neoplasia (MEN) types 2A and 2B.
778
What type of cancer is linked to MEN 2A and 2B?
MEN 2A and 2B are associated with medullary thyroid cancer.
779
What condition is this woman likely experiencing due to pancreatic cancer?
Splenic vein thrombosis.
780
Where does the splenic vein course in relation to the pancreas?
The splenic vein courses along the posterior aspect of the pancreas.
781
What happens to the spleen when the splenic vein is thrombosed?
Splenomegaly occurs due to the obstruction of blood flow.
782
Which veins does the splenic vein drain?
The splenic vein drains blood from the spleen and the short gastric veins of the stomach.
783
What is a potential consequence of splenic vein thrombosis in terms of gastric veins?
Congestion of the short gastric veins can lead to gastric varices along the greater curvature of the stomach.
784
What syndrome can also cause gastric varices along the greater curvature of the stomach?
Budd-Chiari syndrome, characterized by thrombosis of the hepatic veins.
785
What is the hallmark of hepatic cirrhosis related to varices?
Esophageal varices, which develop from collateral formation between esophageal veins and the left gastric vein.
786
How do umbilical veins become enlarged in relation to hepatic conditions?
They become enlarged due to elevated portal venous pressures, typically seen in hepatic cirrhosis.
787
Which rectal veins are affected by increased portal venous pressure in hepatic cirrhosis?
The superior rectal vein, which drains into the inferior mesenteric vein, can dilate and lead to internal hemorrhoids.
788
Why are internal hemorrhoids a concern in patients with hepatic cirrhosis?
Increased portal venous pressure can cause dilation of the superior rectal vein, leading to potential rupture and bleeding.
789
What condition is this man likely suffering from due to chronic pancreatitis?
Pancreatic insufficiency.
790
What are the classic findings in the pancreas associated with chronic pancreatitis?
White calcifications due to chronic inflammation.
791
What is a common symptom of pancreatic insufficiency?
Diarrhea associated with malabsorption of fat, known as steatorrhea.
792
How is steatorrhea characterized?
Greasy, foul-smelling stools that float.
793
What can chronic pancreatitis lead to in terms of blood sugar regulation?
Diabetes from destruction of insulin-producing pancreatic beta cells.
794
What symptoms may indicate hyperglycemia in this patient?
Excessive thirst and frequent urination.
795
What does an elevated Hemoglobin A1C indicate?
Chronically elevated serum glucose levels.
796
Why is Hemoglobin A1C important in managing diabetes?
It provides an average of blood glucose levels over the past 2-3 months.
797
What blood count finding is commonly associated with acute pancreatitis but not chronic pancreatitis?
Leukocytosis (elevated white blood cell count).
798
How do blood counts, electrolytes, and liver function tests typically present in chronic pancreatitis?
They are usually normal.
799
What may happen to serum lipase and amylase levels in chronic pancreatitis?
They may be normal or low due to fibrotic changes in the pancreas.
800
What does serum creatinine indicate, and how is it affected in chronic pancreatitis?
Serum creatinine is a marker of kidney function and is not directly affected by chronic pancreatitis.
801
What conditions could cause an increase in serum creatinine if the patient had chronic pancreatitis?
Poorly controlled hypertension or volume depletion.
802
What is alkaline phosphatase, and when are its levels elevated?
Alkaline phosphatase is secreted by bile duct epithelium, and elevated levels occur in cholestasis (bile duct obstruction, inflammation, or tumor).
803
What common nutritional deficiencies occur in patients with chronic pancreatitis?
Deficiencies of fat-soluble vitamins A, D, E, and K.
804
What does the acronym CREST stand for?
Calcinosis, Raynaud’s phenomenon, Esophageal dysmotility, Sclerodactyly, and Telangiectasias.
805
What form of scleroderma is associated with CREST syndrome?
Limited cutaneous scleroderma.
806
What is a characteristic feature of sclerodactyly?
Thickening and tightening of the fingers and toes due to collagen buildup in the skin.
807
What are telangiectasias?
Spider veins, often seen on the face, associated with conditions like CREST syndrome.
808
What does the acronym CREST stand for?
Calcinosis, Raynaud’s phenomenon, Esophageal dysmotility, Sclerodactyly, and Telangiectasias.
809
What form of scleroderma is associated with CREST syndrome?
Limited cutaneous scleroderma.
810
What is a characteristic feature of sclerodactyly?
Thickening and tightening of the fingers and toes due to collagen buildup in the skin.
811
What are telangiectasias?
Spider veins, often seen on the face, associated with conditions like CREST syndrome.
812
What specific antibodies are characteristic of CREST syndrome?
Anticentromere antibodies.
813
What contributes to loss of tone in the lower esophageal sphincter (LES) in scleroderma?
Esophageal smooth muscle atrophy.
814
How does LES hypotension in scleroderma differ from classic gastroesophageal reflux disease (GERD)?
LES hypotension in scleroderma is persistent, while GERD typically involves intermittent/transient hypotension.
815
What symptoms can persistent LES hypotension in scleroderma cause?
Severe reflux symptoms.
816
Which feature of CREST syndrome can be visibly noted during a physical exam?
Sclerodactyly and telangiectasias.
817
What is the primary virus associated with esophagitis in immunocompromised patients?
Herpes simplex virus type 1 (HSV-1).
818
What common symptoms are associated with HSV-1 esophagitis?
Dysphagia and chest pain.
819
What does endoscopy typically reveal in HSV-1 esophagitis?
Numerous ulcers with a “punched-out” appearance that often coalesce.
820
How is the diagnosis of HSV-1 esophagitis confirmed?
By biopsy.
821
What do the pathology findings show in HSV-1 esophagitis?
Squamous epithelial cells with dense eosinophilic intranuclear inclusion bodies.
822
What is a key endoscopic finding in cytomegalovirus (CMV) esophagitis?
One or more deep linear ulcers.
823
What condition is associated with gastroesophageal reflux disease (GERD) and can lead to Barrett's esophagus?
Reflux esophagitis.
824
What are the typical symptoms of reflux esophagitis?
Long-standing history of GERD symptoms like heartburn.
825
What does endoscopy reveal in Candida esophagitis?
Glossy white lesions lining the esophagus.
826
What is eosinophilic esophagitis?
A hypersensitivity reaction of the esophageal mucosa, presenting with GERD-like symptoms or dysphagia.
827
A key difference from HSV-1 esophagitis is that endoscopy in ?shows one or more deep linear ulcers.
CMV
828
What are the initial symptoms of esophageal cancer?
Dysphagia (difficulty swallowing), initially to solids and then to liquids, often associated with weight loss.
829
What is the 5-year survival rate for esophageal cancer?
Approximately 15%.
830
Which gender is more affected by esophageal cancer?
Men, who are affected three times more than women.
831
What are the two main types of primary esophageal cancers?
Squamous cell carcinoma (SCC) and adenocarcinoma.
832
Where is squamous cell carcinoma (SCC) more commonly found?
More commonly seen in the developing world.
833
What is the common treatment approach for esophageal cancer?
A combination of surgery, radiation, and chemotherapy.
834
What lifestyle factor is strongly associated with adenocarcinoma?
Obesity.
835
How does untreated gastroesophageal reflux disease (GERD) contribute to adenocarcinoma?
It can cause metaplasia of esophageal stratified squamous epithelium to gastric columnar epithelium (Barrett’s esophagus), increasing the risk of adenocarcinoma.
836
What type of epithelium is normally found in the esophagus?
Stratified squamous epithelium, not glandular cells.
837
What can lead to malignant transformation of normal squamous mucosa in the esophagus?
Other esophageal injuries that are not associated with metaplasia.
838
What long-term habit is a risk factor for squamous cell carcinoma (SCC) of the esophagus?
Consumption of very hot liquids, such as tea.
839
Where are approximately half of the reported new cases of esophageal cancer each year located?
In China, where hot tea consumption is common.
840
What type of caustic ingestions can increase the risk of esophageal strictures and SCC?
Ingestions of substances like lye and battery acid.
841
How does alcohol abuse affect the risk of esophageal SCC?
Alcohol abuse confers an increased risk of esophageal SCC.
842
Besides esophageal SCC, what other cancers are associated with alcohol consumption?
SCC of the head and neck, breast, liver, and colon cancer.
843
What type of esophageal cancer is associated with alcohol consumption?
Squamous cell carcinoma (SCC).
844
Why might the lack of association between alcohol and esophageal adenocarcinoma be counterintuitive?
Because alcohol is associated with gastroesophageal reflux disease (GERD), which can lead to adenocarcinoma.
845
What is "steakhouse syndrome"?
Acute, complete obstruction of the esophagus by a food bolus, often a large piece of meat.
846
What is the most common cause of "steakhouse syndrome"?
The presence of a Schatzki ring, a benign stricture that narrows the lumen of the esophagus.
847
Where is a Schatzki ring typically located?
Just above or at the squamocolumnar (SC) junction.
848
What is the primary risk factor for developing a Schatzki ring?
Gastroesophageal reflux disease (GERD).
849
What type of epithelium lines rings at the squamocolumnar (SC) junction?
Stratified squamous epithelium proximally (toward the mouth) and gastric epithelium distally (toward the stomach).
850
How are rings located above the squamocolumnar junction lined?
Entirely with stratified squamous epithelium.
851
What are esophageal webs associated with?
Plummer-Vinson syndrome.
852
Where are esophageal webs typically found?
Mostly in the proximal esophagus.
853
What are the key features of Plummer-Vinson syndrome?
Dysphagia, iron deficiency anemia, and an increased risk of squamous cell carcinoma (SCC) of the esophagus.
854
What are the two main types of esophageal neoplasms?
Esophageal squamous cell carcinoma and esophageal adenocarcinoma.
855
How do patients with esophageal cancer typically present?
Chronic, progressive dysphagia initially to solids and then liquids, along with appetite change, weight loss, and night sweats.
856
What are the characteristic features of eosinophilic esophagitis?
Esophageal strictures, linear furrows, whitish papules, or esophageal rings.
857
In which patients is eosinophilic esophagitis often seen?
Those with asthma or food allergies.
858
What complication can arise from portal hypertension in the setting of cirrhosis?
Esophageal varices.
859
In addition to cirrhosis, what other condition can lead to esophageal varices?
Portal venous thrombosis.
860
What is achalasia?
A rare disorder of the esophagus characterized by abnormal smooth muscle tone and obstruction to flow.
861
What causes achalasia?
Loss of ganglion cells in the myenteric plexus due to inflammation, thought to be autoimmune in nature.
862
What is the usual age of diagnosis for achalasia?
Between 25 and 60 years.
863
How does achalasia affect the distal esophagus?
It develops high smooth muscle tone (spasm), obstructing flow.
864
What compensatory changes occur in the esophagus due to flow obstruction in achalasia?
Hypertrophy and thickening of smooth muscle cells in the circular muscle layer.
865
What type of dysphagia is associated with achalasia?
Dysphagia that affects solids and liquids equally.
866
What are the conventional findings on esophageal manometry in achalasia?
Absence of peristaltic waves in the distal two-thirds of the esophagus and elevated relaxed lower esophageal sphincter (LES) pressure (often >100 mmHg).
867
What does a biopsy of the distal esophagus in achalasia reveal?
Inflammatory changes and absence of ganglion cells in the myenteric plexus.
868
What does a barium esophagram show in cases of achalasia?
Distal tapering and proximal dilatation of the esophagus.
869
What causes transient relaxations of the lower esophageal sphincter (LES)?
Gastroesophageal reflux disease (GERD).
870
What is the motility status of the esophagus in conventional GERD?
Esophageal motility is normal; however, the LES inappropriately relaxes.
871
What are the three criteria for diagnosing acute pancreatitis?
1) Characteristic abdominal pain, nausea, vomiting
2) Elevation of serum amylase/lipase at least 3 times the upper limit of normal
3) CT findings consistent with acute pancreatitis.
872
How many criteria must be met to diagnose acute pancreatitis?
Two out of the three criteria must be met.
873
What are the characteristic symptoms of acute pancreatitis?
Abdominal pain, nausea, and vomiting.
874
In this case, what is the level of serum amylase, and is it sufficient for diagnosis?
Serum amylase is elevated at 349 U/L, but it is not elevated to greater than 3 times the upper limit of normal (125 U/L).
875
What is the next step required for diagnosis in this patient?
An abdominal CT is required to make a diagnosis of acute pancreatitis.
876
What imaging study can be used to evaluate for underlying causes of pancreatitis?
Right upper quadrant ultrasound.
877
What may an ultrasound reveal in cases of gallstone pancreatitis?
Gallstones or common bile duct dilation.
878
What liver function test abnormalities may indicate gallstone pancreatitis?
Elevations in aspartate aminotransferase (AST), total and direct bilirubin, and alkaline phosphatase.
879
How useful is an abdominal radiograph in diagnosing acute pancreatitis?
It is generally not helpful for diagnosing acute pancreatitis and is more useful if bowel obstruction is suspected.
880
What are common causes of acute pancreatitis?
Gallstones, alcohol, trauma, toxins, hypertriglyceridemia, endoscopic manipulation of the common bile duct (e.g., during ERCP), and rarely, medications.
881
Name some medications that may cause pancreatitis
Sulfa drugs and 6-mercaptopurine (6-MP).
882
What class of medications for type 2 diabetes has been associated with pancreatitis?
Glucagon-like peptide 1 (GLP-1) agonists.
883
Give examples of GLP-1 agonists.
Liraglutide and exenatide.
884
What effects do GLP-1 agonists have on insulin secretion and gastric emptying?
They increase insulin secretion after meals, delay gastric emptying, and decrease post-prandial glucagon secretion.
885
What is the primary action of metformin in diabetes management?
It inhibits hepatic gluconeogenesis.
886
What are common side effects of metformin?
Diarrhea, nausea, vomiting, and flatulence.
887
Why should metformin not be prescribed in patients with chronic kidney disease?
There is an increased risk of lactic acidosis.
888
What class of medications do SGLT2 inhibitors belong to?
Sodium/glucose cotransporter 2 (SGLT2) inhibitors.
889
What is the mechanism of action of SGLT2 inhibitors like gliflozin and canagliflozin?
They block reuptake of glucose by the kidneys, leading to glucose excretion in the urine.
890
What are common side effects of SGLT2 inhibitors?
Increased risk of urinary tract infections and yeast infections.
891
What do alpha-glucosidase inhibitors do?
They inhibit the brush border enzyme alpha-glucosidase, inhibiting the absorption of glucose in the GI tract.
892
Name two examples of alpha-glucosidase inhibitors.
Acarbose and miglitol.
893
What is the most common side effect of alpha-glucosidase inhibitors?
Osmotic, watery diarrhea.
894
What condition is this patient experiencing?
Acute pancreatitis secondary to hypertriglyceridemia.
895
What serum triglyceride level is associated with causing pancreatitis?
Greater than 1000 mg/dL.
896
How does blood appear when triglyceride levels are significantly elevated
Thickened and milky-white color.
897
What are some potential causes of hypertriglyceridemia in this patient?
Poorly controlled diabetes, beta blocker therapy, and hydrochlorothiazide.
898
What is the pathophysiology behind triglyceride-induced pancreatitis?
Increased circulating levels of chylomicrons obstruct small capillaries within the pancreas, leading to ischemia.
899
What happens when excessive chylomicrons obstruct capillaries in the pancreas?
This leads to damaged capillary endothelium, exposure of circulating triglycerides to pancreatic lipase, formation of free fatty acids, decreased pH, and tissue injury resulting in pancreatitis.
900
What type of cell destruction occurs in autoimmune pancreatitis?
Antibody-mediated destruction of pancreatic exocrine cells.
901
What is the typical presentation of autoimmune pancreatitis?
Recurrent pancreatitis with enlargement of the pancreas over time.
902
What laboratory finding is often associated with autoimmune pancreatitis?
Elevated IgG4 levels.
903
What is the first-line treatment for autoimmune pancreatitis?
Steroids.
904
What is the mechanism of action in pancreatitis secondary to hypercalcemia?
Calcium deposition in pancreatic ducts.
905
What does calcium deposition in the pancreatic ducts lead to?
Inappropriate activation of trypsinogen.
906
What happens after the inappropriate activation of trypsinogen?
It initiates a cascade of activation of pancreatic enzymes.
907
What is the result of pancreatic auto-digestion?
Development of pancreatitis.
908
Is a rare cause of pancreatitis. This can be seen in children with abdominal pain following a car accident with restraint by a seat belt.
Trauma
909
Obstruction of the main pancreatic duct leading to decreased flow of pancreatic secretions is the cause of
Gallstone pancreatitis.
910
What is a pancreatic pseudocyst?
A collection of fluid with a well-defined inflammatory wall usually located outside the pancreas.
911
How is a pancreatic pseudocyst diagnosed?
By CT or MRI imaging of the abdomen.
912
What distinguishes pseudocysts from true cysts?
Pseudocysts contain no epithelium or endothelium.
913
What is a pancreatic pseudocyst composed of?
Pancreatic fluid surrounded by a thin fibrous layer.
914
When should suspicion for a pancreatic pseudocyst be raised?
When pancreatitis does not resolve with conventional therapy, such as when amylase or lipase fail to normalize, or when abdominal pain persists or returns.
915
How do pancreatic pseudocysts typically resolve?
They generally resolve without intervention.
916
When might a pancreatic pseudocyst require drainage?
Occasionally, if symptoms persist or complications arise.
917
What risks are associated with the drainage of a pancreatic pseudocyst?
It can lead to infection or rupture, resulting in peritonitis.
918
A pancreatic abscess can result from infection of pseudocyst. This generally occurs within 10 days of development of acute pancreatitis. This is unlikely in this patient, as he does not have signs of infection (fevers, severe pain, etc.). Causative organisms include
E. coli, Pseudomonas, Klebsiella, and Enterococcus.
919
Occurs in the setting of acute pancreatitis via inflammation of fat surrounding the pancreas. Formation of free fatty acids combined with calcium leads to calcium saponification, which can be seen on abdominal imaging.
Pancreatic fat necrosis
920
What does hypocalcemia in the setting of acute pancreatitis suggest?
Extensive involvement of the surrounding fat.
921
Is characterized by right upper quadrant pain that typically occurs after eating and lasts for 2 to 3 hours. There is often associated nausea and vomiting.
Biliary colic
922
What serum glucose level is one of Ranson’s criteria indicating a poor outcome in pancreatitis?
Serum glucose greater than 200 mg/dL.
923
What factors contribute to hyperglycemia in severe cases of pancreatitis?
Impaired insulin release and activation of the sympathetic nervous system.
924
What age is associated with a poor prognosis in acute pancreatitis?
Age greater than 55 years.
925
What laboratory finding is associated with a poor prognosis in acute pancreatitis?
Elevated serum lactate dehydrogenase (LDH).
926
What causes hypocalcemia in acute pancreatitis?
Marked inflammation of pancreatic fat, which binds with calcium (saponification), pulling calcium from the plasma.
927
Patients with acute and chronic pancreatitis can have
Reduced duodenal pH after meals.
928
A fall in hematocrit by ? at 48 hours after admission predicts a worse prognosis among patients with acute pancreatitis.
10%
929
What is celiac sprue also known as?
Celiac disease or gluten sensitivity.
930
What triggers the autoimmune response in celiac disease?
Gluten exposure, specifically the deamidated form of gliadin.
931
Which enzyme catalyzes the deamidation of gliadin?
Tissue transglutaminase (tTG).
932
What type of hypersensitivity reaction is associated with celiac disease?
Type IV hypersensitivity reaction.
933
Which human leukocyte antigens (HLA) are strongly associated with celiac disease?
HLA-DQ2 and HLA-DQ8.
934
What are the pathological hallmarks of celiac sprue observed in small intestine biopsy?
Blunting (atrophy) of villi, crypt hyperplasia, and increased intraepithelial lymphocytes.
935
What are common symptoms of celiac disease?
Bloating, flatulence, diarrhea, and weight loss.
936
What rash is associated with celiac disease, and where does it typically occur?
Dermatitis herpetiformis, commonly on the buttocks, knees, and elbows.
937
What is the first-line antibody test for celiac sprue?
IgA anti-tissue transglutaminase (anti-tTG).
938
What are the sensitivity and specificity of the IgA anti-tTG test?
Sensitivity is 95% and specificity is 97%.
939
What is done after a positive IgA anti-tTG screening?
A duodenal biopsy is performed to confirm the diagnosis.
940
What is the exception to the IgA anti-tTG testing algorithm?
In patients deficient in IgA antibodies, the IgG anti-tTG level can be measured instead.
941
What condition is characterized by persistent, watery diarrhea after traveling to the Caribbean?
Tropical sprue.
942
What causes tropical sprue?
An unknown infectious agent leading to malabsorption.
943
How does tropical sprue progress in the small intestine?
It begins in the duodenum and progresses to affect the entire small bowel.
944
What vitamin deficiency commonly occurs in tropical sprue?
Folate deficiency.
945
Why can B12 deficiency occur in tropical sprue?
It can occur if the disease progresses to involve the ileum, but this is less common than folate deficiency.
946
What are the hematological features of megaloblastic anemia due to vitamin deficiencies?
Reduced hemoglobin, reduced hematocrit, and elevated mean corpuscular volume.
947
What do peripheral blood smears typically show in megaloblastic anemia?
Hyper-segmented neutrophils.
948
What is the typical treatment for tropical sprue?
Tetracycline and folate supplementation.
949
An elevated serum ferritin can be seen in primary and secondary hemochromatosis, both disorders of
Iron overload.
950
Decrease serum lipase occurs in pancreatic insufficiency. Predisposing factors include
Chronic pancreatitis, cystic fibrosis, and obstruction.
951
Mesenteric lymphadenopathy is seen in Whipple’s disease. Whipple’s disease is characterized by four cardinal features:
Abdominal pain, diarrhea, weight loss, and migratory arthralgias of the large joints.
952
Patients with IgA deficiency have decreased serum IgA antibodies. When screening these patients for celiac sprue, IgA tissue transglutaminase (tTG) antibodies cannot be used, and
IgG tissue transglutaminase antibodies must be measured instead.
953
Celiac sprue and tropical sprue can have similar clinical presentations. Because this man recently traveled to the Caribbean, tropical sprue is likely, but celiac disease still must be ruled out. To do this, testing for tissue ? should be performed. These antibodies are not present in tropical sprue.
Transglutaminase antibodies
954
What is Whipple’s disease caused by?
Tropheryma whipplei, a gram-positive rod related to actinomycetes.
955
Who is most commonly affected by Whipple’s disease?
Middle-aged Caucasian males of European descent.
956
What are the cardinal signs of Whipple’s disease?
Diarrhea from malabsorption of fats and sugars, abdominal pain, weight loss, and migratory joint pains.
957
What percentage of patients with Whipple’s disease experience arthralgias?
Up to 80%.
958
What other clinical features may be present in Whipple’s disease?
Mesenteric lymphadenopathy, encephalopathy, and darkened skin (hyperpigmentation).
959
What is the treatment for Whipple’s disease?
Antibiotics, commonly ceftriaxone.
960
What is the pathologic hallmark of Whipple’s disease observed on biopsy?
Foamy macrophages in the lamina propria of the small intestine.
961
How do foamy macrophages stain in Whipple’s disease?
They turn red when stained with periodic acid-Schiff (PAS) stain.
962
What condition is associated with normal fecal fat excretion?
Lactose intolerance.
963
What causes lactose intolerance?
Deficient activity of lactase, the enzyme that breaks down lactose into galactose and glucose.
964
What type of diarrhea is associated with lactose intolerance?
High-volume, watery diarrhea.
965
What mechanism causes the diarrhea seen in lactose intolerance?
Osmotic diarrhea, where undigested lactose draws water into the intestines.
966
What is a positive fecal fat test indicative of?
Inability to break down and/or absorb fat, leading to steatorrhea.
967
What fecal fat level is considered abnormal?
Greater than 7 g of stool fat per day.
968
Chronic pancreatitis and pancreatic insufficiency lead to impaired pancreatic function including the secretion of enzymes such as lipase and colipase. These enzymes are necessary for breaking down fat for absorption. Patients with chronic pancreatitis or pancreatic insufficiency develop
Steatorrhea (greasy, foul-smelling stools that float) by this mechanism.
969
Short gut syndrome occurs following bowel resections where more than 100 cm of bowel are removed, for conditions like Crohn’s disease. Bile acids emulsify fats to improve digestion and absorption. Bile acids are reabsorbed in the terminal ileum, then recycled into the bile for emulsification of dietary fats. Following ileal resection, fat malabsorption and steatorrhea develop due to
Insufficient enterohepatic circulation of bile acids.
970
Occurs in pancreatic and biliary cancer, autoimmune conditions such as primary biliary sclerosis and primary sclerosing cholangitis, and gallstone disease. These conditions lead to impaired secretion of bile acids necessary for emulsification of fats.
Biliary obstruction
971
Normal digestion of fats requires three elements: ?. Loss of any of these elements may lead to steatorrhea.
Pancreatic enzymes, bile acids from the liver, and bile acid reabsorption in the ileum.
972
What does the D-xylose test evaluate?
Carbohydrate absorption in the small intestine.
973
Does D-xylose require enzymatic modification for digestion?
No, it does not require enzymatic modification.
974
What is necessary for the absorption of D-xylose?
An intact mucosa in the small intestine.
975
What should happen to D-xylose in a normal small intestine?
It should appear in the bloodstream and urine in normal amounts.
976
What conditions can lead to an abnormal D-xylose test result?
Small intestinal bacterial overgrowth and Whipple’s disease.
977
How do small intestinal bacterial overgrowth and Whipple’s disease affect D-xylose absorption?
They disrupt the integrity of the small intestinal mucosa, impairing absorption.
978
How is the small intestinal mucosa in lactose intolerance?
It is normal, except for the absence of the enzyme lactase.
979
What condition leads to impaired secretion of pancreatic enzymes necessary for fat absorption?
Pancreatic insufficiency.
980
Why is D-xylose absorption unaffected by pancreatic enzyme deficiency?
D-xylose is a monosaccharide and does not require pancreatic enzymes for absorption.
981
What is irritable bowel syndrome (IBS)?
A functional bowel disorder characterized by chronic abdominal pain and altered bowel habits with no structural cause.
982
What condition affects the stomach and can lead to malabsorption of vitamin B12?
Atrophic gastritis, due to impaired secretion of intrinsic factor.
983
Where are the majority of peptic ulcers located?
In the duodenum (over 90%).
984
How does food affect the pain associated with duodenal ulcers?
Pain often improves with food due to alkaline fluid production that raises duodenal pH.
985
When do symptoms of duodenal ulcers typically worsen?
About 2 to 3 hours after eating when pH falls again and symptoms worsen in the acidic environment.
986
What type of pain is associated with gastric ulcers?
Epigastric pain that worsens with food, as food stimulates gastric acid production.
987
What is the rule of thumb for distinguishing between duodenal and gastric ulcer pain?
Duodenal Ulcers: Pain decreases with meals.
Gastric Ulcers: Pain increases with meals.
988
What are common risk factors for duodenal ulcers?
Helicobacter pylori infection, NSAID use, and smoking.
989
Does alcohol have a consistent association with peptic ulcer disease?
No, alcohol has no consistent association, though it can cause gastritis.
990
What is autoimmune gastritis also known as?
Atrophic gastritis or type A chronic gastritis.
991
What causes autoimmune gastritis?
Autoimmune destruction of gastric parietal cells.
992
What physiological change occurs due to the loss of parietal cells in autoimmune gastritis?
Hypochlorhydria (high luminal pH) with reflex hypergastrinemia.
993
What complication arises from impaired intrinsic factor release?
Impaired absorption of vitamin B12 in the terminal ileum, leading to pernicious anemia.
994
What type of anemia is caused by vitamin B12 deficiency due to autoimmune gastritis?
Megaloblastic anemia (characterized by elevated mean corpuscular volume, MCV).
995
What is the increased risk associated with atrophic gastritis?
Increased risk for gastric adenocarcinoma.
996
With which HLA antigens is autoimmune gastritis associated?
HLA-DR antigens, and it may run in families.
997
Which parts of the stomach are affected in autoimmune gastritis?
The gastric body and fundus.
998
Risk of MALT lymphoma is increased in the setting of chronic gastritis from
Helicobacter pylori (H. pylori) infection.
999
H. pylori infection is diagnosed via breath test as well as detection of H. pylori stool antigen. This typically causes
Type B chronic gastritis that affects the antrum (portion of stomach nearest the duodenum).
1000
What is the most common cause of duodenal ulcers?
H. pylori infection (over 90% of cases).
1001
Where do duodenal ulcers typically occur?
On the anterior wall of the duodenum, less often on the posterior wall.
1002
How do patients with duodenal ulcers typically present?
With epigastric pain that improves with eating and worsens at night.
1003
Why does pain from a duodenal ulcer improve after meals?
Food stimulates bicarbonate secretion in the duodenum, creating an alkalotic environment that decreases irritation from stomach acid.
1004
What are Brunner’s glands, and where are they located?
Brunner's glands are located in the submucosa of the duodenum and secrete alkaline fluid to protect the mucosa from acidic chyme.
1005
What occurs to Brunner’s glands in the setting of a duodenal ulcer?
They undergo hypertrophy, increasing the thickness of the submucosal layer of the duodenum.
1006
Are seen in diffuse gastric cancer. When this cancer metastasizes to the ovaries, the ovarian tumors are termed Krukenberg’s tumors. Patients generally present with early satiety.
Signet ring cells
1007
May be seen in duodenal ulcers, but eosinophils are uncommon.
Surface neutrophils
1008
The muscularis mucosa is a thin layer of smooth muscle below the submucosa. In the setting of ulcers, the muscularis mucosa is
Eroded and becomes thinner.
1009
What type of bacteria is Helicobacter pylori (H. pylori)?
A curved, gram-negative bacillus.
1010
Why is H. pylori often described as “triple positive”?
Because it is catalase, oxidase, and urease positive.
1011
What is a key pathogenic mechanism of H. pylori?
It uses flagella for motility.
1012
What conditions are associated with H. pylori infection?
Acute and chronic gastritis, peptic ulcers, gastric adenocarcinoma, and MALT lymphoma.
1013
What is the standard treatment for H. pylori infection?
Triple therapy consisting of a proton pump inhibitor (PPI), clarithromycin, and either amoxicillin or metronidazole.
1014
hat should be done after initial treatment of H. pylori?
Repeat testing is indicated, as the initial therapy is only about 80% effective.
1015
What is a concerning sign if ulcers do not resolve with H. pylori treatment?
It may indicate gastric malignancy.
1016
Does H. pylori have a type III secretion system?
No, it does not; this system is found in some other gram-negative rods like E. coli, Salmonella, and Shigella.
1017
Is H. pylori a lactose-fermenting bacteria?
No, H. pylori does not ferment lactose.
1018
Which gram-negative rods are known to ferment lactose?
E. coli, Enterobacter, Klebsiella, Citrobacter, and Serratia species.
1019
From where does the gastroduodenal artery most commonly arise?
The common hepatic artery.
1020
What is a significant complication of a posterior duodenal ulcer?
Bleeding due to erosion into the gastroduodenal artery.
1021
What are the branches of the gastroduodenal artery?
The retroduodenal artery, right gastroepiploic artery, and superior pancreaticoduodenal artery.
1022
What does the gastroduodenal artery supply blood to?
The pylorus and proximal duodenum, and indirectly to the pancreatic head.
1023
The proper hepatic artery is also a branch of the common hepatic artery, and branches to the
Right and left hepatic arteries.
1024
Where does the left gastric artery run, and what does it anastomose with?
It runs along the lesser curvature of the stomach and anastomoses with the right gastric artery
1024
What are the three main branches of the celiac trunk?
Left gastric artery, splenic artery, and common hepatic artery.
1025
What is a common cause of bleeding from the left gastric artery?
Perforated gastric ulcers.
1026
What does the splenic artery supply, and what branches does it give off?
It runs along the greater curvature of the stomach and gives off short gastric branches that supply the fundus and upper part of the greater curvature.
1027
What are gastric varices, and what condition can cause them?
Gastric varices result from dilation of the short gastric vessels, often caused by cirrhosis and portal hypertension.
1028
What is the role of the superior mesenteric artery (SMA)?
It supplies the gut distal to the ampulla of Vater, through the mid-transverse colon.
1029
What arteries are branches of the superior mesenteric artery?
Inferior pancreaticoduodenal artery, right colic artery, middle colic artery, and ileocolic artery.
1030
What type of cancer comprises approximately 95% of gastric cancers?
Gastric adenocarcinoma.
1031
What are common symptoms of gastric adenocarcinoma?
Weight loss, abdominal pain, and early satiety.
1032
What is Virchow's node, and what does its presence indicate?
Virchow's node is an enlarged left supraclavicular lymph node, and its presence may indicate gastric adenocarcinoma.
1033
What is a Sister Mary Joseph’s nodule?
A palpable periumbilical nodule that may indicate metastatic gastric cancer.
1034
What is the five-year survival rate for localized gastric adenocarcinoma?
Approximately 95%.
1035
What is the five-year survival rate for metastatic gastric adenocarcinoma?
Approximately 15%.
1036
What are nitrosamines, and where can they be found?
Nitrosamines, such as N-Nitrosodimethylamine (NDMA), are found in preserved meats, cheeses, and are components of tobacco.
1037
What are important risk factors for gastric adenocarcinoma?
H. pylori infection, smoking, obesity, and consumption of nitrosamines.
1038
Is a risk factor for angiosarcoma of the liver, a rare but highly malignant tumor.
Polyvinyl chloride
1039
Is a risk factor for adenocarcinoma of the stomach.
Type A blood
1040
Which are produced by Aspergillus species, are a risk factor for hepatocellular carcinoma.
Aflatoxins
1041
Chewing tobacco is a risk factor for
oral-pharyngeal squamous cell carcinoma.
1042
Achalasia is a risk factor for
esophageal squamous cell carcinoma.
1043
Although NSAIDs may cause gastritis and peptic ulcers, these drugs have never been associated with gastric cancer.
In fact, some studies have found a decreased risk (“protective effect”) of gastric cancer among patients that take NSAIDs.
1044
What is Ménétrier’s disease?
A form of hypertrophic gastropathy characterized by hyperplasia of mucous cells and excessive gastric mucous secretion.
1045
What physiological change occurs in Ménétrier’s disease that leads to achlorhydria?
Excessive gastric mucous secretion neutralizes gastric acid.
1046
What is "protein-losing enteropathy" and how is it related to Ménétrier’s disease?
A condition where proteins are lost in the stool due to improper protein breakdown, leading to total-body protein depletion.
1047
What are the clinical manifestations of hypoalbuminemia in Ménétrier’s disease?
Lower-extremity edema and facial swelling.
1048
In which demographic is Ménétrier’s disease more commonly found?
More common in men (3:1 ratio), typically between ages 30 and 60.
1049
What endoscopic or imaging finding is characteristic of Ménétrier’s disease?
Striking enlargement of gastric folds, often seen on endoscopy or abdominal imaging.
1050
How does Ménétrier’s disease affect the gastric antrum?
Ménétrier’s disease usually spares the antrum.
1051
What is the risk associated with Ménétrier’s disease?
An increased risk of gastric adenocarcinoma.
1052
What is the main consequence of protein-losing nephropathies?
They lead to proteinuria and are a significant renal cause of hypoalbuminemia.
1053
Name some examples of protein-losing nephropathies.
Acute poststreptococcal glomerulonephritis, rapidly progressive glomerulonephritis, IgA nephropathy (Berger’s disease), Alport’s syndrome, and membranoproliferative glomerulonephritis.
1054
What condition is associated with duodenal ulcers and characterized by excess gastric acid?
Zollinger-Ellison syndrome.
1055
What is linitis plastica?
A variant of diffuse gastric cancer characterized by thickened and rigid gastric walls.
1056
How does linitis plastica differ from most gastric cancers regarding Helicobacter pylori?
It is not associated with Helicobacter pylori infection or chronic gastritis.
1057
What is a key pathological finding in linitis plastica?
The presence of signet ring cells.
1058
Linitis plastica, also known as ? is a variant of diffuse gastric cancer characterized by thickened and rigid gastric walls.
Brinton’s disease or “leather bottle stomach,”
1059
What are Curling’s ulcers?
They are stomach ulcers that occur in the setting of extensive burn injuries.
1060
What causes Curling’s ulcers?
Skin damage from burns leads to fluid volume loss, decreased plasma volume, gastric mucosal ischemia, and necrosis.
1061
How is the treatment for Curling’s ulcers primarily approached?
Treatment involves fluid resuscitation to maintain adequate perfusion.
1062
What is the primary mechanism behind stress ulcers?
Ischemia due to under-perfusion of the stomach, often seen in shock, sepsis, and trauma.
1063
What are Cushing’s ulcers, and what causes them?
Cushing’s ulcers result from increased intracranial pressure, leading to increased vagal tone.
1064
What is the primary mechanism of NSAID-induced gastritis?
Decreased prostaglandin synthesis, which leads to increased acid production and loss of mucus and bicarbonate production.
1065
What is acalculous cholecystitis?
A type of acute cholecystitis that occurs without the presence of gallstones.
1066
In which patient population is acalculous cholecystitis commonly seen?
It is often seen in critically ill patients due to gallbladder ischemia and bile stasis.
1067
What is biliary sludge?
Thickened bile that forms due to bile stasis in the gallbladder.
1068
What is the preferred treatment for acalculous cholecystitis in unstable patients?
Drainage via a percutaneous cholecystostomy.
1069
Why might patients with acalculous cholecystitis be too unstable for surgery?
Critical illness often leads to overall instability, making surgical procedures risky.
1070
What are black stones, and what causes them?
Black stones are pigmented gallstones composed of unconjugated bilirubin, caused by increased bilirubin secretion (hemolysis) or decreased bilirubin excretion (cirrhosis).
1071
What conditions are associated with brown stones?
Brown stones are often found in conditions of infected bile, typically in settings of infection or sepsis.
1072
What is the most common type of gallstone?
Cholesterol stones are the most common type of gallstones.
1073
What are some risk factors for cholesterol gallstones?
Risk factors include female gender, pregnancy or history of multiple pregnancies, obesity, rapid weight loss, and impaired bile salt synthesis/resorption.
1074
What condition is indicated by gallbladder findings on hospital day 4 in a critically ill patient?
Gallbladder sludge (acalculous cholecystitis) is the likely explanation for gallbladder findings in this context.
1075
What causes bile duct strictures?
Bile duct strictures can occur due to neoplasia (cholangiocarcinoma, pancreatic adenocarcinoma) or autoimmune conditions (e.g., primary biliary cholangitis, sclerosing cholangitis).
1076
What is ascending cholangitis?
Ascending cholangitis is a life-threatening infection of the biliary tract that can lead to septic shock and death.
1077
What is the typical treatment for ascending cholangitis?
Treatment involves fluid resuscitation, antibiotics, and biliary drainage, usually via endoscopic retrograde cholangiopancreatography (ERCP).
1078
What are the most common causative organisms of ascending cholangitis?
The most common organisms are gastrointestinal flora, particularly gram-negative rods like Klebsiella pneumoniae and Enterobacter.
1079
Why is it important to treat for anaerobes in ascending cholangitis?
Obstruction and ischemia create a hypoxic environment, making anaerobic bacteria significant contributors to infection.
1080
What are common antimicrobial regimens for treating ascending cholangitis?
Common regimens include ceftriaxone or ciprofloxacin (for gram-negative rods) and metronidazole (for anaerobes), or a single broad-spectrum agent.
1081
A rare cause of ascending cholangitis is ?, a helminth found in infected fish. Blood work in these cases will show eosinophilia. Praziquantel is the drug of choice for treatment. Although this woman ate sushi recently, her neutrophil-predominant leukocytosis indicates bacterial infection, not helminth infection.
Clonorchis sinensis (Chinese liver fluke)
1082
Chronic infection of the biliary tree with a virus can be seen in the setting of AIDS due to infection with ?. This is rarely seen in the modern era with widespread use of antiretroviral therapy.
Cytomegalovirus (CMV)
1083
What does the X-ray finding of calcification along the perimeter of the gallbladder indicate?
This finding is known as "porcelain gallbladder," associated with chronic gallbladder inflammation.
1084
What symptoms may be associated with porcelain gallbladder?
Patients may be asymptomatic or present with right upper quadrant abdominal pain, and occasionally a palpable mass.
1085
What complications can arise from common bile duct stones in patients with porcelain gallbladder?
Complications include jaundice, fever, cholangitis, or pancreatitis.
1086
Why is porcelain gallbladder concerning in elderly patients?
It indicates an increased risk of gallbladder carcinoma, which is a rare cancer with a poor prognosis.
1087
What causes chronic gallbladder inflammation that can lead to porcelain gallbladder?
Prolonged, untreated gallstone disease or chronic infection with Salmonella typhi, particularly in endemic regions.
1088
Which countries are known for high rates of Salmonella typhi gallbladder infections?
Endemic areas include South American countries like Chile, Bolivia, Ecuador, and Asian countries like India, Pakistan, Japan, and Korea.
1089
What is choledocholithiasis?
Choledocholithiasis is the presence of a gallstone in the common bile duct (CBD) that obstructs bile flow into the duodenum.
1090
What are the clinical signs of choledocholithiasis?
Signs include jaundice (yellowing of the skin and sclera), dark urine, and elevated serum bilirubin.
1091
How does choledocholithiasis affect liver function tests?
It leads to elevated serum alkaline phosphatase due to obstruction of bile flow, but it typically does not cause severe liver failure or elevated INR.
1092
What major causes of acute liver failure are associated with elevated INR?
Major causes include acetaminophen toxicity and ischemic hepatitis.
1093
What ultrasound findings would be expected in a case of acute pancreatitis?
Ultrasound would show an enlarged pancreas with heterogeneous tissue due to edema.
1094
What is ascending cholangitis, and how does it present?
Ascending cholangitis is an infection of the bile duct that presents with Charcot’s triad: jaundice, right upper quadrant pain, and fever.
1095
What is Reynolds' pentad?
Reynolds' pentad includes Charcot’s triad plus hypotension and altered mental status, indicating severe sepsis.
1096
What is pneumobilia?
Pneumobilia is the presence of air in the biliary tree, often indicated by radiologic findings.
1097
What condition is associated with pneumobilia and intestinal obstruction?
Gallstone ileus, which occurs when a gallstone erodes into the bowel, causing obstruction.
1098
How does gallstone ileus develop?
It typically occurs after chronic cholecystitis leads to the formation of a fistula between the gallbladder and the small intestine, allowing gallstones to enter the intestines.
1099
Which part of the intestine is most commonly obstructed in gallstone ileus?
The ileum, as it is the narrowest section of the intestines.
1100
What clinical findings are consistent with gallstone ileus?
Evidence of intestinal obstruction (nausea, vomiting, abdominal fullness, lack of bowel movements) combined with pneumobilia.
1101
What does "ileus" mean?
"Ileus" refers to a lack of movement of the intestines.
1102
How does gallstone ileus occur?
A large gallstone erodes into the bowel, causing intestinal obstruction and forms a fistula between the bowel and bile ducts.
1103
In what condition does gallstone ileus typically occur?
Gallstone ileus generally occurs in the setting of chronic cholecystitis.
1104
Why does gallstone ileus happen in the ileum?
The ileum is the narrowest section of the intestines; a large stone that cannot pass through leads to obstruction.
1105
Why might pneumobilia be present after ERCP or biliary surgery?
It is a normal consequence of the procedure and typically resolves on its own.
1106
What are other causes of pneumobilia?
Mesenteric ischemia, gastric ulcers, diverticulitis, or post bowel surgery.
1107
What might a woman's history of recurrent abdominal pain suggest in relation to gallstone ileus?
It may indicate untreated gallstone disease that has led to gallstone ileus.
1108
What is primary sclerosing cholangitis (PSC)?
PSC is an autoimmune disorder of the biliary tree associated with ulcerative colitis, characterized by immune-mediated fibrosis
1109
What happens to the bile ducts in PSC?
Immune-mediated fibrosis leads to narrowing (stenosis) or obliteration of the bile ducts, causing dilation behind these areas.
1110
What is the classic imaging finding in PSC?
Numerous intra- and extra-hepatic bile duct strictures, often described as “beads on a string” or a “chain of lakes.”
1111
How many patients with PSC are asymptomatic at diagnosis?
Up to half of patients with PSC may be asymptomatic at the time of diagnosis.
1112
What are the most common symptoms of PSC?
Fatigue and pruritus are the most common symptoms.
1113
What rare symptoms may occur due to cholestasis in PSC?
Symptoms like jaundice and dark urine may occur due to impaired bile flow.
1114
What does pathology reveal in patients with PSC?
Pathology typically shows periductal fibrosis of the bile ducts.
1115
What is the risk associated with PSC?
Patients with PSC are at increased risk of cholangiocarcinoma and should be screened every 6-12 months.
1116
What are the treatment options for PSC?
Treatment options include endoscopic stenting and liver transplant.
1117
How is autoimmune hepatitis often discovered?
It is often found incidentally through blood work showing transaminitis (increased ALT and AST).
1118
Is autoimmune hepatitis typically acute or chronic?
Autoimmune hepatitis is a chronic disease.
1119
Does autoimmune hepatitis commonly progress to cirrhosis?
It rarely progresses to cirrhosis.
1120
What is the hallmark of diagnosis for autoimmune hepatitis?
The presence of anti-smooth muscle antibodies is the hallmark for diagnosis.
1121
Primary biliary cholangitis (PBC; also called primary biliary cirrhosis) is an autoimmune disorder of the biliary tree. It typically affects middle-aged women and presents with symptoms consistent with biliary obstruction, including fatigue, pruritis, pale stools, jaundice, and bilirubinuria. Lab findings include elevated AST, ALT, total bilirubin, and direct bilirubin. Markedly elevated alkaline phosphatase is a classic finding.
PBC is distinguished from PSC by imaging. In PBC, there is no extrahepatic bile duct obstruction. The serum hallmark of diagnosis is presence of anti-mitochondrial antibodies. PBC patients often have additional autoimmune disorders such as Sjögren’s syndrome. Serum lipids can be markedly elevated (>1,000). Ursodeoxycholic acid is the only effective pharmaceutical agent for this disease. The definitive treatment is liver transplant.
1122
Is a clinical feature of many disorders of cholestasis (obstructed bile flow). Itching is a classic feature of primary biliary cirrhosis where it occurs in up to 80% of patients, but may also occur in other biliary disorders including PSC.
Itching (pruritus)
1123
Is characterized by a long history of intermittent right upper quadrant pain, nausea, and vomiting. Left untreated, it can increase the risk of gallbladder carcinoma.
Chronic cholecystitis
1124
What is primary biliary cholangitis (PBC)?
PBC is an autoimmune disease of the biliary tree, also known as primary biliary cirrhosis.
1125
Who is typically affected by PBC?
PBC primarily affects middle-aged women.
1126
What are common symptoms of PBC?
Symptoms include fatigue, pruritus, pale stools, jaundice, and bilirubinuria.
1127
What laboratory findings are indicative of PBC?
Elevated transaminases (AST and ALT), total and direct bilirubin, and markedly elevated alkaline phosphatase.
1128
How is PBC distinguished from primary sclerosing cholangitis?
PBC shows no extrahepatic bile duct obstruction on imaging.
1129
What is the serum hallmark for diagnosing PBC?
The presence of anti-mitochondrial antibodies.
1130
What does a liver biopsy reveal in PBC?
A dense lymphocytic infiltrate with granulomatous inflammation, known as a “florid duct lesion.”
1131
What characterizes late-stage PBC?
Late disease is characterized by direct hyperbilirubinemia.
1132
Why might a patient have normal bilirubin levels in early PBC?
Normal bilirubin levels indicate that the disease is relatively mild at that point.
1133
Hepatic fibrosis is characteristic of cirrhosis. This patient’s presentation does not fit cirrhosis. She has no history of chronic liver disease or alcohol use. Also, AST and ALT are often normal or even decreased in cirrhosis because the normal hepatic parenchyma has been replaced by fibrous tissue. Key lab findings in cirrhosis include
Low platelets, decreased albumin, and elevated prothrombin time and INR.
1134
Are eosinophilic intracytoplasmic inclusions in hepatocytes that occur in alcoholic hepatitis.
Mallory bodies
1135
What are classic features of ulcerative colitis?
Abdominal pain, bloody diarrhea, fatigue, weight loss, arthralgias, and a family history of gastrointestinal disease.
1136
What is the “lead pipe” appearance in X-ray imaging?
A smooth colon with a lack of haustra, typically seen in chronic ulcerative colitis.
1137
What lab findings are consistent with primary sclerosing cholangitis?
Elevations in AST and ALT in a ~1:1 pattern, along with elevated alkaline phosphatase and total bilirubin.
1138
What percentage of patients with PSC have coexisting inflammatory bowel disease?
The majority, most commonly ulcerative colitis.
1139
What symptoms indicate a patient with ulcerative colitis may have PSC?
Evidence of cholestasis such as hyperbilirubinemia, jaundice, and elevated alkaline phosphatase.
1140
What antibodies are found in up to 80% of patients with PSC?
Perinuclear antineutrophil cytoplasmic antibodies (p-ANCAs).
1141
What conditions are associated with p-ANCA antibodies?
Ulcerative colitis (without PSC), microscopic polyangiitis, crescentic glomerulonephritis, and rheumatoid arthritis.
1142
What imaging study should be performed to confirm the diagnosis of PSC?
A cholangiogram to image the biliary tree.
1143
What does a cholangiogram typically show in PSC?
Numerous strictures and dilatations of the extrahepatic bile ducts.
1144
Are a diagnostic marker of primary biliary cholangitis
Anti-mitochondrial antibodies
1145
Occur in granulomatosis with polyangiitis (formerly known as Wegener’s granulomatosis).
Cytoplasmic antineutrophil cytoplasmic antibodies (c-ANCAs)
1145
Occur in autoimmune hepatitis.
Anti-smooth muscle antibodies
1146
Anti-double-stranded DNA antibodies are highly specific for
Systemic lupus erythematosus
1147
What is biliary atresia?
A congenital abnormality of the biliary ducts where the biliary tree fails to develop or develops abnormally.
1148
What are common signs of cholestasis in infants with biliary atresia?
Hyperbilirubinemia, dark urine, and pale (“acholic”) stools.
1149
What is the appearance of vomitus in a baby with biliary atresia?
Non-bilious vomitus (clear to light yellow), as bile is absent in the intestinal lumen.
1150
What is a classic finding on a cholangiogram in biliary atresia?
Failure to visualize the biliary tree, indicating it is not present.
1151
How might the gallbladder appear in biliary atresia?
The gallbladder may be absent or have an irregular shape.
1152
What is the etiology of biliary atresia?
Biliary atresia is idiopathic, meaning its exact cause is unknown.
1153
What is the surgical management for biliary atresia?
The Kasai procedure, which aims to restore bile flow.
1154
Does not result in absence of one or more lobes of the liver, as it affects the biliary tract itself and not the surrounding liver parenchyma.
Biliary atresia
1155
A blind jejunal pouch is consistent with jejunal atresia. This is associated with ?use during pregnancy.
Maternal cocaine
1156
Is consistent with renal hypoplasia.
A shrunken kidney at birth
1157
What is autoimmune hepatitis (AIH)?
AIH is an inflammatory liver condition that primarily affects women in their forties and fifties.
1158
How is AIH often discovered?
AIH is often asymptomatic and identified through incidental findings of elevated AST and ALT on blood work.
1159
What can AIH lead to if left untreated?
It can lead to chronic liver disease and, rarely, cirrhosis.
1160
What are key diagnostic criteria for AIH?
Presence of antinuclear antibodies (ANA) and anti-smooth muscle antibodies (ASMA), which are specific for type I AIH.
1161
How does type 2 AIH differ from type 1?
Type 2 AIH is often ASMA negative and is far less common than type 1.
1162
What is the management for acute episodes of AIH?
Management typically involves steroids and immunosuppressants.
1163
Are highly specific for systemic lupus erythematosus (SLE) and are believed to be implicated in the pathogenesis of lupus nephritis.
Anti-double stranded DNA antibodies
1164
Are specific for CREST syndrome
Anti-centromere antibodies
1165
Are associated with drug-induced lupus. Common drugs implicated include procainamide, penicillamine, isoniazid, and methyldopa.
Anti-histone antibodies
1166
Are found in patients with anti-phospholipid syndrome, a hypercoagulable state that causes thrombosis in arteries and veins. It causes a number of pregnancy-related complications, including miscarriage, stillbirth, preterm delivery, and preeclampsia.
Anti-cardiolipin antibodies
1167
What is a pyogenic liver abscess?
A walled-off infection of the liver.
1168
What is the most likely etiology of a pyogenic liver abscess in a patient with diverticulitis?
Seeding of the portal venous system with bacteria from diverticulitis.
1169
What are the common causative organisms of a pyogenic liver abscess?
Enteric flora, including gram-negative rods like E. coli and Klebsiella pneumoniae.
1170
Why are gram-positive cocci like Staphylococcus aureus and Staphylococcus epidermidis unlikely causes of liver abscess?
They generally do not lead to intra-abdominal infections except in the setting of abdominal surgery.
1171
What role do mycobacteria, such as tuberculosis, play in liver abscess formation?
They are a rare cause of liver abscess, unlikely in patients with recent diverticulitis.
1172
Are spirochetes like Treponema pallidum common causes of liver infection?
No, they are very rare causes of liver infection and unlikely in this patient.
1173
What is acute alcoholic hepatitis?
Hepatitis occurring in the setting of acute binge drinking in individuals with a history of alcohol-use disorder.
1174
What are common symptoms of acute alcoholic hepatitis?
Right-upper-quadrant abdominal pain, fever, and jaundice.
1175
What is the pathophysiology of acute alcoholic hepatitis?
It is caused by the toxic effects of acetaldehyde, a metabolic by-product of alcohol.
1176
How does acetaldehyde affect hepatocytes?
Acetaldehyde damages intermediate filaments within hepatocytes.
1177
What is the classic histopathological finding in acute alcoholic hepatitis?
The presence of “Mallory bodies,” which are cytoplasmic inclusions within hepatocytes representing damaged intermediate filaments.
1178
In alcoholic liver disease, nuclei may be pushed aside by fat accumulation with cells, but nuclear abnormalities are
Not a classic feature of alcoholic hepatitis.
1179
An overabundance of microtubules can be seen in cardiac myocytes in patients with
Hypertrophic cardiomyopathy.
1180
Structural and functional alterations of the Golgi apparatus are seen in several neurodegenerative, diseases including
Amyotrophic lateral sclerosis (ALS), Parkinson’s disease, Alzheimer’s dementia, and Huntington’s disease
1181
In ?, AAT builds up in the endoplasmic reticula of hepatocytes. AAT polymers can be seen on periodic acid-Schiff (PAS) staining of hepatocytes of affected individuals.
Alpha-1 antitrypsin (AAT) deficiency
1182
What is Budd-Chiari syndrome?
A rare condition caused by hepatic vein thrombosis.
1183
What are common clinical features of Budd-Chiari syndrome?
Abdominal pain, ascites, and hepatomegaly.
1184
What does Doppler imaging show in Budd-Chiari syndrome?
Obstruction in the outflow of the hepatic vein.
1185
What underlying conditions are associated with Budd-Chiari syndrome?
Hepatocellular carcinoma, polycythemia vera, and hypercoagulable states.
1186
What structures make up the portal triad in the liver?
A single bile duct, hepatic artery, and portal vein.
1187
How is the liver organized in terms of zones?
Zone I (periportal zone), Zone II (midzone), and Zone III (centrilobular zone).
1188
How does blood flow through the liver zones?
Blood from the portal vein and hepatic artery moves from Zone I to Zone III, draining into the hepatic vein.
1189
What occurs in Zone III during hepatic vein thrombosis?
Backflow of blood leads to congestion and subsequent hepatic necrosis in Zone III.
1190
What other conditions can affect Zone III of the liver?
Ischemic insult from shock liver, fatty infiltration in alcoholic liver disease, and fibrosis in cirrhosis.
1191
What is hepatic cirrhosis?
A condition characterized by liver fibrosis with loss of normal liver architecture and function.
1192
What are common etiologies of cirrhosis?
Alcoholic liver disease, viral hepatitis, autoimmune conditions (autoimmune hepatitis, primary biliary cholangitis, primary sclerosing cholangitis).
1193
What physiological functions does cirrhosis impair?
The liver's ability to perform synthetic functions, such as producing albumin and clotting factors.
1194
What would serum albumin levels be in a patient with cirrhosis?
Serum albumin would be decreased.
1195
How does cirrhosis affect clotting factors?
Reduced levels of clotting factors prolong prothrombin time (PT), partial thromboplastin time (PTT), and international normalized ratio (INR).
1196
What is the status of Factor VIII levels in chronic liver disease?
Factor VIII levels are usually normal or increased.
1197
Where is Factor VIII synthesized?
It is synthesized by hepatic sinusoidal endothelial cells and also by endothelial cells in other organs (kidney, spleen, lungs, brain).
1198
What other factor is synthesized outside the liver?
von Willebrand factor (VWF) is also synthesized by endothelial cells outside the liver.
1199
What is Wilson’s disease?
An autosomal recessive disorder of copper metabolism characterized by impaired copper transport and excretion in bile.
1200
What gene is mutated in Wilson’s disease?
The ATP7B gene on chromosome 13.
1201
What is the role of the ATP7B protein?
It incorporates copper into ceruloplasmin and transports copper into bile for excretion.
1202
What are the consequences of impaired ATP7B function?
Accumulation of copper in the liver and other organs, leading to free radical production and tissue damage.
1203
What is a Kayser-Fleischer ring?
A pathological hallmark of Wilson’s disease, representing corneal copper deposits along Descemet's membrane at the limbus of the eye.
1204
What neurological symptoms are associated with Wilson’s disease?
Ataxia and difficulty speaking due to copper accumulation in the brain.
1205
How does total body copper levels compare to normal in Wilson’s disease?
Total body copper is increased, but the majority is trapped in organs.
1206
What do liver biopsy specimens show in Wilson’s disease?
Increased copper content.
