GI Tract Flashcards
(411 cards)
1
Q
VATER association
A
congenital anomalies that occur simultaneously-vertebral, anal anomalies, cardia, TE fistula, renal anomalies, limb anomalies
2
Q
Most common form of intestinal atresia
A
imperforate anus
3
Q
Most common site of fistulization
A
esophagus
4
Q
What other congenital anomalies are TE fistulas associated with?
A
cardiac
5
Q
Occurrance of TE fistula
A
1/3500 births
6
Q
Most common TE fistula
A
esophageal atresia with distal TEF
7
Q
Cause of TE fistulas
A
abnormal septation of caudal foregut during fourth and fifth weeks
8
Q
Clinical presentation of TE fistula
A
aspiration, suffocation, pneumonia, severe fluid and electrolyte imbalances
9
Q
Stenosis
A
incomplete atresia in which lumen is reduced in caliber as a result of fibrous thickening of the wall
10
Q
Most common true diverticulum
A
Meckel diverticulum
11
Q
Cause of meckel diverticulum
A
persistence of vitelline duct, which connects lumen of gut to yolk sac
12
Q
Rule of 2s for Meckel diverticulum
A
2% population, 2 ft from ileocecal valve, 2x more likely in men, 2 inches long, symptomatic by age 2
13
Q
Ectopic tissues that may be present in Meckel diverticulum
A
gastric or pancreatic tissue
14
Q
Presentation of Meckel diverticulum
A
abdominal pain, intussusception, GI bleed, ulceration, inflammation/adhesions
15
Q
Occurrence of pyloric stenosis
A
M>F, monozygotic twins have a high rate of concordance, common in Turner and Edward syndrome, correlation with women who use erythromycin or azithromycin during pregnancy
16
Q
Clinical presentation pyloric stenosis
A
regurgitation, projectile, nonbilious vomiting after feeding, olive sized mass
17
Q
Occurrence of Hirschsprung disease
A
1 of 5000 births
18
Q
Cause of Hirschsprung dz
A
abnormal migration of premature death of entire ganglion cells, failure of NCC migration
19
Q
Hirschsprung obstruction
A
functional
20
Q
Gene mutation often linked to Hirschsprung dz
A
RET mutation
21
Q
Portions of bowel involved inHirschsprung
A
rectum is always involved, will have varying degrees of colonic involvement
22
Q
Diagnosis of Hirschsprung
A
absence of ganglion cells within the affected bowel segment
23
Q
Clinical presentation of Hirschsprung
A
failure to pass meconium, obstruction or constipation, abd distension, bilious vomiting
24
Q
Treatment of Hirschsprung dz
A
surgical removal of aganglionic segment
25
Causes of acquired megacolon
Chagas disease, obstruction by neoplasm, ulcerative colitis, visceral myopathy, etc.
26
Embryonic development of esophagus
develops from cranial portion of foregut, recognizable by third week of gestation
27
Nutcracker esophagus
high amplitude contractions of the distal esophagus due to loss of coordination between the inner and outer circular layers
28
Diffuse esophageal spasm
repetitive, simultaneous contractions of the entire esophagus; completely uncoordinated contractions
29
Zenker diverticulum
outpouching of the esophagus that occurs at Killian's triangle, immediately above UES
30
Cause of Zenker diverticulum
failure of cricopharyngeus muscle to result after swallowing
31
Esophageal webs
ledge-like protrusions of mucosa that may cause obstruction
32
Disease associations of esophageal webs
GERD, C-GVHD, Celiac, Paterson-Brown-Kelly or Plummer-Vinson syndrome
33
Presentation of esophageal webs
nonprogressive dysphagia associated with incompletely chewed food
34
Schatzki ring
circumferential, thicker esophageal strictures
35
Presentation of schatzki ring
progressive dysphagia
36
Achalasia triad
incomplete LES relaxation, increased LES tone, aperistalsis of esophagus
37
Sxs of achalasia
dysphagia for solids and liquids, difficulty in belching, chest pain
38
Cause of primary achalasia
degeneration of ganglion cells
39
Causes of secondary achalasia
Chagas disease, failure of peristalsis, esophageal dilation, achalasia-like diseases, infiltrative disorders, lesions of DMN, HSV1, autoimmune diseases
40
Tx of achalsia
laparoscopic myotomy, pneumatic balloon dilation, Botox injection
41
Characteristics of Mallory-Weiss tear
longitudinal laceration near gastroesophageal junction
42
Cause of Mallory-Weiss tear
binge drinking and severe retching
43
Characteristics of Boerhaave's syndrome
transmural tearing and rupture of distal esophagus
44
Sxs of Boerhaave's syndrome
chest pain, shock, subcutaneous emphysema, mediastinitis
45
Hamman's sign
crunching sound upon auscultation of heart due to pneumomediastinum
46
Tx of variceal hemorrhage
splanchnic vasoconstriction, sclerotherapy, balloon tamponade, variceal ligation
47
Pathogenesis of esophageal varices
collateral vessel channels (due to portal hypertension) become congested; hepatic schistosomiasis
48
Location of upper GI bleed
proximal to ligament of Treitz
49
GE varices clinical features
may be asymptomatic but can hemorrhage and result in hypovolemic shock, hepatic coma, and other life-threatening complications
50
Radiation induced esophagitis is characterized by...
fibrosis, mutagenesis, carcinogenesis, and teratogenesis
51
Pill-induced esophagitis
medicinal pills are lodged in the esophagus and dissolve in the esophagus
52
Sxs of esophagitis
self-limited pain on swallowing, hemorrhage, stricture, perforation
53
Infectious causes of esophagitis
HSV, CMV, fungi (candidiasis, mucormycosis, aspergillosis)
54
Morphological changes of radiation esophagitis
intimal proliferation and luminal narrowing
55
Morphological changes of HSV induced esophagitis
punched-out ulcers, nuclear viral inclusions in squamous cells
56
Morphological changes of CMV induced esophagitis
shallow ulcers, nuclear viral inclusions in capillary endothelium and stromal cells
57
Morphological changes of GVHD esophagitis
basal epithelial apoptosis, mucosal atrophy, submucosal fibrosis
58
Eosinophilic esophagitis sxs
food impaction, dysphagia, or feeding intolerance in infants; food or seasonal allergies that present as asthma, allergic rhinitis, atopic dermatitis
59
Morphological changes of eosinophilic esophagitis
trachealization of esophagus, >25 eosinophils per hpf
60
Atopy
genetic tendency to develop allergic diseases such as allergic rhinitis, asthma, atopic dermatis
61
Most frequent cause of esophagitis
reflux of gastric contents into lower esophagus
62
Pathogenesis of LES relaxation
may be due to vagal mediated pathways, increased intra-abdominal pressure, alcohol and tobacco, obesity, hiatal hernia, delayed gastric emptying idiopathic
63
Clinical features of GERD
heartburn, dysphagia, regurgitation of sour-tasting gastric contents; may be punctuated by attacks of sever chest pain
64
Morphological changes in GERD
hyperemia, histology often unremarkable; eosinophils may be recruited with more significant disease
65
Complications of GERD
ulceration, hematemesis, melena, stricture development; often see metaplasia (squamous-to-columnar) in severe, prolonged cases
66
Barrett esophagus
complication of chronic GERD characterized by intestinal metaplasia in esophageal squamous mucosa
67
Barrett esophagus and CA association
increased risk of esophageal adenocarcnioma
68
Endoscopic examination of Barrett esophagus
tongues or patches of red, velvety mucosa extending upward from GE junction
69
Diagnostic appearance of Barrett esophagus
endoscopic evidence of metaplastic columnar mucosa above GE junction
70
Characteristics of dysplasia
atypical mitoses, nuclear hyperchromasia, irregularly clumped chromatin, increased N:C ratio, failure of epithelial cell maturation
71
Tissue derivative of benign esophageal tumors
mesenchymal, grow in submucosa layer
72
Esophageal adenocarcinomas arise from...
Barrett esophagus
73
Geographic distribution of adenocarcinoma of the esophagus
highest rates in the US, UK, Canada, Australia
74
Highest risk group for esophageal adenocarcinomas
Caucasian men
75
Risk factors for esophageal adenocarcinoma
Barrett esophagus, tobacco, radiation, reduced H. pylori
76
Morphological changes of esophageal adenocarcinoma
flat or raised patches in intact mucosa, large masses of 5cm or more in diameter may develop, can infiltrate diffusely or ulcerate and invade deeply
77
Location of esophageal adenocarcinomas
distal third of esophagus
78
Histological appearance of esophageal adenocarcinoma
mucinous, form gland structures, may be composed of diffusely infiltrative signet-ring cells
79
Clinical features esophageal adenocarcinoma
pain or difficulty in swallowing, progressive weight loss, hematemesis, chest pain, vomiting
80
Geographic distribution squamous cell carcinoma
Iran, central China, Hong Kong
81
Highest risk group for squamous cell carcinoma
>45, males 4:1, african americans are 8x more likely
82
Risk factors for SCC
alcohol, tobacco, poverty, caustic esophageal injury, achalasia, tylosis, radiation, Plummer-Vinson syndrome, diets deficient in fruits or vegetables, frequent consumption of very hot beverages
83
Morphological appearance of esophageal SCC
small, gray-white, plaque-like thickenings
84
Tylosis mutation and sxs
RHBDF2 mutation, squamous hyperplasia of hands and feet
85
Presentation of esophageal SCC
dysphagia, odynophagia, obstruction, weight loss and debilitation, hemorrhage and sepsis may occur
86
Cells that secrete HCl and IF
parietal cells
87
Cells that secrete pepsinogen
chief cells
88
Cells that secrete gastrin
G cells
89
Cells that secrete mucin
mucous cells
90
Actions of gastrin
enhance gastric mucosal growth, motility and secretion of HCl
91
Which part of the stomach is most often involved in gastric adenocarcinomas?
gastric antrum, lymph flow to lesser curvature
92
Ectopia
ectopic tissues in GI tract; pancreatic tissue, if present in the pylorus, may lead to inflammation and scarring/obstruction
93
Gastritis
mucosal inflammatory process
94
Acute gastritis
mucosal inflammatory process when neutrophils are present
95
Gastropathy
mucosal inflammatory process when inflammatory cells are rare or absent
96
Actions of exogenous prostaglandins
inhibit acid secretion, stimulate mucus and bicarb secretion, alter mucosal blood flow
97
Stress ulcers are common in individuals with...
shock, sepsis, severe trauma
98
Curling ulcers
proximal duodenal ulcers associated with severe burns or trauma
99
Cushing ulcers
gastric, duodenal, esophageal ulcers arising in persons with intracranial disease
100
Pathogenesis of stress-related mucosal injury
local ischemia due to systemic hypotension or reduced blood flow
101
Dieulafoy lesion
submucosal artery that does not branch properly in stomach, resulting in a large mucosal artery; often found in lesser curvature, if overlying epithelium erodes, bleeding will occur
102
Gastric antral vascular ectasia
longitudinal stripes of edematous erythematous mucosal created by ectatic mucosal vessels; antral mucosa shows gastropathy with dilated capillaries containing fibrin thrombi
103
Most common cause of chronic gastritis
H. pylori infection
104
Long-standing chronic gastritis that involves the body and fundus may lead to...
mucosal atrophy and intestinal metaplasia
105
H. pylori is most common in which area of the stomach
antrum
106
H. pylori infection most commonly affects which populations?
impoverished, crowded housing, those with limited education, AA or Mexican American, those who live in rural areas or were born outside US
107
multifocal atrophic gastritis causes what morphological changes
patchy mucosal atrophy, reduced parietal cell mass and acid secretion, intestinal metaplasia and increased risk of gastric adenocarcinoma
108
Virulence factors of H. pylori
flagella, urease, adhesins, toxins (CagA)
109
Endoscopic appearance of H. pylori infection
erythematous, nodular appearance of gastric mucosa
110
Histologic appearance of H. pylori infection
inflammatory infiltrate generally involves neutrophils, plasma cells, macrophages, lymphocytes; can increase rugal folds and create areas of lymphoid aggregates
111
diagnostic tests for H. pylori
noninvasive serologic test for abs, fecal bacterial detection, urea breath test, gastric biopsy
112
effective tx for H. pylori
2 abx and 1 PPI
113
Common location of autoimmune gastritis
body of the stomach
114
Characteristics of autoimmune gastritis
abs to parietal cells and intrinsic factor, reduced pepsinogen I concentration, endocrine cell hyperplasia, vitamin B12 deficiency, achlorydia
115
Pathogenesis of autoimmune gastritis
loss of parietal cells, CD4+ T cells against parietal cell components and autoabs to parietal cells
116
Morphological changes in autoimmune gastritis
diffuse mucosal damage of oxyntic mucosa within body and fundus, inflammatory infiltrate is composed of lymphocytes and macrophages, rxn centered around glands
117
Clinical presentation of autoimmune gastritis
pernicious anemia, other autoimmune dz, atrophic glossitis, megaloblastosis of RBCs and epithelial cells, peripheral neuropathies
118
Eosinophilic gastritis
tissue damage associated with dense infiltrates of eosinophils in mucosa and muscularis; occurs in association with allergies, immune disorders, parasites, H. pylori ifx
119
Lymphocytic gastritis
often associated with celiac and most common in women; endoscopic appearance of thickened folds covered by small nodules with aphthous ulceration, increase in T cells
120
Granulomatous gastritis
well-formed granulomas or aggregates of macrophages
121
Peptic ulcer disease
chronic mucosal ulceration affecting the stomach or duodenum
122
Causes of PUD
H. pylori, NSAIDs, cigarette smoking
123
What GI secretions change in response to chronic H. pylori infection in antrum and duodenum
increased gastric acid secretion, decreased bicarb
124
Endoscopic appearance of peptic ulcer
round to oval, sharply punched-out defect
125
Clinical features of PUD
epigastric burning or aching pain (1-3 hrs after meals, referred to back, LUQ or chest; complications include bleeding, perforation, obstruction, dysplasia, mucosal atrophy and intestinal metaplasia
126
Gastritis cystics
epithelial proliferation associated with entrapment of epithelial-lined cysts
127
Hypertrophic gastropathies are characterized by...
"cerebriform" enlargement of rugal folds due to epithelial hyperplasia without inflammation
128
Menetrier Disease
excess secretion of TGFa, diffuse hyperplasia of mucosal cells and hypoproteinemia
129
Inflammatory infiltrate of menetrier disease
lymphocytes
130
Sxs of Menetrier Disease
hypoproteinemia, weight loss, diarrhea
131
What CA is Menetrier Dz associated with?
adenocarcinoma
132
Zollinger Ellison syndrome
caused by gastrin-secreting tumors often found in the small intestine or pancreas, increase in parietal cells
133
Inflammatory infiltrate of ZE syndrome
neutrophils
134
Risk factors for development of ZE syndrome
MEN (multiple endocrine neoplasia)
135
Is ZE associated with adenocarcinoma?
No
136
Percentage of UGI endoscopies that reveal a polyp
5%
137
Most common gastric polyp
inflammatory or hyperplastic polyps
138
Hyperplastic polyps are most common in what population?
50-60 yo with chronic gastritis
139
Morphological changes of hyperplastic polyps
irregular, cystically dilated foveolar glands; edematous lamina propria, may have surface ulceration
140
Fundic gland polyps are associated with what genetic syndrome?
familial adenomatous polyposis
141
Patho of fundic gland polyps due to PPI use
inhibition of acid production increases gastrin being secreted and increases oxyntic gland growth
142
Gastric adenomas occur in association with...
chronic gastritis with atrophy and intestinal metaplasia
143
Most common malignancy in stomach
adenocarcinoma
144
Gastric adenocarcinoma is most common in which countries?
Japan, Chile, Costa Rica, Eastern Europe
145
Sites most commonly involved in gastric adenocarcinoma metastasis
Virchow node, Sister Mary Joseph nodule, left axillary LN, krukenberg tumor, pouch of douglas
146
Precursor lesions associated with gastric adenocarcinoma
gastric dysplasia and adenomas
147
Genetic mutation in the development of diffuse gastric adenocarcinoma
CDH1 LOF mutation; loss of E-cadherin is a key step
148
Genetic mutation in development of sporadic intestinal-type gastric cancers
increased signaling via WNT, loss-of-function of adenomatous polyposis coli, 5q21 tumor suppressor, gain-of function in B-catenin
149
Precursor lesions for intestinal-type gastric CA
metaplasia, atrophy, dysplasia, adenoma, Menetrier
150
Population most at risk for intestinal-type gastric CA
high risk geographic areas, M>F, mean age 55
151
Area of stomach most commonly affected by gastric adenocarcinomas
gastric antrum and lesser curvature
152
Histological morphology of intestinal-type gastric CA
glandular structures, form exophytic mass or ulcerated tumor, apical mucin vacuoles
153
Histological morphology of diffuse type gastric adenocarcionoma
singet ring cells (large mucin vacuoles), discohesive cells
154
Lintis plastica
rugal flattening and rigid, thickened wall give the stomach a leather bottle appearance
155
Most powerful tool for prognosis of gastric CA
depth of invasion and extent of nodal and distant metastases
156
Most common extranodal site of marginal zone B-cell lymphomas
GI tract
157
Translocation most commonly associated with MALToma
t(11;18)
158
MALT is most commonly induced as a result of what
chronic gastritis - H. pylori
159
Histological appearance of gastric MALToma
dense lymphocytic infiltrate in lamina propria, create diagnostic lymphoepithelial lesions, reactive appearing B cell follicles
160
Most common presenting symptoms of MALToma
dyspepsia and epigastric pain, hematemesis, melena, and constitutional sxs
161
Most important prognostic factor for carcinoid tumor
location
162
Location of GI tract in which carcinoid tumors are most aggressive
jejunum and ileum
163
Gastric carcinoid tumors are most commonly associated with what diseases
endocrine cell hyperplasia, autoimmune chronic gastritis,
| MEN-I, ZE syndrome
164
Histological appearance of carcinoid tumor
salt and pepper chromatin, positive synaptophysin and chromographin, neurosecretory granules, uniform cells with granular cytoplasm
165
Morphological appearance of carcinoid tumor
circumscribed yellow mass
166
Clinical features of carcinoid tumors
cutaneous flushing, sweating, bronchospasm, colicky abdominal pain, diarrhea, right-sided cardiac valve fibrosis
167
Most common mesenchymal tumor of the abdomen
Gastrointestinal stromal tumor
168
From which cells does GIST arise from
interstitial cells of Cajal
169
Peak age of GIST
approx 60 yrs
170
Carney syndrome triad
GIST, paraganglioma, pulmonary chondroma
171
Mutation in GIST
gain-of-function tyrosine kinase KIT or PDGFRA
172
Symptoms of GISTs
mass effects, blood loss, anemia
173
Prognosis of GIST is related to...
size, mitotic index, and location
174
Most common site of GI neoplasia in Western populations
colon
175
When, during embryologic development do the intestines grow and form?
Weeks 4 and 5, NCC enter foregut wk 4 and hindgut wk 5
176
Omphalocele
abdominal viscera herniating into base of umbilicus, covered by membrane
177
Gastroschicis
uncovered bowel protruding through abdominal wall without a membrane covering
178
Two main purposes of GI tract
transport of food and absorption of nutrients
179
Main causes of mechanical obstruction in intestines
hernias, intestinal adhesions, intussusception, volvulus
180
Clinical manifestations of intestinal obstruction
abdominal pain and distention, vomiting, and constipation
181
Functional bowel obstruction
paralytic ileus, temporary disturbance of peristalsis in absence of mechanical obstruction, may be caused by metabolic disturbances, endocrinopathies, certain drugs
182
Hernia
weakness or defect in abdominal wall that permits protrusion of a serosa-lined pouch of the peritoneum
183
Most common cause of intestinal obstruction worldwide
hernia
184
Progression of hernia if not treated
pressure at the neck of the pouch may impair venous draining resulting in stasis and edema, leading to permanent incarceration, strangulation, and infarction
185
Cause of adhesions
surgical procedures, infection, peritoneal inflammation
186
Most common cause of intestinal obstruction in the US
adhesions
187
Volvulus
twisting of loop of bowel about its mesenteric point of attachment
188
Clinical presentation of volvulus
obstruction and infarction of bowel
189
Most common location of volvulus
sigmoid colon
190
Intussusception
segment of intestine telescopes into an immediately distal segment
191
Most common cause of intestinal obstruction in children <2
intussusception
192
Potential causes of intussusception in children
idiopathic, viral infection, rotavirus vaccine
193
Potential cause of intussusception in adults
intraluminal mass or tumor
194
How are the intestines able to tolerate a slowly progressive loss of blood supply?
Collateral circulation and interconnections between arcades
195
Acute vascular compromise of the intestines affects what layers
mucosal, submucosal, muscularis; may be mucosal, non-transmural, or transmural
196
Obstruction of what artery causes the worst outcome for ischemic bowel disease
superior mesenteric artery
197
Etiologies of acute obstruction of blood flow
sever atherosclerosis, cardiac mural thrombi, hypercoagulable states, tumors, trauma, cirrhosis
198
Etiologies of chronic obstruction of blood flow
cardiac failure, shock, dehydration, drugs (vasoconstrictors - cocaine)
199
Hypoxic injury in vascular compromise
epithelial cells are mostly resistant to transient hypoxia
200
Reperfusion injury in vascular compromise
may trigger multiorgan failure; free radical formation, neutrophil infiltration, release of inflammatory mediators
201
Variables that determine severity of ischemic bowel disease
severity of compromise, time frame, vessels affected
202
Microscopic appearance of ischemic intestine
atrophy or sloughing of epithelium, hyperproliferative crypts, fibrous scarring due to chronic ischemia, pseudomembrane formation
203
Most common population to have ischemic bowel disease
females >70
204
Presentation of acute colonic ischemia
sudden onset of cramping, left lower abdominal pain, desire to defecate, passage of blood or bloody diarrhea
205
Pain on which side of the abdomen is associated with a worse outcome in ischemic bowel disease
right
206
CMV induced ischemic GI disease
viral tropism for endothelial cells
207
Radiation enteritis
epithelial damage and vascular injury may cause changes similar to ischemic disease
208
Angiodysplasia
lesion characterized by malformed submucosal and mucosal blood vessels that are thin walled
209
Angiodysplasia is most common where in the GI tract and in what population?
most common in cecum or right colon, usually becomes clinically significant in 6th decade of life
210
Presentation of angiodysplasia
can range from chronic, intermittent to acute, massive hemorrhage
211
Malabsorption is characterized by defection absorption of what?
fats, fat- and water-soluble vitamins, proteins, carbs, electrolytes, minerals and water
212
Common clinical presentation of malabsorption
chronic diarrhea, weight loss, anaorexia, abdominal distention, borborygmi, muscle wasting, steatorrhea
213
Most common chronic malabsorptive disorders in the US
pancreatic insufficiency, celiac disease, Crohn disease
214
Phases of nutrient absorption
intraluminal digestion, terminal digestion, transepithelial transport, lymphatic transport of fats
215
Definition of diarrhea
increase in stool mass, frequency, fluidity greater than 200 gm per day
216
Dysentery
Painful, bloody, small-volume diarrhea
217
Secretory diarrhea
isotonic stool that persists during fasting
218
Osmotic diarrhea
excessive osmotic forces exerted by unabsorbed luminal solutes, fluid is more than 50 mOsm more concentrated than plasma, subsides with fasting
219
Malabsorptive diarrhea
failure of nutrient absorption, often associated with steatorrhea, relieved by fasting
220
Exudative diarrhea
purulent, bloody stools that continue during fasting
221
Phases of nutrient absorption affected in cystic fibrosis
intraluminal digestion
222
Patho of malabsorption in CF
pancreatic abnormalities cause an accumulation of mucus in exocrine glands, impaired fat absorption, avitaminosis A and formation of viscid plugs
223
Clinical manifestations of avitaminosis A
bitot spots (Xerophthalmia), derm manifestations, poor bone growth
224
Celiac disease
immune-mediated enteropathy triggered by gluten-containing foods
225
Autoimmunity in celiac disease occurs due to...
inherited gene susceptibility and environmental triggers
226
Disease producing component of gluten
gliadin
227
Gliadin triggers the release of what inflammatory mediator and what are the downstream effects?
IL-15, triggers activation and proliferation of CD8 intrapeithelial lymphocytes
228
Receptor interaction of CD8 and enterocytes
MIC-A on epithelial cells, NKG2D on CD8 T cells
229
Enzyme that deaminates gliadin
tissue transglutaminase
230
HLA susceptibility for celiad disease
HLA DQ2 or DQ8
231
Adaptive response to gliadin in celiac disease
sensitization of CD4 Tcells and B cells
232
Morphologic changes of intestinal biopsy in patients with celiac disease
increased CD8 cells, crypt hyperplasia, villous atrophy, increased crypt mitotic activity
233
Diagnostic serology for patients with celiac disease
IgA endomysial antibodies, IgA tTG abs
234
Clinical features of Celiac Disease in adults
F>M 30-60 yo, bloating, diarrhea, fatigue, malabsorption, dermatitis herpetiformis
235
Clinical features of Celiac Disease in children
typically presents between 6-24 mo with irritability, abdominal distension, chronic diarrhea, weight loss, muscle loss, FTT
236
Extraintestinal manifestations of CD in children
arthritis/joint pain, aphthous ulcers, stomatitis, anemia, delayed puberty, short stature
237
Environmental enteropathy is commonly seen in which populations
populations with poor sanitation and hygiene, parts of sub-Saharan Africa and aboriginal populations in northern Australia
238
Clinical manifestations of environmental enteropathy
malabsorption, malnutrition, stunted growth, defective intestinal mucosal immune function
239
Phases of nutrient absorption that are defective in celiac disease and environmental enteropathy
terminal digestion, transepithelial transport
240
Autoimmune enteropathy
X-linked disorder characterized by severe persistent diarrhea and autoimmune disease that occurs most often in young children
241
IPEX
immune dysregulation, polyendocrinopathy, X-linkage, enteropathy
242
Germline mutation in IPEX
germline loss of FOXP3 function
243
Autoantibodies to what are common in autoimmune enteropathy?
enterocytes and goblet cells, may have abs to parietal or islet cells
244
Tx of autoimmune enteropathy
immunosupressive drugs like cyclosporine and HSC transplant
245
Phases of nutrient absorption disrupted in autoimmune enteropathy
terminal digestion and transepithelial transport
246
Lactase deficiency
absence of lactase results in the inability to breakdown lactose, cannot be absorbed and exerts an osmotic force causing osmotic diarrhea
247
Congenital lactase deficiency
mutation in gene encoding lactase, autosomal recessive; presents as explosive diarrhea with watery, frothy stools and abdominal distention upon milk ingestion
248
Acquired lactase deficiency
downregulation of lactase gene expression; presents as abdominal fullness, diarrhea, and flatulence
249
Microvillus Inclusion disease
rare autosomal disorder of vesicular transport that leads to deficient brush-border assembly
250
Microvillus inclusion disease mutation
MYO5B gene, motor protein
251
Abetalipoproteinemia
rare autosomal recessive disease characterized by inability to assemble triglyceride-rich lipoproteins
252
Mutated protein in abetalipoproteinemia
microsomal triglyceride transfer protein
253
Absence of MTP causes what to accumulate
lipids in enterocytes
254
Clinical presentation of abetalipoproteinemia
presents in infancy as FTT, diarrhea, steatorrhea, no apolipoprotein B, lipid membrane defects causes acanthocytic RBC
255
Phase of nutrition disrupted in abetalipoproteinemia
transepithelial transport
256
Clinical presentation of infectious enterocolitis
diarrhea, abdominal pain, urgency, perianal discomfort, incontinence, and hemorrhage
257
Diagnostic tests for infectious enterocolitis
selective serologic testing, fecal leukocytes and lactoferrin assay, stool culture, assays for toxins, stool for ova and parasites
258
Vibrio cholerae characteristics
comma-shaped, G- bacteria that cause cholera; endemic in Ganges Valley of India and Bangladesh
259
What does the cholera toxin bind to on intestinal epithelial cells?
GM1 ganglioside
260
Actions of A subunit of cholera toxin
activate Gsalpha to stimulate cAMP production and pump Cl- out of the cell
261
Clinical features of V. cholerae
may be asymptomatic or have mild diarrhea; severe disease results in watery diarrhea and vomiting
262
Stool in Cholera
rice water with a fishy odor
263
Most common bacterial enteric pathogen in common countries
Campylobacter jejuni
264
C. jejuni infections are associated with ingestion of...
improperly cooked chicken, unpasteurized milk, contaminated water
265
Virulence of C. jejuni is due to
motility, adherence, toxin production, invasion
266
Clinical presentation of C. jejuni infection
watery or bloody diarrhea, enteric fever, reactive arthritis (HLA-B27), Guillain-Barre and erythema nodosum
267
Guillain-Barre syndrome
acute inflammatory demyelinating polyneuropathy that causes paresthesias in hands and feet, symmetrical and ascending muscle weakness
268
Erythema Nodosum
skin inflammation located in fatty layer of skin, reddish, painful, tender lumps commonly located in front of legs or below knees
269
Shigella characteristics
G- unencapsulated, nonmotile, facultative anaerobes that belong to Enterobacteriaceae family
270
Stool in Shigellosis
bloody diarrhea
271
Populations commonly effected by Shigellosis in US and Europe
children in daycare centers, migrant workers, travelers to low resource countries, individuals in nursing homes
272
Where in the GI tract are shigella infections most common?
left colon
273
Morphologic appearance of shigellosis
hemorrhagic and ulcerated mucosa with pseudomembranes
274
Clinical presentation of Shigellosis
7-10 days of diarrhea, fever, and abdominal pain; watery diarrhea that progresses to dysentery
275
Shigellosis may mimic what disease?
new-onset ulcerative colitis
276
Complications of shigellosis
extra-intestinal manifestations (reactive arthropathy), HUS, toxic megacolon
277
Causes of salmonella infection
contaminated meat, poultry, eggs, milk
278
Populations commonly affected by salmonella infection
young children and older adults, especially during summer and fall
279
Population commonly affected by S. typhi in endemic areas
children and adolescents
280
Areas of the world where S. typhi is endemic
India, Mexico, Philippines, Pakistan, El Salvador, Haiti
281
Clinical manifestations of Salmonella infection
fever, diarrhea
282
Morphological changes due to Salmonella infection
Peyer patches in terminal ileum enlarge into delineated, plateau-like elevations, neutrophils accumulate in lamina propria with macrophages, oval ulcers
283
Morphological changes due to disseminated S. typhi infection
enlarged, soft spleen, phagocyte hyperplasia, liver is punctated by foci of parenchymal necrosis in which hepatocytes are replaced by macrophage aggregates (typhoid nodules)
284
S. typhi acute infection
anorexia, abdominal pain, bloating, nausea, vomiting, bloody diarrhea
285
S. typhi disseminated infection
encephalopathy meningitis, seizures, endocarditis, myocarditis, pneumonia, cholecystitis
286
At risk groups for salmonella infection
CA patients, immunosuppressed, EtOH, CV, sickle cell, hemolytic anemia
287
Three species of yersinia that are human pathogens
Y. enterocolitica, Y. pseudotuberculosis, Y. pestis
288
Yersinia infections are commonly linked to ingestion of ;...
pork, raw milk, contaminated water
289
What molecule in the body can enhance the virulence of Yersinia?
Iron
290
Where do Yersinia infections commonly occur in the GI tract?
ileum, appendix, right colon
291
Morphological changes associated with Yersinia infections
regional LN and peyer patch hyperplasia, overlying lymphoid tissue may be hemorrhagic with apthous erosions and ulcers
292
Post infectious complications due to Yersinia
reactive arthritis with urethritis and conjunctivitis, myocarditis, erythema nodosum, and kidney disease
293
E. coli subset that is the principle cause of traveler's diarrhea
ETEC, enterotoxigenic
294
E. coli subset prevalent in developing countries as an important cause of endemic diarrhea
enteropathogenic, EPEC
295
important type of EHEC E. coli
O157:H7
296
E. coli subset biologically similar similar to shigella
EIEC, enteroinvasive
297
E. coli with "stacked brick" morphology
EAEC, enteroaggregative
298
Pathologic organism responsible for pseudomembranous colitis
C. difficile
299
Risk factors of pseudomembranous colitis
antibiotic treatment, advanced age, hospitalization, immunosuppression
300
Pseudomembrane morphology
adherent layer of inflammatory cells and debris
301
Pathognomic histology of C. difficile colitis
denuded surface epithelium, dense infiltrate of neutrophils in lamina propria, damaged crypts become distended by mucopurulent exudate
302
Clinical presentation of pseudomembranous colitis
fever, leukocytosis, abdominal pain, cramps, watery diarrhea, dehydration, hypoalbuminemia
303
Common therapies for pseudomembranous colitis
metronidazole, vancomycin
304
Whipple disease most commonly affects...
Caucasian men, particularly farmers or others with occupational exposures to animals or soil
305
Clinical presentation of Whipple disease
diarrhea, weight loss, arthralgia, fever, LAD, neuro, cardio, pulm dz
306
Morphologic hallmark of Whipple disease
dense accumulation of distended, foamy macrophages in small intestinal lamina propria
307
Organism responsible for whipple disease
Topheryma whippelii
308
Malabsorptive diarrhea of Whipple disease is due to
lymphatic obstruction
309
Macrophage appearance in whipple disease
macrophages are PAS positive with diastase-resistant granules, NOT acid-fast
310
Most common cause of viral gastroenteritis
norovirus
311
Population most commonly affected by rotavirus
6-24mo, outbreaks commonly occur in hospitals and daycare centers
312
Life cycle of Ascaris lumbricoides
soil contamination -> ingestion of eggs -> larvae penetrate intestines and migrate to lungs where tehy are coughed and swallowed
313
Life cycle of Strongyloides stercoralis
soil and dog infection -> larvae penetrate skin -> migrate to small intestines
314
Life cycle of Intestinal hookworm
larvae penetrate skin, enter lungs, coughed up and swallowed
315
Life cycle of enterobius vermicularis
eggs in perianal folds are ingested by humans where they hatch in the small intestine
316
Life cycle of Schistosoma
penetrate skin in water, enter circulation and migrate to portal blood and mature; can cause cirrhosis
317
Life cycle of Taenia
infected meat is consumed, attach to intestines
318
Life cycle of Diphyllobothriid tapeworms
ingestion of infected fish, adults live in small intestine
319
Life cycle of amebiasis
mature cysts ingested, common in India, Mexico, and columbia; development of hepatic and pulmonary abscesses
320
Life cycle of Giardia
contamination of water or food with cysts, mature in small intestine
321
Life cycle of Cryptosporidium
thick walled oocyst, contaminated water is ingested, mature and develop in small intestine
322
Irritable bowel syndrome
chronic, relapsing abdominal pain, bloating, changes in bowel habits without obvious gross or histo pathology
323
Epidemiological impact of IBS
prevalence 5-10%, female predominance in high income countries
324
Populations most commonly impacted by IBD
teens/early 20s, Caucasians, 3-5x more likely in Ashkenazi Jews, most common in developed countries
325
Common causes of increased bacterial exposure in patients with intestinal inflammation
disruption of mucus layer, dysregulation of epithelial tight junctions, increased intestinal permeability, increased bacterial adherence to epithelial cells
326
Characteristics of Crohn disease
commonly occurs in ileum, ileocecal valve, cecum; transmural inflammation, deep ulcers, malabsorption; skip lesions
327
Morphological characteristics of CD
thickened and rubbery intestinal wall, stricture formation, creeping fat
328
Ulcer appearance in CD
aphthous ulcers coalesce into elongated, serpentine ulcers, fissures and fistulas can develop, cobblestone appearance of the mucosa
329
Characteristics of ulcerative colitis
always involves rectum and extends proximally; inflammation limited to mucosa, thin walls without stricture
330
Gross appearance of colonic mucosa in UC
red and granular or extensive, broad-based ulcers; mucosal atrophy with smooth mucosal surface
331
Extra-intestinal manifestations of IBD
uveitis, nephrolithiasis, fistulae, UTI, erythema nodosum, stomatitis, steatosis, gallstones, spondylitis
332
Neoplasia in IBD is related to...
duration of disease, extent of disease, neutrophilic response
333
Diversion colitis
blind colon segment as result of surgical treatment that results in ostomy
334
Microscopic collagenous colitis
collagen layer below epithelium, watery diarrhea without weight loss in middle aged women
335
Microscopic lymphocytic colitis
watery diarrhea without weight loss in setting of celiac and autoimmune disease
336
Graft-versus-host disease in intestine occurs following...
allogenic hematopoietic stem cell transplant, crypts may be completely destroyed; presents as watery diarrhea that may become bloody
337
Diverticular disease occurs due to...
pseudodivderticular outpouchings of colonic mucosa and submucosa
338
Prevalence of diverticular disease
rare under 30 but common after age 60
339
Pathgenesis of diverticular disease
result from unique structure of colonic muscularis propria and elevated intraluminal pressure in sigmoid colon; focal musclar discontinuities
340
Clinical manifestations of diverticulitis
intermittent cramping, continuous lower abdominal discomfort, constipation, distention
341
Where in the GI tract are polyps most common?
colon and rectum
342
sessile polyp
small elevation without a stalk
343
pedunculated polyp
polyp with stalks
344
Four types of polyps
hyperplastic, inflammatory, hamartomoatous, adenoma
345
Hyperplastic polyps result from...
decreased epithelial cell turnover and delayed shedding of surface epithelial cells, leading to a "piling up" of goblet cells and absorptive cells
346
When and where are hyperplastic polyps typically found?
Left colon in the 6th-7th decade of life
347
Hyperplastic polyps must be differentiated from what malignant growth?
sessile serrated adenomas
348
Triad of solitary rectal ulcer syndrome
rectal bleeding, mucus discharge, anterior rectal wall
349
What causes the formation of inflammatory polyps?
chronic cycles of injury and healing
350
Histologic features of inflammatory polyps?
mixed inflammatory infiltrates, erosion, and epithelial hyperplasia with prolapse-induced lamina propria fibromusclar hyperplasia
351
Most hamartomatous polyps are caused by what?
germline mutation of tumor suppressor genes or protooncogenes
352
When and where do juvenile polyps typically occur?
typically occur under 5 years of age, rectal location
353
Complications of juvenile polyps
rectal bleeding, intussusception, intestinal obstruction, polyp prolapse
354
Extraintestinal manifestations of juvenile polyposis
pulmonary AV malformation and other congenital malforamations, digital clubbing
355
Mutated genes of Juvenile polyposis
SMAD4, BMPR1A
356
Peutz-Jeghers syndrome
autosomal dominant syndrome that presents around 11 yo with multiple GI hamartomatous polyps and mucocutaneous hyperpigmentation
357
Common locations of Peutz-Jeghers polyps
small intestine, stomach and colon, bladder and lungs
358
LOF mutation in what gene is responsible for Peutz-Jeghers
STK11, a tumor suppressor enzyme
359
Histologic appearance of Peutz-Jeghers polyp
arborizing network of CT, smooth muscle, lamina propria, and glands lined by normal-appearing intestinal epithelium
360
What types of CA are at a greater risk for development in Peutz-Jeghers syndrome?
colon, breast, lung, pancreatic, thyroid
361
Most common neoplastic polyps
adenomatous polyp
362
Sex predominance of adenomatous polyps
male
363
Colorectal adenomas are characterized by what histological feature?
presence of epithelial dysplasia; nuclear hyperchromasia, elongation, stratification
364
Most important characteristic of a polyp that correlates with malignancy risk
size
365
Familial adenomatous polyposis
autosomal dominant disorder in which patients develop colorectal adenomas as teenagers
366
Genetic mutation that causes FAP
somatic mutation in APC gene
367
Extraintestinal manifestations of FAP
congenital hypertrophy of retinal pigment epithelium
368
Risk of CA in patients with FAP
Colorectal adenocarcinoma develops in 100% of untreated FAP patients
369
Most common cause of malignancy of GI tract
adenocarcinoma of the colon
370
Where does colonic adenocarcinoma most commonly occur in the world?
North America
371
Peak age of colonic adenocarcinoma
60-70 yo
372
Dietary factors that contribute to colonic adenocarcinoma
low fiber, high fat and refined carbs
373
Pharmacologic chemoprevention of colonic adenocarcinoma
ASA and NSAIDs can contribute to polyp regression
374
Two genetic pathways that contribute to pathogenesis of Colonic Adenocarcinoma
APC/B-catenin/Wnt pathway and Microsatellite instability pathway
375
What gene must be mutated for adenomas to develop
both copies of APC at 5q21
376
Function of APC
negative regulator of B-catenin (involved in Wnt signaling
377
Function of B-catenin
binds to DNA and upregulates gene transcription that promote cell growth
378
Mutations in KRAS promote what?
12p12, promotes cell growth and prevent apoptosis
379
SMAD2/SMAD 4 mutation result
uncontrolled cell growth
380
Microsatellite instability
mutations accumulate in microsatellite repeats
381
Hereditary non polyposis colorectal cancer mutation
inherited mutations in mismatch repair genes
382
What CAs have the highest risk in HNPCC?
Colon, endometrium, stomach
383
Morphology of GI tract adenocarcinoma in colon
tumors in proximal colon grow as polypoid, exophytic masses that extend along wall of cecum and colon; tumors in distal colon tend to be annular, narrowing lumen
384
Histology of adenocarcinomas
tall columnar cells, signet-ring cells, stromal desmoplastic response
385
Clinical features of GI adenocarcinoma (R vs. L)
R will present with fatigue and weakness due to IDA, L will present with occult bleeding, changes in bowel habits, cramping and LLQ discomfort
386
Most important prognostic factors for GI adenocarcinoma
depth of invasion and LN metastases
387
5 year prognosis for colon adenocarcinoma
65% at five years
388
Epithelium in upper anal canal
columnar rectal
389
Epithelium in middle anal canal
transitional epithelium
390
Epithelium in lower anal canal
stratified squamous epithelium
391
CAs below pectinate line are usually
squamous cell carcinomas
392
CAs above pectinate line are usually
adenocarcinoma
393
What LN do anal canal cancers spread to?
inguinal lymphnodes
394
Most common viral cause of SCC of anal canal
HPV
395
Hemorrhoids develop secondary to...
elevated venous pressure in hemorrhoidal plexus--due to pregnancy, straining, constipation, portal hypertension
396
External hemorrhoids are located...
below anorectal line
397
Histological presentation of hemorrhoids
thin-walled, dilated, submucosal vessels that protrude beneath the anal or rectal mucosa
398
Clinical presentation of hemorrhoids
pain and rectal bleeding
399
Acute appendicitis is most common in what age groups?
adolescents and young adults, males are slightly more affected
400
DDx for acute appendicitis
Meckel diverticulum, mesenteric lymphadenitis, acute salpingitis, ectopic pregnancy, mittelschmirtz
401
Pathogenesis of acute appendicitis
overt luminal obstruction--fecalith, gallstone, tumor, mass of worms
402
Clinical presentation of acute appendicitis
periumbilical pain that localizes to RLQ followed by N/V and fever
403
most common tumor of the appendix
well-differentiated neuroendocrine tumor
404
Pseudomyxoma peritonei
syndrome of progressive intraperitoneal accumulation of mucinous ascites related to a mucin-producing neoplasm
405
Cause of sterile peritonitis
leakage of bile or pancreatic enzymes
406
Causes of peritonitis
perforation of biliary system, acute hemorrhagic pancreatitis, foreign material, endometriosis, ruptured dermoid cysts
407
Sclerosing retroperitonitis is characterized by...
dense fibrosis that may extend to involve the mesentery, often surrounds abdominal aorta and ureters
408
Most common presenting symptom of sclerosing retroperitonitis
back and abdominal pain
409
Peritoneal mesotheliomas are almost always associated with what kind of environmental exposure?
asbestos
410
Most common soft tissue tumor of peritoneum
desmoplastic small round cell tumor
411
Peritoneal carcinomatosis
secondary tumors that involve peritoneum by direct spread or metastatic seeding
