Chapter17: GIT: Congenital DO Flashcards
(121 cards)
1
Q
\Congenital abnormalities GIT
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AtresiaDuplicationsFistula
2
Q
Most common congenital is ______. Developmentally incomplete
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Atresia
3
Q
It rsults to mechanical obstruction due to replacement of noncanalized cord.
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Esophageal atresia
4
Q
Atresia most commonly occurs in the _______. It is usually assoc with a _____ connecting the upper and lower esophageal pouches to a bronchus or trachea.
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Near tracheal BifucationFistula
5
Q
Is less common than esophageal atresia but it frequently involves the duodenum and is characterized by a segment of bowel lacking a lumen.
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Intestinal Atresia
6
Q
It is an incomplete form of atresia in which the lumen is reduced in caliber as a result of fibrous thickening of the wall resulting in partial or complete obstruction.Most commonly affected is in the esophagus and small intestine.
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Stenosis
7
Q
The most common congenital intestinal atresia due to failure of the cloacal diaphragm to involute.
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Imperforate anus
8
Q
Are saccular or congenital cystic masses that contain redundant smooth muscle layers. May be present in the esophagus,intestines or colon.
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Congenital duplication cyst
9
Q
What is the tx of ménétrier dse
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- Supportive 2. IV albumin 3. Parenteral nutritionSevere cases: gastrectomy
10
Q
A disease caused by gastrin-secreting tumors, gastrinomas, that are most commonly found in the small intestine and pancreas.Px often present with duodenal ulcer and chronic diarrhea.Within the stomach the most remarkable feature is DOUBLING OXYNTIC MUCOSAL THICKNESS DUE TO A FIVEFOLD INCREASE IN PARIETAL CELLS
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Zollinger Ellison Syndrome
11
Q
Gastric polyps and tumors
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- Inflammatory and hyperplastic polyps2. Fundic gland polyps3. Gastric adenoma4.gastric adenocarcinoma5. Lymphoma6. Carcinoid tumor7. Gastrointestinal stromal tumor
12
Q
Nodules or masses that project above the level id the surrounding mucosa and are i.d in up to 5% of upper GI endoscopiesIt may develop as a result of epithelial or stromal cell hyperplasia, inflammation, ectopia or neoplasia.
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Polyps
13
Q
Approx 75% of all gastric polypsAre most common in indiv bet 50-60 yo.Polyps that usually develop in assoc with chronic gastritis, which initiates the injury and reactive hyperplasia that leads to polyp growth.In indiv with H.pylori, regresses after removal of insult.
A
Inflammatory and hyperplastic polyps
14
Q
Occur sporadically and in indiv with FAP.Increased gastric secretion, in response to reduced gastric acidity, and the resulting glandular hyperplasia.5x more commom in women and an average of 50y0.May be asymptomatic or assoc with nausea, vomiting, or epigastric pain.Morphology:Occur in gastric body and fundusWell circumscribed lesions with smooth surfaceSingle or multipleCystically dilated irregular glands lined by flattened parietal and chief cellsInflammation is typically absent or minimal.
A
Fundic gland polyps
15
Q
10% of all gastric polyps.Incidence increases progressively with age. Bet 50-603x more in malesLike fundic gland polyp it is assoc with FAPRisk of gastric ca is related to the size of lesion and is elev in leasion greater than 2cm in diameter
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Gastric adenoma
16
Q
Morphology:Usually solitary lesions less than 2cm in diameterMost commonly loc in the antrumMajority are composed of intestinal-type columnar epithelium.
A
Gastric adenoma
17
Q
Is the most common malignancy in the stomach.90% of all gastric ca.Early symptoms resemble those of chronic gastritis, including,Dysphagia, dyspepsia, and nausea.Often discovered at advanced stages when symptoms such as wt loss, anorexia, altered bowel ha its, anemia a s hemorrhage trigger further diagnostic evaluation.It is. Ore common in lower socioeconomic status and in indiv with multifocal mucosal atrophy and intestinal metaplasia. PUD doesnt impart as risk factor except to those who had partial gastrectomy for PUD.Majority is not inherited.
A
Gastric adenocarcinoma
18
Q
What is the pathogenesis in gastric adenocarcinoma?
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Germline mutations in CDH1 which encodes E-cadherin , a protein that contributes to epithelial intercellular adhesion are associated with familial gastric ca of which is a diffuse type.
19
Q
What is the pathogenesis of intestinal-type gastric ca?
A
Mutation in beta-catenin, a protein that binds to both E-cadherinand adenomatous polyposis coli ( APC ), as well as microsatellite instability and hypermethylationof several genes including TGF B RII, BAX, IGFR II and p16 /INK4.
20
Q
Morphology charac:Irreg enlargement of gastric rugae.Some areas appear polypoid.Enlarged rugae present in body and fundus except antrum( gen spared)Most characteristic feature: HYPERPLASIA OF FOVEOLAR MUCOUS CELLS.THe glands are elongated with CORK-SCREW appearance and cystic dilation is common.Inflammation is only modest although some cases show marked intraepithelial lymphocytosis.Diffuse or patchy glandular atrophy, evident as hypoplasia or parietal and chief cell is typical
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Ménétrier dse
21
Q
2 diseases associated in hypertrophic gastrophaties
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- Ménétrier dis2. Zollinger ellison syndrome
22
Q
Uncommon diseases charac by GIANT CEREBRIFORM ENLARGEMENT OF THE RUGAL FOLDS due to epithelial hyperplasia W/O inflammation.As expected they are linked to excessive GF release
A
HYPERTROPHIC GASTROPHATIES
23
Q
Rare d/oCaused by x’ss secretion TGF-alphaCharac by: diffuse hyperplasia of foveolar epithelium of the. Body and fundus and hyperproteinemia due to protein losing enteropathySecondary symptom: wt loss, diRrhea, peripheral edema.Pathologic feature in children same in adult but pedia dse is self- lim and often follows respi infection.Risk of gastric adenocarcinoma is ⬆️ in adult.
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Ménétrier dse
24
Q
Intestinal obstruction occurs at any level but which is commonly affected and why?
A
Small intestine because of its narrow lumen
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what are the collection of intestinal obstruction?
1. hernias2. intussuception3. volvulus4. adhesions
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this account for 80 % of intestinal obstructions
volvulus
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how many percent does tumors account for intestinal obstruction?
10-15%
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what are the clin manifestation of intestinal obstruction?
abdomina pain and distentionvomitingconstipation
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What is the weakness or defect in the wall of the peritoneal cavity that may permit protrusion of a serosa-lined pouch of peritoneum
hernial sac
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Acquired hernias most commonly occured in the?It is via?
anterioringuinal, femoral canals, umbilicus, or sites of surgical scars
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The resultant stasis and edema increases the bulk of the herniated loop, leading to permanent entrapment called \_\_\_\_\_\_\_. In which overtime, arterial, and venous compromise ______ develpps that can result in infarction.`
incarcerationstrangulation
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Surgical procedures, infections, or other causes of peritoneal inflammation, such as endometriosis, may result in development of _______ between bowel segmens, the abdomina wall and operative sites.
adesions
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Complete twisting of a loop bowel about its mesenteric base of attachment is called _____ and produces both luminal and vascular compromise. Thus presentation includes features of obstruction and infarction. It occurs most often in large redundant loops of sigmoid colon, followed in frequency by the :cecumsmall bowelstomachor rarely transverse colon.Because this is rare, it is often missed clinically
volvulus
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It occurs when a segment of the intestine, constricted by a wave of peristalsis, telescopes into te immediately distal segment. Once trapped, the invaginated segment is propelled by peristalsis and pulls the mesentery along. If left untreated may result in or progress into intestinal obstruction, compression of mesenteric vessels and infarction.When encountered in infants no underlying cause but come cases are associated with\_\_\_\_\_\_\_.In older children and adults an intraluminal mass or tumor generally serves as the point of traction that causes this.
IntussusceptionRota virus
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Acute compromise of any major vessel can lead to infarction of several meters of intestine. Damage can range from\_\_\_\_\_\_.
1. mucosal infarction2. mural infarction3. transmural infarction
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Infarction extending no deeper than te muscularis mucosa
mucosal infarction
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Infarction extending of mucosa to submucosa
mural infarction
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infarction involving all three wall layers
transmural infarciton
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Mucosal or mural infarctions are often secondary to\_\_\_\_
acute or chronic hypoperfusion
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transmural infarciton is generally caused by \_\_\_\_\_
acute vascular obstruction
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what are the two major variables in IBD?
1. Time frame which it develops2. vessels affected
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Intestinal segments at the end of their respective arterial supplies are particularly susceptible to iscemia. These are called\_\_\_\_\_\_\_ which includes:\_\_\_\_\_\_\_\_\_\_
Watershed zonesplenic flexure where the superior and inferior mesenteric arterial circulation endsto a lesser extent the sigmoid colon andrecutm where inf mesenteric, pudendal and iliac arteries circulations end.
43
What is a morphologic signature of iscemic intestinal disease? why?
Surface epithelial atrophy or even necrosis and sloughing with normal or hyperproliferative crypts .The reason is intestinal capillaries run alongside the glands, form the crypt to surface, before making a hairpin turn at the surface to empty into the post-capillary venules. This allows oxygenated blood to supply crypts but leaves the surce epithelium vulnerable to ischemic injury. This anatomy protects the crypts which contain the epithelial stem cells.
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Microscopic examination showing ATROPHY OR SLOUGHING OF SURFACE EPITHELIUM. In contrast, crypts may be hyperproliferative. Inflammatory infiltrates are initially absent in acute ischemia nut neutrophils are recruited within hours of reperfusion. Chronic ischemia is accompanied by fibrous scarrring of the lamina propria and uncommonly stricture forms.
IBD
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In acute phase of IBD bacterial superinfection and enterotoxin release may induce pseudomembrane formation that can resemble \_\_\_\_\_\_
C. difficile- associated pseudomembranous colitis
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It tends to occur in older individual with coexisting cardiac or vulvular disease. Acute transmural infarction typically presents wit sudden abdominal pain and tenderness, sometimes accompanied by nausea, vomiting, bloody diarrhea, or grossly melanotic stool.Patients may progress to shockand vascular collapse within hours as a result of blood loss. Peristaltic sound diminished or disappear and muscular spasm creates board- like rigidity of the abdomina wall.These physical signs overlaps with other abdominal emergencies that results in delayed or missed diagnosis.
IBD
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These themselves may not be fatal. However, may progress to more extensive infarction if the vascular supply is not restored by correction of the insult or in chronic dse by dev of adequate collateral supplies. Diagnosis is partially difficult since there may be a confusing array of nonspecific abdominal symptoms including intermittent bloody diarrhea and intestinal psuedo-obstruction.
Mucosal and mural infarction
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May masquarade as IBD with episodes of bloody diarrhea interspesed with periods of healing
chronic ischemia
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This causes iscemic GI dsew due to viral tropism for and infection of endothelial cells. This is a complication of an immunosuppressive therapy
CMV
50
This occurs when the GI tract is irradiated. In add to epitelial damage, radiation-induced vascular injury may be significant and produce changes that are similar to ischemic disease. The presence of BIZARRE " RADIATION FIBROBLAST" within the stroma may provide important clue to the etiology. It manifest as anorexia, abdominal cramps, and a malabsorptive diarrhea while chronic radiation enteritis or colitis is often more indolent and may present as an inflammatory colitis.
Radiation enterocolitis
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Is an acute do of the small and large intestines that can result in transmural necrosis. It is the most common acquired GI emergency of neonates, particularly those who are premature of LBW and occurs most oftenat the time of oral feeding.
NEC
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Characterized by malformed submucosal and mucosal blood vessels. It occurs most often in the CECUM or RIGHT colon because cecum has the largest diameter that develops tha greatest wall tension. It is usally after the 6th decade of life. Prevalence is \< 1 % in adult, it accounts for 20 % major episodes of lower intestinal bleeding; intestinal hemorrage may be chronic and intermittent, acute and massive. Pathogenesis is attributed to mechanical and congenital factors.
angiodysplasia
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Presents most commonly as chronic diarrhea characterized by defective absorption of fats, fat- and water- soluble vit ,proteins, carbohydrates,electrolytes and mineral and water.
Malabsorption
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It is accompanied by wt loss, anorexia, abdominal distention, borborygmi and muscle wasting.
chronic malabsorption
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Steatorrhea is the hallmark of this condition which is characterized by excessive fecal fat and bulky, frothy greasy, yellow or clay colored stool.
Malabsorption
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Malabsorption results from distrubance of the ff phases:
1. intraluminal digestion2. terminal digestion3. transepithelial digestion4. lymphatic transport
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The phase of digestion in which fats, protein, CHOH are broken down intor forms suitable for absorption.
intraluminal digestion
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The phase that involves the hydrolysis of carboydrates and peptieds by dissacharides and peptidases, respectively in the brush boder of the mall intesinal mucosa.
terminal digestion
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Phase where nutritiens, electrolytes are transported across and processed within the small intetinal epithelium.
transepithelial digestion
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transport of absorbed lipids
lymphatic transport
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What are the general sypmtoms of malabsorption
diarrea ( nutrient malabsorption and excessive intestinal secretion)flatusabdominal painand weight loss.
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It is defined as an increase in stool mass, frequency or fluidity, typically greater than 200g per day. In severe cases, stool volume can exceed 14 L per day and without fluid resusscitation can result in death.
diarrhea
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Painful, bloody, small volume diarrhea is known as \_\_\_\_\_
dysentery
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What are the 4 major categories of diarrhea?
1. secretory diarrhea2. osmotic diarrhea3. malabsorptive diarrhea4. exudative diarrhea
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Isotonic stool and persist during fasting
secretory diarrhea
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Excessive osmotic forces exerted by unabsorbed luminal solutes. The diarrhea fluid is more than 50 mOsm more concentrated than plasma and abates with fasting. An example is lactase deficiency.
Osmotic diarrhea
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It follows generalized failures of nutient absorption and is associated with steatorrhea and is relieved by fasting
Malabsorptive diarrhea
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It is due to inflammatory disease and characterized by purulent, bloody stools tat continue during fasting.
Exudative diarrhea
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This is due to absence of CFTR, individuals have defects in intestinal chloride ion secretion. This interferes with bicarb, sodium and water secretion, ultimately resulting in defective luminal hydration.
Cystic Fibrosis
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It is an immune-mediated enteropathy triggered by te ingestion of gluten-containing cereals, such a wheat, rye or barley, in genetically predisposed individuals. It is common in European and caucasian descent with a prevalence rate of 0.5% to 1%.
Celiac disease, celiac sprue or gluten-sensitive enteropathy.
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This is a malabsorption that occurs almost exclusively in people living in or visiting the tropics, including Puerto Rico, the Caribbean, northen South America, West Africa, India and Southeast Asia. Histologic changes are similar to celiac disease, but toal villous atrophy is uncommon and tends to inolve the distal small bowel. The latter probably explains the freq of folate and vit B12 deficiencies with megaloblastic anemia. There is no definite casual organism but various infections including Cyclospora or enterotoxigenic bacteria have been suggested as etiologic factors.
Tropical Sprue
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It is an X-linked do characterized by severe diarrhea and autoimmune disease that occurs most often in young children. There is a germline mutation in te FOXP3 gene which is located on the X chromosome.
Autoimmune enteropathy
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What does IPEX stands for?
Immune dysregulation, polyendocrinopathy, enteropathy and X- linkage
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What is the pathophysio of IPEX?
There is a germline mutation of FOXP3 which is located in X chromosome. FOXP3 is a transcriptor factor expressed in CD4+ regulatory T cells and individuals with IPEX and FOXP3 mutations have defective T-regulatory function.
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Where is the disaccharide lactase located?
apical brus-border membrane of the villous
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It is caused by mutation in the gene encoding lactase, is an autosomal recessive disorder. The disease is rare and presents as EXPLOSIVE DIARRHEA with watery, FROTHY stools and abdomina distention upon milk ingestion.
Congenital Lactase deficiency
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It is a down regulation of lactase gene expression and is particularly common among native Americans, African Americans and Chinese populations. Disease presents after childhood, peraps reflecting the fact that , before farming of dairy animals, lactase was unnecessary after children stopped drinking mother's milk
acquired lactase deficiency
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This is a rare autosomal recessive disease characterized by an inability to secrete triglyceride-rich lipoprotein due to mutation in the microsomal triglyceride transfer protein ( MTP) that catalyzes transport of triglycerides, cholesterol esters and phospholipids. MTP-deficient are unable to export lipoproteins and free faty acids as a result that monoglycerides cant be assembled as chylomicrons and TG accumulate within the epithelial cells. This presents in infancy and clinical picture is dominated by failure to thrive, diarrhea and steatorrhea. There is presence of acanthocytic red cells (burr cells) in PBS.
ABETALIPOPROTEINEMIA
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What are the infectious Enterocolitis?
1. Cholera2. Campylobacter Enterocolitis3. Shigellosis4.Salmonellosis5. Typhoid Fever6. Yersina7. Eschericia Coli8. Pseudomembranous Colitis9. Whipple Disease10. Viral Enterocolitis11. Parasitic Enterocolitis
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It is a comma -shaped , Gr negative bacteria, a diseases that as been endemic in the Ganges Valley of India and Bangladesh for all recorded history. It is primarily transmitted by contaminated drinking water. However, it can also be present in food and causes sporadic cases of sea-food associated disease in North America.
Vibrio cholera
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There is a marked seasonal variation in most climates due to rapid growth of vibrio bacteria at warm temperature; the only animal resovoirs are\_\_\_\_\_\_
shellfish and planktons
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It is the most common cause of seafood- associated gastroenteritis in North America.
V. Parahaemolyticus
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What virulence factor in V. cholerae is responsible for te bacterial detachment and shedding in stool.
Hemaglutinin
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It is the most common bacterial enteric patogen in developed countires and is an important cause of traveler's diarrea. Most infections are associated wit ingestion of improperly cooked chicken but outbreaks can also be caused by unpasteurized milk or contaminated water. The clinical presentation watery diarrhea , either acute or following an influenza-like prodrome is the primary symptom and dysentery develops in 15 % of patient.
Campylobacter enterocolitis
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True or False. In Campylobacter enterocolitism, antibiotic therapy is required?
FALSE
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Gr. Neg bacilli that were initially isolated during the Japanese red diarrhea epidemic of 1897. These are unencapsulated, nonmotile, facultative anaerobes that belong to the Enterobacteriacea and are closely related to enteroinvasive E.coli. Humans are the only known reservoir and they are the most common cause of bloody diarrhea.
Shigella
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What are the four majour subgroup of E.coli
ETEC ( Enterotoxigenic E.coli)EHEC ( Enterohemorrhagic E.coli)EIEC ( Entero invasive E.coli)EAEC ( Enteroaggregative E.coli)
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These are the principal cause of traveller's diarrhea that is most common un underdeveloped regions affecting children younger than 2 years of age are susceptible.
ETEC
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In developed countries assoctiate with the consumption of inadequately cooked ground beef, sometimes from fast food. Contaminated milk and vegetables are also vehicles.
E.coli 0157:H7
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These are organism that are bacteriologic similar to Shigella and are transmitted by person to person, food and water. These dont produce toxins but instead they cause to invade epithelial cells and cause nonspecific features of acute limited colitis.
Enteroinvasive E. coli
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Identified on the absis of their uniques pattern of adherence to epithelial cells. It also cause traveller's diarrhea. They attach to epithelial cell via ADHERENCE FIMBRIAE and are aided by dispersin, a bacterial surface protein that neutralizes the negative surface charge of LPS. It produces enterotoxin related to SHIGELLA and ETEC ST toxin
EAEC
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Generally caused by \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_, is also known as antibioticassociated colitis or antibiotic-associated diarrhea. The latter terms apply to diarrhea developing during or after a course of antibiotic therapy and may be due to C. difficile as well as Salmonella, C. perfringens type A, or Staphylococcus aureus. The latter two organisms produce enterotoxins and are common agents of food poisoning.
Pseudomembranous colitis
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Morphology. Fully developed\_\_\_\_\_ is accompanied by formation of pseudomembranes , made up of an adherent layer of inflammatory cells and debris at sites of colonic mucosal injury. While pseudomembranes are not specific and may occur in ischemia and necrotizing infections, the histopathology of this is striking. The surface epithelium is denuded, and the superficial lamina propria contains a dense infiltrate of neutrophils and occasional fibrin thrombi within capillaries. Superficially damaged crypts are distended by a mucopurulent exudate thatforms an eruption reminiscent of a volcano ( These exudates coalesce to form the pseudomembranes
pseudomembranous colitis
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a rare, multivisceral chronic disease first described as intestinallipodystrophy. original case report described an individual with malabsorption, lymphadenopathy,and arthritis of undefined origin.Postmortem examination demonstrated the presence of foamy macrophages and large numbers of argyrophilic rods in the lymph nodes, providing evidence that the disease was infectious. Clinical symptoms occur because organism-laden macrophages accumulate within the small intestinal lamina propria and mesenteric lymph nodes, causing lymphatic obstruction. Thus, the malabsorptive diarrhea of Whipple disease is due to impairedlymphatic transport.
Whipples Disease
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The Gram-positive actinomycete, named \_\_\_\_\_\_\_\_, that is responsible for Whipple disease was identified by PCR in 1992 and finally
Tropherymawhippelii
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the malabsorptive diarrhea of Whipple disease is due to impaired\_\_\_\_\_\_\_\_\_.
lymphatic transport
97
This is a disease is a dense accumulation of distended, foamy macrophages in the small intestinal lamina propria ( Fig. 17-30A ).The macrophages contain periodic acid–Schiff (PAS)-positive, diastase-resistant granules that represent lysosomes stuffed with partially digested bacteria ( Fig. 17-30B ). Intact rodshaped bacilli can also be identified by electron microscopy ( Fig. 17-30C ). A similar infiltrate of foamy macrophages is present in intestinal tuberculosis ( Fig. 17-30D ), and in both diseases the organisms are PAS-positive. The villous expansion caused by the dense macrophage infiltrate imparts a shaggy gross appearance to the mucosal surface. Lymphatic dilatation and mucosal lipid deposition account for the common endoscopic detection of white to yellow mucosal plaques. In this disease, bacteria-laden macrophages can accumulate within mesenteric lymph nodes, synovial membranes of affected joints, cardiac valves, the brain, and othersites
Whipple disease
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The morphologic hallmark of Whipple disease is a \_\_\_\_\_\_\_\_
dense accumulation ofdistended, foamy macrophages in the small intestinal lamina propria
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a rare, multivisceral chronic disease first described as intestinal lipodystrophy. Its original case report described an individual with malabsorption, lymphadenopathy,and arthritis of undefined origin. Postmortem examination demonstrated the presence of foamymacrophages and large numbers of argyrophilic rods in the lymph nodes, providing evidence Infectious Enterocolitis that the disease was infectious. Clinical symptoms occur because organism-laden macrophagesaccumulate within the small intestinal lamina propria and mesenteric lymph nodes, causing lymphatic obstruction. Thus, the malabsorptive diarrhea is due to impairedlymphatic transport
Whipple's Disease
100
The clinical presentation of is usually a triad of diarrhea, weight loss, andmalabsorption. Extraintestinal symptoms, which can exist for months or years beforemalabsorption, include arthritis, arthralgia, fever, lymphadenopathy, and neurologic, cardiac, orpulmonary disease.
Whipple disease
101
is a common cause of nonbacterial infectious gastroenteritis. [87] These are small icosahedral viruses with a single-stranded RNA genome that forms a genus within the Caliciviridae family. Norovirus causes approximately half of all gastroenteritis outbreaks worldwide and is a common cause of sporadic gastroenteritis indeveloped countries. Local outbreaks are usually related to contaminated food or water, but person-to-person transmission underlies most sporadic cases.Infections spread easily within schools, hospitals, nursing homes, and, most recently, cruise ships. Following a short incubation period, affected individuals develop nausea, vomiting, watery diarrhea, and abdominal pain.Biopsy morphology is nonspecific. When detected, abnormalities are most evident in the small intestine and include mild villous shortening, epithelial vacuolization, loss of the microvillus brush border, crypt hypertrophy, and lamina propria infiltration by lymphocytes (Fig. 17-31A ). The disease is self-limited.
Norovirus
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This encapsulated virus with a segmented double-stranded RNA genome infects 140 million people and causes 1 million deaths each year, making rotavirus the most common cause of severe childhood diarrhea and diarrheal mortality worldwide. Children between 6 and 24 months of age are most vulnerable.Protection in the first 6 months of life is probably due to the presence of antibodies to rotavirus in breast milk, while protection beyond 2 years is due to immunity that develops following the first infection. [88] Outbreaks in hospitals and daycare centers are common, and infection spreads easily; the estimated minimal infective inoculum isonly 10 viral particles.It selectively infects and destroys mature enterocytes in the small intestine, and the villus surface is repopulated by immature secretory cells. This results in loss of absorptive function and net secretion of water and electrolytes that is compounded by an osmotic diarrhea from incompletely absorbed nutrients. Like norovirus, rotavirus this has short incubation period followed by several days of vomiting and watery diarrhea.
Rotavirus.
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The second most common cause of pediatric diarrhea (after rotavirus), _______ also affectsimmunocompromised patients. [89]Small intestinal biopsy specimens can show epithelial degeneration but more often exhibit nonspecific villous atrophy and compensatory crypt hyperplasia. Viral nuclear inclusions are uncommon. Disease typically presents after an incubation period of 1 week with nonspecific symptoms that include diarrhea, vomiting, andabdominal pain. Fever and weight loss may also be present. Symptoms generally resolve within 10 days.
adenovirus
104
It is characterized by chronic, relapsing abdominal pain, bloating,and changes in bowel habits. Despite very real symptoms, the gross and microscopicevaluation is normal in most IBS patients. Thus, the diagnosis depends on clinical symptoms.
Irritable Bowel Disease
105
Explain the pathophysio of IBS
The pathogenesis of IBS remains poorly defined, although there is clearly an interplay between psychologic stressors, diet, and abnormal GI motility. Data showing disturbances of intestinal motility and enteric sensory function suggest that impairment of signaling in the brain-gut axis contributes to IBS. A small subgroup of IBS patients also relate onset to a bout of infectious gastroenteritis, suggesting an immune or neuroimmune contribution.
106
This is a chronic condition resulting from inappropriate mucosalimmune activation.
Inflammatory Bowel Disease ( IBD )
107
The two disorders that comprise IBD are :
Crohn's diseaseulcerative colitis
108
The distinction between ulcerative colitis and Crohn disease is based, in large part, on the \_\_\_\_\_\_\_\_\_.
distribution of affected sitesmorphologic expression of diseaseSTUDY( Table17-8 ) at those sites.
109
Molecular linkage analyses of affected families have identified _______ as a susceptibility gene in Crohn disease. This encodes a protein that binds to intracellular bacterial peptidoglycans and subsequently activates NF-κB. It has been postulated thatthis variants are less effective at recognizing and combatingluminal microbes, which are then able to enter the lamina propria and triggerinflammatory reactions. Other data suggest that it may regulate immune responsesto prevent excessive activation by luminal microbes. Whatever the mechanism by which thiscontribute to Crohn disease pathogenesis, it should beremembered that fewer than 10% of individuals carrying this mutations developdisease.
NOD2
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Crohn disease may occur in any area of the GI tract, but the most commonsites involved at presentation are the \_\_\_\_\_\_\_\_\_\_.Disease is limited to the small intestine alone in about 40% of cases; the small intestine and colon are both involved in 30% of patients; and the remainder have only colonicinvolvement. The presence of multiple, separate, sharply delineated areas of disease,resulting in skip lesions, is characteristic of Crohn disease and may help in thedifferentiation from ulcerative colitis. Strictures are common ( Fig. 17-34A )
terminal ileum, ileocecal valve, and cecum
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The earliest Crohn disease lesion, the \_\_\_\_\_\_, may progress, and multiple lesionsoften coalesce into elongated, serpentine ulcers oriented along the axis of the bowel.Edema and loss of the normal mucosal texture are common.
aphthous ulcer
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The earliest Crohn disease lesion, the \_\_\_\_\_\_\_, may progress, and multiple lesions often coalesce into elongated, serpentine ulcers oriented along the axis of the bowel. Edema and loss of the normal mucosal texture are common.
aphthous ulc
113
This is most common in the colon but may occur in the esophagus, stomach, or smallintestine. Most, if not all, begin as small elevations of the mucosa. These are referred to as sessile, a term borrowed from botanists who use it to describe flowers and leaves that grow directly from the stem without a stalk.
polyps
114
The most common neoplastic polyp is the\_\_\_\_\_\_, which has the potential to progress to cancer.
adenoma
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The nonneoplastic polyps can be further classified as \_\_inflammatory, hamartomatous, or hyperplastic\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.
inflammatory, hamartomatous, or hyperplastic
116
The polyp that forms as part of the solitary rectal ulcer syndrome is an example of a purely type of this. Patients present with a clinical triad of rectal bleeding, mucus discharge,and an inflammatory lesion of the anterior rectal wall. The underlying cause is impaired relaxation of the anorectal sphincter that creates a sharp angle at the anterior rectal shelf and leads to recurrent abrasion and ulceration of the overlying rectal mucosa.This may ultimately form as a result of chronic cycles of injury and healing. Entrapment of this polyp in the fecal stream leads to mucosal prolapse. Thus, the distinctive histologic features are those of a typical with superimposed mucosal prolapse and include lamina propria fibromuscular hyperplasia, mixed inflammatory infiltrates, erosion, and epithelial hyperplasia
Inflammatory polyp
117
Solitary rectal ulcer syndrome.A, The dilated glands, proliferativeepithelium, superficial erosions, and inflammatory infiltrate are typical of an \_\_\_\_\_\_\_\_However, the smooth muscle hyperplasia within the lamina propria suggests that mucosalprolapse has also occurred.B, Epithelial hyperplasia.C, Granulation tissue-like capillaryproliferation within the lamina propria caused by repeated erosion and re-epithelialization
inflamatory polyp.
118
This occurs sporadically and in the context of various genetically determinedor acquired syndromes ( Table 17-9 ). Recall that these are tumor-like growthscomposed of mature tissues that are normally present at the site in which they develop.Although these syndromes are rare, they are important to recognizebecause of associated intestinal and extra-intestinal manifestations and the possibility that other family members are affected
HAMARTOMATOUS POLYPS
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Mean Age at Presentation (yr)--- Mutated Gene : SMAD4, BMPR1AGastrointestinal Lesions : Juvenile polyps; risk of gastric, small intestinal,colonic, and pancreatic adenocarcinomaSelected Extra-Gastrointestinal Manifestations: Pulmonaryarteriovenousmalformations, digital clubbing
Juvenile polyposis
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Mean Age at Presentation (yr) :10–15 Mutated Gene :LKB1/STK11Gastrointestinal Lesions : Arborizing polyps; Small intestine \> colon \> stomach; colonic adenocarcinomaSelected Extra- Gastrointestinal Manifestations : Skin macules; increasedrisk of thyroid, breast, lung, pancreas, gonadal, and bladder cancers
Peutz-Jegherssyndrome
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Mean Age atPresentation (yr) :Mutated Gene :Gastrointestinal Lesions :Selected Extra- Gastrointestinal Manifestations :
Cowden syndrome,Bannayan- Ruvalcaba-Riley syndrome
