Chapter 17 - GI Tract Flashcards
Rule of 2’s for Meckels
Occurs in 2% of pop Present within 2 ft of ileocecal valve Approx. 2 inches long 2x more common in males Most often symptomatic by age 2
Condition characterized by new onset regurgitation and projectile nonbilious vomiting after feeding in assocation with palpable, firm 1-2 cm ovoid abdominal mass
Pyloric stenosis
Disease more common in pts with Down syndrome in which there is failure to pass meconium in immediate postnatal period and subsequent abdominal distention
Hirschprung
Pathogenesis of hirschprung
NCC fail to migrate from cecum to rectum or ganglion cells undergo premature death
Dx and associated genetics with Hirschprung
Dx by rectal suction biopsy
Associated with heterozygous LOF in RTK gene RET
Secondary achalasia may occur with infection by what organism?
Trypanosoma cruzi —> Chagas disease
What conditions might accompany esophageal mucosal webs in the upper esophagus?
Iron-deficiency anemia
Glossitis
Cheilosis (cracking at corners of mouth)
May be part of Paterson-Brown-Kelly or Plummer-Vinson syndrome
CREST syndrome associated with systemic sclerosis
Calcinosis Raynaud phenomenon Esophageal dysmotility Sclerodactyly Telangiectasias
Symptoms of achalasia
Dysphagia for solids and liquids, difficulty belching, chest pain
Mucormycosis of GI tract is most commonly seen in pts with what condition?
Diabetes
Most common cause of reflux esophagitis and associated morphology
GERD
Simple hyperemia may be only alteration, may also see basal zone hyperplasia and elongation of LP papillae
Plummer Vinson syndrome
Upper esophageal mucosal webs
Iron deficiency anemia
Glossitis
Cheilosis
MCC of esophageal varices is portal HTN. What is the second most common cause worldwide?
Hepatic schistosomiasis
Describe metaplasia associated with Barrett esophagus
Columnar metaplasia of the esophageal squamous mucosa
[goes from nonkeratinized stratified squamous to nonciliated columnar epithelium with goblet cells]
Risk factors for esophageal SCC
Adults > 45 Males 4x more likely African Americans 8x more likely Alcohol use Tobacco use Poverty Caustic esophageal injury Achalasia Tylosis Plummer-vinson syndrome Fruit-deficient diet Hot beverages Mediastinal radiation Ingestion of mursik (Kenya)
Molecular pathogenesis of esophageal SCC
Amplification of SOX2
LOF mutations in tumor suppressors, TP53, E-cadherin, and NOTCH1
Most common cause of chronic gastritis
H.pylori
Most common cause of diffuse atrophic gastritis
Autoimmune gastritis
Toxin associated with H.pylori
Cytotoxin-associated gene A (CagA) - associated with increased risk of gastric cancer
Stain used to detect H.pylori
Warthrin-Starry silver stain
Most common type of gastric polyps
Hyperplastic (inflammatory) polyps
Most common malignancy of the stomach
Gastric adenocarcinoma
Geographic distribution of gastric adenocarcinoma
Variable, but high in Japan, China, Costa Rica, and Eastern Europe
H.pylori eradication often results in remission of what type of gastric cancer?
MALToma
Most common mesenchymal tumor of abdomen
Gastrointestinal stromal tumor (GIST)
Mutation of ____ or ______ is usually an early event in sporadic GIST
KIT; PDGFRA
Diagnostic marker of GIST
KIT in interstitial cells of Cajal
Most common acquired GI emergency of neonates
Necrotizing enterocolitis; presents when oral feeding is initiated
Hallmark of malabsorption
Steatorrhea
What would biopsy of duodenum or proximal jejunum need to show to be diagnostic of celiac disease
Increased numbers of CTLs, crypt hyperplasia, and villous atrophy
Characteristic finding in 10% of celiac patients caused by anti-gluten Abs cross-reacting with basement membrane proteins in the skin
Dermatitis herpetiformis - presents as itchy blistering skin lesion
