GI Disorders & Diseases 3 — Questions and Answers
Question 1: Which serologic marker is most specific for primary biliary cholangitis (PBC)?
- Anti-smooth muscle antibody (ASMA)
- Anti-mitochondrial antibody (AMA) (Correct answer)
- Antinuclear antibody (ANA)
- p-ANCA
Correct answer: Anti-mitochondrial antibody (AMA)
Anti-mitochondrial antibody (AMA) is present in over 90% of patients with primary biliary cholangitis and is highly specific for this autoimmune liver disease.
Question 2: A patient presents with painless obstructive jaundice, weight loss, and a palpable non-tender gallbladder. This presentation is known as:
- Charcot's triad
- Courvoisier's sign (Correct answer)
- Murphy's sign
- Grey Turner's sign
Correct answer: Courvoisier's sign
Courvoisier's sign refers to a palpable, non-tender gallbladder in the setting of jaundice, suggesting malignant biliary obstruction (most commonly pancreatic head cancer) rather than gallstones.
Question 3: Which genetic mutation is most commonly associated with hereditary hemochromatosis?
- CFTR gene mutation
- HFE gene C282Y mutation (Correct answer)
- ATP7B gene mutation
- PRSS1 gene mutation
Correct answer: HFE gene C282Y mutation
Hereditary hemochromatosis is most commonly caused by the C282Y mutation in the HFE gene, leading to excessive iron absorption and deposition in organs.
Question 4: What is the hallmark pathologic finding in celiac disease on small bowel biopsy?
- Crypt abscesses and goblet cell depletion
- Villous atrophy with crypt hyperplasia and increased intraepithelial lymphocytes (Correct answer)
- Non-caseating granulomas
- Submucosal fibrosis and eosinophilic infiltration
Correct answer: Villous atrophy with crypt hyperplasia and increased intraepithelial lymphocytes
Celiac disease is characterized by villous atrophy, crypt hyperplasia, and an increased number of intraepithelial lymphocytes on duodenal biopsy, which reverses with a gluten-free diet.
Question 5: A 60-year-old man presents with epigastric pain, early satiety, and weight loss. Upper endoscopy reveals a ulcerated gastric mass. Which H. pylori-associated gastric cancer type arises from lymphoid tissue?
- Adenocarcinoma
- MALT lymphoma (Correct answer)
- Gastrointestinal stromal tumor
- Carcinoid tumor
Correct answer: MALT lymphoma
MALT (mucosa-associated lymphoid tissue) lymphoma is strongly associated with H. pylori infection and can often be treated with H. pylori eradication alone in early stages.
Question 6: Which condition is associated with terminal ileum disease or resection leading to fat-soluble vitamin deficiency and bile salt malabsorption?
- Ulcerative colitis
- Crohn's ileitis (Correct answer)
- Celiac disease
- Microscopic colitis
Correct answer: Crohn's ileitis
Crohn's disease affecting the terminal ileum disrupts bile salt and vitamin B12 absorption, and resection of >100 cm of terminal ileum causes clinically significant malabsorption.
Question 7: A patient develops 'nutmeg liver' on imaging. This finding is associated with which condition?
- Non-alcoholic fatty liver disease
- Congestive hepatopathy from right heart failure (Correct answer)
- Autoimmune hepatitis
- Primary sclerosing cholangitis
Correct answer: Congestive hepatopathy from right heart failure
Congestive hepatopathy (cardiac cirrhosis) from right-sided heart failure causes hepatic venous congestion, creating the characteristic mottled 'nutmeg' appearance on gross pathology.
GI Disorders & Diseases 3
Which serologic marker is most specific for primary biliary cholangitis (PBC)?