PANRE Gastroenterology 5 — Questions and Answers
Question 1: A 55-year-old woman presents with fatigue, arthralgias, and elevated transaminases (AST/ALT 3× ULN). ANA titer is 1:320 and anti-smooth muscle antibody is positive. Liver biopsy shows interface hepatitis. What is the diagnosis?
- Primary biliary cholangitis
- Autoimmune hepatitis (Correct answer)
- Drug-induced liver injury
- Wilson's disease
Correct answer: Autoimmune hepatitis
Autoimmune hepatitis is characterized by elevated transaminases, positive ANA and anti-smooth muscle antibodies, and interface hepatitis on biopsy.
Question 2: A 38-year-old man presents with severe epigastric pain radiating to the back, nausea, and vomiting. He denies alcohol use. Lipase is 4× normal and triglycerides are 1,800 mg/dL. What is the cause of his pancreatitis?
- Gallstone pancreatitis
- Hypertriglyceridemia-induced pancreatitis (Correct answer)
- Idiopathic pancreatitis
- Medication-induced pancreatitis
Correct answer: Hypertriglyceridemia-induced pancreatitis
Triglyceride levels above 1,000 mg/dL can cause acute pancreatitis, and this patient's markedly elevated triglycerides with no other identified cause confirms hypertriglyceridemia-induced pancreatitis.
Question 3: A 25-year-old woman presents with watery diarrhea (8-10 stools/day) and mild cramping. She recently completed a course of clindamycin. Stool testing is positive for C. difficile toxin. What is the first-line treatment?
- Metronidazole
- Vancomycin (oral) (Correct answer)
- Fidaxomicin
- Fecal microbiota transplant
Correct answer: Vancomycin (oral)
Current IDSA/ACG guidelines recommend oral vancomycin as the first-line treatment for initial C. difficile infection, having replaced metronidazole as first-line therapy.
Question 4: Which of the following features distinguishes Crohn's disease from ulcerative colitis?
- Rectal involvement
- Continuous mucosal inflammation
- Transmural inflammation with skip lesions (Correct answer)
- Pseudopolyps on colonoscopy
Correct answer: Transmural inflammation with skip lesions
Crohn's disease is characterized by transmural inflammation that can affect any part of the GI tract in a discontinuous (skip lesion) pattern, unlike the continuous mucosal inflammation of UC.
Question 5: A 68-year-old man undergoes colonoscopy and is found to have a 25 mm pedunculated polyp in the transverse colon. Pathology shows invasive adenocarcinoma confined to the stalk with clear margins. What is the most appropriate next step?
- Immediate right hemicolectomy
- Repeat colonoscopy in 3 months
- No additional surgery if resection margins are clear and no high-risk features (Correct answer)
- Radiation therapy
Correct answer: No additional surgery if resection margins are clear and no high-risk features
Pedunculated polyps with invasive cancer at clear margins, no lymphovascular invasion, and well-differentiated histology can be managed endoscopically without surgery.
Question 6: A 50-year-old man with long-standing GERD undergoes surveillance endoscopy revealing Barrett's esophagus with high-grade dysplasia. What is the recommended management?
- Intensify PPI therapy and repeat endoscopy in 3 months
- Endoscopic eradication therapy (radiofrequency ablation) (Correct answer)
- Esophagectomy
- Continue surveillance every 6 months
Correct answer: Endoscopic eradication therapy (radiofrequency ablation)
Endoscopic eradication therapy, particularly radiofrequency ablation, is the recommended treatment for Barrett's esophagus with high-grade dysplasia as it effectively eliminates dysplastic epithelium.
Question 7: A 45-year-old man presents with diarrhea, flushing, and wheezing. Urine 5-HIAA levels are elevated. CT abdomen shows a liver mass. What is the most likely primary tumor location?
- Stomach
- Pancreas
- Small intestine (Correct answer)
- Colon
Correct answer: Small intestine
Carcinoid syndrome (diarrhea, flushing, wheezing) with elevated 5-HIAA and liver metastases most commonly originates from a small intestinal carcinoid tumor.
PANRE Gastroenterology 5
A 55-year-old woman presents with fatigue, arthralgias, and elevated transaminases (AST/ALT 3× ULN).
ANA titer is 1:320 and anti-smooth muscle antibody is positive.
Liver biopsy shows interface hepatitis.
What is the diagnosis?