PANCE Gastrointestinal 5 — Questions and Answers
Question 1: A 55-year-old with long-standing GERD undergoes endoscopy showing replacement of squamous epithelium with columnar epithelium in the distal esophagus. What is the most serious concern with this finding?
- Increased risk of esophageal squamous cell carcinoma
- Increased risk of esophageal adenocarcinoma (Correct answer)
- Esophageal stricture formation
- Increased risk of aspiration pneumonia
Correct answer: Increased risk of esophageal adenocarcinoma
Barrett esophagus (intestinal metaplasia of the distal esophagus) is a premalignant condition that increases risk of esophageal adenocarcinoma by 30-40 fold.
Question 2: A patient presents with watery diarrhea, hypokalemia, and achlorhydria. CT shows a pancreatic mass. Which hormone is most likely responsible?
- Gastrin
- Vasoactive intestinal peptide (VIP) (Correct answer)
- Glucagon
- Somatostatin
Correct answer: Vasoactive intestinal peptide (VIP)
VIPoma secretes vasoactive intestinal peptide causing profuse watery diarrhea, hypokalemia, and achlorhydria — known as WDHA or Verner-Morrison syndrome.
Question 3: A 35-year-old presents with episodic peptic ulcers refractory to PPI therapy and diarrhea. Fasting serum gastrin is 1,200 pg/mL. What is the most likely diagnosis?
- H. pylori gastritis
- Zollinger-Ellison syndrome (Correct answer)
- VIPoma
- Autoimmune gastritis
Correct answer: Zollinger-Ellison syndrome
Zollinger-Ellison syndrome is caused by a gastrin-secreting tumor (gastrinoma), leading to massively elevated gastrin, multiple refractory peptic ulcers, and diarrhea.
Question 4: Which of the following is the most appropriate initial management for a patient presenting with acute upper GI bleeding and hemodynamic instability?
- Emergent upper endoscopy immediately
- IV fluid resuscitation and blood transfusion, then endoscopy (Correct answer)
- Oral PPI therapy and observation
- Surgical consultation without prior endoscopy
Correct answer: IV fluid resuscitation and blood transfusion, then endoscopy
Hemodynamically unstable patients require initial resuscitation with IV fluids and blood products before proceeding to urgent upper endoscopy within 24 hours.
Question 5: A newborn fails to pass meconium within 48 hours of birth. Abdominal X-ray shows a distended colon with a transition zone. Rectal biopsy confirms absence of ganglion cells. What is the diagnosis?
- Meconium ileus
- Hirschsprung disease (Correct answer)
- Imperforate anus
- Anal stenosis
Correct answer: Hirschsprung disease
Hirschsprung disease is caused by absence of enteric ganglion cells (neural crest migration failure) resulting in a functional obstruction and failure to pass meconium.
Question 6: A patient with alcoholic cirrhosis develops tense ascites and acute kidney injury with urine sodium <10 mEq/L and no response to diuretics or albumin. What is the most likely diagnosis?
- Prerenal azotemia
- Hepatorenal syndrome (Correct answer)
- Acute tubular necrosis
- Glomerulonephritis
Correct answer: Hepatorenal syndrome
Hepatorenal syndrome is a functional renal failure in cirrhosis with ascites, characterized by very low urine sodium, no response to volume expansion, and exclusion of other causes.
Question 7: A 60-year-old presents with rectal bleeding, mucus discharge, and tenesmus. Digital rectal exam reveals a rectal mass 4 cm from the anal verge. Which is the most appropriate next step?
- CT scan of the abdomen and pelvis
- Flexible sigmoidoscopy with biopsy (Correct answer)
- MRI of the rectum
- CEA level and colonoscopy
Correct answer: Flexible sigmoidoscopy with biopsy
Flexible sigmoidoscopy with biopsy is the most appropriate initial step to directly visualize and obtain tissue from a palpable rectal mass for histologic diagnosis.
PANCE Gastrointestinal 5
A 55-year-old with long-standing GERD undergoes endoscopy showing replacement of squamous epithelium with columnar epithelium in the distal esophagus.
What is the most serious concern with this finding?