skip to main content

Gastrinoma — ESEGH MCQ

Instant feedback + full explanation. One question, done properly.

HardLuminal GIGastrinomaESEGH

A 59-year-old man has recurrent peptic ulceration despite high-dose proton pump inhibitor therapy, watery diarrhoea and weight loss. Endoscopy shows multiple ulcers in the second and third parts of the duodenum. Under specialist supervision, acid-suppressing treatment is safely interrupted for biochemical assessment. On two occasions, fasting serum gastrin is 1480 ng/L (upper reference limit 100 ng/L), with a simultaneous gastric aspirate pH of 1.4. Gastric biopsies show preserved oxyntic glands without atrophy, and renal function is normal. What is the most likely diagnosis?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: C — Gastrinoma

This is a gastrinoma producing Zollinger–Ellison syndrome. The decisive combination is marked fasting hypergastrinaemia with continuing gastric acid secretion (pH 1.4), together with refractory, multiple post-bulbar duodenal ulcers and diarrhoea. Excess acid causes both the ulceration and diarrhoea, partly through acid-mediated inactivation of pancreatic enzymes and mucosal injury. Autoimmune atrophic gastritis causes hypergastrinaemia because of achlorhydria, so gastric pH would be high and oxyntic atrophy would be present. PPI-associated hypergastrinaemia likewise occurs with pharmacological acid suppression and is excluded by supervised interruption and the low pH. Antral G-cell hyperplasia is a much less likely explanation for this marked biochemical and clinical syndrome. Normal renal function excludes impaired gastrin clearance from chronic kidney disease.

Reference: British Society of Gastroenterology. Andreyev J, et al. British Society of Gastroenterology practice guidance on the management of acute and chronic gastrointestinal symptoms and complications as a result of treatment for cancer. Table 7: Functioning neuroendocrine tumours and their syndromes affecting the GI tract. 2025. https://www.bsg.org.uk/getmedia/a1740ab6-2987-4fd5-ba3b-96612d6e66c5/gutjnl-2024-333812.pdf