Snapshot A 42-year-old male executive complains of upper abdominal pain. He says he is under considerable stress at work and smokes a pack of cigarettes daily. He has no history of shortness of breath, swelling of the feet, chest pain, or allergies. Further history reveals that the pain is worse at night and often wakens him from sleep. It occurs between meals and is subsided by drinking milk and avoiding spicy foods. On 1 occasion he vomited blood. Testing reveals serum gastrin level of 1000 pg/ml (normal < 300 pg/ml). Introduction Clinical definition syndrome characterized by the secretion of gastrin by duodenal or pancreatic neuroendocrine tumors (gastrinomas) Epidemiology demographics annual incidence is 0.5-2 per million high incidence in men compared to women only 25% of gastrinomas arise in the pancreas with the majority occurring in the duodenum Pathogenesis excessive gastrin secretion from gastrinoma leads to high gastric acid output gastrin has trophic action on gastric parietal cells and histamine-secreting enterochromaffin-like cells high gastric acid secreting overwhelms the neutralizing capacity of pancreatic bicarbonate secretion, resulting in low pH of intestinal contents the low pH inactivates pancreatic digestive enzymes and thus interferes with the emulsification of fat by bile acids results in maldigestion and malabsorption high serum gastrin concentrations inhibit the absorption of sodium and water by the small intestine Associated conditions multiple endocrine neoplasia type 1 (MEN1) Presentation Symptoms peptic ulcer disease heartburn weight loss diarrhea Physical exam abdominal tenderness Imaging Upper endoscopy Contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) Somatostatin receptor scintigraphy Endoscopic ultrasound usually indicated prior to surgical resection as it has greater sensitivity in detecting small tumors Studies Fasting serum gastrin concentration and gastric pH best initial test serum gastrin value > 10 times the upper limit of normal (> 1000 pg/mL) in the presence of gastric pH < 2 is diagnostic Secretin stimulation test indicated in patients with elevated gastrin/low gastrin pH that do not meet the diagnostic criteria differentiates gastrinomas from other causes of hypergastrinemia (e.g., antral G-cell hyperplasia) patients with gastrinomas will have a dramatic rise in serum gastrin following secretin stimulation (normal gastric G cells are inhibited by secretin) Calcium infusion study indicated in patients with strong clinical suspicion despite a negative secretin stimulation test MEN1 evaluation serum parathormone levels ionized calcium levels prolactin levels Differential Antral G-cell hyperplasia distinguishing factors poor response to secretin stimulation ltest absence of gastrinoma on imaging Treatment First-line medical management with proton pump inhibitors (e.g., omeprazole) and H2-receptor anatagonists (e.g., ranitidine) surgical resection eliminates need for antisecretory medical therapy and protects against the morbidity and mortality of metastasis Second-line octreotide (rarely required) reoperation indicated in patients with intractable symptoms who fails dietary and medical therapy Complications Stricture Perforation Metastatic gastrinoma liver is the most common site most common cause of morbidity and mortality
QUESTIONS 1 of 4 1 2 3 4 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.GI.13.25) A 41-year-old female complains of frequent diarrhea and abdominal pain between meals. Endoscopy reveals a duodenal ulcer distal to the duodenal bulb. CT scan of the abdomen demonstrates a pancreatic mass, and subsequent tissue biopsy of the pancreas reveals a malignant islet cell tumor. Which of the following hormones is likely to be markedly elevated in this patient: QID: 101082 Type & Select Correct Answer 1 Gastrin 59% (56/95) 2 Cholecystokinin 5% (5/95) 3 Secretin 11% (10/95) 4 Vasoactive intestinal peptide 20% (19/95) 5 Motilin 1% (1/95) M 1 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic (M1.GI.13.174) A 45-year-old male patient with a history of recurrent nephrolithiasis and chronic lower back pain presents to the ER with severe, sudden-onset, upper abdominal pain. The patient is febrile, hypotensive, and tachycardic, and is rushed to the OR for exploratory laporotomy. Surgery reveals that the patient has a perforated gastric ulcer. Despite appropriate therapy, the patient expires, and subsequent autopsy reveals multiple ulcers in the stomach, duodenum, and jejunum. The patient had been complaining of abdominal pain and diarrhea for several months but had only been taking ibuprofen for his lower back pain for the past 3 weeks. What is the most likely cause of the patient's presentation? QID: 101231 Type & Select Correct Answer 1 A gastrin-secreting tumor of the pancreas 58% (61/106) 2 A vasoactive-intestinal-peptide (VIP) secreting tumor of the pancreas 6% (6/106) 3 Cytomegalovirus infection 1% (1/106) 4 H. pylori infection 17% (18/106) 5 Chronic NSAID use 19% (20/106) M 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic