Snap Shot A 42-year-old male executive complains of upper abdominal pain. He say he is under considerable stress at work and smokes a pack of cigarettes every day. He has no history of SOB, 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 appeased by drinking milk and eating a bland diet. On one occasion he vomited blood. Testing reveals a basal acid output (BA)) of 60 mEq (normal is <5 mEq and a serum gastrin level of 1000 pg/ml (normal is <300 pg/ml). Introduction Caused by a malignant islet cell tumor that secretes excessive amounts of gastrin causes excessive secretion of acid results in peptic ulcer disease Presentation Symptoms similar to PUD diarrhea because the acidity in the duodenum inactivates pancreatic enzymes Evaluation Basal Acid Output test Secretin stimulation test normal gastric G-cells are inhibited by secretin secretin stimulates release of gastrin from gastrinoma cells positive test result is an increase in gastrin concentration Elevated insulin glucagon gastrin ( >1000 pg/mL) Differential GERD, CAD, gastritis, pancreatitis, cholecystitis, aortic aneurysm, and other causes of an acute abdomen Treatment Immediate treatment with proton blockers Surgical resection of the tumor