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 login to view 1 more bullet Epidemiology login to view 4 more bullets Pathogenesis login to view 6 more bullets Associated conditions login to view 1 more bullet Presentation Symptoms login to view 4 more bullets Physical exam login to view 1 more bullet Imaging Upper endoscopy Contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) Somatostatin receptor scintigraphy Endoscopic ultrasound login to view 1 more bullet Studies Fasting serum gastrin concentration and gastric pH login to view 2 more bullets Secretin stimulation test login to view 3 more bullets Calcium infusion study login to view 1 more bullet MEN1 evaluation login to view 3 more bullets Differential Antral G-cell hyperplasia login to view 3 more bullets Treatment First-line login to view 3 more bullets Second-line login to view 3 more bullets Complications Stricture Perforation Metastatic gastrinoma login to view 2 more bullets