SELECTED CASES Case 1 A 45-YEAR-OLD woman with a threeyear history of epigastric pain was treated initially with cimetidine and then with ranitidine hydrochloride and antacids, with only mild relief. Her fasting serum gastrin level was elevated at 496 ng/L (496 pg/mL) (normal, 200 pg/mL]). Ultrasound, computed tomographic (CT) scan, and selective angiogram all failed to demonstrate a gastrinoma. Selective venous sampling was performed and a marked step-up in gastrin levels was found in the superior pancreaticoduodenal vein (Fig 1). The patient underwent an exploratory laparotomy, and intraoperative ultrasound demonstrated a lesion in the posterior head of the pancreas (Fig 2). After enucleation,