Hemobilia due to biliary intraepithelial neoplasia associated with Zollinger–Ellison syndrome

A 58-year-old man was transferred to us from his local hospital because of failure to control his gastrointestinal bleeding by endoscopic hemostasis. Abdominal imaging suggested a hypervascular tumor of the pancreatic head (36 mm diameter), and laboratory testing showed an elevated serum gastrin level (17,800 pg/mL). Gastroduodenal endoscopy revealed multiple duodenal ulcers and active bleeding from the ampulla of Vater. The selective arterial secretagogue injection test suggested a gastrinoma in the pancreatic head, but no gastrinoma in the pancreatic tail. The patient was diagnosed with solitary pancreatic head gastrinoma complicated by hemosuccus pancreaticus, and pancreaticoduodenectomy was performed. Intraoperatively, the diagnosis was changed to primary peripancreatic lymph node gastrinoma without pancreatic involvement. The gastrointestinal bleeding stopped postoperatively and serum gastrin levels returned to normal. Histological examination of the surgical specimens revealed a small submucosal gastrinoma in the duodenum (7 mm diameter). The final diagnosis was microgastrinoma of the duodenum with peripancreatic lymph node metastasis. The cause of bleeding from the ampulla of Vater was initially obscure, but eventually a hemorrhagic erosion with moderate atypia was found in the common bile duct, indicating biliary intraepithelial neoplasia (BilIN). This is the first report of hemobilia due to BilIN with gastrinoma.