Poorly Vascularized Malignant Insulinoma Displaced the Pancreatic Ducts around the Mass on Endoscopic Retrograde Cholangiopancreatography

A 66-year-old woman with an altered mental status caused by hypoglycemia was referred to Akita City Hospital. Abdominal ultrasonography (US) and endoscopic US revealed an isoechoic mass measuring 25 mm in the head of the pancreas. Endoscopic retrograde Cholangiopancreatography (ERCP) revealed that the main pancreatic duct and its branches were displaced around the mass in the head of the pancreas. On arteriography, a poorly vascularized tumor was observed. Dynamic contrast-enhanced computed tomography (CT) showed a low-attenuation mass in the head of the pancreas. A pylorus-preserving pancreaticoduodenectomy was performed. Microscopically, the diagnosis was malignant insulinoma. (Internal Medicine 40: 28-31, 2001)