A Resected Case of Endocrine Tumor of the Pancreas with Difficulty in Diagnosis

A 67-year-old woman seen locally for hypertension and diabetes mellitus was referred due to a worsening blood sugar. Abdominal ultrasonography (US) showed an obstruction of the main pancreatic duct and dilatation of the distal pancreatic duct. Serum elastase-1 rose to 900ng/dl. Abdominal US showed a SOL in the pancreatic body 10mm in diameter. Magnetic resonance cholangio-pancreatography (MRCP) showed an obstruction of the main pancreatic duct and dilation of the distal pancreatic duct. Endoscopic retrograde cholangiopancreatography (ERCP) showed an obstruction of the main pancreatic duct. Abdominal computed tomography (CT) did not show any lesions. No other gastrointestinal tract examinations showed abdominal lesions. The preoperative diagnosis was pancreatic ductal carcinoma. In February 2005, we performed a distal pancreatectomy. The histological findings of a pancreatic tumor showed nodular and alveolar proliferation of oval cells and that stained for chromogranin. Other immunohistochemical examinations showed that tumor cells stained only serotonin. The definitive diagnosis based on histopathological analysis was endocrine tumor of the pancreas.