Non-functioning pancreatic neuroendocrine tumor with stenosis of the main pancreatic duct

Abstract

A-65-year-old man with a mass in the body of the pancreas seen on ultrasonography was referred for further evaluation. Abdominal contrast-enhanced computed tomography scan revealed a 10mm enhancing lesion in the body of the pancreas along with stenosis of the main pancreatic duct stenosis near the lesion and caudal dilation. Although a pancreatic neuroendocrine tumor was suspected, we performed endoscopic ultrasonography-guided fine-needle aspiration because pancreatic ductal carcinoma could not be ruled out. Histopathological analysis revealed a PNET G1. Distal pancreatectomy was performed, and immunostaining was positive for chromogranin A, synaptophysin and serotonin. Fibrosis caused by serotonin was thought to be involved in the pathogenesis of the main pancreatic duct stenosis in this patient.