A Small Pancreatic Neuroendocrine Tumor with Marked Pancreatic Duct Dilatation and Parenchymal Atrophy

Abstract

Pancreatic ductal adenocarcinomas often cause marked pancreatic duct dilatation and associated parenchymal atrophy. We present the case of a small pancreatic neuroendocrine tumor with upstream pancreatic duct dilatation and severe parenchymal atrophy. A small enhancing tumor was observed at the head of the pancreas on computed tomography (CT). Endoscopic ultrasonographyguided fine-needle aspiration was negative for malignancy. We performed a pylorus-preserving pancreatoduodenectomy since we could not exclude the presence of pancreatic ductal adenocarcinoma. The pathological and immunohistochemical examination revealed a serotonin-positive neuroendocrine tumor, measured 1.0 × 0.5 cm. The pathological specimen was remarkable for the marked stromal fibrosis in the area of the tumor, which resulted in narrowing of the main pancreatic duct. Here, we report a rare small pancreatic neuroendocrine tumor, the CT image of which resembled that of pancreatic ductal adenocarcinoma, in which the expression of serotonin and associated fibrosis might be a possible mechanism for the marked main pancreatic duct dilatation. (Korean J Med 2014;86:598-602)