A neuroendocrine tumor of the accessory papilla of vater

Abstract

We describe a case of a neuroendocrine tumor of the accessory papilla of Vater. A 37-year-old woman was admitted due to a tumor located in the duodenum which was found during a routine medical checkup. Duodenal endoscopy showed a slightly depressed submucosal tumor, measuring 10 mm. Computed tomography showed an enhanced tumor in the descending portion of the duodenum. Endoscopic ultrasonography revealed that the tumor invaded the muscularis propria. A pylorus-preserving pancreatoduodenectomy was done. On pathology, a diagnosis of a neuroendocrine tumor with a glandular pattern involving the accessory papilla of Vater was made ; reactivity to chromogranin A and somatostatin antibody was found on immunohistochemical analysis. The nuclear fission index was very low (<2%). The tumor was 7 mm in diameter and invaded to the muscularis propria layer. On microscopy, a lymph node metastasis was seen.