Mixed Neuroendocrine Non-Neuroendocrine Neoplasm of the Ampulla of Vater: Report of a Rare Location.

Abstract

Background: Mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) are rare tumors of the gastrointestinal tract with neuroendocrine and non-neuroendocrine components. Ampullary MiNENs are extremely rare, with few cases reported to date.

Case report: A 41-year-old male was diagnosed incidentally with a dilated common bile duct and intrahepatic biliary radicles while being evaluated for right ureteric calculi. Contrast-enhanced computed tomography scan of the abdomen showed a mass in the ampullary region with a positive double duct sign. Side-viewing endoscopy indicated an ampullary growth, and biopsy confirmed adenocarcinoma. The patient underwent total robotic pancreatoduodenectomy with an uneventful postoperative course. His final histopathologic examination revealed a tumor with 2 components, each of which accounted for at least 30% of the tumor: a neuroendocrine tumor and an adenocarcinoma with signet ring cells. The patient received adjuvant chemotherapy and at 1-year follow-up showed no evidence of recurrence.

Conclusion: Ampullary MiNENs are rare composite gastroenteropancreatic tumors characterized by histologic heterogeneity; they can be effectively treated with robotic pancreatoduodenectomy. The more aggressive component of the MiNEN should be considered when determining an adjuvant therapy.