A Case of Mixed Adenoneuroendocrine Carcinoma of the Duodenum

Abstract

A 64-year-old man with weight loss and worsening of diabetes was performed upper gastrointestinal endoscopy elsewhere and was referred to our hospital with a diagnosis of carcinoma of the ampulla of Vater. Subtotal stomach-preserving pancreatoduodenectomy with regional lymph node dissection was performed with the preoperative diagnosis of carcinoma of the papilla of Vater. A type 2 ulcerated tumor was present in the second portion of the duodenum around the papilla of Vater. The structure of the papilla was kept intact. Pathological examination showed neuroendocrine carcinoma (NEC) with well to moderately differentiated adenocarcinoma. The papilla of Vater was surrounded by these two components, but no cancer cell invasion was detected in the papilla itself. This case was finally diagnosed as mixed adenoneuroendocrine carcinoma (MANEC) of the duodenum.

In accordance with the 2010 World Health Organization (WHO) classification, neoplasms in which each adenocarcinoma and neuroendocrine carcinoma (NEC) component represents at least 30% of the lesion are defined as MANEC. A few cases of MANEC have been reported in recent years. Here we report a case of MANEC arising from the duodenum with some literature review.