[A Case of Mixed Adenoneuroendocrine Carcinoma(MANEC)of the Duodenum].

A 79-year-old man was admitted to our hospital because of a positive fecal occult blood test. Gastrointestinal endoscopy revealed a tumor in the duodenal bulb. Histologically, biopsy specimens indicated adenocarcinoma. The patient underwent distal gastrectomy. Histopathological examination showed a neuroendocrine carcinoma with an adenocarcinoma. According to the 2010WHO Classification of Tumours of the Digestive System, this case was diagnosed as mixed adenoneuroendocrine carcinoma(MANEC). There was no metastatic lesion in the resected lymph node. The patient has been followed up for 2 years without evidence of recurrence. We report a rare case of MANEC in the duodenum.