Mixed adenoneuroendocrine carcinoma in the stomach: a case report with a literature review.

Mixed adenoneuroendocrine carcinoma (MANEC) is a rare disease that was first defined in the 2010 World Health Organization classification of endocrine tumors. We present the case of a 65-year-old man with an ulcerative depressed lesion measuring 3 cm in diameter and found in the lower gastric body. It was diagnosed as a MANEC, and we performed subtotal gastrectomy with D2 lymph node dissection. The patient is still alive, and no recurrence was observed at a 12-month follow-up. Most MANECs tend to have a poor prognosis. Curative resection, including an adequate lymph node dissection, should be considered, and intense follow-up is needed.