A Rare Type of Colorectal Cancer: Mixed Adeno-Neuroendocrine Carcinoma (MANEC).

The aim of this paper is to report the clinicopathological data of one case of mixed metastatic adenoneuroendocrine carcinoma (MANEC) in the caecum; less than ten cases of which have been described in the English literature. A 57-year-old male patient presented with a mixed adenoneuroendocrine carcinoma (MANEC) of the caecum with liver metastasis and peritoneal carcinomatosis. An emergency right hemicolectomy and omentectomy were performed, followed by several cycles of unsuccessful palliative chemotherapy. The metastasis developed further, and the patient died 10 months after presenting to the emergency room. MANECs are defined as containing at least 30% of both a neuroendocrine and an adenocarcinomatous component. The location of the tumour and the proportions and behaviour of its two components influence the treatment. However, chemotherapy guidelines remain poorly defined, and prognosis remains sombre, with median survival of less than one year.