[A Case of Mixed Adenoneuroendocrine Carcinoma of the Distal Bile Duct].

We diagnosed distal cholangiocarcinoma in a 76-year-old woman who was then treated by subtotal stomach-preserving pancreaticoduodenectomy. Histopathological examination revealed a well-differentiated tubular adenocarcinoma on the side of the bile duct, and a neuroendocrine carcinoma in an area outside the bile duct where the tumor had infiltrated. Immunohistochemical staining identified homology between cytokeratins and MUC, indicating a similar origin. This report discusses problems associated with diagnosis and treatment by summarizing 22 patients who underwent curative resection and subsequently had a confirmed prognosis.