The resected specimen and microscopic findings. (A) The resected specimen contained a polypoid tumor at the hepaticojejunostomy (arrow). (B, C) Microscopic findings showed well-differentiated adenocarcinoma with mucinous carcinoma similar to the primary and secondary cancers. The polypoid tumor grew from the submucosal layer of the bile duct (dotted arrow), in which many dilated lymphatic vessels with tumor invasion were observed. Intraepithelial spread of tumor cells was evident in neither the bile duct nor the jejunum ((B) H&E, original magnification; (C) H&E, high magnification).