Rectal carcinoma with metachronous metastasis to the extrahepatic bile duct without liver tumor

In July 2003, a 63-year-old man received a low anterior resection for rectal cancer. In February 2006, he underwent a right hepatectomy for a solitary metastatic liver tumor; the liver tumor had not invaded the bile duct, and a curative resection was performed. In August 2008, an enhanced computed tomography examination revealed a massive focal lesion at the point of the common bile duct. Endoscopic ultrasonography clearly revealed a hyperechoic polypoid lesion that had spread laterally on the surface of the slightly dilated bile duct and had a smooth outer hyperechoic layer. No lymph nodes were present in this region. Endoscopic retrograde cholangiopancreatography revealed an irregular stricture, and a biopsy was performed through the scope. Microscopic examination revealed a tumor characterized as a moderately differentiated adenocarcinoma resembling the liver tumor. We diagnosed the intrabiliary tumor as a metachronous metastatic bile duct tumor from rectal cancer without involvement of the liver parenchyma. This is a very rare case, with recurrence only in an extrahepatic bile duct after the complete resection of a metastatic liver tumor. This is the first clinical, pathological, and radiological description of this rare condition.