Intrabile duct metastasis from colonic adenocarcinoma without liver parenchyma involvement: contrast enhanced ultrasonography detection.

It is well-known that biliary duct invasion with intraluminal growth is one of the developmental patterns of primary liver tumors, and macroscopic intrabiliary growth of liver metastases in colorectal cancer is found with high frequency. Surgical treatment is the only potential curative therapy. However, many patients die of intrahepatic and/or extrahepatic recurrence after the resection. One of the causes of high recurrence rate after resective surgery, particularly surgical margin recurrences, is the invasion of biliary ducts mainly due to intraluminal tumor growth. We describe the first recorded case of a metastasis from colorectal cancer involving solely the common hepatic biliary duct, without invasion of contiguous liver parenchyma. A correct diagnosis was obtained by means of contrast enhanced ultrasound and ultrasound-guided fine needle aspiration biopsy.