A Case of Bile Duct Metastasis from Colorectal Cancer

Abstract

A 73-year-old man previously underwent laparoscopic colon resection for cancer of the ascending colon. Four years later, contrast-enhanced computed tomography showed a low-density mass in segment 3, and endoscopic retrograde cholangiography revealed a translucency in the peripheral intrahepatic bile duct. Cytological examination suggested malignancy and left hepatectomy was performed, with a diagnosis of intraductal papillary neoplasm of the bile duct. The initial postoperative pathological diagnosis was an invasive intraductal papillary tumor in the bile duct. However, subsequent immunohistochemical staining confirmed the diagnosis of bile duct metastasis from colorectal cancer. The patient is currently being followed up as an outpatient, with no recurrence after 7 months. Bile duct metastasis of colorectal cancer is rare and challenging to differentiate from biliary tract tumors on imaging. This metastatic condition is known for its slow growth and relatively good prognosis. We present a case of bile duct metastasis from colorectal cancer mimicking a biliary tract tumor.