Colorectal liver metastasis with bile duct tumor thrombus discovered 15 years post primary tumor resection: a case report and literature review

Colorectal liver metastasis (CRLM) appears in 25–50% of patients with colorectal cancer (CRC). However, CRLM with bile duct tumor thrombus (BDTT) is rare and often diagnosed after surgical resection. We report a case of CRLM associated with BDTT in a 79 year-old woman. She underwent sigmoid colectomy for sigmoid colon carcinoma at the age of 64. Fifteen years later, abdominal computed tomography revealed a liver tumor with a biliary tumor thrombus in segment IV/V and localized dilation of the intrahepatic bile duct. Additionally, magnetic resonance imaging confirmed a tumor in liver segment IV/V and mass in the bile duct (B4). Extended left hepatic lobectomy was performed under the diagnosis of intrahepatic cholangiocarcinoma or metastatic liver tumor with tumor development in the intrahepatic bile duct. The resected specimen showed significant cancer infiltration into the intrahepatic bile duct (B4), forming a tumor thrombus. The tumor was a moderately differentiated adenocarcinoma, histologically similar to sigmoid colon cancer. CRLM with BDTT may have a relatively low invasive potential of malignancy with a long interval after primary resection. When a patient with a history of CRC presents with BDTT, the possibility of CRLM with BDTT and surgical treatment should be considered, because resection could lead to a good prognosis. It is important to ensure a secure surgical margin in the bile ducts during surgery and anatomical hepatic resection should be considered.