RESUMO
Liver metastases from colorectal carcinoma commonly form nodular lesions in the liver parenchyma. We report a case of liver metastasis from rectal adenocarcinoma that extended predominantly into the bile duct. A 62-year-old Japanese man underwent low anterior resection for rectal adenocarcinoma 9 years ago. Approximately 3 years later, he underwent radiofrequency ablation therapy for a metastatic liver tumor. Nine years after surgery, a tumor in liver segment III exhibiting intrabiliary extension was discovered; it was unclear if this was a metastatic liver tumor or intrahepatic cholangiocarcinoma. Accordingly, we performed a left hepatectomy with lymph node dissection. The tumor was negative for cytokeratins 7 and 20, and was histologically similar to the primary rectal adenocarcinoma; it was diagnosed as rectal carcinoma metastasis. The patient has survived for 3 years after the hepatic surgery, for 9 years after radiofrequency ablation therapy, and for 12 years after the primary surgery. This case shows that liver metastasis from colorectal carcinoma can present as a predominantly intrabiliary growth that mimics intrahepatic cholangiocarcinoma on imaging. Moreover, our case provides evidence for the superiority of anatomical hepatectomy over partial hepatectomy for metastatic liver tumors with intrabiliary growth arising from rectal adenocarcinomas.