Abstract
The patient was a 68-year-old man who had undergone surgery for ascending colon cancer 4 years 6 months ago. He was admitted to our hospital for an ache in the right hypochondrium. Abdominal CT revealed a late enhanced 40-mm tumor in the medial segment (S4) of the liver, accompanied by infiltration into the left hepatic duct. Low-density nodular scattering was also confirmed in the left lobe of the liver. Based on a diagnosis of cholangiocellular carcinoma, we conducted an extended left hepatic lobectomy with extrahepatic bile duct resection. Histopathologically, the liver tumor was a moderately differentiated adenocarcinoma, and the multiple small nodules in the left lobe of the liver consisted of infiltrating inflammatory cells and fibrosis. Additional immunohistological study revealed that the tumor was CK7 negative and CK20 positive, and contrary findings were noted in the normal bile duct. Therefore, we diagnosed this case as liver metastasis from colon cancer. Because liver metastasis from colorectal cancer rarely invades the intrahepatic biliary tracts or vessels, its differentiation from cholangiocellular carcinoma should be made with caution.
