Metastatic colon cancer from intrahepatic cholangiocarcinoma.

A 62-year-old man had been followed because of an elevated serum level of carcinoembryonic antigen without the detection of any cancer lesions. However, there was a sudden increase in the serum level of carcinoembryonic antigen, and abdominal imagings showed a hepatic tumor with peripheral intrahepatic bile duct dilatation, and a submucosal tumor at the sigmoid colon with intact mucosa. Histopathological findings showed that the hepatic tumor had perineural invasion, suggesting an intrahepatic cholangiocarcinoma, and that the colon tumor infiltrated the submucosa, while its mucosa was intact. Both tumors showed similar pathological features and were positive for cytokeratin 20 and 7. These findings suggested intrahepatic cholangiocarcinoma with metastatic sigmoid colon cancer.