A case of small combined hepatocellular-cholangiocellular carcinoma

A 56-year-old man who had been visiting our hospital for type B cirrhosis since 1988 was admitted for the treatment of hepatic tumor that was detected using an EOB-MRI study in July 2017. Blood test showed elevated aminotransferase and thrombocytopenia due to liver cirrhosis; however, tumor markers were negative. In CT during angiography, CTAP showed low absorption, and CTHA showed heterogeneously high absorption. We diagnosed the tumor as hepatocellular carcinoma, followed by a laparoscopic partial resection of the liver. In 16 months after surgery, there was no recurrence. As per the pathological findings, the tumor consisted of (1) well-differentiated hepatocellular carcinoma component, (2) moderately-differentiated hepatocellular carcinoma component, (3) transitional portion between hepatocellular carcinoma and intrahepatic cholangiocarcinoma, and (4) intrahepatic cholangiocarcinoma component. Thus, the tumor was diagnosed as classical type combined hepatocellular-cholangiocellular carcinoma as per the WHO classification. It was suggested that dedifferentiation and transformation occurred in the untreated small hepatocellular carcinoma.