Sarcomatoid hepatocellular-carcinoma showing rhabdomyoblastic differentiation in the adult cirrhotic liver

An unusual case of a massive liver tumour composed of rhabdomyosarcoma with a small focus of hepatocellular carcinoma in a 52-year-old man is presente d. He had hepatitis B virus (HBV) surface antigen in his serum, Macroscopic ally, a large tumour with satellite nodules occupied the right lobe of the cirrhotic liver. Microscopically, the rumours were composed of small and sh ort spindle-shaped undifferentiated cells, mixed with desmin-positive round rhabdomyoblasts and elongated striated muscle cells, strongly, suggestive of rhabdomyosarcoma of the liver. Elevated levels of alpha-fetoprotein in t he serum led us to examine the liver tumour closely in multiple sections, w hich disclosed a hepatocellular carcinoma component measuring 2 cm in diame ter within the massive tumour. Immunohistochemically, the hepatocellular ca rcinoma cells were alpha-fetoprotein positive. There was neither a tumour c apsule, nor distinct demarcation, and cytokeratin-positive clusters of undi fferentiated cells were intermingled with the hepatocellular carcinoma and rhabdomyosarcoma at the border. The invading tumour outside the liver and m etastatic tumours were pure rhabdomyosarcomas. It is suggested that the pre sent case should be diagnosed as rhabdomyosarcoma transformed from hepatoce llular carcinoma.