AN AUTOPSY CASE OF HEPATIC SARCOMATOID TUMOR - IMMUNOHISTOCHEMICAL COMPARISON WITH A SARCOMATOUS COMPONENT OF HEPATOCELLULAR-CARCINOMA

A case of primary hepatic tumor exclusively composed of malignant cell s with sarcomatous features is described and compared immunohistochemi cally with two cases of hepatocellular carcinoma (HCC) with a sarcomat ous component. More than 30% of HCC cells were positively stained with anti-cytokeratin (CAM5.2), anti-albumin, anti-fibrinogen and anti-alp ha(1)-antitrypsin antibodies, and some with anti-epithelial membrane a ntigen. The present sarcomatoid tumor and the sarcomatous component wi th HCC showed similar immuno-histochemistry; many tumor cells were str ongly immunoreactive for vimentin and some positive for cytokeratin, a lbumin, fibrinogen and alpha(1)-antitrypsin. Other immunohistochemical markers, indicating specific differentiations to lineage of macrophag es, muscle cells, glial cells, endothelial cells and so forth, were no t detected in sarcomatous tumor cells of all cases. These findings sug gest that the present sarcomatoid tumor would belong to an anaplastic sarcomatous variant of HCC.