Immunohistochemical detection of Fas and Fas ligand in sarcomatoid renal cell carcinoma

Sarcomatoid renal cell carcinomas (SRC) are rare neoplasms associated with a very poor prognosis. The aim of this study was to evaluate biomarker expr ession and clinical significance in this uncommon renal cancer. Cytokeratin , epithelial membrane antigen, vimentin, desmin, smooth muscle actin, CD34, S-100 protein, MIB 1, p53, Fas and Fas ligand immunohistochemical expressi on was investigated in seven renal cell carcinomas with sarcomatoid changes . No significant difference between sarcomatoid and nonsarcomatoid areas wa s observed with the different biomarkers, excepted for Fas ligand. Fas expr ession was diffuse in sarcomatoid and nonsarcomatoid areas. However, Fas li gand had a higher expression in sarcomatoid in comparison to nonsarcomatoid areas. Our results showed that Fas and Fas ligand are both expressed in re nal cancer. We suggest that the aggressive behavior of sarcomatoid carcinom a may be related to a higher expression of Fas ligand by tumor sarcomatoid cells. These findings may indicate that Fas ligand is a possible therapeuti c molecular target for treatment of SRC.