SARCOMATOID VARIANT OF CHROMOPHOBE RENAL- CELL CARCINOMA - 2 CASES

In this paper, we report two cases of sarcomatoid carcinoma arising in chromophobe carcinoma. The sarcomatoid component appeared as white, s hiny areas, occupying less than 10 % of each tumor and containing nume rous mitotic figures. Whereas both components expressed cytokeratin, o nly the carcinomatous cells were positive for epithelial membrane anti gen and only the sarcomatoid cells were found to express vimentine. Sa rcomatoid transformation in chromophobe cell carcinoma has been report ed exceptionally. Ail aggressive behavior may be expected. The variabl e proportion of sarcomatoid component may lead to multiplication of th e samples, especially when white, firm and shiny areas are detected on gross findings.