CHROMOPHOBE RENAL-CELL CARCINOMA - A REPORT OF 2 CASES

Chromophobe renal cell carcinoma (RCC) is a recently established subty pe of RCC, which has rarely been reported in Japan. In this communicat ion, the authors report two Japanese cases of chromophobe RCC together with the immunohistochemical findings. The tumors were composed of sh eets and cribriform glands formed by tumor cells with cloudy and retic ular cytoplasm. Ultrastructurally, the cytoplasm was filled with numer ous microvesicles. The tumor cells were positive for cytokeratin, epit helial membrane antigen, and Tamm-Horsfall protein. Occasionally, LeuM 1-positive cells were also noted. Vimentin was negative, unlike the us ual RCC. Reactivity for peanut agglutinin was more frequent than that to Lotus tetragonolobus agglutinin. The results of this study suggest that the tumor cells possessed phenotypes similar to the distal nephro n rather than to the proximal tubular cells.