Chromophobe renal cell carcinoma: clinicopathological study of 7 cases.

Chromophobe renal cell carcinoma (CRCC) may be grossly and microscopically confused with oncocytoma. It is now believed that many, if not all, of the so-called malignant oncocytomas or oncocytomas with metastases reported in the literature were indeed chromophobe renal cell carcinomas. CRCC is characteristically positive for colloidal iron and shows cytoplasmic microvesicles in electron microscopy. This study of CRCC is thought to be the first one done in Latin America. Of a total of 106 renal epithelial neoplasms, 7 (6.6%) fulfilled the criteria for chromophobe renal cell carcinoma. This frequency in Brazil is similar to that in other parts of the world. There was no difference in age, sex, and race distribution of CRCC compared to usual renal epithelial tumors. Grossly, the CRCC ranged in size from 3.5 to 20 cm (average: 10.2 cm) in greatest dimension. Most frequently, the tumor was brown on the cut surface. The growth pattern showed compact areas in all tumors and, in most of the cases, both clear and ...