Abstract

We report 13 chromophobe renal cell carcinomas (10.8%) observed among 120 renal cell carcinomas in adults. The average age was 53 (range: 34-72) years old, and 6 were males and 7 females. The mean tumor size was 10 (range: 5-17) cm, mean nuclear grade 2.4, and mean Robson's stage was 1.9. There were two distinct histologic variants; typical variant (n=9) and eosinophilic variant (n=4). Both of them showed typical light microscopic features and positive reaction with Hale's colloidal iron and carbonic anhydrase II, a marker protein of intercalated cells of renal collecting ducts. A strong positive immunoreactivity for epithelial membrane antigen was noted in the cytoplasm in 12 of 13 tumors. Numerous microvesicles, 180~440 nm in diameter, were identified ultrastructurally. DNA aneuploidy was found in 3 out of 10 cases. Neither local recurrence nor metastasis have been identified during the following period of 4~144 (mean 48) months.

• Keywords: Chromophobe cell renal cell carcinoma;Typical variant;Eosinophilic variant;Hale's colloidal iron;Carbonic anhydrase II;Microvesicle