Six chromophobe cell carcinomas and one mixed renal cell carcinoma with chromophobe cell features: Clinical and pathological implications

Objective: To determine the incidence and clinical and pathological features of chromophobe cell carcinoma (CCC) among renal cell carcinomas (RCCs). Materials and methods: The records and nephrectomy samples from 166 patients who were operated on and followed up thereafter with a diagnosis of RCC were re-evaluated. New sections were cut and specific staining performed when deemed necessary. Results: Of 166 patients with RCC, six were diagnosed as having CCC and, unusually, one patient had a mixed RCC with areas of CCC. Neither the symptoms nor radiological features of these seven patients differed from those of the patients with RCC; the serum ferritin levels of these seven patients were also within the normal range. These patients appeared to have a favourable clinical course. Conclusion: Chromophobe cell carcinoma is a distinct entity and must be distinguished particularly from oncocytoma and other variants of RCC. Although it seems to have a low malignant potential, metastatic CCC may have a worse prognosis.