Prognostic implications of histological features in patients with chromophobe cell renal carcinoma

Objective To assess the relationship between the histological features of renal chromophobe cell carcinoma (CCC) and clinical outcome in patients with renal cell carcinoma. Patients and methods From 1957 to 1996, 41 patients with CCC of the kidney (4.9% of all kidney carcinomas) were treated at our university hospitals. Of these histologically defined cases, four who died from other types of cancer and two who were lost to follow-up were excluded, leaving 35 patients in the study; the carcinoma was classified as the typical variant in 26 and the eosinophilic variant in nine. Based on the differences of the variants, the histological features affecting prognosis were analysed. Results The overall survival rates at 1, 3, 5, 10, 15 and 20 years were 97%, 82%, 82%, 70%, 62% and 47%, respectively. The prognosis was more favourable in those with the eosinophilic than for the typical variant (there were no cancer-related deaths in the former). Of those with the typical variant, five died within 2 years of surgery; of these, three with high-stage disease had various degrees of sarcomatoid change. Conversely, two patients had a recurrence > 10 years after surgery (late recurrence). Both these patients and the others who later died from cancer had no sarcomatoid change in the tumour areas examined. Conclusion The eosinophilic variant of CCC has a better prognosis; on the contrary, during long-term surveillance, early recurrence was detected especially in those with sarcomatoid change and late recurrence only in two typical variant. These prognostic implications of the histological differences are important for understanding the outcome of renal CCC.