OBJECTIVESTo investigate the diagnosis, therapy and prognosis of renal oncocytoma.

METHODSThe data of 26 patients of renal oncocytoma in the department of urology of the Peking University First Hospital from 1999 to 2010 were collected. Retrospective analysis of renal oncocytoma clinical characteristics of patients including pathological characteristics and long term follow-up, treatment methods, and prognosis was undergone.

RESULTSThe mean age of these patients was (55 ± 14) years, mean tumor size was (4.1 ± 1.3) cm, corresponding to a mean tumor volume of (24.0 ± 21.1) cm(3). All of these cases were unilocular unilateral. All of these 26 patients received surgical treatment, 5 cases accepted partial nephrectomy while the other cases accepted radical nephrectomy. After a median follow-up time was (47 ± 34) months (range 4 - 144 months) for 25 patients who had been followed up, there was no disease recurrence, progression or death attributed to oncocytoma.

CONCLUSIONSRenal oncocytoma is an uncommon tumor. It exhibits numerous features which are characteristic but not necessarily unique.Preoperative renal mass biopsy is the only way for pre-nephrectomy histologic diagnosis of oncocytoma.