The importance of recognising renal oncocytomas

Oncocytomas of the kidney are infrequently reported tumours. They have distinct clinical and pathological features, but most cases have been discovered retrospectively. Nine series have been analysed (including four cases in Norwich) to define the features of these tumours. One of our cases is noteworthy because it is the largest individually reported tumour of this type and it contained a large cyst. Oncocytomas are benign and have an excellent prognosis. Failure to identify this subgroup may bias the perceived effectiveness of treatment for renal carcinoma.