Incidentally discovered solid renal masses: what are they?

In 36 of 99 consecutive patients operated on for the presumptive diagnosis of renal carcinoma the tumour was discovered accidentally during investigations for a variety of complaints. CT and ultrasound scans were responsible for discovery of the tumour in 24 of the 36 patients. Renal carcinoma accounted for 92% of incidentally discovered solid renal masses. Of 33 incidentally diagnosed renal carcinomas 27 were stage 1. An incidentally discovered solid renal mass should be regarded as a low stage renal carcinoma until proven otherwise.