Objectives. To determine the proportion of renal cell carcinomas that are discovered serendipitously, and to compare the tumor stages of symptomatic versus incidental tumors.

Methods. We reviewed the charts of 131 consecutive patients who had a nephrectomy for renal cell carcinoma between 1989 and 1993. We excluded from the numerator any patients with abdominal pain or mass related to the tumor, even if the diagnosis of renal cell carcinoma had not been entertained before imaging studies.

Results. Eighty (61%) of 131 patients were diagnosed with renal cell tumors in the absence of flank pain, flank mass, or hematuria. Of these 131 patients, 31 (24%) presented with gross hematuria, 13 (10%) with flank pain, and 10 (8%) with flank or abdominal mass. Only 1 patient presented with the classic triad of flank pain, flank mass, and gross hematuria. Eighty-five percent of asymptomatic tumors were Stage I or II, and 77% of symptomatic tumors were Stage I or II.

Conclusions. The great majority of renal cell tumors are found incidentally. The tumor stage is the same in the incidentally discovered cases as it is in the symptomatic cases.