This study was designed to gain more insight into the incidence of satellites of renal cell carcinoma related to the pathologic stage and grade of the primary tumor.

One hundred eight nephrectomized kidneys with renal cell carcinoma were sectioned at 3-mm intervals and inspected microscopically for satellite carcinomas. The number, site, size, and distance of satellite carcinomas found were recorded in relation to the primary carcinoma.

The overall incidence of satellite carcinoma was 6.5% (7 of 108). The incidence of satellite carcinoma in relation to the pathologic staging of the primary tumor was 7.1 % (1 of 14) in pT1, 3.0% (2 of 66) in pT2, and 14.3% (4 of 28) in pT3. The incidence was higher in patients with N1 disease (25%) than in those with NO (5.0%), and higher in M1 disease (25%) than in those in MO (5.77%). There was no relationship between the grade and multicentricity.

The incidence of satellite carcinoma was higher in cases with high-stage primary carcinoma. However, even in localized diseases (pT1, pT2), satellite carcinomas were found at a 3.75% incidence. When nephron-sparing surgery is indicated in low-stage cases, precise clinical staging using a combination of various imaging modalities is mandatory, with intraoperative ultrasonography being one possible modality for detecting a concomitant satellite carcinoma.