Multicentricity in renal cell carcinoma: can primary tumor location serve as a co-determinant of surgical treatment?

To assess the incidence of multicentricity in our series of renal cell carcinoma (RCC) patients and to investigate whether certain clinicopathological parameters could assist the selection of the appropriate surgical modality.

We performed a retrospective analysis of 235 RCC specimens that had been resected by radical nephrectomy at our institution from June 1995 to 2001.

Twenty-six (11%) kidneys contained at least one small accompanying nodule. Fourteen (6%) kidneys exhibited satellite tumors that were histologically consistent with the adenomas, while "true" multicentricity was detected in 12 (5%) specimens. In the latter, the number of concomitant foci was independent of the size of the primary tumor. No correlation was observed between histological pattern and multifocality. In five out of seven (71%) specimens that contained the main tumor mass within the upper or middle portion of the kidney, satellite lesions were found to be located at the mid-kidney, whereas specimens with lower-pole RCC demonstrated no restriction in the distribution of accompanying nodules. All patients had been screened pre-operatively by ultrasonography and CT scanning.

Our findings may be suggestive of a putative link between primary tumor location and multicentricity, although this relation could not be statistically confirmed. The 5% incidence of multicentricity renders the biological significance of satellite adenomas and/or adenocarcinomas unclear.