Bilateral multicentric papillary renal tumors with heteroclonal origin based on tissue-specific karyotype instability.

BACKGROUND

Papillary chromophilic renal tumors were cytogenetically characterized by combined trisomies 7 and 17 along with other numeric chromosome aberrations. They occurred as bilateral multifocal lesions.

METHODS

A patient was presented who simultaneously developed bilateral multicentric papillary renal tumors. Tissue specimens from six tumors and tumor-free kidneys were cytogenetically characterized.

RESULTS

The tumors showed trisomy of chromosomes 7, 16, and 17 along with various other numeric abnormalities. In normal tissue from both kidneys, a wide variety of clonal and nonclonal numeric and structural chromosome aberrations were found.

CONCLUSIONS

The cytogenetic heteroclonality of the tumors strongly favors the assumption that they arose as independent primaries. A tissue-specific karyotype instability may be the basic event of multiple tumorigenesis.