Detection of trisomy 12 on ovarian sex cord stromal tumors by fluorescence in situ hybridization.

Trisomy of chromosome 12 has been frequently described in various neoplasms, particularly in tumors of the female genitourinary tract. Fluorescence in situ hybridization with a centromeric repetitive DNA probe, specific for chromosome 12, was done to detect such cytogenic changes on frozen-tissue sections from 10 cases of ovarian sex cord stromal tumors. The case series was composed by granulosa cell tumors (four cases), fibromas (four cases), thecoma (one case), and Sertoli-Leydig cell tumor (one case). In granulosa cell tumors, the range of trisomy was 12 to 32% and in fibromas 8 to 22%, whereas in the single case of thecoma trisomy was present in 8% and in the Sertoli-Leydig cell tumor in 4% of the nuclei examined. These results represent an additional series of cases of trisomy 12 in ovarian neoplasms, namely, in ovarian sex cord stromal tumors.