Chromosome changes in benign prostatic hyperplasia and their significance in the origin of prostatic carcinoma.

Cytogenetic studies of benign prostatic hyperplasia (BHP) are scarce. We analyzed primary cell cultures obtained from biopsies of prostatic tissues from 10 patients (mean age: 60.7 years) with histologic diagnosis of BHP to compare the eventual chromosome changes with those reported in prostatic adenocarcinoma. Clonal chromosome abnormalities were noted in five of the 10 cases, with loss of Y chromosome in all. In one case, a clonal t(1;20) was observed with a -Y clone. Different numerical and structural sporadic abnormalities were evident in eight. Chromosome 1 was the chromosome most frequently involved in sporadic rearrangements. We concluded that -Y is a frequent nonrandom chromosome abnormality in BHP in this sample of patients. Immunohistochemical studies showed that loss of Y occurs in fibroblasts and not in epithelial cells; therefore, this anomaly is not related to cancer development.