Prostate cancer in Klinefelter syndrome during hormonal replacement therapy.

Prostate cancer detection is a rare occurrence in patients with Klinefelter syndrome, in whom chronically low circulating androgen levels are common findings. Administration of exogenous testosterone has increasingly been used to treat young adolescents diagnosed with Klinefelter syndrome and documented androgen deficiency. Although testosterone replacement in adult patients has been associated with prostatic enlargement, it remains unknown whether chronic supplementation of exogenous testosterone to pubescent males with hypogonadism results in early prostate carcinogenesis. We report a first case of prostate cancer in a patient with Klinefelter syndrome who had undergone long-term testosterone replacement therapy since childhood for chronically depressed levels of testosterone.