Prostate cancer following testosterone replacement in Klinefelter syndrome.

Klinefelter syndrome is a common cause of hypogonadism. Testosterone replacement therapy has beneficial effects on bone, muscle and psychosexual function. However, it may remove the relative protection from adenocarcinoma of prostate, which is otherwise rare in uncomplicated Klinefelter syndrome. We report the case of a 55-year-old man with Klinefelter syndrome who developed prostate cancer after only 7 years of androgen supplementation. Androgen deprivation therapy was complicated by the presence of testosterone implants. The patient was treated with androgen blockade followed by radiation therapy. We recommend that serum prostate specific antigen (PSA) and digital rectal examinations be carried out during, as well as before androgen replacement.