Persistent hyperprolactinemia after orchidectomy due to a feminizing Leydig cell tumor. Effect of treatment with quinagolide (CV 205-502)

Hyperprolactinemia after orchidectomy in patients with feminizing Leydig ce ll tumors has not been described previously. We report the case of a 24-yea r-old man with bilateral gynecomastia of 6 months' duration who was found t o have a Leydig cell tumor in his left testis. Hormone studies performed be fore surgery revealed mild hyperprolactinemia, increased follicle stimulati ng hormone (FSH), and normal testosterone and estradiol levels. Spermatogen esis was abnormal. Testicular endocrine function and spermatogenesis did no t return to normal after surgery. Over 2 years of "follow up," FSH levels g radually increased while luteinizing hormone levels remained at the upper l imit of the normal range. Estradiol levels decreased by 75%, and prolactin (PRL) remained high at preorchidectomy values. Treatment with quinagolide ( CV 205-502) normalized PRL levels but failed to correct sperm ab normalitie s. We conclude that lack of endocrine normalization after hemicastration might suggest pre-existing testicular damage aggravated by long-term exposure to high levels of estrogen.