Gynecomastia associated with isolated ACTH deficiency.

A 57-year-old man with gynecomastia associated with isolated adrenocorticotropic hormone deficiency is reported. Basal levels of estrogens, luteinizing hormone and prolactin were elevated, whereas plasma testosterone levels were normal. Luteinizing hormone and prolactin showed exaggerated responses to gonadotropin-releasing hormone and thyrotropin-releasing hormone, respectively. These hormonal abnormalities were corrected and gynecomastia resolved with steroid replacement therapy. These findings suggest that gynecomastia may result from hormonal changes which were modified by glucocorticoid deficiency.