Elevated serum testosterone levels secondary to a gonadotropin-producing pituitary adenoma

A case of an adult man with a gonadotropin-producing pituitary adenoma asso ciated with elevated serum testosterone levels is described, and the relate d medical literature is reviewed. The patient presented with visual difficu lties and hypopituitarism, and had no clinical manifestations referable to his excess gonadal steroid level. Eight other cases of gonadotroph adenomas with elevated levels of gonadal steroids have been reported previously, an d these include instances of precocious puberty, ovarian hyperstimulation, and an elevated sperm count. The rarity of supranormal gonadal steroid leve ls in gonadotroph adenomas may relate to the secretion of uncombined LH sub units, or potentially altered LH glycosylation.