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

A case of an adult man with a gonadotropin-producing pituitary adenoma associated with elevated serum testosterone levels is described, and the related medical literature is reviewed. The patient presented with visual difficulties 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, and these include instances of precocious puberty, ovarian hyperstimulation, and an elevated sperm count. The rarity of supranormal gonadal steroid levels in gonadotroph adenomas may relate to the secretion of uncombined LH subunits, or potentially altered LH glycosylation.