Gonadotrophin-secreting pituitary adenomas masquerading as primary ovarian failure

Three women, 20-35 years old, appeared on initial presentation to have primary ovarian failure, because each had amenorrhoea or oligomenorrhoea and markedly supranormal serum concentrations of gonadotrophins. On further evaluation, however, each had ovaries that could secrete oestradiol normally, and one had normal oestradiol secretion without any treatment. Another secreted oestradiol normally only after reduction of her gonadotrophins following partial excision of a pituitary adenoma. The third secreted oestradiol normally only after exogenous oestrogens were administered to reduce her gonadotrophins and were then withdrawn. Each had an enlarged, contrast-enhancing pituitary gland by computed tomographic scan and a markedly supranormal serum concentration of glycoprotein alpha subunit. We conclude that each of these women had a gonadotrophin-secreting pituitary adenoma that masqueraded as primary ovarian failure. Their persistently supranormal serum gonadotrophins appear to have inhibited ovarian function.