Prolactin-secreting pituitary microadenoma: detection and evaluation.

Eleven women with secondary amenorrhea associated with hyperprolactinemia were studied. Base line evaluations, visual field determinations, and routine sella turcica x-rays were normal. Prolactin-secreting pituitary microadenomas were found in all of the patients only after further diagnostic studies were carried out. These studies included polytomography of the sella turcica; dynamic pituitary testing of growth hormone reserve, adrenocorticotropic hormone reserve, and gonadotropin reserve; and prolactin suppression with L-dopa. The early diagnosis of a small prolactin-secreting adenoma may be possible if several diagnostic criteria are utilized. The most sensitive diagnostic indices available are (1) polytomography, (2) the magnitude of the plasma prolactin elevation, and (3) the failure to suppress prolactin secretion with L-dopa. Our findings emphasize the importance of an extensive evaluation of all women with amenorrhea associated with hyperprolactinemia.