Surgical treatment of prolactin-secreting microadenomas

Fourteen women (aged 19 to 38 years) with amenorrhea of 1 to 7 years' duration underwent transsphenoidal pituitary exploration for selective removal of potential prolactin secreting microadenomas. Preoperatively, serum prolactin levels were elevated in all (90 to 970 ng/ml), standard sella turcica x-ray films were normal, but polytomography revealed localized erosion in 12 women. Growth hormone reserve (assessed with insulin-induced hypoglycemia) was compromised in one of 13 women; cortisol responsiveness (to insulin-induced hypoglycemia) was attenuated in three of 10 women, while gonadotropin reserve (assessed with subcutaneous 100μg luteinizing hormone-releasing factor) was borderline in two of 13 women. At operation, pituitary adenomas were removed in 13 women, while a sellar diverticuium was found in the remaining woman. In the 13 women with pituitary adenoma removal, plasma prolactin levels decreased in all and reached normal levels in five women. Despite pituitary surgery, trophic hormone function (i.e., growth hormone reserve, cortisol responsiveness, thyroid-stimulating hormone, follicle-stimulating hormone, and luteinizing hormone) was preserved in most instances and perhaps improved. Adjunctive radiotherapy was utilized in two patients. With follow-up of 6 months' to 3 years duration, cyclic menses have resumed in six and pregnancy occurred in three of seven women desiring fertility. Factors associated with successful surgical treatment of these microadenomas included: (1) tumor size (< 8 mm in diameter), (2) surgical technique, and (3) the surgeon's operative experience.