Alteration of prolactin secretion after transsphenoidal adenomectomy for prolactinomas

The author studied the dynamics of prolactin (PRL) secretion after adenomectomy, and considered the treatment for prolactinomas. The study group comprised a total of 74 patients with prolactinomas who underwent transsphenoidal surgery between 1979 and 1986, and 61 patients out of them were followed up more than one year. Post-operatively, hyperprolactinemia was cured (under 20 ng/ml) in 19 of 36 microadenomas (53%), and 7 of 38 macroadenomas (18%). Pre-operatively, PRL response to TRH was blunt except 3 patients, but it recovered in 16 patients after surgery, and 5 more patients during follow-up. Recurrence of hyperprolactinemia occurred in only one of 19 patients who were followed up more than one year, and she was not a PRL responder to TRH. Bromocriptine was administrated to 46 patients after surgery, and hyperprolactinemia was restored to normal in 40 patients. And in 7 patients whose basal PRL levels were between 23 and 41 ng/ml after surgery, hyperprolactinemia was cured still after withdrawal of bromocriptine. During pregnancy, PRL levels were relatively low in surgically cured patients, but in most of others they became over 200 ng/ml promptly after withdrawal of bromocriptine. Recurrence of hyperprolactinemia was rare, and PRL response to TRH recovered in most of surgically cured patients. Even if it is not cured surgically, lowered PRL levels have a good effect on the additional bromocriptine therapy. I prefer transsphenoidal surgery in respect of curative treatment for prolactinomas.