Surgical outcomes in hyporesponsive prolactinomas: analysis of patients with resistance or intolerance to dopamine agonists

Surgery for prolactinoma patients is usually reserved for those who are intolerant of or have an inadequate response to medication. We report the results of surgical treatment in these patients. We retrospectively analyzed a consecutive series of patients with histopathologically confirmed prolactinomas; two patients treated with craniotomy and 77 patients with prolactinomas treated by transsphenoidal surgery between 1993 and 2003. We evaluated symptomatic patients who did not tolerate or did not respond to dopamine agonist therapy (persistent hyperprolactinemia and/or no shrinkage of tumor mass). We report remission rates, prolactin levels, and medications either not tolerated or ineffective. Eighteen patients were intolerant of medical therapy (nine with macroadenomas and nine with microadenomas). Postoperatively, 12 patients (67%) achieved normalization of prolactin and relief of symptoms from surgery alone. Sixty-one patients were resistant to dopamine agonist therapy (45 with macroadenomas and 16 with microadenomas). Forty-six patients had both elevated prolactin levels and no shrinkage. 22 patients (36%) achieved normal postoperative prolactin levels. Ten of the remaining 39 patients required adjunctive medical therapy to maintain normal prolactin levels and relief of symptoms. Remission through surgery was achieved in 67% (12 of 18 patients, 4 macroadenomas and 8 microadenomas) of prolactinoma patients who fail medical therapy with dopamine agonists because of intolerance to medication. Remission was also achieved in 36% (22 of 61 patients, 12 macroadenomas and 10 microadenomas) of patients who demonstrated resistance to dopamine agonist medication.