Surgical outcome and pathological effects of bromocriptine preoperative treatment in prolactinomas

The case histories of 40 patients with prolactinomas were retrospectively reviewed. Twenty patients treated preoperatively with bromocriptine were compared to 20 untreated patients. The two groups were comparable according to tumor size and sex. All the patients had an immuno-cytochemically confirmed prolactin adenoma. They were operated on by a transsphenoidal approach. Intraoperative findings were studied. The surgical cure rates (serum PRL level less than 30 micrograms/l) of the bromocriptine-treated group were higher than those of the control group, both in microprolactinomas (87.5% vs 50%) and macroprolactinomas (33% vs 17%). This improvement of surgical success rate may not be due solely to bromocriptine. Surgical cure also depends on preoperative serum PRL levels (less than 500 micrograms/l) and tumoral size (less than grade II0). Tumoral tissue remained in all cases. No increase in fibrosis was observed. By inducing tumoral shrinkage, bromocriptine makes surgical removal of macroprolactinomas easier and safer. This tumoral shrinkage could be explained not only by reduction of cell size, but also by decrease in intratumoral hemorrhage. Preoperative bromocriptine treatment does not adversely affect surgical outcome. Moreover, it may be useful in cases of macroprolactinomas with suprasellar extension.