Results of primary treatment with bromocriptine of prolactinomas with extrasellar extension

Nineteen patients, seven women and twelve men, with macroprolactinomas characterized by extrasellar extension and basal prolactin levels above 6 U/l were treated with 10-20 mg bromocriptine daily in four divided doses for a mean period of 3.4 years (range 1.5-5.5 years). Plasma prolactin levels fell dramatically in all patients and values in the low normal range were obtained in sixteen patients. Tumor size was reduced by more than 75% in seventeen patients and by 50-75% in two patients. Tumor reduction was associated with the development of a partial empty sella in fourteen cases. In seventeen cases the pituitary became visible. Diminished visual acuity (six patients), bitemporal hemianopia (nine patients), unilateral and bilateral central scotomas (three patients) and oculomotor palsy (two patients) improved or normalized in all cases. Hypogonadism (all patients), hypothyroidism (nine patients) and hypocorticism (four patients) improved or normalized in most cases. It is concluded that in the medical treatment of macroprolactinomas 10-20 mg bromocriptine in four divided doses effectively reduces both plasma prolactin level and tumor size. The good results in this study may be related to the continued use of a fixed dose regimen of bromocriptine regardless of the plasma prolactin lowering effect.