Acute effects of Parlodel-LAR® and response to long-term treatment with bromocriptine in a patient with a follicle stimulating hormone-secreting pituitary adenoma

A 68-year-old male patient presented with visual impairment due to a large pituitary tumor. After transsphenoidal adenomectomy the elevated serum FSH levels were lowered but not normalized. Deterioration of the vision was detected five years later and tumor regrowth was evidenced. The patient was treated with the long-acting and repeatable form of bromocriptine (Parlodel-LAR®). Three days after the first intramuscular injection it already resulted in an important improvement of the visual field defects. Serum FSH concentration was suppressed during a prolonged period, but no change in the size of the pituitary adenoma was recorded on CT scan. Long-term oral treatment with bromocriptine resulted in a sustained suppression of the serum FSH levels, without further visual improvement, but with a significant reduction of the volume of the adenoma. The rapid and prolonged effect of Parlodel-LAR® upon the FSH secretion, with a possible correction of the visual field defects and a reduction of the tumor mass, could make this medication appropriate as adjunctive treatment in some gonadotroph cell adenomas.