Effect of bromocriptine treatment on the fibrous tissue content of prolactin-secreting and nonfunctioning macroadenomas of the pituitary gland.

We performed a quantitative study using a point-counting technique at the light microscope level of the fibrous tissue content of PRL-secreting and nonfunctioning pituitary macroadenomas from patients treated or untreated with bromocriptine (BC) before surgery. There was a significant increase in the fibrous tissue content of PRL-secreting, but not nonfunctioning, tumors after BC treatment. The extent of the increase in fibrous tissue in prolactinomas correlated with the duration of treatment with BO.