Size Reduction of Prolactinomas	

Since surgical therapy of large prolactin-secreting pituitary tumours normalises serum prolactin levels or gonadal function in less than twenty per cent of patients, particularly those with high prolactin levels, there is a need for another approach to the problem. Three major lines of evidence suggest that medical therapy may help in the treatment of these large tumours: 
• Visual field defects due to prolactinomas pressing on the optic chiasm have improved with bromocriptine therapy alone. 
• Dopamine agonist therapy has been shown, by neuroradiologic evaluations, to reduce the size of prolactinomas. 
• Bromocriptine reduces DNA turnover and the mitotic index in the in situ pituitary of the rat.