A prolactinoma can be treated with bromocriptine as your doctor said or dostinex is another option. Outside the US, there is a third medication. You have to stay on the meds as once you stop taking them, well, the effect stops. You need to be monitored consistently.
If the lesion does not respond to meds, then you have the option of surgery.
I had one of these. I had it surgically removed as I had another one as well.
I take dostinex/cabergoline .5 mg once weekly. It has generally less side effects and only once or twice a week so that is nice compared to bromocriptine... however the major downside is that if you have history of heart problems it can increase that as well as create new valve problems, however that is usually seen with MUCH higher doses that are used to treat people with parkinsins.