Can health insurance deny coverage of a pre existant condition if it's a medical necessity?

I have a uterine fibroid that showed up on an ultrasound before I got health insurance. The doctor has put me on lupron shots to shrink the fibroid and they've been paying for my treatments, but refuse to pay for my surgery. Is it possible that the insurance company will pay if it's a medical necessity? Thanks
--------------------
Yes they can. It's pre existing, it doesn't matter what it is. But in most cases there is also an elimination period. Once that time is up, you can have a necessary procedure and receive benefits under you policy for it. To know if you qualify and how long the elimination period is (typically 12-24 mo), read your policy carefully and if you still don't know, talk to the person you bought it from or a representative of that company and they can tell you. But keep in mind that some policies carry a permanent exclusion for some conditions. Also know that you might need to have the procedure before the elimination period is up and if you do, you will have to pay for it out of pocket.
Source