Good link and essential reading for everyone.
Here's a link to the book:
www.amazon.co.uk/Doing-Harm-Medicine-Dismissed-Misdiagnosed/dp/0062470809?tag=mumsnetforum-21
My Prolactinoma was mis diagnosed at first and when the symptoms didn't go (after a disastrous course of fertility pills that I had to stop after a week), I went to another doctor who quickly recognised what the cause of my periods stopping might be and he was right. I was recommended to go to him by a friend. Thankfully, excretion of prolactin dropped in my late 20s and I was able to have children without the need for medication.