In my case I have had a firm diagnosis, unfirmed, reaffirmed, modified, etc. Various doctors have had various opinions. After I was convinced that my only real disease was Porphyria (also dx'd by 3 doctors), a doctor at UW hospital in Seattle told me I didn't have Porphyria, I had MS.
So what do you do with THAT? It was over 25 years ago that I first got an MS dx, and all this has gone on since then, so I figure it is absolutely no use trying to get doctors to come up with the REAL SCORE. I have to live as if I have Porphyria whether or not I have it; I have to cope with symptoms which are MSy whether or not I have it. I have never been able to take the MS drugs, so that is irrelevant; my only MS therapy has been the Swank Diet for over 25 years, slightly modified to add an egg a day.

It's all somewhat irrelevant, as I now have a form of non-malignant cancer (I know, try that DX on for size) which means I have to get radiated when my platelets go over 800 (I have only had one radiation so far, at Mayo Scottsdale). I have to have a phlebotomy every six or seven weeks to keep hematocrit below 42. This disease is called Polycythemia Vera, and there is NO doubt that I have it. Absolutely NO doctor would say I didn't have it. Or am I just having false confidence, and there IS a doctor lurking who would remove this diagnosis?