I have Erdheim-Chester disease. If you've never heard of it, I'm not surprised
Out of a world population of over 8 billion people, there have been 1,500 documented cases of this disease.
The good news is that this is a disease, though chronic and incurable, is generally not fatal. Which is why it took so long for it to be detected. Mostly through autopsy.
As my oncologist quipped: "This is one of those diseases you die with, not die of".
It's going to be an interesting (hopefully very long) ride.
With compensating medication the symptoms are mostly unnoticeable.
Just an interesting factoid.
It narrows your chances of identifying me IRL from 8,000,000,000: 1 to 1:1,500
= new reply since forum marked as read
Wikipedia left me not much the wiser but there IS an episode of 'House' about this. Stay well. 
Not "technically" blood cancer, as I recall, but more along the lines of an autoimmune dysfunction that presents in a lot of different (confusing) ways and may have a genetic predisposition.
Good, that now you know what you are dealing with and have some good input on care. 
I am so grateful that your disease is not fatal. That you can live with it, given good medicine.
You are one of the good guys and I treasure you. May your years be ongoing and joyful!
