It sucks. hah.
For me, the entire process involved a great deal of disbelief – some of it rather normal, I suppose, and some of it quite intentionally brought about by myself.
I’d actually first noticed the tumor myself. Not even being out of my 20s yet, I had a hard time believing it could be what I suspected it was, and managed to convince myself it was fairly harmless. At one point, while seeing a doctor for an entirely unrelated thing, I pointed out the lump to him and he gave it a quick look and feel but didn’t seem overly concerned by it and nothing came of it after that particular visit. That ended up adding to my own idea that it was something harmless and not worth thinking about much further.