Brown raised spot on nose!?

Hello! I would really appreciate all your help! Ollie is a 3 year old male strictly indoor cat. He recently had his annual check up and everything was fine! However before he went in even, I noticed a slight discoloration on his nose. Well, it has gotten progressively worse over the past few days. He doesn't seem bothered at all, and continues eating and using the litter box as normal. I've been reading a lot and trying to find an answer, but nothing much is coming close to what this looks like! Any ideas would be great!!

Did you point it out to the Vet during the visit?  I would say another visit is in order, especially since it's getting larger, or see if you can just send in that picture and see what they say about it, since you were just there? 

Does he spend a lot of time in the window to get exposed to the sun?  If so, be sure to tell the Vet that.

Hello! Thanks for responding. I didn't point it out at the vet because I had just noticed it at the time. The progress seems to have slowed, but the raised bump is still there. It's not really like a "bump" exactly, it's literally like a raised portion of skin. It is the weirdest thing! He spends a decent amount of time in the window, however.

This looks to me like early skin cancer caused by uv rays, through the window is just as penetrating.

His white color is lacking pigmentation that can handle the sun.

The nose is a common place for this to pop up.

Just so you know, the sooner this is removed the better. It does progress fairly fast, and grows deeper into the tissue, and surely you wouldn't want a chunk of his nose to be removed, at this point it should be rather easy to get rid of, but they do have to take an area of skin around the spot too, so please get this handled asap.