White hard lump on cats back

Hello Cat Site Friends--

I'm new to this forum and I'm hoping somebody may be able to give me an answer.

My wife and I have three lovely cats (1 male and 2 females). They are like are children.

Recently we noticed a hard white lump on our male cat's back while we were petting him. It is on the top of his back about 3-4 inches from his tail.

We are not sure what this could be. It doesn't seem to hurt or bother him when we touch it.

Anybody have any ideas? He is a Turkish Van (mostly white with orange patches and an orange and white striped tail).


Thank You,

nwbound

I guess I should also point out that Henry is about 9 years old

He's a 100% indoor cat but he loves to lay in the sunlight that comes in through the windows.

He hasn't had any other major medical problems. He is neutered. 

You can't really tell from the picture but the size of the lump is about half the size of a pencil eraser, maybe a bit less.

I am a human doctor, not a vet.  Assuming that the tumour is not a tick, because he never goes out, it is a small skin tumour, but I cannot tell whether it is benign or malignant from the picture.  I can see, however that it is most unlikely to be a melanoma as it is white and a lump.  I don't like hard lumps, however as hard lumps on a human (and presumably a cat), can be malignant. 

You should  take your cat to the vet as soon as you can and obtain his/her opinion.

With all best wishes,

Geoffrey