Mysterious Bump

My cat is a 10 year old Siamese. I noticed a bump on his back a few weeks ago. It's right next to his spine, and is about 3/4" wide and a perfect half-sphere shape. It's hard but with a little give. He doesn't complain when I touch it, so I guess it doesn't hurt him. I thought it was an abscess, but it is still exactly the same size as it was the first day I noticed it. He is acting fine, doesn't seem any different. Anyone have any ideas what this could be? I'm saving to take him to the vet, but it might be a while...

Has your cat recently had any vaccinations? Sometimes following a vaccination the site can have a lump for a bit.

I would encourage you to have your kitty checked as soon as possible, best to have lumps checked out ASAP.

No, no recent vaccinations. Like I said, I will take him in as soon as possible, but I was just hoping to hear from someone with a similar experience until then.

It could be a cyst. They are pretty common as cats age. When you take him to the vet, they should do a fine-needle aspiration to check on it. My vet can usually tell that's it's a harmless cyst by looking at the cell from the aspirate. It is important to get it checked to make sure it's something benign.

Hopefully the vet finds it's nothing to worry about

Sounds like a cyst to me too. You may want to just keep an eye on it for a few weeks, to see if it changes. If it remains stable, and is not causing any problems, it is probably a cyst. Of course, the vet should always see things like this, but for many of us, getting our cat to the vet is not a small matter. Even if the money is not an issue, it is a lot of stress for the cat. For me, getting any of my cats into a carrier is very difficult for both of us. I try to avoid vet visits unless I feel it's absolutely necessary.