Sore on my cats paw :(

Hello,

I have a cat that is 2 years old. I noticed in November of 2011 that my cat had some kind of sore on the padding of his foot. I was very concerned so I brought him to the vet. At that point and time they had never seen anything like it and the best thing they could come up with that would cause this was that he might have stepped on the stove element. I noticed last week that it had gotten significantly bigger so I took a picture and brought him to the vet again yesterday. The sore on the padding of his toe fell off but the one on the bigger portion of the padding is still there. His toe is not really pink anymore it's more yellow/ orangish ever since the sore fell off.  It looks like a callus and it is a brownish/ yellow color, completly dried out, no puss. When he was sleeping I touched it to see if it cause him any discomfort and he was fine, but when he's grooming himself his constantly knawing at it. My vet yesterday had strongly recommended that I get a biopsy to find out what it is (if they can find out). I was all for it, until I found out it was almost a thousand dollars that I do not have at the moment. I'm just very scared that if I don't do anything about it now that it could develope into something bigger but at the same time I cannot afford it. Do you think it is something worth getting a biopsy for? Please help! I love my cat to pieces and I don't want anything more to come out of this. Thank you for your time and help!
- Liz

It does look nasty and probably a biopsy would be a good idea. But I do not understand why it should be so expensive - I had a skin biopsy done on my Wellington a few months ago to test for allergies and the whole thing, including sedation, was just over 50 euros. Can you get a second opinion?

did vet want to cut it off in office? seems bigger then the cutanious horns my cats ahve had but wonder if it is one.
 

I could get a second opinion but they would probably want to put him on antibiotics or something which I don't want to put him on any meds unless I know it's going to work, aswell for this biopsy he cannot be under any medication.

No they didn't cut it off. I'm assuming that the one on his toe either fell off or he bite it off the night before I took him to the vet. He was knawing at it for a while. All the vet did was suggest a biopsy. They didn't really give me much more of an option.

Could they be fungal in origin? My first thought was that they look a bit like plantar warts, i.e., viral, but the top one is rather high for something like that. $1,000 sounds awfully extreme. Our Miezi has had a number of cysts/tumors (she has basal cell carcinoma), and the biopsies have always cost between $25 and $75, depending on the location and size. Perhaps another vet wouldn't charge as much.

ETA: Found this: Cutaneous horn formation on cat's foot

It's not all that uncommon.  It's sometimes called a "cutaneous horn," and it's similar to a wart.  According to what I can find, it might be caused by a virus, an underlying tumor, some other problem, or nothing at all.  It can usually be easily removed or at least cut down with no pain to the cat, but it may well grow back.