Okay, here's another thing you probably don't know about the surgery itself.
Feline abcesses (which is what most "skin lumps" are) are usually
liquid inside, not solid. The general practice is to lance the abcess and create a large enough incision to install a plastic drain, which they the suture in place and remove a week or so later. While the cat is wearing the drain, they put it in an Elizabethan Collar so it doesn't mess with it.
What you see on the surface of the skin is just the tip of the iceburg. When my cat had an abcess, there was a small bump on her skin--just enough to disturb the fur over it, which is how we first noticed it. The abcess under her skin was the size of an orange.
Any mis-step that results in the liquid contents of the abcess being released into the cat's abdominal cavity can result in sepsis, systemic infection, and death. Or at least very high vet bills for something you can't handle with an x-acto knife.
I applaud your DIY instincts here, but surgery is best left to professionals. (Anyone who wants to take that sentence as part of your signature is more than welcome.
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