small knot under jaw?

I took in an adult bp a few months ago and right away I noticed he had scars on top his head and a what looked like a rat bit under his chin(two slit like wounds about a quarter inch apart). One of the marks under his chin has got a bigger as in about the size of a bb now. Is there anything I can do?
If I were to take him to the vet what can I expect them to do? Is this an easy fix with just lancing it and flushing it out?
I have to decide if I take him to our local vet which in a dog/cat vet or drive two hours to a reptile vet..thanks for any help.

I think the only way to know what the mark is would be to go get it checked out. I also think it is worth it to travel to a reptile vet rather than go with the dog/cat one who probably doesn't know much about treating your snake.