He'll be OK! He's always been OK with anesthesia, so that should ease your mind just a bit.
So, this is a *new* lump, or it is the one that ruptured? For some reason I thought if it ruptured, it'd have drained and be gone. Anyway, no matter, it's going away anyway. I know how hard it is to watch owies—it'll be so such better, soon!