why does my hamster have a bumb on its belly?

  One day i picked up my hamster and scracted him on the belly, i felt a big bump on him and is so terrified! I have never seen it there before! WHAT NOW?
I don't mean to worry you but it may be a tumor or cancer so you really need to take him ot a vet
you should take him to a vet it could either be serious, better to be safe then sorry ayy
If you feed him to a snake, you won't have to worry anymore.