Hamster Large Growth on Stomach

Question
Help!  My dwarf siberian (spelling?) has a large growth on her belly!  It literally looks like a brain!  It's been growing for about a year, and started out quite small.  I thought it was just a small growth at first, or even a bite mark or scab.  It is now the diameter of a dime!  It literally looks like a brain growing out of her stomach.  Any clues as to what this is and how to treat it??  She's about a year and a half old.  She doesnt seem to let it bother her too much, she still moves around, occasionally plays on the wheel, and is eating.

Answer
Dear Anna,

THIS IS A TUMOR!!! (probably) I would get your little guy to the doctor (vet) immediately. The sooner you get her treated the better. I am not 100% positive it is a tumor, but it sounds like one, especially by the growth rate you mentioned earlier. Get your hammie checked out ASAP. Unfortunately there is no way you personally can treat this, only a vet can.