My Hamster Has A Lump On His Bum What Is It?

My hamster has had a red ball on his bum it comes and goes . I work up the other day   and I was there and I looked at it today and it is still there but it looks like iit is getting betta iff not I am taking her the vet I don't care how much it is its not about the money thias is about iff he lkives or dies any one know about this
         
                thanks XxXx

Mine has that now too, noticed yesterday and I don't know what it is. Taking her to vet tomorrow. Really hope she doesnt get put down. Can they remove it x

My Hamster Died Because Of The Lump On It's Bum About A months Ago Or Two And I Am Very Sad And I only have one left but now this one has a problem too when you look at him his eye is half way closed and he keeps it that way if someone can answer this what would that be

Yes if it is a male.

Probably cancer they get tumors really easily. The
vet bill wouldn't be worth it. It is either Benign and won't kill him
or malignant and he will grow more and more sleepy and curl up one day
and pass on. Mine did that. It is sad.