Yes.
Here is a dodgy picture of a sickly hamster, with a nasty looking lump near its vagina: www.sinpets.com/dogpix/20071231Hamster_Day1_skin_tumour_ToaPayohVets.jpg
( Bats, Mon 1 Jun 2009, 14:38, archived)

That's quite a small tumour for a hamster.
One of mine had one removed from his abdomen that was half the size of him.
( Esme Weatherwax I swear on my tash it's daycent hash, Mon 1 Jun 2009, 14:48, archived)