Why is there a lump on my dwarf hamsters face

He has a lump below his eye. I can see through the fur and it is red. I am starting to think it is a tumour. Or could it have something to do with his eye sticking closed together? He and his buddy are getting old (over a year old). I am really worried about that lump.

it is probaly a tumor.it is very common in dwarfs. i had at least 2 that did it. do you have a barred cage for the hamster to put its nose through? caue thats what happened to mine and she is still here. it went a away after a few days. you could bring it to a vet to look at it. i hope he gets better!