Hamster ear tumor

Please help! I run a small animal rescue and need some assistance with a hamster problem. Recently a siberian hamster was surrendered to me and it has a very large lump or tumor of some sort growing from his ear. It looks sort of like cauliflower. Pink and black in color. It seems to have caused a problem with his eye also. I assume pressure from it has caused the problem but he can no longer open his left eye. If anyone knows what this growth may be I would greatly appreciate your help!

Hello :)
   
So i did some clicking around and i found a few other people who have been reporting the same type of growth in their hamster's ears. From what i found it is mostly compared to cauliflower ear in humans.
   
I read that it is more common in older female hamsters and allegedly some vets have surgically removed the growths, also thought to be tumors. One person asked if maybe it was possible that the hamster was bitten and the area has become infected?
   
I would contact your local vet and she what he or she thinks :)

Thank you so much for taking the time to look into this a bit. I have found a few other people asking questions about similar lumps but no one seemed to get a definite answer. He is a very aggressive hamster and bites every time you get near him. I was hoping to get him to warm up to me a bit before taking him to the vet. I hate to stress him out with another trip so soon but it looks like I may have to take him in sooner than planned. I have attached pics in case this looks like something anyone has seen before. Thanks again for your thoughts!!