Lump under hamsters chin

Question
my hamster has a lump under it's chin, I only found out after coming back from the Maldives. My maid was looking after it so it was not being left alone. The lump looks quiet big and since my hamster is quiet old, I am scared it will hurt him. I was away for only 4 days and it was fine before. It still has fur on it, and he is sometimes tripping over it, he is not as active as usual and the lump is quiet soft but with a harder lump in the middle. My mum thinks it is full of puss. I have looked on the Internet for information but the lump that my hamster has does not sound like any of the usual. I was wondering if I go to the vet, weather they will have to put him down, weather they could help or weather it is just old age and he can go on with his normal life. He is about 3 years old. He has had no vaccinations. While I was away my maid fed him egg every night and a new type of dry food to him because his old one ran out. His cage has two levels and he doesn't seem to be able to reach the second. I hope this is enough information, if not tell me what you need to know.
thanks.

Answer
Well I am not a hamster expert but it sounds like an abscess Genevieve. I would get him to the vets and see if they can lance it and give you some antibiotics for his water or drops for his mouth to help clear it up.

Otherwise you can ask Heather who is a hamster expert in here.

http://www.allexperts.com/ep/2005-34607/Gerbils-Hamsters/Heather.htm

Dr. Gotthelf does answer questions about skin so maybe he knows something about Hamsters as well:

http://www.allexperts.com/ep/700-23614/Ask-Veterinarian/Dr-Louis-N-Gotthelf.htm

Good luck with him. A 3 yr old hamster is quite old.