my dwarf hamster has a lump

[Blaketh]

can someone please help me i went to put my hamster Henry into his ball for his exercise when i noticed this huge lump on his right side it feels like a tumor but im not a doctor it came up really quick like within a day or 2 any information will help ive had him a little over a year and i feed him hamster food and give him treat like dried fruit and nuts i love him alot and take great care of him i just cant afford to take him to a vet they told me it would be over $100