My hamster has 2 sqiushy lumps?

my hamster has always had a lump on his back its squishy and now he has another on the other side they dont seem to be causing him pain, I asked the vets how much it was for an appointment and they quoted �19.00 + treatment, seeing as he is not in pain I didnt take him as I cant afford the bill. does anyone know what this could be or has any1 got/had anything similar on their hamster? please help..