Amber I have never had a lab but I had a Red Bone Coon Hound and when he got older he got alot of cysts which is common on Red Bones they formed on his hips, neck and so on they started small then just got bigger.They were called sebaceous cysts which meant thay were fatty deposits there are a few others that are the same but only cosmetic.I did some research when I had him and found out that if a dog gets a big slow growing lump try to pick it up if its floating in the skin and you can actually get your finger under it and its not attached directly to the body its not a problem just cosmetic, if its attached to the body it could be more serious and I stress it could be.
I find it really helpful to invest in a dog veterinary book I have one called Dogs Home Veterinrary Hand Book by Delbert G. Carlson, DVM. & James M.Griffin M.D and it helps you to do a little research.If you are not happy with what your vet is telling you by all means get a second or third opinion as you would for yourself.I totally understand what a pet can mean to you I dont think of them as pets but as best friends.If you want private email me and tell me more and I will do any thing and I mean anything you need to find out more.JP