I Found A Few Lumps On My Cats Neck My Cat Has Lumps On His Body :( What Could They Be?

My cat has lumps on his body :( what could they be? - i found a few lumps on my cats neck

A month ago I realized that my cat had a rope around his right leg behind, and then took the form of egg him since I felt it was a bit sharp. Then a few days ago was gone, but his swollen leg. now seems good, but many small cysts in the neck: (
Who have diabetes and I think it was a kind lot of respiratory infections and a cough. Ball too much, what I thought was a pain, but he did not. I took him to the vet and is carefully cough, but I am now so I did not break the X-ray can get to see what could be the pieces ... Ideas?