He had the feline leukemia vaccine as well? Since my cats are indoor cats, that's one vaccine I refuse to have done. It's scary. My sis works at a vet and says they see cats with these sarcoma from vaccines way too often. They used to do injections around the neck, but after the sarcomas started appearing they stopped and only do it on the legs. Because it's easier to amputate a leg if they get a bad sarcoma. >_<

Here's a link on info about the sarcomas that cats can get from certain vaccines:
http://en.wikipedia.org/wiki/Vaccine-associated_sarcoma

Poor Lucas, having such a hard time on his trip to the vet. My kitties sympathize with him cause they hate the vet too.