The vet called last night after dinner. As suspected, the news was not good. Casey has lymphoma - fairly advanced, although they can't officially stage it from the aspirate they collected.
I told the kids last night before bedtime which resulted in all of us sobbing for a good hour or so. They don't remember life before her and can't imagine life without her.
When I picked up the prednisone prescription from the vet today, she had a great suggestion for the family to make a stepping stone with Casey's paw prints while she's still feeling well enough. I actually found a handprint/paw print kit today at Target that's a picture frame on one half and clay for the prints on the other half. So, we're going to do that in stead of a stone. That way we can have something indoors and have her picture as part of it.
The whole thing just sucks. Sucks. Sucks. Sucks.