You people are too kind. The vet said we may not know how successful the surgery would be; she did not sound optimistic as the tumor is so massive, she's afraid it may be further along than she can feel right now.

Chest X-ray showed no mets to the lungs. We're doing an ultrasound on Saturday to check for other mets. However Nancy, the pet psychic said:

"she is older...she is not that young. she has a bone tumor that may have gone to other parts of her body besides her lungs. an intense surgery like that at her age is not only stressful but traumatic. she is confused and stressed. i will be gone to a pta meeting the rest of the night. make a peaceful decision for both of you. "

For now, Mitzi is home, resting on pain meds. She ate a lot and drank some water, used the litter box (nice low box she can get into). So we wait; keep her comfortable and wait.