Daisy went back to the vet today to get her stitches removed. The tests came back and while this was a mast cell tumor(more info here for those who want it) it was a relatively benign Grade II on a scale of 1-4. The vet, who also did the surgery, says she believes they got it all. The tests show no problem cells in the border of the area removed, so that is a good sign. Basically what this all means is, Daisy is fine. Other than the big scar and bald spot on her side.