We took the cat to a vet clinic not that far away from where I live. The prior vet choice is across town and the vet would not be in until Friday, so we didn't want to wait that long. They took a look at her and saw the bump... They assume that it is in fact a tumor and that the chances for it to be malignant is 80%, especially since she's an older cat and cats are more prone to malignant around the area it is at. We got an estimate price for the shots, checkup and biopsy and we couldn't pay it up front to get it all done to confirm, so we're going to seek the other vet clinic that we first wanted to go to and see what it is there. I don't want to lose all hope just yet, but... Right now I feel a little numb.