I don't know why they didn't do a needle biopsy. That's what they did on both Payton and Bourbon. Payton's came back a fatty tumor and Bourbon's, well, his came back inconclusive, so we went surgery biopsy and found out the bad news. It only takes a few days to get the results back from this. I definitely would not wait. And call the main vets; I had breaking in a new vet. Good luck.