New insights on mast cell tumors

What are some controversies or misconceptions about mast cell tumors (MCTs)? In a preconference interview, Craig A Clifford, DVM, MS, DACVIM (Oncology), talked about his lecture “Controversies in Oncology: Mast Cell Tumors,” presented at the Fetch dvm360 conference in Long Beach, California. In the interview, Clifford discussed various aspects of mast cell tumors, including grading, prognosis with multiple MCTs, subcutaneous MCTs, and the new treatment for MCT in dogs: Stelfonta.

Below is a partial transcript. It has been lightly edited for clarity.

Craig A Clifford, DVM, MS, DACVIM (Oncology): The goal of this lecture is to look at a variety of different things associated with mast cell tumors that are either considered controversial or things that we don't have a perfect answer for. Perfect example would be now we have the ability to do grading, which traditionally was only through taking a piece of the tumor tissue. We can actually do it through cytology. The parameters that are looked at can be seen under [histopathology] and can be seen cytologically. So for select cases where maybe it's a challenging tumor in a tough location, and the primary care doctor, you know, doesn't know ‘how aggressive should I be’? Well, if we do cytologic grading first and the cytologic grading suggest it's a low-grade tumor, well now the primary care doctor can look at it and be like, ‘I just need to do a marginal surgery.’ If, say, it's between the digits, ‘I don't have to take a digit. I can do a really close surgery, barely get it all out, but that's probably enough.’ While, conversely, if it turns out it's [a] more aggressive tumor, well, that's when we have to have very good margins. So just going in and trying to pull it out—not going to be enough, we probably need to take a digit. So that's one that they either may want to downsize first or potentially refer.