Mast Cell Tumour Not Fully Removed: Surgery or Radiation?
by Jane
(Lincoln, UK)
Reader Question
My 7-year-old Pug has had a mast cell skin tumour removed from her right lower thigh, slightly toward the back of the leg, a little above the knee joint. Unfortunately not enough of the tumour was removed, and cancer cells remain down one side of the incision. What is the best course of action to help her: another surgery to try again, or radiation therapy quickly? Any advice would be gratefully received. She is very fit otherwise. Thank you. Sorry, no picture; it initially looked like an insect bite.
Answer from Our Team
We're sorry to hear about your Pug. The good news is that incompletely removed mast cell tumors are common, and there are good options. Pugs often get low-grade tumors that behave mildly.
The best choice depends mainly on the tumor's grade (low or high) on the pathology report, and on whether the nearby lymph node is affected. Both options you mention are standard:
- A second surgery to remove the scar with wider margins is often the first choice when there's enough loose skin to close the wound, and it can be curative.
- Radiation therapy is used when another surgery isn't practical, for example near a joint. After an incomplete removal, it controls the tumor long-term in most dogs.
- For low-grade tumors, some vets also discuss careful monitoring, because many incompletely removed low-grade tumors never come back.
Ask your vet for the grade and margin report, and whether the lymph node was checked. A consultation with a veterinary oncologist would help you weigh the options. Our guide to mast cell tumors in dogs explains grading, treatment and outlook in more detail.
This is general information, not a diagnosis. Please follow your own vet's advice.
