Mast Cell Tumor
Mast cells are immune cells normally involved in allergic reactions. They contain packets of chemicals (called granules) that are released upon stimulation by an allergen. Mast cells are located throughout the body and dogs have a large proportion located within their skin. Mast cell tumors are found more frequently in Boxers, Boston Terriers, Labrador Retrievers, Golden Retrievers, Beagles, Pugs, Shar Peis, and Bulldogs.
A diagnosis of a mast cell tumor can usually be made via a fine needle aspirate. A small needle, the same size that’s used to draw a blood sample or give a vaccine, is introduced into the mass and a syringe is used to extract cells. These cells are distributed onto a slide and evaluated either by your veterinarian or submitted to a lab for analysis by a clinical pathologist.
Surgical removal is recommended for all confirmed mast cell tumors. A pathologist will review the sample and assign a “grade” to the tumor. The grade is the best predictor of whether follow-up testing and treatment is recommended. Low-grade tumors are usually cured with complete excision, whereas high-grade tumors are more likely to grow back and spread to distant sites in the body. In those cases, radiation therapy and chemotherapy are recommended to extend survival time.