Animal Care Clinic Tips

Nov 28, 2012 12:43 PM by Marissa Greenberg, DVM

Mast Cell Tumors

Kaia is a 10-year-old Boxer. Unfortunately, boxers are a breed predisposed to many kinds of cancers. One of those is a cancer called a Mast Cell Tumor. Mast cells are a kind of cell that is found in many types of tissues in the body, including the skin. They have little granules in them that contain a product most people are familiar with, called histamine. Histamine is what is responsible for allergies and allergic reactions. Medications like Benadryl, which many people take for allergies, are called anti-histamines.

Mast cell tumors come in all shapes, sizes, and forms. In veterinary medicine we often call them the great pretender or imitators, as they can look like anything. When we see a skin mass on any dog, it should be sampled with a procedure called a fine needle aspirate to see if there are mast cells present, as these tumors can be very locally aggressive, and can spread to other organs (metastasize) and cause many issues for an animals whole body because of the histamine they can release.

Kaia came to see us in November of 2006 with a new skin mass on the back of her right hind leg. A fine needle aspirate was done, and it was confirmed that this mass was a mast cell tumor. Ideally, mast cell tumors are removed surgically with a good margin of what appears to be healthy tissue around them. This is because even from where we can feel a mass extend to, the cells often go past this. In order decrease the chances of a mast cell tumor re-growing, we have to try and get all the cells. Because of the location of Kaia's mass, a surgeon performed a special surgery to remove the mass and to stretch her skin to be able to close the hole that remained once the mass was removed. Some nursing care and bandages were required to allow Kaia to heal. She did quite well after this surgery.

Though Kaia's mass has not re-grown in that location, many dogs that have one mast cell tumor often develop others. In March of 2010, Kaia came in with a new mass on her tail. This mass looked and felt different than the mass on her leg, but again, it was sampled with a fine needle aspirate and suspected to be a mast cell tumor. In order to confirm this, larger samples were taken for the labs, and it was in fact another mast cell tumor. Again, it was in a difficult location to be removed, and amputating her tail was considered. Her owner chose to not put her through more surgery. Kaia developed yet another new mass that is suspected to be a mast cell tumor on her right elbow in June of this year. Her owner has decided to treat Kaia in a conservative manner-she is on medications that should limit the side effects of mast cell tumors, and may even help to shrink them and keep them from growing larger.

Mast cell tumors are one of the most common types of skin cancer we see. For more comprehensive information about them, please check out this web site from my own Alma matter, Washington State University College of Veterinary Medicine.

And if your dog has any skin masses, please schedule an appointment with one of our doctors to have it evaluated.



Offensive or inappropriate comments are subject to removal. To report a comment, please e-mail us at, and include the name of the story and information on the comment.

Thank you!

Most Popular

Top Videos

1 2 3 4