People get to know their cats very well from petting and interacting with them. In return, cats will soon develop unique behaviours to make them special to you. Grooming and petting will help you develop a knowledge of their body so when you find a lump that you can’t recall was present before you should become concerned. This, in fact, is the story of Daisy and her ear. Cats at Home has known Daisy since her kitten-hood (2005). With a normal development for a Ragdoll, Daisy’s annual checkups identified dental issues which were addressed with routine cleaning. A few years ago Daisy’s Mom noticed a lump developing on her left ear and decided to have Dr. Thompson look at it. At that time, the owner’s decision was to just monitor the lump because it was very small (pea size). Dr. Thompson checked it annually and in 3 years it had continued to grow to the point that it was becoming too large and would be impossible to remove without a major amputation of the ear tissue. Keeping in mind that whenever a lump is removed the surgeon has to go beyond the edge of the lump to ensure the margins of the cut are not leaving any of the suspect tissue behind. In order to diagnose the lump Dr. Thompson decided to first do a fine needle aspirate and send the tissue (cytology) to the lab for a Veterinary Pathologist to identify its origin and development. The answer was that it was a Mast Cell Tumour (MCT) and it was decided that complete removal would be the best solution for the health of Daisy. Mast cell tumors (MCT) comprise a small portion of all cutaneous (skin) tumors in the cat. These tumors can be benign (not cancerous) or malignant (cancerous and able to spread to other parts of the body).
The Pathologists story: The job of the Veterinary Pathologist is to identify the nature of the cells collected and classify them to prescribe treatment for the patient. Mast cell tumors (or mastocytomas) are graded according to their location in the skin, presence of inflammation, and how well they are differentiated. Grade 1 cells are well differentiated with a low potential for metastasis; Grade 2 cells are intermediately differentiated with a potential for locally invasive metastasis; and Grade 3 cells are poorly differentiated or undifferentiated with a high potential for metastasis. Differentiation determines of how much a particular tumor cell looks like a normal cell; the more differentiated, the more like the normal cell. In general, the more differentiated the mast cell tumor, the better the prognosis.
Surgery is the recommended treatment for mast cell tumors. This requires removing a mass on the skin or in the body with a safety margin of normal cells to ensure that there are no abnormal cells left behind to re-grow.
Surgical recovery takes an average of 2-4 weeks of restricted activity, confinement and a plastic cone (Elizabethan collar). Antibiotics, pain medications and antihistamines are continued at home. Additional treatment, such as chemotherapy, will depend on the biopsy results.
Generally, mast cell tumors in cats are “good” in the skin and “bad” in the belly. However, it is very important to work closely with your family vet, your surgeon and/or your oncologist to obtain the best possible outcome.
Cats with cutaneous mast cell tumors typically do very well.
The tumors are not very likely to come back after surgery. It can be curative. Most cats live many years post-surgery. This is the case with Daisy. Her recovery has been successful and she looks great after her gorgeous fur returned.