Mast Cell Tumor (MCT)

Mast Cell Tumor (MCT)

Species: Cat

Breeds Affected: All breeds (skin form sometimes in young Siamese)

A tumor arising from mast cells. In cats, cutaneous MCTs are most common and are usually benign or low-grade, though they can also occur in internal organs (eg, spleen). Cutaneous lesions are often solitary and may regress spontaneously.

• For skin MCT
• a solitary
• firm
• raised nodule (often hairless and non-pigmented) is typical. It may be itchy or red. Visceral forms can produce systemic signs such as weight loss or anorexia.

Surgical excision with clean margins is the treatment of choice for cutaneous MCT. For visceral involvement, such as splenic MCT, splenectomy is performed. Adjunct chemotherapy may be considered in malignant or widespread cases, and antihistamines are used to counteract histamine release.

Antihistamines (eg, diphenhydramine) pre-treatment; prednisolone as a corticosteroid; for malignant cases, chemotherapy (eg, lomustine or vinblastine); H2 blockers (eg, famotidine) to prevent gastric ulceration; pain management as needed.