Canine Mast Cell Tumors

Canine mast cell tumors (MCTs) are the most common skin tumors in dogs and the second most common in cats, originating from mast cells integral to the immune system. These tumors exhibit clinical behaviors ranging from benign to highly malignant, with mast cells containing granules rich in histamine, heparin, and vasoactive substances. Clinically, MCTs are present as solitary or multiple nodules with diverse appearances and systemic signs due to histamine release. Diagnosis involves physical examination, fine-needle aspiration, and cytology, though biopsy is essential for reliable grading. Treatment options include surgery with adequate margins, intratumoral injections like tigilanol tiglate (Stelfonta) or yttrium-90 (IsoPet), and systemic therapy. The choice of treatment depends on tumor grade, size, location, and metastasis status. This chapter discusses the clinical presentation, diagnostic evaluation, and treatment strategies for MCTs, highlighting the importance of accurate grading and tailored treatment plans for optimal patient outcomes. The chapter discusses the treatment of canine mast cell tumors (MCTs) using various therapeutic approaches, including intratumoral injections, systemic therapy, and supportive treatments.