Surgical Treatment of Primary Mast Cell Tumor in Mucosal Surface of Lower Lip in a Dog: A Case Report

Introduction: Mast cell tumors (MCTs) have been described as a form of cancer affecting a specific type of blood cell that typically plays a role in the body's reaction to allergens and inflammatory processes. The MCTs have been classified as skin tumors in dogs which can also affect other areas of the body, such as the spleen, liver, gastrointestinal tract, and bone marrow. The present study investigated the clinical and histological signs, biological behavior, and treatment of primary oral mast cell tumors. Case report: A 3-year-old neutered female, weighing 18 kg and classified as a medium mixed breed, was referred to a veterinary clinic in Mashhad (Iran) due to the presence of a pink, lobulated mucosal mass located on the internal surface of her lower lip. Although the vital signs were normal, clinical examination, radiology, and an incisional biopsy were performed from the lesion site under general anesthesia for histology study. Histopathological features were similar to those of mastocytoma in this case. On presentation, no concurrent mass was found on other sides of the body. Mandibular lymph nodes were not enlarged; however, the incisor teeth of the mandible were loosed. Accordingly, the primary oral MCTs were diagnosed. The surgery was done and After a follow-up period of 150 days post-excisional surgery for a Mast cell tumor, the patient remained alive and exhibited no visible signs of tumor recurrence or surgical complications. Conclusion: The current case report defined a primary Mast cell tumor with slow tumor growth and without metastasis in the mucosal surface of the lower lip in a dog treated by complete excisional surgery only, unlike some previous studies of primary oral MCTs in dogs with aggressive biological behaviors.