Concurrent multiple skin mast cell tumors and lung adenocarcinoma in a cat

Abstract

An 8-year-old, castrated male, Scottish Fold cat, previously diagnosed with multiple cutaneous mast cell tumors, visited our hospital to discuss future treatment. Thorough systemic examination was performed, revealing five areas with cutaneous mast cell tumors and a lesion in the left thoracic cavity. The skin nodules were surgically removed and diagnosed as well-differentiated mast cell tumors by histopathology. After surgery, the cat was treated with toceranib phosphate (Palladia; Zoetis, Japan) administered orally (10mg/head, MWF) between Day 21 and Day 479. On Day 260, the growth of the intrathoracic lesions was observed, and surgery was performed. Histopathology revealed lung adenocarcinoma. Post-surgical treatment with toceranib was discontinued due to gastrointestinal side effects, and the patient’s condition deteriorated due to hypercalcemia and kidney disease, leading to death.