Abstract
Primary central nervous system (CNS) neoplasia is relatively rare in most domestic animal species, except dogs and cats, being directly associated with aging. On the other hand, hemangiosarcoma, lymphoma, mammary carcinoma and melanoma are the most common secondary tumors affecting CNS. They usually represent metastasis, and less frequently arising from nearby areas that infiltrate or compress CNS normal tissue, resulting in neurological clinical signs. This case report documents a 10-year-old female spayed Pinscher presenting with severe thoracolumbar pain and paraplegia due to a primary vertebral hemangiosarcoma (HSA). CT revealed a lytic lesion in the L1 vertebra causing dorsal displacement and spinal cord compression. Surgical removal of the neoplasm involved a bloc vertebral resection and stabilization with screws, cement, and soft tissue reconstruction, leading to marked clinical improvement. Histopathology confirmed an infiltrative primary bone HSA with positive immunohistochemical staining for endothelial marker. Postoperative adjuvant therapy with metronomic cyclophosphamide and propranolol was associated with extended survival and maintained quality of life over 13 months. This report underscores the importance of combined surgical and chemotherapeutic management for primary vertebral HSA in dogs, and this neoplasm as a less likely differential diagnosis for local invasive compressive neoplasms in CNS in dogs.