A dog with extraskeletal osteosarcoma of the salivary glands survived long-term, following surgical resection and adjuvant therapy

A 12-year-old French bulldog presented with a mass on the right lower jaw. Computed tomography revealed that the mass originated from the salivary gland and was not continuous with the right mandible. The mass was surgically removed and subsequently diagnosed as extraskeletal osteosarcoma of the salivary gland following histopathological and immunohistochemical examinations. Although the surgical margin was clear, postoperative adjuvant therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) was initiated. Lung metastasis was observed 249 days after the initial examination; therefore, toceranib was initiated with NSAIDs. The dog died 496 days after the initial examination of this disease progression but had good long-term management with a combination of surgery, NSAIDs, and toceranib.