Abstract
Background:
Extraskeletal osteosarcoma, unlike skeletal osteosarcoma, is a rare malignant mesenchymal tumor with a soft tissue primary that has been reported to occur in a variety of soft tissues.
Case Description:
Case is a 14-year-old, unneutered male Miniature Pinscher, weighing 6.7 kg, who had been treated medically for more than 5 years with a management strategy of puncture extirpation of a salivary gland cyst in the mandible; one month earlier, the fluid retention could not be removed, and after a CT scan showed no lesion in the mandible adjacent to the mass lesion, surgical resection was surgical resection was performed.
Conclusion:
Previous reports of extraskeletal osteosarcoma from the salivary glands in dogs have been rare. However, treatment of a salivary gland cyst in the mandible by long-term puncture extirpation may be a potential predisposing factor for the development of an extraskeletal osteosarcoma around the mandible.

Key words: Dogs, Extraosseous osteosarcoma, Mandible, Salivary gland