Primary temporal bone osteosarcoma presenting as a parotid tumor: A case report with diagnostic challenges.

Osteosarcoma rarely arises from the temporal bone, and few primary cases have been reported in adults. The prognosis of head and neck osteosarcoma is generally poor because of the complex anatomy in the region. Complete resection with negative margins is essential to adequately treat head and neck osteosarcoma. Preoperative imaging is crucial given the importance of complete surgical resection to prognosis. In this case, preoperative imaging, including computed tomography and magnetic resonance imaging, revealed a lobulated mass with coarse internal calcification, displacing the parotid gland and extending into the parapharyngeal space. The lesion lacked abnormal findings in the adjacent temporal bone on imaging, but a sarcomatous mass with central calcification could be the basis for including osteosarcoma in the differential diagnosis. We report this case of primary osteosarcoma originating from the temporal bone that was initially discovered as a parotid tumor.