Multifocal osteosarcoma of the skull: multiple primary or metastatic? A case report.

Osteosarcoma of the skull is a very rare condition. Moreover, it is extremely rare for osteosarcoma to present as multiple lesions confined to the skull. A 58-year-old woman was admitted with two masses in the parietal area of the skull, accompanied by mild headache and tenderness. Imaging revealed two masses with a heterogeneous consistency in the cranial bones. Excision craniectomy was performed and the pathology was consistent with osteoblastic osteosarcoma. Two nodules in the heart were found on routine follow-up imaging while the patient was undergoing chemotherapy. The nodules were biopsied and found to be metastatic osteosarcoma.