Epithelioid osteosarcoma presenting as a rapidly expanding maxillary mass.

BACKGROUND: Osteosarcomas of the jaws account for less than 10% of reported neoplasms of this type. Patients with osteosarcoma in this region tend to be in the late-third to mid-fourth decades of life. The osteoblastic, chondroblastic, and fibroblastic variants constitute the majority of lesions.

METHODS: A mass was observed in the maxilla of a 50-year-old male who presented for a complete odontectomy. Over the ensuing weeks, the mass substantially increased in size, despite multimodality treatment efforts.

RESULTS: Radiographic findings revealed a mixed density mass of the left maxilla. Histologic, immunohistochemical, and electron microscopy examination of the tumor showed a malignant mesenchymal neoplasm consisting of sheets of epithelioid and spindle cells exhibiting focal osteoid formation.

CONCLUSIONS: We report a rare and aggressive case of epithelioid osteosarcoma arising in the maxillofacial complex.