Primary osteosarcoma of the sphenoid bone with extensive periosteal extension

A 28-year-old male presented with a primary osteosarcoma of the sphenoid bone with extensive periosteal extension manifesting as severe headache and right exophthalmos. Computed tomography (CT) and magnetic resonance imaging revealed an anterior middle cranial fossa tumor extending into both the orbit and the extracranial space. However, roentgenography and CT with bone windows showed no marked osteolytic changes of the sphenoid bone. Total removal of the tumor was performed via the orbitozygomatic approach. Surgery revealed that the tumor had extended periosteally without macroscopic bone destruction, but no obvious abnormalities of the skull. The histological diagnosis was osteosarcoma. The patient was treated with chemotherapy and radiation therapy, but died of tumor recurrence 10 months after the surgery.