Contributor: Gordon K. Klintworth
Osteosarcoma (osteogenic sarcoma) is a highly malignant tumor derived from osteoblasts. It characteristically presents between the ages of 10 and 30 years and has a male predominance. The sarcoma most often involves the limb bone metaphyses. Involvement of the skull and more particularly of the orbit is extremely rare. Some orbital osteosarcomas may arise de novo, but many develop 13-20 years after ionizing radiation for retinoblastoma. Paget disease of bone is also a risk factor. Metastases to the lung are extremely common  and occur in 40-50% of patients. The tumor is usually treated with wide tumor resection and adjunctant chemotherapy. Despite treatment the prognosis is poor and a fatal outcome is the rule.