Radiation-induced osteosarcoma 16 years after surgery and radiation for glioma--case report.

A 35-year-old man developed osteosarcoma of the left parietal and occipital bones 16 years after radiotherapy for glioma in the right occipital lobe. Radiotherapy of the primary neoplasm used 50 Gy administered to a localized field through two lateral ports. The secondary neoplasm arose contralateral to the primary lesion but within the irradiated field. The tumor had a multilocular cyst with considerable intracranial extension, and symptoms of elevated intracranial pressure were prominent early in the course. After a short-lived initial remission following surgical intervention and chemotherapy, the patient deteriorated because of tumor recurrence and died 18 months after the diagnosis. Radiation-induced osteosarcoma is a well-known but rare complication of radiotherapy for brain neoplasms with a poor prognosis.