Successful treatment of a radiation-associated extradural osteosarcoma with chemotherapy in an adolescent girl.

Bone sarcomas are the most common second malignant neoplasms in survivors of a malignant solid tumor in childhood. In contrast to de novo tumors, secondary bone cancers are typically associated with a poor prognosis, reflecting both a preponderance of primary sites that preclude complete resection in the flat bones of the axial skeleton, and the tendency for local invasiveness or distant metastasis. We describe a patient who developed malignant extradural osteosarcoma of the temporal bone 6 years after successful treatment for a malignant cerebellar astrocytoma with surgical resection and local irradiation. A complete resection of the sarcoma was not possible; however, she achieved a biopsy-proven complete response after intensive chemotherapy with ifosfamide, followed by cisplatin and doxorubicin. At age 13, she remains free of recurrence 3 years after completing all therapy. In view of the rarity of prolonged disease control after incomplete resection for osteosarcoma, this report suggests the value of intensive combination chemotherapy in achieving a durable unmaintained remission in our patient.