Radiation-induced osteosarcoma of the skull mimicking cutaneous tumor after treatment for frontal glioma.

Radiation-induced sarcomas are recognized complications of radiation therapy and are associated with poor prognosis. Radiation-induced osteosarcoma is one of the rare types of radiation-induced sarcomas, with the risk of radiation-induced osteosarcomas being only 0.01%-0.03% among all patients treated with radiotherapy. There have been only four reported cases of radiation-induced osteosarcomas after radiotherapy for gliomas. Here, we report a unique case of radiation-induced osteosarcomas arising on the skull and extending to the skin, with a short latent period. We also review the clinical features of the previously reported cases.