Radiation-induced osteosarcoma with a rhabdomyosarcoma component arising from the dura mater: a case report.

Objective: Radiation-induced tumors are a rare complication of radiation therapy. Here, we describe the first case of a radiation-induced osteosarcoma with a rhabdomyosarcoma component arising from the dura mater after radiation therapy for an astrocytoma. Patient: An 18-year-old man with generalized seizures presented with a neoplastic lesion in the dura mater of a previously irradiated (56 Gy) region 5 years after the initial radiation therapy. A tumor resection was performed, and histological examination revealed an osteosarcoma with a rhabdomyosarcoma component. The tumor recurred despite eight tumorectomies and the addition of chemotherapy and radiotherapy. The patient died from tumor progression 5 years after the first surgical removal of the radiation-induced tumor. Conclusion: This radiation-induced tumor may have originated from primitive, multipotent mesenchymal cells, as it included both osteosarcoma and rhabdomyosarcoma components.