Unique Case Report of a Meningeal Sarcoma Arising duringOngoing Treatment for Progressing Intraparenchymal Glioma

Radiation-induced sarcomas in the brain are extremely rare, usually occur with an average latency of 9 years, and are associatedwith poor outcomes. Latency periods shorter than 1 year may indicate a genetic predisposition such as Li-Fraumeni syndrome.A 34-year-old man underwent initial tumor resection and radiation therapy for a World Health Organization (WHO) Grade IIAstrocytoma. Within 6 months, the tumor recurred as WHO Grade III and was treated with temozolomide and thenbevacizumab. Despite the patient’s apparent improving condition, MRI revealed new dural-based lesions 10 months afterradiation therapy and identified as high-grade sarcoma. The patient resumed bevacizumab, began NovoTTF treatment forprogressing glioma, and ifosfamide/doxorubicin for the sarcoma. Genetic testing revealed no pathogenic mutation in the TP53gene. Ultimately, treatment was unsuccessful and the patient succumbed to glioma and sarcoma within 2 years of initialdiagnosis. This case was unique due to the rapidly progressing glioma and sudden appearance of a high-grade sarcoma. It isunusual to have two separate intracranial primary cancers with each requiring a different chemotherapy regimen. We discussthe difficulty of simultaneously treating with separate chemotherapy regimens. It remains unclear whether the sarcoma wasinduced by the radiation treatment or a genetic predisposition