Progressive Multifocal Glioblastoma in a Patient with Multiple Sclerosis: Case Report & Management Considerations

Abstract Background Multiple sclerosis is a chronic immune-mediated demyelinating disorder of the central nervous system characterized by blood-brain barrier disruption and lymphocytic infiltration. Glioblastoma is the most common primary malignant brain tumor, marked by aggressive growth, angiogenesis, and invasion, with limited survival despite multimodal therapies. Available literature on the co-occurrence of these disorders is limited to case reports and small series. Case Presentation: A 65-year-old woman with a 40-year history of relapsing-remitting multiple sclerosis treated with glatiramer acetate for > 2 decades, presented with new-onset focal seizures. She was found to have multifocal glioblastoma involving the right frontal and temporal lobes. Histopathology confirmed glioblastoma with wild-type isocitrate dehydrogenase and unmethylated O 6 -methylguanine-DNA methyltransferase promoter. Despite multimodal therapies, including a trial of everolimus, her clinical course was marked by progressive neurologic decline and death. Conclusions Detailed radiologic interpretation, timely biopsy of atypical lesions, and individualized treatment strategies are essential for managing concurrent multifocal glioblastoma and multiple sclerosis. This case also highlights treatment decisions to balance tumor control while limiting the risk of exacerbating demyelination. Temozolomide chemotherapy and everolimus, which inhibit the mechanistic target of rapamycin, represent therapies with dual activities against tumor progression and immune-mediated inflammation.