Elderly-Onset Brainstem Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease: A Glioma Mimic

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an autoimmune inflammatory demyelinating disorder of the central nervous system with a broad clinical spectrum, although brainstempredominant presentations in the elderly are rare and may closely mimic neoplastic lesions.We report a case of an 81-year-old female who presented with progressive gait imbalance, binocular diplopia, right-sided sensory symptoms, and mild headache.Magnetic resonance imaging demonstrated an expansile contrastenhancing pontine lesion extending to the pontomesencephalic junction, initially raising strong suspicion for glioma.Evaluation for infectious, neoplastic, and autoimmune etiologies was unrevealing except for lowpositive (1:32) serum myelin oligodendrocyte glycoprotein immunoglobulin G (MOG-IgG), supporting the diagnosis of MOGAD.The patient was treated with high-dose intravenous corticosteroids, resulting in marked clinical improvement.Two early symptomatic recurrences after corticosteroid treatment led to initiation of mycophenolate mofetil.Follow-up imaging demonstrated near-complete resolution of the lesion on T2-weighted fluid-attenuated inversion recovery imaging, with complete resolution of contrast enhancement.This case emphasizes that MOGAD should be included in the differential diagnosis of atypical enhancing brainstem lesions in older adults, as early antibody testing and prompt immunotherapy may help avoid misdiagnosis and unnecessary neurosurgical or oncological interventions.