Right Frontal Isocitrate Dehydrogenase (IDH)-Mutant WHO Grade 3 Oligodendroglioma Presenting With Morning Headache and Gait Imbalance.

Oligodendroglioma is a diffuse glioma characterized by isocitrate dehydrogenase (IDH) mutation and 1p/19q codeletion. We report the case of a 45-year-old woman who presented with progressive headaches, nausea, vomiting, blurred vision, and gait imbalance associated with rapid neurological deterioration. Neuroimaging demonstrated a large right frontal intra-axial lesion with heterogeneous enhancement, cystic components, surrounding edema, and significant mass effect with midline shift. The patient underwent subtotal surgical resection, and histopathological evaluation confirmed an IDH-mutant, 1p/19q-codeleted oligodendroglioma. Postoperatively, she received adjuvant chemoradiotherapy followed by temozolomide, with subsequent clinical and radiographic improvement. This case highlights the importance of early recognition of progressive neurological symptoms and multidisciplinary management in patients presenting with aggressive intracranial tumors.