Primary Focal Intracranial Leptomeningeal Glioma: Case Report and Review of the Literature.

BACKGROUND: Primary focal intracranial leptomeningeal glioma (PFILG) is considered a rare solitary glial tumor arising from the leptomeninges without brain attachment or evidence of primary neoplasm elsewhere within the neuraxis. We report a case of PFILG in a left parietal location and provide a concise review on its clinicoradiologic, histopathologic, and management characteristics.

CASE PRESENTATION: A 75-year-old woman presented with focal motor seizures involving the right upper limb with associated occasional headache. Magnetic resonance imaging (MRI) of the brain revealed a small focal lesion attached to the left parietal dura with underlying brain parenchymal signal changes, and contrast-enhanced images showed heterogeneous enhancement of the tumor and meninges. The repeated MRI brain images within a month of primary imaging revealed significant progression of the size of lesion along with invasion of underlying parietal lobe parenchyma. The patient underwent gross total resection of the lesion, and the histopathologic diagnosis was glioblastoma multiforme (GBM), World Health Organization grade 4, isocitrate dehydrogenase wild type. The patient recovered well from surgery without deficits; however, she refused adjuvant treatment. MRI of the brain repeated 3 months after surgery revealed significant progression of the GBM with mass effect. Although adjuvant treatment was then started, she could not tolerate it and died 4 months after surgery.

CONCLUSION: The possibility of high-grade PFILG should be considered in any aggressive extra-axial focal lesion. The definitive diagnosis can be made after histologic examination. Although surgery followed by adjuvant treatment is considered the mainstay of treatment, the overall prognostic outcome of high-grade PFILG is dismal.