Low-Grade Glioma in the Differential Diagnosis of Limbic Encephalitis

BACKGROUND: Limbic encephalitis (LE) is an inflammatory syndrome affecting the limbic system, often presenting with seizures, memory impairment, and behavioral disturbances. While autoimmune and infectious causes are common, gliomas can mimic this condition, leading to diagnostic challenges. METHODS: A retrospective review of glioma cases initially diagnosed as LE was conducted at two centers in Mexico (The American British Cowdray and National Institute of Neurology and Neurosurgery) from 2010 to 2022. Inclusion criteria included acute clinical presentation, magnetic resonance imaging (MRI) T2 hyperintensities in the limbic system, lumbar puncture, paraneoplastic panel, cerebrospinal fluid (CSF) viral studies, and histopathological confirmation. Patients with infectious, autoimmune, or other identified etiologies were excluded. RESULTS: Nine patients (mean age 45.2 years; six males, three females) met the criteria. Initial presentations included seizures (5/9), encephalopathy (5/9), fever (1/9), and psychotic symptoms (2/9). MRI revealed limbic system hyperintensities with minimal contrast enhancement. Spectroscopy and perfusion MRI findings suggested low-grade gliomas (LGGs). Histopathology confirmed astrocytoma (5/9), oligoastrocytoma (3/9), and oligodendroglioma (1/9). All patients received steroids, and some received additional therapies (plasma exchange (PLEX), acyclovir, immunoglobulin). CONCLUSIONS: Gliomas can present as LE, leading to potential misdiagnosis. Advanced imaging and histopathological confirmation are essential for accurate differentiation, ensuring appropriate treatment and improved patient outcomes.