Thalamic Tuberculoma Masquerading as a High-Grade Glioma.

Intracranial tuberculomas are rare granulomatous infections that can closely mimic high-grade gliomas on imaging, posing significant diagnostic challenges, particularly in non-endemic regions. We present a case of a 54-year-old immunocompetent male patient with a background of schizophrenia who presented with acute right-sided weakness, left facial droop, and slurred speech. Initial imaging revealed a large left thalamic mass with midline shift and uncal herniation, concerning for a high-grade glioma. Magnetic resonance imaging (MRI) findings demonstrated a heterogeneous thalamic lesion with extensive surrounding white matter changes, elevated choline peak, and decreased N-acetylaspartic acid (NAA) on magnetic resonance (MR) spectroscopy, further supporting the preliminary diagnosis of glioma. However, systemic imaging revealed mediastinal lymphadenopathy and hepatic lesions suggestive of a lymphoproliferative or infectious process. Stereotactic biopsy of the lesion revealed chronic necrotizing granulomatous inflammation without evidence of neoplasia. Although acid-fast bacilli culture and mycobacterial polymerase chain reaction (PCR) were pending, empirical antituberculous therapy was initiated based on histopathology findings. Subsequent follow-up imaging showed marked reduction and near-complete resolution of the lesion, confirming the diagnosis of intracranial tuberculoma. This case highlights the radiologic and clinical overlap between intracranial tuberculomas and high-grade gliomas. Despite advanced imaging modalities such as MR spectroscopy and perfusion studies, differentiation remains challenging. Biopsy remains the gold standard for definitive diagnosis. Awareness of atypical presentations and careful integration of clinical, radiologic, and epidemiologic data are critical to avoid misdiagnosis and unnecessary neurosurgical interventions. Early initiation of antituberculous therapy can lead to excellent clinical and radiologic outcomes, as illustrated in this case.