Primary diffuse leptomeningeal gliomatosis mimicking meningeal tuberculosis.

Primary diffuse leptomeningeal gliomatosis (PDLG) is a rare condition, with only 45 cases recorded to date, characterized by infiltration of the meninges by glial cells without evidence of primary tumor in the brain or spinal cord parenchyma. Here, we describe a patient with PDLG who was managed with tuberculostatic drugs owing to multiple findings that were suggestive of tuberculous meningitis. A 19-year-old woman presented with headaches and behavioral changes. A sudden decrease in visual acuity with papilledema, bilateral sixth nerve palsies, and neck stiffness developed. Lumbar puncture showed elevated opening pressure (50 cm H2O). Cerebrospinal fluid (CSF) analysis showed glucose 30 mg/dL, protein 26.5 mg/dL, white blood cell count 150 (60% lymphocytes, 40% neutrophils). The second sample of CSF provided adenosine deaminase activity 21.9 U/L. Polymerase chain reaction for Koch's bacillus was positive in the third CSF sample. Magnetic resonance imaging revealed meningeal thickening of the quadrigeminal cistern, tentorium cerebelli, cerebral convexity, and spinal cord, with gadolinium enhancement in nodular lesions. The patient died 22 weeks after symptom onset owing to brainstem infarction. Postmortem pathologic studies revealed PDLG. This entity should be included in the differential diagnosis of tuberculous meningitis that does not respond to treatment with antituberculous drugs. Surgical biopsy should be considered in contrast-enhanced areas in magnetic resonance imaging.