Diffuse Leptomeningeal Glioneuronal Tumor: A Unique Leptomeningeal Tumor Entity

Diffuse leptomeningeal glioneuronal tumor (DLGNT) is a recent addition to the World Health Organization classification schema of brain tumors, under the heading of neuronal and mixed neuronal-glial tumors. DLGNTs have a classic imaging appearance. However, it has often been misdiagnosed owing to its rarity, its resemblance to granulomatous/leptomeningeal etiologies, and the clinical presentation.

We have described the case of a 3-year-old girl who had presented with complaints of nonprojectile vomiting and altered sensorium that had been initially diagnosed and treated as a case of tubercular meningitis at a peripheral health facility. However, the nonresponse to antitubercular medication necessitated a repeat magnetic resonance imaging evaluation at our institute, which had revealed the classic imaging appearance of DLGNT. The diagnosis was further established by meningeal biopsy and the histopathological evaluation findings.

We have described the classic imaging appearance of this rare brain tumor. Radiologists and clinicians should be aware of this entity to avoid misdiagnosis and a delay in management.