Diffuse leptomeningeal glioneuronal tumor: A review of diagnosis and management with an illustrative case.

Diffuse leptomeningeal glioneuronal tumors (DLGNTs) are a rare indolent neoplasm described in the 2016 WHO classification of tumors of the central nervous system (CNS). We describe a case of an 11 year old boy who initially presented intermittent headache, low back pain and communicating hydrocephalus, misdiagnosed as having tuberculous meningitis. Further clinical deterioration with seizures was observed and follow-up MRI showed further aggravation of leptomeningeal enhancement in the basal cisterns. Biopsy of the brain and leptomeninges revealed a diffuse leptomeningeal glioneuronal tumor. DLGNT should be considered in the differential diagnosis of conditions presenting as communicating hydrocephalus with nodular lesions and leptomeningeal enhancement. A timely histologic diagnosis through a biopsy of the brain is necessary to confirm the diagnosis.