Dysembryoplastic neuroepithelial tumor

Definition

A rare mixed neuronal-glial tumor characterized by a benign, usually supratentorial lesion with predominantly cortical location and multinodular architecture. The tumor typically becomes symptomatic in the second or third decade of life with drug-resistant partial seizures. Histological hallmark is the specific glioneuronal element, columns oriented perpendicularly to the cortical surface, formed by bundles of axons attached to oligodendroglia-like cells, while neurons appear to float in an abundant eosinophilic matrix.