Dysembryoplastic neuroepithelial tumor classification
Two distinct forms (do not appear to have different prognoses):
Simple form: glioneuronal elements consisting of axon bundles perpendicular to the cortical surface, lined with oligodendroglial-like cells that are S-100 positive and GFAP negative. Normal appearing neurons floating in a pale eosinophilic matrix are scattered between these columns (no resemblance to ganglion cells, unlike gangliogliomas).
Complex form: glioneuronal elements as described above in the simple form, with glial nodules scattered throughout. The glial component may mimic a low-grade fibrillary astrocytoma. Foci of cortical dysplasia occur 1).
Molecular studies are needed to better understand the biological nature of GNTs and to refine their classification system 2).