MAP2 and nestin co-expression in dysembryoplastic neuroepithelial tumors.

BACKGROUND

The ontogeny and maturity of neurons and oligodendroglia-like cells (OLC) found in dysembryoplastic neuroepithelial tumors (DNT) remains controversial. A developmental origin has been proposed based on the close association to cortical dysplasia and the benign microscopic and clinical course. Our goal was to characterize the expression of nestin, a neuroepithelial precursor/stem cell antigen in DNT, along with other pathological and clinical features of this entity.

METHODS

The clinical and operative features of 13 surgical specimens meeting the histological criteria for DNT were reviewed. Nestin, microtubule-associated protein 2 (MAP2), neurofilament (NF) and glial fibrillary acidic protein (GFAP) were examined by immunohistochemistry and confocal scanning laser microscopy.

RESULTS

Select neuronal cells in all cases demonstrated strong MAP2 immunoreactivity. Nestin-positive cells of neuronal morphology were found in 6 cases. OLC demonstrated frequent selective staining for MAP2, GFAP and nestin. Confocal microscopy demonstrated numerous examples of cells co-expressing nestin and MAP2.

CONCLUSIONS

Our study suggests that OLCs represent a united population of immature neuronal (nestin + MAP2) and glial (GFAP) phenotypes. Larger, morphologically recognizable neurons also showed occasional co-expression of nestin and MAP2, suggesting a degree of dysmaturity in common with their OLC counterparts. The apparent mixed lineage of OLCs lends support to theories suggesting that DNTs arise from pluripotent neuroepithelial cells.