Different pattern of expression of nestin in the non-specific form of dysembryoplastic neuroepithelial tumors compared to the simple and complex forms.

Dysembryoplastic neuroepithelial tumors (DNTs) are benign glial-neuronal neoplasms with characteristic cliniopathologic features. Three histologic forms of DNTs have been described (simple, complex, and non-specific). The developmental origin of the tumors remains controversial. To determine the developmental origin and nature of the histologic forms of DNTs, immunohistochemical studies of nestin, TrkA, TrkB, p75, and NeuN were conducted in 40 cases of DNTs, including 11, 9, and 20 simple, complex, and non-specific forms, respectively. Nestin positivity of oligodendroglia-like cells (OLCs) was present in 50 and 27.3% of simple and complex forms, respectively. In the non-specific form of DNT, 94.7% of the cases were positive for nestin. Most DNTs exhibited diffuse, strong staining for TrkA and TrkB, irrespective of the histologic subtypes. Both p75 and NeuN positivity were found in about one-half of the simple, complex, and non-specific forms, respectively. Our study suggests that OLCs are a heterogeneous population of cells, and higher expression of nestin in the non-specific form of DNTs compared to the simple or complex forms suggests that the non-specific form has an earlier developmental origin than the simple or complex forms.