Dysembryoplastic neuroepithelial tumours: clinical, proliferative and apoptotic features

Aims: Dysembryoplastic neuroepithelial tumours (DNTs) have been considered benign lesions characterised by a chronic, indolent clinical course. Previous studies have suggested that increased proliferation rates may be balanced by corresponding rates of apoptosis. The objective of this study was to determine whether a correlation exists between histological features and indices of proliferation/apoptosis. Methods: Fourteen consecutive surgical specimens meeting the histological criteria for DNT were retrospectively reviewed for evidence of aggressive histological features, including anaplasia, mitotic activity, and Ki67 labelling. Immunohistochemistry was performed semi-quantitatively to evaluate and compare proliferation (Ki76) and apoptosis (TUNEL). The clinical course of the patients was also reviewed. Results: Atypical histological features were demonstrated in the glial component of select complex DNTs. TUNEL indices, however, had negligible correlation with proliferative indices. A balance between cell proliferation and apoptosis was not evident particularly in those cases displaying aggressive histological features. Conclusions: While there is no clearly defined clinical or pathological pattern to indicate aggressive growth of DNTs, elevated proliferative indices coupled with atypical histological features in complex DNTs should be taken into consideration in determining the aggressiveness of surgical extirpation and follow-up until experience with these uncommon tumours is greater.