Dysembryoplastic neuroepithelial tumor: a clinicopathological study of 32 cases.

Dysembryoplastic neuroepithelial tumor (DNT) is a relatively newly described entity and is an important cause of intractable epilepsy. We report 32 cases of DNT who were operated and treated in our hospital over a period of 12 years. Immunostaining for various proliferative markers and tumor suppressor gene proteins was done to assess the proliferative potential of these tumors. The most common presentation was partial complex seizures followed by generalized tonic-clonic seizures, focal motor seizures, and myoclonus. The most common location was temporal lobe followed by frontal and in one patient lesion was multifocal. All patients were seizure free at the last postoperative follow-up which varies from 12 to 96 months with mean of 33.7 months. Microscopic examination showed classical histology comprising of intracortical multinodular microcystic lesions with floating neurons. Proliferative indices were very low (<1%) and tumor suppressor gene protein expression was not seen in the present study. Cortical dysplasia of the surrounding brain was observed in 37.3% of cases.