DYSEMBRYOPLASTIC NEUROEPITHELIAL TUMOR (D NT) - NEURORADIOLOGICAL FEATURES

Dysembryoplastic neuroepithelial tumors (DNT) were first described as a new tumor entity by Daumas-Duport et al. in 1988 and were introduced into the revised WHO classification of brain tumors in 1993. The purp ose of this study was to work out neuroradiological CT and MRT pattern s of DNT Five patients, aged 11-61 years (three female, two male) unde rwent complete presurgical neuroradiological exploration (5 CT, 4 MRT investigations, 2 angiography) because of brain tumor. Four cases comp lained of seizures and one of occipital-located headache. Total micros urgical excision was achieved in two cases. Two further lesions were r esected subtotally after stereotactic biopsy diagnosis. In one case, s tereotactic biopsy alone was carried out. All DNTs were localized cort ically: two frontobasal medial in the gyrus rectus, two tem porobasal in the gyrus occipitotemporalis lateralis and one infratentorial in th e lobus caudalis cerebelli. They were sharply demarcated from the surr ounding brain tissue. Cortical localization was better visualized by M RT, especially on coronal and sagittal images. CT scans showed a hypod ense lesion, MRT a high-signal intensity in T-2, low signal in T-1 and in proton-weighted images a hyperintense rim with a slightly hyperint ense small cyst. The multinodular tumor architecture was best seen in MRT. Two DNTs presented partial contrast enhancement, while three DNTs did not take up contrast. In two lesions there were focal calcificati ons. The infratentorial DNT was associated with a bony defect of the t abula interna into which the tumor expanded. Two angiographies showed no pathological tumor neovascularization. A hypodense, sharply demarca ted lesion with a multinodular pattern in MRT with cortical location a nd without space-occupying signs is, in combination with the clinical symptom of epileptic seizures, highly suggestive of DNT. As our result s demonstrate, DNT can also occur in the infratentorial space.