Neuroradiologic and clinicopathologic features of dysembryoplastic neuroepithelial tumor

Objective: To evaluate MRI or CT appearance and clinicopathologic features of dysembryoplastic neuroepithelial tumor (DNT). Methods: MRI or CT appearance and clinicopathologic features in 12 cases of histopathology confirmed DNT were retrospectively studied. Results: There were 6 men and 6 women, and the age ranged from 12 to 68 years with the average age of 36.7 years. Most patients had partial seizures, but the neurological deficits were absent. All lesions were located in the supratentorial region and involved the cerebral cortex on MRI scan. Localization of lesions was predominantly in the frontal (n=4) and temporal (n=3) lobes. The maximum lesion diameter ranged in size from 2 cm to 5 cm, and the lesion showed round, lobular- or irregular-shaped. The white matter was involved in 2 cases, and 7 were with cystic change (58.3%). All lesions were hypointense on T1-weighted images and hyperintense on T2-weighted images as well as devoid of peritumoral edema or mass effect. MRI signal intensity of cystic lesions was homogeneous on T1-weighted images which was equal to or slightly higher than that of cerebrospinal fluid. CT scan of 6 cases disclosed moderately hypodense lesion, 2 of which were markedly hypodense cystic-lobular shaped, and foci of calcification was observed in 1 case. Contrast enhancement was absent in 4 cases and only 1 case showed slight enhancement unevenly. Histologically, the DNT were classified into three subtypes: simple form (n=4), complex form (n=6), and non-specific variant (n=2). All patients experienced lesion gross total or subtotal surgical removal, and had received no chemo- or radiotherapy postoperatively. Conclusion: DNT is a benign lesion, and its characterization is better disclosed by MRI compared to CT scan. (authors)