Dysembryoplastic Neuroepithelial Tumor: MR Imaging Findings

PURPOSE: To describe the characteristic MR imaging findings of dysembryoplastic neuroepithelial tumor(DNT). MATERIALS & METHODS: We retrospectively reviewed MR images and pathologic findings of seven patients(five maleand two female, mean age 22) with surgically proven DNTs. We analyzed the location, size, configuration, signal intensity and contrast enhancement of nodules and accompanying calcifications, surrounding edema and calvarialchanges. RESULTS: All tumors were located in the cortical and subcortical portions of the temporal lobes. Most tumors showed small well-demarcated gyriform cystic nodules with almost the same signal intensity as that of the cerebrospinal fluid. Nodule margins were more sharply delineated on T2 than on T1-weighted images because on the former the peripheral portion of nodules shows high signal intensity. None of the patients showed surrounding edema or mass effect. On contrast-enhanced study, one of five patients showed subtle peripheral enhancement. Two patients showed included dense calcified nodules adjacent to cystic nodules, and two showed overlying calvarial thinning. CONCLUSION: Multiple small gyriform intracortical cystic nodules and occasional dense nodular calcifications are the characteristic findings of DNTs, and these may be differentiated from other focal lesion sin patients with temporal lobe epilepsy with the help of MR imaging.