Radiologic appearance of the dysembryoplastic neuroepithelial tumor

PURPOSE: To evaluate the computed tomographic (CT) and magnetic resonance (MR) imaging features of dysembryoplastic neuroepithelial tumor (DNT). MATERIALS AND METHODS: Six CT studies (four with contrast material enhancement) and 10 MR imaging studies (seven with gadolinium enhancement) obtained in 10 patients with a history of seizures and pathologically proved DNT were retrospectively reviewed. RESULTS: All tumors were intracortical or subcortical. CT showed a low-attenuation mass in all cases except one of mixed isoattenuation and low attenuation. The DNT had decreased signal intensity on T1-weighted MR images and well-demarcated increased signal intensity on T2-weighted images without peritumoral edema. Prominent MR imaging features were a gyriform configuration on T1- or T2-weighted images in 10 patients (100%), well-demarcated lobular tumor margins on T2-weighted images in eight (80%), and a high rate of bone remodeling of the adjacent calvaria on MR (60% [n = 61) and CT (67% [n = 4]) images. CONCLUSION: Diagnosis of DNT with imaging modalities alone may be difficult, but these radiologic features may aid in differentiating DNT from other gliomas.