Tumors and Tumoral Epilepsy
Dysembryoplastic neuroepithelial tumors: Where are we now?
Version of Record online: 12 DEC 2013
Wiley Periodicals, Inc. © 2013 International League Against Epilepsy
Special Issue: Tumors and tumoral epilepsy
Volume 54, Issue Supplement s9, pages 129–134, December 2013
How to Cite
Chassoux, F. and Daumas-Duport, C. (2013), Dysembryoplastic neuroepithelial tumors: Where are we now?. Epilepsia, 54: 129–134. doi: 10.1111/epi.12457
- Issue online: 12 DEC 2013
- Version of Record online: 12 DEC 2013
- Dysembryoplastic neuroepithelial tumors;
- Focal cortical dysplasias;
- Epileptogenic zone;
- Temporal lobe epilepsy;
- Intracranial recordings
Dysembryoplastic neuroepithelial tumors (DNTs) belong to the surgically treatable long-term epilepsy–associated group of tumors. Based on cortical specimens provided through epilepsy surgery at Sainte-Anne hospital, three histologic subtypes (simple, complex, and nonspecific) have been described. Electroclinical data, imaging, intralesional recordings (stereo–electroencephalography [EEG]) and histologic correlations have been recently reviewed in order to assess the relationship between the epileptogenic zone (EZ), the tumor, and associated focal cortical dysplasia (FCD), and to determine optimal strategy for curing epilepsy. Based on a large series (78 patients, 50 male, aged 3–54 years, temporal location 73%, nonspecific forms 68%), we found similar electroclinical data in all DNT subtypes, and demonstrated that magnetic resonance imaging (MRI) features allow differentiation of histologic subtypes. Type 1 (cystic/polycystic-like) always corresponded to complex or simple forms, whereas type 2 (nodular-like) and type 3 (dysplastic-like) corresponded to nonspecific forms. It is notable that we demonstrated intrinsic epileptogenicity in all cases, but found that the EZ differed significantly according to MRI subtype, colocalizing with the tumor in type 1 MRI, including perilesional cortex in type 2 MRI, and involving extensive areas in type 3 MRI. The main prognostic factors for favorable outcome (83% of seizure-free patients) were complete tumor and EZ removal, short epilepsy duration, and lack of cortico-subcortical damage. According to these findings, surgical resection may be restricted to the tumor in type 1 MRI but should be more extensive in other MRI subtypes, especially in type 3 MRI. This MRI-based scheme may be helpful for optimal resection in epilepsy due to DNTs. In addition, we emphasize that early surgery is crucial in curing epilepsy.