Dysembryoplastic neuroepithelial tumors. Analysis of 16 cases.

Objectives. - We report on 16 cases of dysembryoplastic Neuroepithelial tum or (DNT) treated in the Nancy University Hospital from 1987 to 1997 Patients and methods. - There were 9 males and 7 females. Mean age at onset of symptoms was 9.5 years (range: 3 months to 29 years) and the mean age a t surgery was 16 years. Nine patients experienced partial complex seizures, 5 patients generalized seizures, I patient partial seizures with secondary generalization and one patient ataxia. The diagnosis of DNT was made under consideration of clinical, radiological and neuropathological features. Al l patients underwent surgery. Results. - Removal of the tumor was complete for 10 patients, subtotal or p artial for 6 patients. Histological examination revealed that 7 cases were specific forms of DNT due to the presence of the specific glioneuronal elem ent. For the 9 remained cases, the diagnosis of DNT could only be mane with the consideration of clinical and radiological features. Mean post-surgica l follow-rip was 3.5 years (range : 1-8 years). Fight patients were seizure s-free, 7 had a significative reduction in seizures frequency with minimal anti-convulsivant treatment. The patient with ataxia remained unchanged. Fa r the patients with partial resection of the tumor, follow-up MRI and CT sc an showed no significant growth of the remnant and the remaining patients h ave had no recurrence to date. Conclusion. - The recognition of this surgically curable entity is mandator y. Knowledge of the good prognosis associated with the DNT is essential to avoid deleterious side effects of overtreatment by radiotherapy and/or chem otherapy.