RESUMO
INTRODUCTION: Brain tumors are a frequent cause of epilepsy in the pediatric population. The last International League Against Epilepsy (ILAE) classification of focal cortical dysplasias (FCDs) includes a subgroup consisting of tumors with surrounding dysplastic abnormalities (FCD type IIIb). Although its pathogenesis is still unclear, it has several clinical and therapeutic (surgical) implications. BACKGROUND: A number of benign tumors (such as dysembryoplastic neuroepithelial tumors and gangliogliomas) frequently present with medically refractory epilepsy associated with cortical dysplasia. In such cases, planning of surgical resection needs to take into consideration not only the tumor but also the whole area of epileptogenicity. The use of intraoperative electrocorticography recordings is reported to result in better postoperative outcomes, since they help delineate the abnormal cerebral cortex that needs to be resected to provide seizure freedom to patients. Clinical, radiological, and pathological features are also discussed herein.