A patient with a dysembryoplastic neuroepithelial tumor who underwent epilepsy surgery after initial seizure

Since dysembryoplastic neuroepithelial tumors (DNTs) are benign tumors that are frequently associated with long-standing medically intractable epilepsy, it is well known that the surgical strategy is resection of the associated epileptogenic zone as well as the tumor. However, the surgical strategy for DNT with a single seizure has not been fully discussed.

We report an 8-year-old boy with DNT in the nondominant frontal lobe who underwent epilepsy surgery at 3 months after his initial seizure.

An intraoperative electrocorticogram revealed frequent paroxysmal cortical activity lateral to the tumor. Since resection of the tumor resulted in persistent paroxysmal activity in this cortex, additional resection was performed. The histological findings in the cortex revealed the presence of cortical dysplasia (CD) (Palmini type IIA). Lesionectomy alone might have left the epileptogenic CD.

It is thought that epilepsy surgery should be recommended in patients with typical neuroimaging findings of DNT, even if the patients had only one episode of seizure.