OBJECTIVETo study the clinicopathologic features and radiologic findings of dysembryoplastic neuroepithelial tumor (DNT).

METHODSThe clinical presentations, radiologic findings, histologic features and immunophenotype of 9 cases of DNT were analyzed.

RESULTSThe age of patients ranged from 12 to 51 years (mean age = 32 years). Most presented with partial seizures, sometimes accompanied by transient aphasia, agraphia and decreased visual acuity. One case was asymptomatic and discovered incidentally during a routine check-up. All patients had no neurological deficit found on physical examination. All tumors were located in the supratentorial cerebral cortex. There was no peritumoral edema or space-occupying effect on radiologic examination. The tumors involved either frontal lobe (number = 4), temporal lobe (number = 4), frontoparietal lobe (number = 1) . Two cases showed cystic changes. Two histologic variants of DNT were recognized: simple (number = 3) and complex (number = 6). Simple variant was composed mainly of the glioneuronal element, accompanied by surrounding oligodendrocyte-like cells, and the complex variant contained a low-grade glioma component, in addition to the glioneuronal element and sometimes foci of cortical dysplasia.

CONCLUSIONSDNT is a benign tumor with excellent prognosis after surgical excision. Local recurrence is rare. Complex variant of DNT needs to be distinguished from other types of low-grade glioma.