Dysembryoplastic neuroepithelial tumor in the left lateral ventricle.

Extracortical location of dysembryoplastic neuroepithelial tumor (DNT) is rare. We present a case of DNT localized in the left lateral ventricle of a 21-year-old female patient. Magnetic resonance imaging of the brain showed a round mass lesion in the floor of the anterior horn of the left lateral ventricle. The lesion was hypointense on T (1)-weighted images and slightly hyperintense on T (2)-weighted images without contrast enhancement. Total removal of the yellowish-white colored soft tumor was performed through a transcallosal approach. Histologically, the tumor was of simple type of DNT that was composed of small oligodendrogliocytes clustered tightly about perivascular spaces with neurons floating in mucoid pools showing an eosinophilic fibrillary matrix in the background. The recognition of DNT with an unusual location in lateral ventricle has therapeutic and prognostic significance since DNT is curable by surgical excision and radiation therapy is of no obvious benefit.