Dysembryoplastic Neuroepithelial Tumor (DNT): Morphological and Immunohistochemical Features

Abstract. Dysembryoplastic neuroepithelial tumor is a rare mixed neuronal-glial tumor. The recognition and correct diagnosis of dysembryoplastic neuroepithelial tumor is important because this tumor is curable by excision. The records of the Pathology Department at King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia, were reviewed for cases that were histologically diagnosed as dysembryoplastic neuroepithelial tumor between 2000 and 2007; five cases were found. The clinical, radiological, histological and immunohistochemical findings were reviewed. The ages ranged between 9 and 25 years. There were 2 males and 3 females. All patients were diagnosed with epilepsy. Three patients had temporal tumor and the other two had frontal tumors. Radiological evaluation showed non-enhancing mass without mass effect or vasogenic edema. All five cases were characteristically composed of small round oligodendroglia-like cells, astrocytes and mature neurones in varying proportions. Immunocytochemistry for glial fibrillary acidic protein and neuronal markers (neuron-specific enolase; and synaptophysin) highlights the astrocytic and neuronal components. The recognition of this tumor is very important because it is a surgically curable lesion with excellent prognosis. Pathologists need to be familiar with the characteristic histopathological findings to avoid unnecessary overtreatment by radiotherapy or chemotherapy