Abstract: Background and purpose: Dysembryoplastic neuroepithelial tumor (DNT) is a rare and benign mixed neuronal-glial tumor. This paper was to study the clinicopathological features and the key points of differential diagnosis of DNT. Methods: The data of 6 cases with DNT diagnosed by pathological examination in The First Affiliated Hospital of Soochow University and Suzhou Municipal Hospital from March 2009 to January 2021 were collected, the clinicopathological features, imaging characteristics and immunohistochemical phenotype were retrospectively analyzed, and the patients were followed up. Results: The main symptoms of the patients were limb convulsions and epilepsy. Four tumors were located in temporal lobe, 1 in parietal lobe, and 1 in frontal lobe. On magnetic resonance imaging (MRI), tumors mainly showed cystic lesions with septum and “triangle sign”, T1-hypointensity and T2-hyperintensity. Peripheral edema was inconspicuous. The histopathological hallmarks were so called specific glioneuronal element with myxoid matrix, floating neurons or proliferative astrocytes scattering among oligodendrocyte-like cells, which distributed in bundles, nests, microcysts with focal calcification. Immunohistochemistry showed that scattered neurons expressed Syn, NeuN and MAP2, oligodendrocyte-like cells expressed Olig-2 and S-100, and GFAP was expressed in proliferative astrocytes. The expression of P53 was wild-type. The index of Ki-67 was less than or equal to 2%. All patients received surgical treatment without radiotherapy or chemotherapy. Five patients were followed up, and one of them had recurrent epilepsy 3 years after operation. Conclusion: DNT can be cured by surgery, and it can be diagnosed by combination of clinical features, imaging examination and pathology without the need for radiation and chemotherapy.

Key words: Dysembryoplastic neuroepithelial tumor, Clinicopathological feature, Imaging characteristics, Immunophenotype