[Clinicopathologic analysis of dysembryoplastic neuroepithelial tumor].

OBJECTIVE: To study the clinicopathologic features, radiologic findings, treatment options and prognosis of dysembryoplastic neuroepithelial tumor (DNT).

METHODS: The clinicopathologic and radiologic features were retrospectively analyzed in 10 cases of DNT.

RESULTS: Intractable partial seizure was the main presenting symptom in all patients. The tumor was located in temporal lobe (number = 5), frontal lobe (number = 3) or parietal lobe (number = 2). CT scan displayed a hypodense lesion. MRI scan revealed the tumor was non-enhancing T1WI hypointense and T2WI hyperintense, with internal septation and hyperintense ring around the tumor seen on FLAIR image. There was neither peritumoral edema nor mass effect. Histologically, the tumor showed the presence of glioneuronal element, with oligodendrocyte-like cells, floating neurons, astrocytes and associated microcystic changes. Immunohistochemical study demonstrated positivity for NeuN and synaptophysin in the neurons and some oligodendrocyte-like cells. Olig2 and S-100 protein were also expressed in the oligodendrocyte-like cells. Ki-67 index were lower than 1% in all cases. Nine cases were treated by complete surgical excision and the remaining case was subtotally excised. No post-operative chemotherapy or radiotherapy was given. One of the 10 cases recurred on follow up.

CONCLUSIONS: Correct diagnosis of DNT requires correlation with clinicopathologic, radiologic and immunohistochemical findings. Complete resection of the tumor and epileptogenic foci is the mainstay of treatment for DNT, with intraoperative EEG monitoring. Post-operative chemotherapy or radiotherapy is not required.