Mesial temporal dysembryoplastic neuroepithelial tumor mimicking oligodendroglioma: a case report and review of the literature.

Dysembryoplastic neuroepithelial tumor (DNT) is an uncommon congenital tumor occurring in children. We report a 12-year-old boy who had a focal motor seizure involving his left face 6 months prior to admission. Preoperative computed tomography of the brain demonstrated a focal calcified tumor measuring 2.5 cm in diameter in the right temporal lobe. Initial pathological diagnosis was oligodendroglioma, and postoperative radiotherapy with a total dose of 5000 cGy in 28 fractions over 5&1/2 weeks was given. At follow-up 8 months later, neither clinical nor radiological recurrence was found. Because of the benign clinical course, a review of the surgical specimen was made, which led to the diagnosis of DNT. It is important to distinguish DNT from other tumors that have a worse prognosis. Correct diagnosis may prevent unnecessary radiotherapy or chemotherapy. The pathologic and radiologic diagnostic criteria of DNT are discussed, with a review of the literature.