[Clear cell ependymoma--a case report].

A case of intraaxial clear cell ependymoma is reported. A 46-year-old man complained of right hemiparesis. CT scan showed a mass lesion on the median plane with a huge cyst in the left frontal lobe. MRI showed an iso-low intensity mass by T1-weighted image. The tumor was heterogeneously enhanced by Gd-DTPA and the wall was enhanced as well. Angiogram revealed a tumor stain from the right internal carotid artery. The main mass of the tumor was totally removed but the cystic wall was left removed. Histopathological examination revealed clear cell ependymoma. Immunohistochemical examination revealed that, although vimentin and NSE were positive, GFAP, synaptophysin and S-100 were negative. Ultrastructual examination revealed cilia, microvilli and desmosomal junctions. The patient fully recovered after operation and showed no sign of recurrence after an year of follow-up. Clear cell ependymoma is a rare variant of ependymoma. Ultrastructual examination was more useful than immunohistochemical examination for diagnosis.