Intracranial ependymomas: prognostic aspects.
According to the grading of brain tumors as proposed by the WHO in 1976, out of 128 ependymomas 83 tumors could be classified as grade II and 38 as grade III Only seven subependymomas were benign and could be assigned to grade I. In contrast to most series known from the literature, 73 ependymomas were located above the tentorium and only 55 in the posterior cranial fossa. The grade of malignancy rised with an increased distance from the ventricular level. Macroscopically complete exstirpations were usually possible in hemispheric ependymomas, whereas tumors arising from the floor of the fourth ventricle often allowed only a partial removal. The operative mortality in the infratentorial group was more than twice as that in the supratentorial group. Postoperative survival was predominantly dependent on the histologic grade of malignancy. The five year survival rate without recurrence was 57.4% in grade II ependymomas as compared to 24.1% in grade III ependymomas. It could be improved by postoperative radiation therapy in both groups of malignancy. The almost identical longterm results indicate that even in less malignant ependymomas new tumor growth will occur later on.