Ependymomas of childhood. I. Histological survey and clinicopathological correlation.

We have conducted a correlative histological and clinical study on 34 cases of childhood ependymomas encountered at the Children's Memorial Hospital from 1953 to 1974. The cases were classified into grades A, B and C according to the extent of cytological differentiation and the correlation between the histological grades and the clinical outcome was obtained. It is concluded that the biological behavior of an ependymoma could be predicted to a large extent by the degree of cytological differentiation and by its anatomical location. A large share of the infratentorial ependymomas are well differentiated (grade A) and prognosis in this group is good when complete surgical removal could be accomplished. Most of the supratentorial ependymomas belong to the intermediate grade B and the malignant grade C; prognosis in these two grades is less predictable, approximately two thirds of these patients died within 3 years. The most malignant form is the ependymoblastoma. This is a highly primitive neoplasm histologically similar to medulloblastoma but shows evidence of ependymal differentiation. Most of the ependymoblastomas are located in the supratentorial region and the average length of survival is 20 months.