Malignant cerebellar gliomas. Report of 4 cases with special reference to tissue culture study.

The rare malignant cerebellar gliomas have been considered as an unusual form of brain glioblastomas. However, different forms have been described which can be divided into three groups: (a) cerebellar astrocytomas with malignant features; (b) undifferentiated tumors mimicking the cerebral glioblastomas; (c) malignant glioblastomatous recurrences of primary benign cerebellar astrocytomas. The present series is composed of four cases studied with silver impregnation or with tissue culture and time-lapse cinematography. It appears from this study that the cerebellar glioblastomas bear no relationship to the cerebral glioblastoma. Silver impregnation shows many astrocytes taking part in the tumor cell population and the behavior in vitro is similar to that of the common benign astrocytomas from which they seem to be derived. Thus, a sequence can be established: benign cerebellar astrocytoma, malignant cerebellar astrocytoma, cerebellar glioblastoma.