SINCE Cushing's exhaustive report in 1931,1 little has been added to his analysis of the pathologic anatomy and treatment of astrocytomas of the cerebellum. Several authors have stated the opinion that an astrocytoma in this location is an entity among gliomas because these lesions occur most frequently in children, have an unusually long life history and demonstrate a strong tendency to formation of cysts, differing in these main respects from supratentorial astrocytomas.2 Cushing3 expressed the belief that because of these differences the cerebral astrocytomas should be scrutinized more carefully, but he certainly did not consider the astrocytomas located in the cerebellum and those situated in the cerebral hemispheres as separate subgroups of the gliomas. However, there must undoubtedly be a reason that these astrocytomas, differing only in locale, have strikingly different life histories, even though in most respects they are histologically the same tumor. It is our