Cerebellar astrocytomas. Clinical characteristics and prognostic indices.

The present study has been based on a detailed, computer-assisted, analysis of 112 astrocytomas from patients of all ages seen at The Radcliffe Infirmary between 1938 and 1984. There have been only six studies larger than the present one. From the results obtained in the present study, and the review of the literature, the following conclusions have been reached. Between 70 and 80% of cerebellar astrocytomas are found in children. Few patients are less than 1 year of age or older than 40 at the time of diagnosis. There appear to be no age peaks. Prognosis is poorest at the extremes of life, children less than 5 years old tending to suffer an early recurrence and patients in the oldest age groups having not only a very rapid recurrence but also a very low overall survival rate. In the present study, there was a slight predominance of males although basically, when all studies are considered, the incidence appears to be equal amongst the sexes. Around puberty there appears to be an abrupt drop in the number of tumours in females and a concomitant rise in the number of males. There appears to be no relationship between sex and the length of survival. It would appear that cerebellar astrocytomas can begin either within the vermis or one hemisphere. There appears to be no laterality, the right and left sides of the cerebellum being affected equally. In the present study, the hemispheres were affected three times more frequently than the vermis (34.8%: 12.5%). The rate of recurrence is much faster with tumors of the vermis, whilst the length of survival to death is much longer with tumours of one hemisphere at least up to 10 years after surgery. The most rapid recurrences take place in tumours which involve both hemispheres and the vermis whilst the poorest survival is associated with tumours infiltrating the brain stem. The average length of history is 18.7 months, being under forty-eight months in approximately 60% of patients, but only greater than 60 months in 6.2% of cases. The length of history was not related to either patient age or survival time. Most patients present with obstructive hydrocephalus with or without localising symptoms. The presentation is usually chronic and intermittent but may also be acute.(ABSTRACT TRUNCATED AT 400 WORDS)