RESUMEN
In an attempt to describe epidemiologic features to generate etiological hypotheses and to study natural history, 121 cases of childhood CNS neoplasms under 15 years of age, occurring during 1950-66 in Manitoba, were analyzed. The incidence of CNS neoplasms in childhood (2.4/100 000 per annum) ranks second only to leukemia in Manitoba. For both sexes somewhat elevated incidences were noted for both extreme age groups; i.e. 0-4 and 10-14. Such peaks were more prominent for gliomas, which may indicate differential factors operation in the genesis of gliomas between early and late childhood. The former may be related to genetic and/or perinatal environmental factors and the latter, to environmental factors, in early childhood. Excess occurrences of gliomas among Irish, Scottish and Icelandic offsprings were observed, which possibly indicates the importance of either genetic or environmental factors peculiar to these ethnic groups. There was no evidence of time clustering (i.e. season and year) by estimated conception or by birth. Further investigation into the relative role of genetic and environmental factor in the genesis of childhood gliomas are in order.