The age-adjusted incidence rate for intracranial meningiomas increased
from 0.6 patients per 100,000 population in the period 1963-1972 to 1
.5 in 1983-1992 for males and correspondingly from 1.0 to 2.8 for fema
les. An incidence fall-off after 70 years of age was evident, presumab
ly because many older patients with small and asymptomatic meningiomas
were undiagnosed due to the low autopsy rate in the population. The p
rognosis for survival in meningioma patients improved over the study p
eriod and was related to type of tumor histology and age at diagnosis.