Incidental Meningioma: Autopsy Study

Incidental meningiomas are not rare at autopsy. The incidence of meningiomas at autopsy is reported to be between 1 to 2%. The authors reviewed 10,033 autopsy cases of the central nervous system at Montefiore Medical Center from 1950 to 1982, and found 272 cases of intracranial meningiomas (2.7%). Most of these meningiomas were incidental cases (231 cases or 2.3%). They increased with age and reached the highest percentage at the age of more than 80 years. Females showed a three times greater frequency than males. The incidental meningiomas were usually small in size, less than 1 cm in 59% of the cases. However, the frequency of the larger sizes increased with age, presumably because brain atrophy prevents them from becoming symptomatic, even if they grow relatively larger. Multiple meningiomas were found in 8.2% of the incidental cases. None of these cases had the stigmata of neurofibromatosis. They were thus the so-called “true multiple meningiomas.” They were also most frequent at the age of more than 80 years. These results indicate that large numbers of meningiomas remain asymptomatic in spite of their growth, and they increase with age.