Background: The prevalence of clinically silent intracranial tumors in specific populations is poorly researched. It is known that, in advanced age groups, the number of clinically manifest meningiomas constitute a small proportion of the actual number of cases. The goals of the current study were to determine the frequency of asymptomatic patients with meningioma in advanced age and to identify risk factors for meningiomas in this population.
Methods: Between May 2000 and November 2002, 532 probands from a specifically defined geographic area of Vienna who were age 75 years underwent a magnetic resonance imaging scan of the brain and were evaluated for the presence of a space-occupying mass. All probands were examined clinically and neurologically as well as by a neuropsychiatrist. The patients' medical histories were carefully documented with regard to previous diseases, medication, and lifestyle, as were their laboratory reports. The collected data were correlated and similarities among subjects with meningioma were determined.
Results: Nine meningiomas that were unknown until the time of investigation were observed among the 318 women included in the trial (corresponding to a calculated prevalence of 2800/100,000 clinically silent meningiomas in 75-year-old women). No tumors were found among men. Associated clinical changes or deficits were not observed in any subject. Apart from advanced age and female gender, no other accepted or well known risk factors were observed in the tumor patients.
Conclusions: Clinically quiescent meningiomas in the elderly female population were more common than was believed to be the case to date. Known and influenceable risk factors were found to be less important than age and gender. The high frequency of this lesion should be considered when deciding on the treatment of patients with incidentally discovered, clinically quiescent meningiomas.
Copyright 2004 American Cancer Society.