Primary intraventricular meningiomas (IVM) are rare, corresponding to 0.5 to 5% of all intracranial meningiomas.
Intraventricular meningiomas are most often seen in the lateral ventricles of adults, more often on the left than on the right 1)
Pediatric intraventricular meningioma tend to have a male preponderance in contrast to adults who have a preference for females 2).
Some studies have reported that they are more common on the left side 3) 4).
A Medline search up to March 2018 using “intraventricular meningioma” returned 98 papers. As a first selection step, we adopted the following inclusion criteria: series and case reports about IVMs, as well as papers written in other languages, but abstracts written in English were evaluated. Six hundred eighty-one tumors were evaluated from 98 papers. The majority of the tumors were located in the lateral ventricles (602-88.4%), fourth ventricle (59-8.7%), and third ventricle (20-2.9%)
The most common location is the trigone (atrium) of the lateral ventricle. Due to the fluid cavity location and their slow growth they can become large tumors before proper diagnosis.
Intraventricular meningiomas typically present between 30 and 60 years of age. The mean age at diagnosis is 42.2 +/- 8.2 years old.
Approximately 90% of them are WHO grade I
They have a female predilection with 1.47 female/1.0 male ratio, lower than dural-based extra-axial meningiomas 5).