Intraventricular meningiomas, although are rare intracranial tumors, are a common type of intraventricular neoplasm in adults. They account for less than 3% of all meningiomas.
Most intraventricular meningiomas presentbetween the 3 and 6 decades with a recognized female predilection (M:F ratio of 1:2) .
Intraventricular meningiomas present usually due to mass effect, either by direct compression of the adjacent brain or from obstruction to normal CSF drainage with resultant hydrocephalus.
Intraventricular meningiomas are thought to arise from mengingothelial inclusion bodies located in the tela choroidea and/or mesenchymal stroma of the choroid plexus . In general, these meningiomas are most commonly of the fibrous meningiomas .
They are most frequently (80%) seen at the trigone of the lateral ventricles and, for reasons that are not clear, slightly more frequently on the left. Considering the distribution of meningiomas, the intraventricular location is comparatively more common in children (20% of pediatric meningiomas).
Their signal and attenuation characteristics are the same as other meningiomas, demonstrating essentially isodensity and intensity to grey matter precontrast and vivid, usually homogenous enhancement following administration of contrast. Compared to extra-axial meningiomas, a greater proportion is calcified (50% compared to 20% for standard meningioma).
For further discussion of the radiographic appearances of these tumors, refer to the general article: meningioma.
Treatment and prognosis
As is the case with other meningiomas, provided complete excision is possible, surgical excision is curative and therefore the treatment of choice.
The differential somewhat depends on the location of the tumor and age of the patient, however, in general considerations should include:
- glial tumor
- choroid plexus metastases
- choroid plexus papilloma (particularly in children)
- CNS lymphoma