Cystic meningioma
Cystic meningiomas are an uncommon variety of meningioma. The term has been applied to both meningiomas with intratumoral degenerative cyst formation (see case 2) as well, peritumoral arachnoid cyst (see case 1).
True cystic meningiomas, those with a few large central cysts, are uncommon. Those with more numerous smaller cysts, are more common (up to 8 - 23% of cases). They are over-represented in male patients and the paediatric population.
Various mechanisms have been proposed, and probably more than one is applicable:
- degeneration / necrosis
- direct secretion by meningioma
- reactive changes (peripheral arachnoid cysts)
