<unk> s are cerebrospinal fluid<unk> s covered by<unk> al cells and collagen. They develop between the<unk>  membrane and the surface of the brain.<unk> s are mostly a congenital disorder.
Arachnoid cyst
Subdural hygroma
Choroid plexus papilloma
Choroidal fissure cyst
Acoustic neuroma
Craniopharyngioma
Meningioma
Cavernous sinus thrombosis