Many CNS<unk> s form in the womb during the first few weeks of development as a result of congenital defects. In adults<unk> s may also form due to a head injury or trauma, resulting in necrotic tissues (dead tissue), and can sometimes be associated with cancerous tumors or infection in the brain. However, the underlying reasons for<unk>  formation are still unknown.
Central nervous system cyst
Glial tumor
Chiari malformation
Brain metastasis
Choroid plexus tumor
Brain stem tumor
Primary central nervous system lymphoma
Central nervous system cavernous hemangioma