[2] Some examples of cysts originating from non-central nervous system tissue include:[citation needed] This category of cysts takes over areas of necrotic tissue in the brain from injuries, diseases, or abnormalities, which occur due to the central nervous system's nonregenerative nature.

These cysts can affect all germ layers of the CNS, but are most common in the arachnoid mater, and the ventricular space, which may block CSF pathways.

Some examples of cysts originating from the CNS tissue include:[citation needed] Symptoms are assessed on a case-by-case basis.

[5] Some cysts in the CNS can be asymptomatic (producing or showing no symptoms), depending on their location in the brain or spinal cord.

[citation needed] Many CNS cysts form in the womb during the first few weeks of development as a result of congenital defects.

Asymptomatic cysts, termed pseudocysts, normally require active monitoring with periodic scans for future growth.

[3] This is commonly used with inflammatory cysts located in the ventricles, and can result in increased ventricular fluid flow within the brain.

[citation needed] A neurosurgeon performs a same day surgery to insert an endoscope, which drains the cyst internally.