Neuroglial cyst

Neuroglial cysts (also known as glioependymal cysts and neuroepithelial cysts) are rare, benign epithelial-lined cystic lesions that can potentially occur anywhere in the neuraxis.

Choroid plexus cysts (CPCs) are a type of neuroepithelial cysts, benign lesions located more frequently in the supratentorial compartment. Symptomatic CPCs in the posterior fossa are extremely rare and can be associated with obstructive hydrocephalus.

They are rare and represent <1% of intracranial cysts.

see Posterior fossa neuroglial cyst.

Neuroglial cysts are congenital lesions that develop a sequestration of neural tube embryonic elements that develop into a glial cell lined, fluid filled cavity, located within the white matter. Location

They can be intra- or extra-parenchymal with the former being more common. The frontal lobe is thought to be the most typical location 1,3.

On imaging they are characterised as CSF-like parenchymal cysts with smooth, rounded borders and minimal-to-no surrounding signal intensity abnormality.

Typically seen as a well defined, non enhancing, hypodense (CSF density) unilocular cystic lesion with no surrounding oedema. They do not calcify.

Neuroglial cysts usually follow CSF signal. Hence they are hypointense on T1 and hyperintense on T2. They do not enhance with gadolinium. They are usually suppressed on T2 FLAIR sequences.

General imaging differential considerations include:

Porencephalic cyst: communicates with the lateral ventricle, usually shows surrounding gliosis

Arachnoid cyst: typically extra-axial, enlarged perivascular space, typically multiple cluster around the basal ganglia

Neurocysticercosis: usually <1 cm, partially enhance

cerebral hydatid cyst: usually spherical, may be indistinguishable

Ependymal cyst: periventricular, may be indistinguishable

Epidermoid cyst: usually does not follow CSF signal in all sequences restricted diffusion