# Cysts

Cysts

These benign fluid-filled intracranial lesions typically present incidentally or with mass e ff ect or hydrocephalus. Treatment of  symptomatic or enlarging lesions is usually surgical, involv - ing excision, endoscopic fenestration into a cistern or ventricle or shunting for hydrocephalus. Cyst types include: - /uni25CF arachnoid cyst: typically middle fossa, CSF enclosed in an envelope of  arachnoid mater; /uni25CF colloid cyst: occur in the roof  of the third ventricle, be - will lieved to represent embryonic endoderm remnants; /uni25CF dermoid and epidermoid cysts: epithelium-lined structures arising from displaced ectodermal remnants, typically in the posterior fossa (midline) and cerebellopontine angle, respectively; /uni25CF porencephalic cysts: brain cavities lined with gliotic white matter, containing CSF in communication with the ventri - cles or subarachnoid space. Cysts

These benign fluid-filled intracranial lesions typically present incidentally or with mass e ff ect or hydrocephalus. Treatment of  symptomatic or enlarging lesions is usually surgical, involv - ing excision, endoscopic fenestration into a cistern or ventricle or shunting for hydrocephalus. Cyst types include: - /uni25CF arachnoid cyst: typically middle fossa, CSF enclosed in an envelope of  arachnoid mater; /uni25CF colloid cyst: occur in the roof  of the third ventricle, be - will lieved to represent embryonic endoderm remnants; /uni25CF dermoid and epidermoid cysts: epithelium-lined structures arising from displaced ectodermal remnants, typically in the posterior fossa (midline) and cerebellopontine angle, respectively; /uni25CF porencephalic cysts: brain cavities lined with gliotic white matter, containing CSF in communication with the ventri - cles or subarachnoid space. Cysts

These benign fluid-filled intracranial lesions typically present incidentally or with mass e ff ect or hydrocephalus. Treatment of  symptomatic or enlarging lesions is usually surgical, involv - ing excision, endoscopic fenestration into a cistern or ventricle or shunting for hydrocephalus. Cyst types include: - /uni25CF arachnoid cyst: typically middle fossa, CSF enclosed in an envelope of  arachnoid mater; /uni25CF colloid cyst: occur in the roof  of the third ventricle, be - will lieved to represent embryonic endoderm remnants; /uni25CF dermoid and epidermoid cysts: epithelium-lined structures arising from displaced ectodermal remnants, typically in the posterior fossa (midline) and cerebellopontine angle, respectively; /uni25CF porencephalic cysts: brain cavities lined with gliotic white matter, containing CSF in communication with the ventri - cles or subarachnoid space.