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Intracranial arachnoid cyst

Intracranial arachnoid cysts are fluid-filled cavities that arise within the cranial arachnoid.

These cystic lesions are congenital.


Arachnoid cysts account for only 1% of all intracranial space-occupying lesions.

Intracranial arachnoid cysts have a predilection for the temporal fossa.


Intracranial cysts are classified as supratentorial, infratentorial, and supra-infratentorial (tentorial notch) 1).

50-66% occurring within the middle cranial fossa in most series. Ten percent occur in the suprasellar and quadrigeminal regions and approximately 5% each in the posterior fossa and over the frontal convexities

Supratentorial are divided into:

Sylvian fissure arachnoid cyst

Cerebral convexity

Interhemispheric arachnoid cyst

Sellar region

Intrasellar arachnoid cyst

Retrosellar arachnoid cyst

Suprasellar arachnoid cyst


Quadrigeminal plate cistern

see Posterior fossa arachnoid cyst.

see Middle fossa arachnoid cyst.


Many theories have been postulated for etiopathogenesis of arachnoid cysts. Various hypotheses are: entrapment of CSF in a diverticulum; CSF flow changes leading to arachnoid cell layer tears during the formation of various cisternae; during embryological separation (at around 15th week of gestation) of arachnoid from the dura mater 2).

Clinical features



Spontaneous intracystic hemorrhage in an arachnoid cyst is a rare complication (although hemorrhagic arachnoid cyst is well known in the clinical setting of trauma), which may present with symptoms of raised intracranial pressure (headache, vomiting, altered sensorium) or focal neurological deficits depending on the location and is an indication for surgery 3) 4).

Although complications such as intracystic, subdural, and extradural hematomas are well known after a trauma, spontaneous hemorrhage in an arachnoid cyst is a rare and serious complication with atypical imaging features on cross-sectional imaging and only less than ten cases are documented in the literature 5).


Case series

Case reports

Candela S, Puerta P, Alamar M, Barcik U, Guillén A, Muchart J, García-Fructuoso G, Ferrer-Rodríguez E. [Epidemiology and classification of arachnoid cysts in children]. Neurocirugia (Astur). 2015 Sep-Oct;26(5):234-40. doi: 10.1016/j.neucir.2015.02.007. Epub 2015 Apr 2. Spanish. PubMed PMID: 25843209.
2) , 4)
Gunduz B, Yassa MIK, Ofluoglu E, et al. Two cases of arachnoid cyst complicated by spontaneous intracystic hemorrhage. Neurology India. 2010;58:312–15.
Ide C, Coene BD, Gilliard C, et al. Hemorrhagic arachnoid cyst with third nerve paresis: CT and MR findings. Am J Neuroradiol. 1997;18:1407–10.
Arora R, Puligopu AK, Uppin MS, Purohit AK. Suprasellar Arachnoid Cyst with Spontaneous Intracystic Hemorrhage: A Rare Complication - Role of MR and Illustration of a Case. Pol J Radiol. 2014 Nov 18;79:422-5. doi: 10.12659/PJR.890992. eCollection 2014. PubMed PMID: 25422677; PubMed Central PMCID: PMC4238756.
intracranial_arachnoid_cyst.txt · Last modified: 2018/11/29 10:22 by administrador