Primary intracranial arachnoidal cysts

Abstract

Sixty-seven cases (41 males and 26 females) of arachnoidal cysts in children under 11 years are reported. About 53% of cases were diagnosed before 1 year of life. Thirty-one (42.2%) were supratentorial (interhemispheric 9, temporal fossa 10, convexity 5, sylvian fissure 3, supra- and/or retrosellar 4); 31 (46.2%) infratentorial (supra- and/or retrocerebellar 22, foramen of Magendie 3, quadrigeminal cistern 5, pontocerebellar 1); 5 (7.5%) supra- and infratentorial. Macrocephaly was the presenting symptom in 48 cases (71.5%). Associated features were frequent: cranial asymmetry in 24; aqueductal stenosis in 10; agenesis of corpus callosum in 8; deficient cerebellar lobullation in 4; Chiari I malformation in 2; neurofibromatosis type 1 with dysgenetic zones of the brain in 1; arteriovenous malformation in 1. Diagnosis was made at autopsy in six cases in the days before computed tomography and magnetic resonance: three patients had a cyst in the supra- and retrocerebellar midline; two had a cyst in the quadrigeminal cistern and the sixth was a rare case with the cyst passing from the posterior fossa to the left lateral ventricle through a hole in the basal surface of the brain. Small and some middle-sized cysts were not treated. Big and some middle-sized cysts were usually treated by cysto- and/or ventriculoperitoneal shunts. Arachnoidal cysts of the quadrigeminal cistern usually present with aqueductal stenosis and have to be treated with ventriculoperitoneal shunt. Craniotomy and fenestration of the cysts were performed in some cases with good results. The average mental level of these children is usually moderately low.

Endoscopic management of posterior fossa arachnoid cyst in an adult: case report and technical note

“…These reports mostly concern the pediatric population, with the biggest series being reported by a European cooperative study that included 54 cysts at the posterior fossa from 17 institutions (27). The posterior fossa location represented the second most common location for arachnoid cysts after the middle cranial fossa (14,28). Symptomatic cases mostly present with a history of increased head size and signs of increased ICP.…”

Unusual Arachnoid Cyst of the Quadrigeminal Cistern in an Adult Presenting With Apneic Spells and Normal Pressure Hydrocephalus. Case Report.

“…Incarceration of ectopic tissue in form of a secretory organ or choroid plexus may rarely develop from embryonic rests, 3,21,22,25,29,35) impeding the free circulation of the fluid. 22) The congenital origin 6,10) is indicated by the presence of ependymal tissue on the cyst wall and functional failure of outlets of the fourth ventricle accompanied by congenital scoliosis, basilar impression, and syringomyelia, 11) and/or aqueductal stenosis, agenesis of corpus callosum, deficient cerebellar lobulation, Chiari 1 malformation, arteriovenous malformation, 28) and/or absent septum pellucidum. Infratentorial arachnoid cysts can be intraarachnoid, subarachnoid, or subdural.…”

“…36) The most generally accepted treatment is cyst excision, 10,22) but opening of the posterior wall of the third ventricle to provide communication between the cyst and the third ventricle, 14,15) and other ventricles 3,10,30,33,36) may be required to avoid shunt dependency. 10,28) Partial removal of the cyst wall and/or external cyst drainage, 27,30) or internal cyst drainage (windowing) 3,10) and/or shunting of ventricles 30,33) are options. The cyst wall with the surrounding arachnoid membrane should be removed if cystoperitoneal shunting is not installed.…”

“…15) Arachnoid cyst of the quadrigeminal cistern usually presents with aqueduct stenosis and requires ventriculoperitoneal (VP) shunting. 28) VP shunting preceding craniotomy, and the resection of cyst wall is also recommended by others. 9) However, extrathecal diversion of CSF from a lateral ventricle is less advisable as the only or initial procedure due to the risk of further enlargement or upward herniation.…”

Benign extracerebral fluid collection in infancy as a risk factor for the development of de novo intracranial arachnoid cysts

“…1 In fact, although the prevalence of headaches and cranial asymmetry have been reported in as many as 70% of children with arachnoid cysts, 23 clear neurological symptoms that may be correlated with such lesions (such as neuropsychological abnormalities or seizures) are found in only a minority of the patients (10%-20%), usually in those in whom further radiological enlargement of the cysts occurs. 33 Although several previous reports have documented the occurrence of subdural hygromas (or other subdural collections) after rupture of arachnoid cysts, 15,36,46 no previous studies in the literature have investigated the possible correlation between subdural hygromas and, more specifically, benign extracerebral fluid collections in infancy as a possible risk factor for development of de novo arachnoid cysts.…”