Glioependymal and arachnoid cysts: unusual causes of early ventriculomegaly in utero

Giant supra and retrosellar glioependymal cyst presenting with only precocious puberty. Clinical study and review of the literature

INTRODUCTION AND IMPORTANCE

Intracranial glioependymal cysts are an uncommon type of neuroepithelial cyst and are encountered much less frequently than arachnoid cysts. These cysts primarily manifest within the parenchyma of the brain, although exceedingly rare instances have been reported in the lateral ventricles.

CASE PRESENTATION

We present a highly unusual case of a glioependymal cyst in a 7-year-old girl. The glioependymal cyst was located in the midline in the suprasellar region and extended to the upper clivus region. Its only manifestation was precocious puberty. We performed endoscopic fenestration of the cyst, leading to a return of hormonal levels to normal and a slight reduction in cyst size.

CLINICAL DISCUSSION

A comprehensive search of the Medline database revealed only a few documented cases of glioependymal cysts (fewer than 30 cases). Remarkably, the majority (if not all) were located laterally rather than in the midline of the brain. Endoscopic fenestration and biopsy are effective and confirm the diagnosis.

CONCLUSION

This instance of a rare glioependymal cyst located in the midline, spanning the suprasellar and retrosellar regions, is an uncommon occurrence. Its sole presentation was precocious puberty. The successful management of this condition was achieved through an endoscopic approach, leading to the normalization of endocrine abnormalities.

Asymmetric ventriculomegaly, interhemispheric cyst, and dysgenesis of corpus callosum (AVID) - case report

AVID (Asymmetric ventriculomegaly, interhemispheric cyst, and dysgenesis of corpus callosum) spectrum is a rare phenomenon as such in its whole and the defects are not exclusive to the condition. Each may occur in isolation or together and have characteristic clinical and imaging findings. The vast array of mimics coexisting with the condition makes it a harder diagnosis to make and requires a great length of experience and observation which may explain the limited recordings of AVID. Sonography and fetal magnetic resonance imaging goes a long way and provide accurate diagnosis ruling out the mimics and aiding in prenatal visualization of the defects. Accurate diagnosis aids in effective management and counseling regarding outcomes and the potential timeline of the severity of the symptoms. In its rarity, this case report of AVID is one of the first report of its kind reported from Nepal.

An Unusual Presentation of Glioependymal Cyst Encroaching Neuronal Parenchyma in an Elderly Female: A Case Report

A glioependymal cyst (GEC) is a rare type of cyst that occurs within the brain and spinal cord. A 42-year-old male patient with a cystic lesion in the right frontal lobe was admitted to the hospital to have his headache, vertigo, and body spasms evaluated. MRI scans showed a mass in the right side of the frontal lobe which caused a mass effect over the lateral ventricle and corpus callosum. The patient became symptom-free after the craniotomy, followed by fenestration of cortices and cyst wall removal.

Prenatal diagnosis of arachnoid cysts: a case series and systematic review

INTRODUCTION

Primary cysts are believed to arise from the splitting of the arachnoid membrane during prenatal development and can be diagnosed in utero. Prenatal diagnosis is uncommon; therefore, the evidence base for counselling expectant mothers is limited. The purpose of this article is to present a case series and review the current literature on prenatally diagnosed arachnoid cysts.

METHOD

A keyword search of hospital electronic records was performed for all patients with a prenatally diagnosed arachnoid cyst at a tertiary neurosurgical centre. Case notes were reviewed for all patients diagnosed between 2005 and 2017. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to structure a systematic review of all English language articles published up to May 2018.

RESULTS

A total of eight eligible patients were identified from our own records and 123 from the literature. Sixty-eight per cent of patients had a normal outcome. Sixty-three per cent of patients underwent surgical intervention which was not associated with abnormal outcome. The diagnosis of syndromic/genetic diagnosis (p < 0.001) and the presence of other intra-cranial anatomical abnormalities (p = 0.05) were significant predictors of abnormal outcome.

CONCLUSION

The pathogenesis and prognosis of a prenatal arachnoid cyst diagnosis remain unclear. These results suggest favourable outcomes from simple cysts without associated abnormalities and expectant mothers should be counselled accordingly. A wider prospective review is required to better established evidence-based practice.

Outcome of Fetuses with Supratentorial Extra-Axial Intracranial Cysts: A Systematic Review

OBJECTIVE

To investigate the incidence of associated anomalies, aneuploidy, cyst progression, need for surgery and neurodevelopmental outcome in fetuses with extra-axial supratentorial intracranial cysts.

DATA SOURCES

Medline, Embase and CINAHL databases were searched and the following outcomes analyzed: associated central nervous system (CNS) and extra-CNS anomalies detected at the scan, chromosomal anomalies, additional CNS anomalies detected only at prenatal MRI, additional CNS anomalies detected only after birth, cyst progression in utero, neurological outcome and need for surgery. Two authors reviewed all abstracts independently. Results were reported as proportions, and between-study heterogeneity was explored using the I² statistic; fixed or random effect models were used accordingly.

RESULTS

Ten studies involving 47 fetuses were included in the meta-analysis. Arachnoid cysts (n = 24) had associated CNS anomalies and extra-CNS in 73% (95% CI 56-88) and 14% (95% CI 4-29), respectively. The most common associated anomalies were ventriculomegaly and callosal abnormalities. Chromosomal abnormalities were present in 6% (95% CI 0-30), but fetuses with isolated cysts were always euploid (0/7; 95% CI 0-29). Fetal MRI and postnatal examination identified 5 additional cases (21%, 95% CI 1-57). Cavum veli interpositi (CVI) cysts had associated CNS and extra-CNS anomalies in 31% (95% CI 13-52) and 6% (95% CI 0-29), respectively. No chromosomal or callosal anomalies were found in these cases. In isolated CVI cysts, no cases of associated anomalies were detected postnatally. Intrauterine regression occurred in 23% of CVI cysts and in none of the arachnoid cysts. In children with arachnoid cyst, the occurrence of hydrocephaly and mass effect on the adjacent structures were observed in 23.9% (95% CI 8.3-4.4) and 26.8% (95% CI 4.0-60.1), respectively. None of the cases included had abnormal motor outcome or intelligence. The rate of surgery was 34.7% (95% CI 16.0-56.4). None of the children with a prenatal diagnosis of isolated CVI cyst experienced any of the adverse outcomes explored in this review.

CONCLUSIONS

Extra-axial supratentorial cysts diagnosed in utero are frequently associated with other neural and extra-neural anomalies. However, this may represent the consequence of a selection bias. Interhemispheric arachnoid cysts were typically associated with callosal anomalies. Abnormal karyotypes were seen only in fetuses with multiple anomalies. Arachnoid, but not CVI, cysts frequently increased in size throughout gestation.

Outcome of 12 antenatally diagnosed fetal arachnoid cysts: case series and review of the literature

OBJECTIVES

To investigate the natural history, associated abnormalities and outcome of 12 fetuses with arachnoid cyst diagnosed antenatally by ultrasound and magnetic resonance imaging and to compare the outcome with cases in the literature.

METHODS

A retrospective study of all cases of antenatally detected fetal arachnoid cysts was performed in patients referred to a tertiary unit between 2007 and 2013. Associated abnormalities, pregnancy outcome and postnatal follow-up were analyzed. All papers about prenatally diagnosed arachnoid cysts, of the last 30 years, were evaluated (search terms in Pubmed: "prenatal diagnosis", "Arachnoid Cysts").

RESULTS

Fetal arachnoid cysts were diagnosed in 12 fetuses, 9 were females. The mean gestational age of diagnosis was 28 1/7 (range 19 1/7-34 2/7 weeks). A total of 9 cases were supratentorial, 3 were located in the posterior fossa. In 10 cases a fetal MRI was performed which confirmed brain compression in 4 out of 5 supratentorial arachnoid cyst. MRI did not reveal other malformations nor signs of nodular heterotopia. Only one fetus presented with additional major anomalies (bilateral ventricumomegaly of >20 mm and rhombencephalosynapsis) leading to a termination of pregnancy. Two neonates underwent endoscopic fenestration of the arachnoid cyst in the first week of life with no additional intervention in childhood. All but one (10/11) had a favorable postnatal outcome. This child suffered from visual impairment at autism was diagnosed at the age of 5. One child had a surgical correction of strabismus later in childhood. In one child the infratentorial arachnoid cyst regressed spontaneously on ultrasound and MRI in the postnatal period.

CONCLUSIONS

The majority of arachnoid cysts in this series are of benign origin and remain stable. Based on the current series and the review of the literature, in the absence of other associated anomalies and when the karyotype is normal, the postnatal overall and neurological outcome is favorable. Large suprasellar arachnoid cysts however, may cause visual impairment and endocrinological disturbances. Rarely associated cerebral or cerebellar malformations are present. Modern postnatal management of suprasellar arachnoid cyst consists of endoscopic cystoventriculostomy.

Asymmetric ventriculomegaly, interhemispheric cyst, and dysgenesis of the corpus callosum (AVID): an imaging triad

A series of 20 cases from 2 academic institutions is presented with a characteristic imaging triad of asymmetric ventriculomegaly, a large interhemispheric cyst, and partial or complete agenesis of the corpus callosum. Most cases were initially referred as aqueduct stenosis and hydrocephalus or focal porencephaly. We describe the imaging findings that identify an abnormal or absent corpus callosum associated with a type 1 interhemispheric cyst in fetuses initially thought to have hydrocephalus attributable to aqueductal stenosis. We suggest that the acronym AVID (asymmetric ventriculomegaly, interhemispheric cyst, and dysgenesis of the corpus callosum) may be useful in recognition of these cases. All cases presented with markedly asymmetric ventriculomegaly on initial sonography, with progressive hydrocephalus throughout gestation. Fetal magnetic resonance imaging was performed in 15 of 20 cases. Thirteen of 20 cases were identified in male fetuses. Associated fetal and postnatal abnormalities are also reported. Technological improvements in sonography and fetal magnetic resonance imaging allow improved characterization of associated intracranial anomalies in the setting of hydrocephalus. Accurate diagnosis can aid parental counseling, especially because isolated aqueductal stenosis suggests a better prognosis than hydrocephalus with anomalies. Markedly asymmetric ventriculomegaly in this series was the key to excluding isolated aqueductal stenosis and was associated with callosal malformation with a type 1a interhemispheric cyst.

Cavum veli interpositi: just an anatomical variant or a potentially symptomatic CSF compartmentalization?

BACKGROUND

The cavum veli interpositi (CVI) usually is a small CSF-containing abnormality of septum pellucidum, asymptomatic and rare after the age of 3 years. When symptomatic, it is large and can be related to psychiatric disorders, syndromic association of mental retardation and seizures or to hydrocephalus.

METHODS

This is the first reported case of an otherwise healthy pediatric patient with a large CVI experiencing episodes of hypertonic loss of consciousness unrelated to epileptic, cardiologic or psychiatric causes without signs of chronic increase in intracranial pressure (ICP).

RESULTS

Supposing a CSF compartmentalization in the CVI as the cause of acute poussés of ICP due to block of CSF pathways and considering the severity of the symptoms, an endoscopic fenestration was performed with a reduction of cyst dimensions.

CONCLUSION

We suggest considering the fenestration of large CVI even in otherwise asymptomatic patients to avoid the risk of CSF compartmentalization with ICP poussés.

Fetal central nervous system malformations on MR images

Sonography is the method of choice for prenatal malformation screening but it does not always provide sufficient information for correct diagnosis or adequate abnormality evaluation. Fetal magnetic resonance imaging (MRI) is considered as a valuable second line imaging tool for confirmation, completion and correction of sonographic findings. Fetal MRI has proven its value in the evaluation of central nervous system pathologies, especially of midline and posterior fossa malformations. The role of MRI is not only to confirm or exclude possible lesions but also to define their full extent, aiding in their characterization, and to demonstrate associated abnormalities. The authors describe the most common anomalies of CNS revealed by fetal MRI in a chronological way related to the age of pregnancy, with a review of own MR images and with reference to the literature and own experience.

Prenatal diagnosis of arachnoid cysts

Arachnoid cysts are a rare central nervous system malformation, representing only 1% of all intracranial masses in newborns. Primary (congenital) arachnoid cysts are benign accumulation of clear fluid between the dura and the brain substance throughout the cerebrospinal axis in relation to the arachnoid membrane and do not communicate with the subarachnoid space. Secondary (acquired) arachnoid cysts result from hemorrhage, trauma, and infection and usually communicate with the subarachnoid space. The common locations of arachnoid cysts are the surface of the brain at the level of main brain fissures, such as sylvian, rolandic and interhemispheric fissures, sella turcica, the anterior cranial fossa, and the middle cranial fossa. Arachnoid cysts may be associated with ventriculomegaly and dysgenesis of corpus callosum. Prenatal ultrasound and magnetic resonance imaging have led to the increased diagnosis of fetal arachnoid cysts. This article provides a thorough review of fetal arachnoid cysts, including prenatal diagnosis, differential diagnosis and associated chromosomal abnormalities, as well as comprehensive illustrations of perinatal imaging findings of fetal arachnoid cysts. Prenatal diagnosis of intracranial hypoechoic lesions should include a differential diagnosis of arachnoid cysts and prompt genetic investigations.

Fetal MRI demonstrates glioependymal cyst in a case of sonographic unilateral ventriculomegaly

We report a fetus of 28 weeks' gestation in which ultrasonography demonstrated unilateral ventriculomegaly and microcephaly. Fetal MRI demonstrated a simple, left paramedian occipital cyst with rarefaction of the corpus callosum and thinning of the adjacent cortical mantle. Ischaemia was suggested as the underlying pathogenesis, but autopsy after termination of pregnancy revealed a glioependymal cyst. This case highlights consideration of the rare diagnosis of glioependymal cyst when a cystic lesion associated with cerebral malformations, particularly dysgenesis of the corpus callosum, is demonstrated and fetal MRI suggests an ischaemic origin.

A different approach to cysts of the posterior fossa

Posterior fossa cysts are frequently identified on MR studies. This paper takes a different approach to analyzing these cysts based on the pathology of the cyst wall and the embryology of the hindbrain, choroid plexus, and meninges. The type of cyst depends on the histologic components of the cyst wall. Frequent types of posterior fossa cysts are arachnoid, Blake's pouch, and cysts associated with Dandy Walker malformation. All of these cysts may mimic the others in terms of position of the torcula, vermian abnormalities, and mass effect on the cerebellum and occipital bone. A clue to the nature of the cyst may be the position of the choroid plexus in the fourth ventricle; normal in arachnoid cyst, absent in Dandy Walker malformation, and displaced into the superior cyst wall in Blake's pouch. When the cyst wall histology is not known, it is suggested to use a descriptive term such as "retrocerebellar cyst".

Malformative intracranial cysts: diagnosis and outcome

INTRODUCTION

Prenatal investigations make it possible to follow up malformative intracranial cysts from their detection in utero through the postnatal period. By including those that will remain silent postnatally, precious information can be provided about their real natural history.

DIAGNOSIS

Contrary to common belief, the vast majority of these lesions, if not associated with other fetal anomalies, are benign in nature, remain clinically silent, do not evolve or even frequently regress spontaneously. They are compatible with a strictly normal life, whether requiring postnatal treatment or not.

TREATMENT

Surgery is rarely needed for the treatment of an evolving hydrocephalus or an expanding cyst.

PROGNOSIS

Clinical outcome is not correlated with cyst volume or location. Prognosis, therefore, does not rely upon brain deformation or translation but rather more upon brain integrity. To establish a correct prognosis all efforts must therefore aim to precisely analyze the brain anatomy. In this respect, fetal MRI is mandatory. Although chromosomal anomalies are rarely associated with isolated intracranial cysts, karyotype study is necessary.

CONCLUSION

The accuracy of diagnosis and prognosis depends mainly upon our ability to correctly interpret images, which in turn depends on the resolution of prenatal imaging and on experience. Median retrocerebellar fluid collections remain the most difficult to prognosticate, retrocerebellar cysts often being difficult to differentiate from mega cisterna magna and Dandy-Walker complex. In our hands, prenatal prognostication was correct in approximately 90% of the cases.

Prenatal diagnosis of cavum velum interpositum cysts: significance and outcome

OBJECTIVES

To describe a fetal cavum velum interpositum cyst (CVIC) and to review its clinical significance.

METHODS

Description and follow-up of two cases with prenatal diagnosis of a midline cyst in the fetal brain, at the Chaim Sheba Medical Center. The cases were reviewed and followed-up by a multidisciplinary team that included sonographers, pediatric neurologists, pediatric neurosurgeons, radiologists, and clinical geneticists. Medline search of cases of cysts of the cavum velum interpositum as reported in the English literature.

RESULTS

Two patients referred for consultation owing to midline cysts were diagnosed with isolated cysts of the cavum velum interpositum without other anomalies. Magnetic resonance imaging (MRI) of the fetal brain did not reveal any additional malformations in either case. Prenatal follow-up showed the cysts to be stable in one case and decreased in size in the other. Postnatal neurodevelopmental outcome to date is normal. (Range of follow-up: 6-24 months.) Eight cases reported in the literature as CVIC resulted in favorable prognosis in all without further intervention. However, one infant required ventriculoperitoneal shunting due to progressive hydrocephalus, but developed normally nonetheless.

CONCLUSION

Prenatal diagnosis of cysts of the cavum velum interpositum, which are isolated, single, stable in size, and not associated with other anomalies, is consistent with a favorable postnatal outcome.

First-trimester diagnosis of fetal arachnoid cyst: prenatal implication

We report a case of the early diagnosis of an arachnoid cyst. Transvaginal ultrasound examination of the fetal brain at 13 weeks' gestation revealed the presence of an anechoic mass above the posterior fossa. After extensive counseling and because of the uncertain prognosis of a first-trimester diagnosis of an arachnoid cyst, the parents opted for termination of pregnancy. The diagnosis was confirmed by postmortem examination.

Prenatal sonographic diagnosis of dilated cavum vergae

Several cases of enlarged cavum vergae have been reported, but prenatal diagnosis of this condition is very rare. We report 3 cases of dilated cavum vergae diagnosed prenatally using sonography. In 1 of the 3 fetuses, ventriculomegaly and lumbar meningomyelocele were additional sonographic findings. In 1 of the 3 infants, a stereotactic cyst-peritoneal shunt was placed at 6 months of age to relieve intracranial hypertension due to progressive enlargement of the cavum vergae. The infant who had a meningomyelocele required surgical repair of this defect shortly after birth; in the third infant, the dilated cavum vergae remained asymptomatic, and no surgery was necessary. When interhemispheric cystic lesions are identified prenatally, physicians must distinguish them from pathologic cysts and determine whether associated malformations are present. Sonography is useful for both the differential diagnosis and identification of associated anomalies.

Prenatal diagnosis of tuberous sclerosis with intracerebral signs at 14 weeks' gestation

We report the ultrasound detection of cranial abnormalities at 14 weeks' gestation in a fetus subsequently confirmed as having tuberous sclerosis using DNA linkage analysis within the affected family. The presence of asymmetrical ventricular enlargement persisted antenatally. Magnetic resonance imaging at 26 weeks indicated the possibility of poor gyral formation consistent with a neuronal migration disorder. Cardiac rhabdomyomata were not visualized on ultrasound scan until 30 weeks' gestation. Postnatal cranial ultrasound confirmed the significant neuropathology which was manifested by severe developmental delay and intractable fits in the child. The potential benefits of earlier diagnosis of tuberous sclerosis by cranial imaging are discussed, although in this patient the routine booking scan resulted in a path of prenatal diagnosis being undertaken which had originally been declined. A mechanism is proposed to explain the variable expression of tuberous sclerosis within this family based on altered TSC2 activity affecting neuronal migration.

Ultrasonographic differential diagnosis of fetal intracranial interhemispheric cysts

OBJECTIVE

Ultrasonographic differentiation between intracranial supratentorial interhemispheric pathologic cystlike lesions and those related to physiologic median structures is essential because the latter have no clinical relevance, whereas the former may carry a poor prognosis. We reviewed our experience with 19 consecutive cases of interhemispheric hypoechoic lesions without parenchymal involvement diagnosed between January 1990 and June 1997 to establish their clinical significance and provide prenatal ultrasonographic criteria to distinguish between pathologic cystlike lesions and those related to physiologic midline structures.

STUDY DESIGN

All patients underwent targeted prenatal scans of intracranial anatomy to establish the relationship between the fluid collections and the surrounding parenchymal and ventricular structures. In addition, a detailed anatomic survey was performed to rule out associated malformations. Follow-up, including neurologic examination, imaging, autopsy evaluation, or a combination was performed in all cases. Statistical analysis used the Wilcoxon rank sum test, the Fisher exact test, and the chi2 test for trend. P <.05 was considered significant.

RESULTS

Cystlike lesions related to physiologic median structures (n = 12) included enlargement of the cavum septi pellucidi (n = 3), enlargement of the cavum vergae (n = 2), and cysts of the velum interpositum (n = 7). These lesions were unilocular and had a median size of 10 mm (range 10-30 mm); they resolved in 5 cases and remained stable in the remainder. They were not associated with overt abnormalities, other than borderline ventriculomegaly in 2 cases. Pediatric follow-up (median 26 months, range 3-84 months) showed normal neurodevelopment in all cases. Pathologic cystlike lesions (n = 7) were significantly larger (median 40 mm, range 10-80 mm, P =.004) and had a significantly worsening trend, growing more at serial prenatal ultrasonographic examinations (P =.039) than fluid collections related to physiologic median structures. Moreover, prenatal ultrasonographic evidence of associated intracranial abnormalities, in the form of partial or total agenesis of the corpus callosum and overt hydrocephalus, was present in 5 of 7 cases of pathologic cystlike lesions and in none of the 12 related to physiologic structures (P =.002). Median gestational age at diagnosis was not different between those with cystlike lesions related to physiologic median structures and those with pathologic lesions (30 and 31 weeks, respectively). Among the latter group, 1 pregnancy was voluntarily terminated, 1 infant died at 4 months of age, 2 infants had neurodevelopmental delay, and 3 infants were neurologically healthy at a mean follow-up of 43 months. Cyst shunting was necessary in 5 of 6 cases.

CONCLUSIONS

Interhemispheric cystlike lesions related to physiologic structures can be prenatally distinguished from pathologic fluid collections on the basis of location, cyst size, change in size with time, and absence of associated anomalies.

Dominantly inherited cerebral dysplasia: arachnoid cyst associated with mild mental handicap in a mother and her son

We report a mother and son who each presented in infancy with hypotonia and global developmental delay. Subsequently, in both subjects, mild mental handicap was diagnosed in association with temporal lobe arachnoid cysts. Mendelian inheritance of this phenotype seems likely and macroscopic cerebral dysplasia in general may be underdiagnosed in people with familial, mild mental handicap.