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

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.

Retrocerebellar Ependymal Cyst Presenting with Obstructive Hydrocephalus in an Infant

Intracranial ependymal cysts (ECs) are rare benign lesions. They are frequently asymptomatic and arise in the supratentorial regions. Retrocerebellar ECs is a rare location. We present a case of 3-months-old infant who developed obstructive hydrocephalus, bulging fontanel, and macrocephaly secondary to a retrocerebellar EC. Magnetic resonance imaging (MRI) showed a large retrocerebellar cyst that compressed the cerebellum and the brainstem, producing fourth ventricle outlet obstruction and supratentorial hydrocephalus. Microsurgical fenestration of the cyst to the obex of the fourth ventricle and a cystic wall biopsy were performed. The procedure improved supratentorial hydrocephalus, as well as the patient's clinical condition. A histopathological study confirmed the diagnosis of an EC.

As far as we know, after a thorough review of the literature, this is the first reported case of retrocerebellar EC. It is a rare cause of hydrocephalus due to outlet obstruction of the fourth ventricle. Treatment of the cause itself was shown to be effective.

Different information by MRI compare to ultrasound in fetal intracranial space occupying lesions

PURPOSE

The purpose of this study was to evaluate the value of prenatal magnetic resonance imaging (MRI) in characterizing fetal intracranial space occupying lesions in comparison to prenatal ultrasound.

METHODS

This retrospective study included 50 fetuses (mean age 26 years, mean gestational weeks 31 + 1 GW) with intracranial space occupying lesions, suspected by prenatal screening ultrasound. T2-weighted, T1-weighted, SSFP, and diffusion-weighted sequences of the fetal brain were obtained on a 1.5 T unit. Pathology (n = 5), postmortem MRI (n = 3), or postnatal US (n = 42) was available as standard of reference.

RESULTS

The fetal MRI provided correct diagnosis in 49 cases (98%), while 35 (70%) by ultrasound, and MRI failed in 1 case (2%), while ultrasound failed in 15 cases (30%). Fetal MR and ultrasound were concordant in 35 of 50 cases (70%), completely discordant in 4 (8%), and partially discordant in 11 (22%) cases.

CONCLUSIONS

MRI could provide detailed information about the minor lesions, such as focal hemorrhage and periventricular nodules. Meanwhile, it could provide whole view of the lesion in order to delineate the surrounding anatomical structure. But there are still some limitations of its soft-tissue resolution in a case with teratoma; more effort is needed to improve the sequences.

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.