Posterior Fossa Cyst Research Articles

A large growing occipital meningocele with Dandy–Walker syndrome: A case report and review of the literature

Background: Dandy–Walker syndrome (DWS) is a well-known developmental anomaly. An occipital meningocele (OMC) is recognized as a malformation that is relatively often associated with DWS, but the association of DWS with OMC has been reported in approximately 40 cases. We present herein a rare clinical course of DWS with OMC, in which the sac was small at birth and became progressively larger. Case Description: A 5-day-old baby boy was referred to our hospital due to OMC. He was born at 33 gestational weeks due to premature rupture of the membranes. He was diagnosed as having DWS associated with OMC. The OMC was covered with skin and its maximum diameter at birth was 3 cm. Magnetic resonance imaging showed an occipital bone defect and continuity of the fourth ventricle, posterior fossa cyst, and OMC sac. The aqueduct was patent, and no hydrocephalus was found. The OMC sac increased progressively with moderate hydrocephalus and reached 7 cm at the age of 54 days when his weight was 2508 g. A cystoperitoneal shunt and repair were performed after sinus venography by contrast computed tomography (CT). At the age of 1 year and 8 months, he had moderate developmental disabilities. Conclusion: In most cases reported, the OMC was relatively small, and large and giant sizes were reported in only six cases. Almost all cases remained the same size as at birth and underwent surgical intervention as early as possible. It was possible to understand the relationship between the occipital bone defect and abnormal running of sinuses such as the superior sagittal sinus, torcular Herophili, and transverse sinus preoperatively from the CT venography (CTV) image. CTV may be an effective and important method for safely performing repair and shunt.

EP06.05: Position of the 4th ventricle choroid plexus in 1st and 2nd trimester: novel approach to early diagnosis of cystic posterior fossa anomalies

EP06.05: Position of the 4th ventricle choroid plexus in 1st and 2nd trimester: novel approach to early diagnosis of cystic posterior fossa anomalies

Staged Neuroendoscopic Management of a Dandy Walker Malformation Case Presenting with Complex Hydrocephalus

Backgroud: Dandy-Walker malformation is a rare congenital condition characterized by alteration of posterior fossa anatomy. Hydrocephalus is a common finding in these patients. VP-shunt placement remains the treatment of choice. Endoscopic Third Ventriculostomy (ETV) is an acceptable alternative for older children. Other techniques have also been proposed. Case presentation: A full-term infant presented with signs of hydrocephalus. An endoscopic foraminoplasty of the posterior fossa cyst was conducted as a first stage. The cyst’s volume was reduced, without any changes of the supratentorial ventricular dimensions. A month post-surgery signs of hydrocephalus reoccurred. An ETV was performed alongside a fenestration of the tentorium. The toddler was discharged in good condition with amelioration of her symptoms. One month later she presented with recurrent hydrocephalus and subdural hygromas. A shunt was placed in the posterior fossa under endoscopic guidance, and an additional one was introduced in the subdural space. The patient was followed-up for 18 months without any further need for treatment. VP-shunt placement is the treatment of choice. Discussion: Lushka and Magendie foraminoplasty seems to be ineffective. ETV should be reserved for older children. The ventriculoscope can be employed for positioning the VP-shunt in a specific anatomical region. Subdural hygromas may present after neuroendoscopic treatment. A staged approach may be mandatory for complex hydrocephalus treatment.

Dorsal craniovertebral junction arachnoid cyst

Arachnoid cysts causing symptoms, at the level of the craniovertebral junction (CVJ), are very infrequently reported. Inadequate imaging (either only of brain up to foramen magnum or only cervical spine) often leads to delayed diagnosis in these cases. Those that straddle the CVJ do not cause tonsillar descent and differ from the more common pure retro or supracerebellar posterior fossa cysts that cause tonsillar descent, although they present in an identical manner. We treated the index case by fenestration of the lower end of the cyst into the spinal subarachnoid space instead of the more extensive surgeries hitherto described as we felt that cerebrospinal fluid flow patterns with an intact foramen magnum and help conferred by gravity would prevent re-accumulation.

Prenatal diagnosis of vermian cyst: a new type of posterior fossa cyst.

Prenatal diagnoses of cystic malformations of the posterior fossa mainly encompass arachnoid cysts, Blake's pouch cysts and Dandy-Walker syndrome. To date, vermian cysts have not been reported prenatally. To report a series of fetuses with a vermian cyst. This was a single-center retrospective study conducted from 2012 to 2021. We included all fetuses presenting with a vermian cyst and excluded all other types of posterior fossa cyst. The cyst was visible at prenatal ultrasound (US) and/or magnetic resonance imaging (MRI). Postnatal imaging and/or clinical outcome data were available. Sixteen fetuses fulfilled the inclusion criteria with a strong female predominance (n=13). US and MRI were performed at a mean gestational age of 29+5 and 33+1weeks, respectively. In all patients, the cyst was in the vermian horizontal fissure. The mean longest dimension was about 10mm. The vermis and other posterior fossa structures were otherwise normal. At postnatal imaging, 13 children underwent brain imaging including 11 MRIs with complete regression (n=9), stability (n=1) and increase in size (n=3) of the cyst. Psychomotor development was normal in 14 children. One child (with an inner ear malformation) showed a slight delay in walking and language acquisition. Slight walking ataxia was present in another child. We report 16 fetuses with posterior fossa cysts located within the vermis at the level of the horizontal fissure, diagnosed at US and/or MRI and carrying an overall excellent neurological prognosis.

Challenges in the pre- and post-natal diagnosis of posterior fossa cysts: A case report and review of historical evolution of descriptive terminologies.

Radiological diagnoses of posterior fossa cystic abnormalities during antenatal and postnatal periods pose significant challenges as they may have similar early imaging features. Some of the frequently described entities are arachnoid cysts and Dandy-Walker malformations. Blake's pouch cyst is relatively underdiagnosed. The main aim of the study was to explore these diagnostic challenges in the context of various descriptive terminologies and their prognostic implications. We illustrate this through our case, where fetal magnetic resonance imaging (MRI) at 36 weeks gestation showed small right cerebellum without hydrocephalus or hemorrhage. Possible differential diagnoses included Dandy-Walker malformation or posterior fossa malformations, facial hemangiomas, arterial anomalies, cardiac and eye anomalies, sternal clefting, and supraumbilical raphe. Postnatal sonography noted posterior fossa cyst without hydrocephalus in a normal term infant, who went on to develop symptomatic hydrocephalus by 15 weeks. Computed tomography brain scan confirmed large subtentorial posterior fossa cyst and extensive internal hydrocephalus. Despite emergent ventriculoperitoneal shunt insertion, head circumference continued to rise. MRI scan showed persistent cyst. Subsequently, infant underwent endoscopic fenestration of the cyst with balloon septostomy and now has an age appropriate developmental profile. There is considerable discordance between antenatal and postnatal neuroimaging findings as highlighted in our case. Diagnostic conundrum here was whether this was an arachnoid or Blake's pouch cyst. Differentiating between posterior fossa fluid collections is crucial for management, prognosis, and parental counseling. Close postnatal follow-up is essential to avert complications due to acute hydrocephalus.

Position of the choroid plexus of the fourth ventricle in first‐ and second‐trimester fetuses: a novel approach to early diagnosis of cystic posterior fossa anomalies

The aim of this study was to describe the sonographic appearance and position of the choroid plexus of the fourth ventricle (4thVCP) between 12 and 21 weeks' gestation in normal fetuses and in fetuses with posterior fossa anomalies. Two-dimensional ultrasound (US) images of the midsagittal and coronal views of the brain through the posterior fontanelle and three-dimensional volumes datasets were obtained between 12 and 21 weeks prospectively from 90 normal singletons and retrospectively from 41 fetuses identified as having an abnormal posterior brain on first-trimester ultrasound examination. In all cases the diagnosis was confirmed at MRI, prenatally and/or postnatally, and/or at postmortem examination. During the study period, 41 fetuses, with apparently isolated cystic posterior fossa anomaly based on first trimester ultrasound assessment of intracranial spaces, were reviewed in the second trimester and were found to have Dandy Walker Malformation (DWM) in 8 cases, Blake's Pouch Cyst (BPC) in 29 and they were normal in 4 patients. The position of 4thVCP was different in DWM, BPC and normal cases either at first and at second trimester examination. In particular, in normal fetuses no cyst was present, and on median and coronal planes of posterior fossa the choroid plexus appeared as an echogenic and oval shaped structure located inside the 4th ventricle apparently attached to the cerebellar vermis. In fetuses with DWM, on median view of posterior fossa, it was not possible to visualize the CP. It was infero-laterally dislocated due to the presence of a cyst which displaced the 4thVCP and could be visualized only on a coronal plane of the posterior brain. In all DWM cases the CP was positioned outside the cyst. In BPC, the 4VthCP was always located inside the cyst, on its superior part, near the vermis and was visualized on median and coronal planes. Our study demonstrated that a longitudinal ultrasound assessment of 4thVCP and its temporal changes from 12 to 21 weeks is feasible. The ability to define the position of the 4thVCP as inside or outside the cyst is a novel finding which can be assessed in the first trimester of pregnancy and it is useful to differentiate DWM from BPC, consistently with the pathophysiology of the two conditions. This article is protected by copyright. All rights reserved.

VP50.04: The role of ultrasound screening in the identification of cystic posterior fossa anomalies at the first trimester of gestation

VP50.04: The role of ultrasound screening in the identification of cystic posterior fossa anomalies at the first trimester of gestation

Case Report on: Dandy Walker Malformation Syndrome

Introduction: Dandy Walker Syndrome is a congenital brain malformation that affects the cerebellum and the fluid filled areas that accompany it. The cerebellum is a part of the brain that deals with movement coordination as well as cognition and behavior.
 Case Presentation: The male patient 8 year old who was apparently admitted in A.V.B.R.H on 18/8/2019 is diagnosed with a known case of dandy walker malformation and came with the complaints of headache since 4 days, fever since 3 days, vomiting since 5 days and 3 episodes of seizures. All the necessary blood investigations has been done. The CT scan as well as MRI reports has shown that large posterior fossa cyst with open communication with fourth ventricle with hypoplastic left cerebellar hemisphere and no visualized cerebellar vermis. Before taking this case, information was given to the patients and their relatives and Informed consent was obtained from patient as well as relatives.
 Therapeutic Intervention: The patient was treated with NSAIDS, antibiotics, anticonvulsant, antiemetic and antacid and physical therapy to help keep muscle strength and flexibility The patient underwent VP shunt head circumference assessed regularly, vital signs hourly, provided vitamins enriched diet as per dietician’s order assisted dressing for drainage and physical therapy. Conclusion: The patient was admitted in A.V.B.R.H in a critical condition with the diagnosis of dandy walker syndrome, after providing the required treatment by the health care team members of hospital the patient condition was improved and satisfactory.

Intracranial Dermoid Cyst in the Posterior Fossa: A Case Report

Introduction: Intracranial dermoid cysts are benign, ectopic squamous epithelial cysts often compose of dermal structures like hair follicles, sweat glands as well as sebaceous glands. This lesions constitutes about 0.5% of all intracranial neoplasms. Thus, the occurrence of a dermoid cyst in the posterior fossa is very rare. We report a rare case of intracranial dermoid cyst in posterior cranial fossa. Case Presentation: Our first case was a 32 years old woman who presented with headaches and dizziness with no nausea, vomiting or fever. CT scan revealed a mass at occipital cistern consistent with a cystic lesion. MRI also revealed an irregular lesion in the posterior part of the medulla oblongata with enhanced edges signifying calcifications. We attained total resection of the tumor in a piece meal approach via surgery. Histopathology confirmed dermoid cyst. Two years follow-up revealed no recurrence of the lesion and no neurological deficits. Conclusion: We advocate that, the goal in surgical decision-making should be safe and total resection while monitoring the cranial nerves with electromyographic and auditory brainstem responses.

Spontaneous Intracystic Hemorrhage in an Adult with Cerebellopontine Angle Arachnoid Cyst and Management: A Case Report

Arachnoid cysts are common findings on neuroimaging and account for approximately 1% of all intracranial lesions. The cerebellopontine angle is the second most common location. When arachnoid cysts become symptomatic due to cyst growth, or rarely, cyst rupture, they create mass effect on adjacent neurovascular structures and may require neurosurgical management. This involves a posterior fossa decompression and cyst fenestration with or without cyst fluid diversion.

Dandy-Walker variant: a diagnosis by clinical and CT evaluation in a tertiary hospital in Nepal

<p class="abstract">Dandy-Walker variant (DWV) has been used to describe a combination of cystic dilation of the fourth ventricle and hypoplastic cerebellar vermis in the absence of an enlargement of the posterior fossa. Magnetic resonance imaging (MRI) is the modality of choice for diagnosing DWV. But it can also be diagnosed by evaluating the subject clinically and by CT scans. We presented here a case report of a patient with DWV who was diagnosed by clinical evaluation and CT scans. A 15 years old girl presented with the symptoms of pain and ear discharge from both ears. She had developmental delay, mental retardation and poor nutritional status. The CT scan of the patient showed a posterior fossa cyst with hypoplastic vermis and communicating hydrocephalus without obvious enlargement of the posterior fossa. Hence, a diagnosis of DWV was made. For the ear pathology, she underwent modified radical mastoidectomy and other medical treatments.</p>

A Possible Association Between Zika Virus Infection and CDK5RAP2 Mutation.

IntroductionFlaviviridae family belongs to the Spondweni serocomplex, which is mainly transmitted by vectors from the Aedes genus. Zika virus (ZIKV) is part of this genus. It was initially reported in Brazil in December 2014 as an unknown acute generalized exanthematous disease and was subsequently identified as ZIKV infection. ZIKV became widespread all over Brazil and was linked with potential cases of microcephaly.Case reportWe report a case of a 28-year-old Colombian woman, who came to the Obstetric Department with an assumed conglomerate of fetal abnormalities detected via ultrasonography, which was performed at 29.5 weeks of gestation. The patient presented with multiple abnormalities, which range from a suggested Arnold–Chiari malformation, compromising the lateral and third ventricles, liver calcifications, bilateral pyelocalic dilatations, other brain anomalies, and microcephaly. At 12 weeks of gestation, the vertical transmission of ZIKV was suspected. At 38.6 weeks of gestation, the newborn was delivered, with the weight in the 10th percentile (3,180 g), height in the 10th percentile (48 cm), and cephalic circumference under the 2nd percentile (31 cm). Due to the physical findings, brain magnetic resonance imaging (MRI) was performed, revealing a small and deviated brain stem, narrowing of the posterior fossa, a giant posterior fossa cyst with ventricular dilatation, a severe cortical and white matter thinning, cerebellar vermis with hypoplasia, and superior and lateral displacement of the cerebellum. In addition, hydrocephalus was displayed by the axial sequence, and the cerebral cortex was also compromised with lissencephaly. Schizencephaly was found with left frontal open-lip, and no intracranial calcifications were found. Two novel heterozygous nonsense mutations were identified using whole-exome sequencing, and both are located in exon 8 under the affection of ZIKV congenital syndrome (CZS) that produced a premature stop codon resulting in the truncation of the cyclin-dependent kinase 5 regulatory subunit-associated protein 2 (CDK5RAP2) protein.ConclusionWe used molecular and microbiological assessments to report the initial case of vertically transmitted ZIKV infection with congenital syndrome associated with a neurological syndrome, where a mutation in the CDK5RAP2 gene was also identified. The CDK5RAP2 gene encodes a pericentriolar protein that intervenes in microtubule nucleation and centriole attachment. Diallelic mutation has previously been associated with primary microcephaly.

ISUOG Practice Guidelines (updated): sonographic examination of the fetal central nervous system. Part 2: performance of targeted neurosonography.

ISUOG Practice Guidelines (updated): sonographic examination of the fetal central nervous system. Part 2: performance of targeted neurosonography.

Neurocutaneous Melanosis: Prenatal Presentation as a Posterior Fossa Cyst.

Neurocutaneous Melanosis: Prenatal Presentation as a Posterior Fossa Cyst.

Giant Epidermoid Cyst of Posterior Fossa-Our Experience and Literature Review.

Introduction. Intracranial epidermoid cysts are the most frequent congenital intracranial lesion. They rare and benign tumors that can present in different clinical situations depending on location and extension of the disease. Diagnosis is obtained with radiological imaging with RM and non-enhanced TC as elective investigating methods. Elective treatment is surgery, based on total/subtotal excision sparring healthy neurovascular structures, considering the benign nature of this lesion. Case Report. In this study we present the case of a 79-year-old woman affected by recidivist epidermal cyst of the posterior fossa. Clinical presentation was characterized by positional subjective vertigo, intense headache localized in the right part of the head increased by Valsalva maneuver and retroarticular subcutaneous swelling. Radiological investigation found a giant epidemoid cyst of the posterior fossa (8,4 x 4,8 x 5,8 cm), treated with surgery. In the postoperative, the patient was fine and no neurological deficit has been encounterd. REVIEW. In this study, we present a review of the literature regarding giant epidermoid cysts of posterior fossa. Only 11 cases were reported before ours, which actually is one of the largest ever described.

Recurrent Cerebellar Hemangioblastoma with Obstructive Hydrocephalus in Pregnancy: Challenges in Management—a Case Report

Hemangioblastoma is a rare brain tumor seen in pregnancy. Its management can be challenging due to the physiological changes of pregnancy. We discuss the challenges of managing such patients during pregnancy and review the literature regarding the management of cerebellar hemangioblastoma during pregnancy. We report a case of recurrent cerebellar hemangioblastoma who presented in pregnancy with a repeated history of severe headache and papilledema at 36 weeks. She was diagnosed to have obstructive hydrocephalus which did not respond to conservative management. Cesarean delivery along with cerebrospinal fluid diversion, ventriculoperitoneal shunt procedure, and excision of posterior fossa cyst was done, which resulted in good maternal and neonatal outcome. The risk of newborn and maternal mortality can be minimized by knowing the challenges and their appropriate management.

Pediatric Cerebellar Pilomyxoid Astrocytoma: Clinical and Radiological Findings in Three Cases.

Pilomyxoid astrocytomas (PMA) is a particular form of glial tumors distinct from pilocytic astrocytomas (PA). On the last 2016 WHO classification for CNS tumours, no definite grade assignment was proposed for these lesions. They may be more aggressive with a different clinical course compared to PA due to their greater propensity for local recurrence and cerebrospinal dissemination. Most cases arise from the hypothalamic region. Only few studies reported cerebellar localization of the lesion. We report 3 pediatric cases treated for pediatric PMA of the posterior fossa. Clinical, radiological, and prognostic features were reviewed. The age of our patients was between 1 and 9 years old. Signs of intracranial hypertension were found in all patients. One of them presented an increased head circumference and the 2 others had a cerebellar syndrome. Brain CT-scan and MRI displayed a large wellcircumscribed intra-axial solid and cystic posterior fossa tumor. Total surgical resection was performed for all tumors. After a 2 years follow up, no signs of recurrence were noticed. In the literature, PMA been reported with overwhelming majority in children aged between 2 months and 4 years. Despite of many pathological similarities with PAs, PMAs have some specific features in histology, leading to their identification as independent type of glioma. Radiological differential diagnosis between PMAs and Pas can be made using arterial spin labeling imaging, which shows low perfusion parameters in PAs. Clinical and radiological follow up are mandatory do to different natural history and higher rates of local recurrence of this tumor compared to PA. Prognosis is favorable when complete surgical exeresis is possible.

Neurocutaneous melanosis concurrent with a posterior cranial fossa cyst (Dandy–Walker complex) and an intradural arachnoid cyst of the spinal canal

The paper describes a female patient with neurocutaneous melanosis (NCM) concurrent with Dandy–Walker malformation and a spinal arachnoid cyst, who has been treated in the A.Ya. Kozhevnikov Clinic of Nervous System Diseases. Over the course of one year, the patient had progressive neurological symptoms as central lower paraparesis and coordination disorders; her medical treatment was ineffective. Neuroimaging revealed Dandy–Walker malformation and a spinal arachnoid cyst. Surgical intervention (fenestration of the upper and lower poles of the arachnoid cyst at the C VI-VII and T IX-X level) was performed. After one month, reoperation (commissure resection in the arachnoid cyst cavity at the T V-VI level; implantation of a cystoperitoneal shunt) was made because of the absence of a clinical result. Reversal of neurological disorders was noted postoperatively. The described clinical case is unique, since NCM is an extremely rare abnormality, especially when concurrent with Dandy–Walker malformation and an arachnoid cyst. In addition, it is of interest that the manifestation of neurological symptoms and verification of the diagnosis occurred just in adulthood, although NCM is most commonly diagnosed in children. The present case shows that an operation aimed at improving cerebrospinal fluid dynamics in patients with arachnoid cysts and Dandy–Walker complex in the presence of NCM can lead to a significant reversal of neurological symptoms and improvement in the quality of life despite gross brain structural changes detected by magnetic resonance imaging.

Rare Association of Dandy-Walker Malformation With a Giant Occipital Meningocele

A 24-year-old unbooked pregnant woman, G2, P1, L1, at 38 weeks gestation was referred to our hospital in active labour. Ultrasound examination revealed vermian aplasia with a wide communication between the fourth ventricle and a large posterior fossa cyst (Figure A, Figure B). This finding was consistent with a diagnosis of Dandy-Walker malformation, which was seen communicating with a giant occipital meningocele (Figure B, asterisk), measuring approximately 18×14×12 cm, through a defect in the occipital bone. Supratentorial hydrocephalus was also noted.