Transcallosal and endoscopic hybrid approach to a rare entity of pediatric intraventricular tumors-cribriform neuroepithelial tumor: a case report and literature review.

PURPOSE: Cribriform neuroepithelial tumor (CRINET) is a provisional category of intraventricular tumors, sharing similarities with AT/RTs, and there is a lack of data about its pathology, prognosis, and surgical approaches in the literature. We have been challenged to describe the surgical approach to a rare case of CRINET and describe the intraoperative features since none has been described before. Surgical resection and chemotherapy hold a great importance of favorable prognosis. METHODS: Twenty-month-old male with intraventricular tumor underwent transcallosal intraventricular tumor resection and endoscopic intraventricular second look stages. The tumor was initially considered choroid plexus carcinoma and histopathological results pointed CRINET. The patient also received Ommaya reservoir for intrathecal chemotherapy employment. The patient's preoperative and postoperative MRI scans and tumor's pathological features are described with a brief history of the disease in the literature. RESULTS: Lack of SMARCB1 gene immunoreactivity and presence of cribriform non-rhabdoid trabecular neuroepithelial cells led to the CRINET diagnosis. The surgical technique helped us to approach directly into the third ventricle and perform total resection and intraventricular lavage. The patient recovered without any perioperative complications and is consulted pediatric oncology for further treatment planning. CONCLUSION: With our limited knowledge on the matter, our presentation may provide an inside to the course and progress of the CRINET as a very rare tumor and may help to set a basis for future investigations focused on its clinical and pathological features. Long courses of follow-up periods are required for establishing treatment modules and assessing the responses to surgical resection techniques and chemotherapy protocols.

Pure endoscopic ultrasonic removal of choroid plexus papillomas of the third ventricle: technical report of two cases.

BACKGROUND: Tumors of the choroid plexus of the third ventricle are uncommon. Surgical excision is technically challenging because of the rich vascularisation, central location, and high incidence in young children. Open microsurgical resection is considered the standard treatment. However, attempts at purely endoscopic removal of choroid plexus tumors of the third ventricle have also been made in the past, with encouraging results. CASE REPORTS: We report our experience with endoscopic ultrasonic removal of two cases of tumors of the third ventricular choroid plexus. The first case was a large atypical choroid plexus papilloma (WHO grade 2) in the anterior third ventricle associated with hydrocephalus; the second case was a smaller choroid plexus papilloma (WHO grade 1) in the middle/posterior third ventricle without overt hydrocephalus requiring a more anterior neuronavigation guided approach. DISCUSSION AND CONCLUSION: Choroid plexus papillomas of the third ventricle can be safely treated by a purely endoscopic approach because they are usually smaller than their counterparts in the lateral ventricle and often have a recognizable vascular pedicle. Early detection and control of the vascular pedicle at the choroidal border is key to success. The use of ultrasonic aspirator facilitates and expedites endoscopic access. By alternating surface coagulation with fragmentation and aspiration with the ultrasonic aspirator, the tumor can be removed without difficult dissection maneuvers.

Pre-operative embolization for staged treatment of infantile choroid plexus papilloma.

Choroid plexus papillomas (CPPs) are benign but rare neuroepithelial neoplasms of the choroid plexus that represent the non-malignant form of a spectrum of tumors of the choroid plexus. The vast majority of CPPs present in children under 5 years of age. Some CPPs are diagnosed prenatally, but many of them reach a large size before diagnosis. CPPs typically present with signs and symptoms of hydrocephalus. Treatment of these tumors has traditionally been with surgical resection. Large CPPs in young children present a challenge due to risk of high blood loss during resection. Here, the authors describe the case of a 3-month-old presenting with hydrocephalus and a large CPP of the third ventricle that was managed with a staged strategy of embolization followed by a delayed resection, allowing the tumor to involute prior to surgery.

Symptomatic bilateral choroid plexus xanthogranuloma in a pediatric patient.

INTRODUCTION: Central nervous system xanthogranulomas are uncommon clinical entities, and symptomatic bilateral choroid plexus xanthogranulomas are rare. CASE PRESENTATION: We present the case of a 15-year-old male patient with bilateral choroid plexus xanthogranulomas with symptoms of increased intracranial pressure. Gross total resection of the tumor in the left lateral ventricle was performed. The patient improved, and asymptomatic right-sided tumor was monitored at follow-up. CONCLUSION: The main treatment objective in these tumors is gross total resection. Asymptomatic tumors can be followed without intervention. However, surgery should be performed for symptomatic tumors that cause hydrocephalus or symptoms of increased intracranial pressure.

Rare Case of Pediatric Disseminated Choroid Plexus Papilloma: Literature Review and Call for Reclassification.

INTRODUCTION: Choroid plexus tumors are rare neuroectodermal tumors that arise from the choroid plexus. Choroid plexus papillomas (CPPs) represent the lowest grade of these types of tumors and have a WHO grade I designation. Despite their typical low grade, some CPPs can exhibit aggressive behaviors including parenchymal invasion and dissemination throughout the neuro-axis. Due to their association with the choroid plexus, patients with CPP commonly present with signs and symptoms of hydrocephalus and increased intracranial pressure. CASE PRESENTATION: A 2-year-old male presented in extremis with acute hydrocephalus and seizure. He was found to have a large left intraventricular mass with innumerable intraparenchymal and extra-axial cysts throughout his neuro-axis. A literature review revealed five similar disseminated CPP cases with innumerable lesions. This is the youngest reported patient with disseminated CPP and the first with multiple compressive lesions. Following cranial resection and thoracic decompression, the patient's lesions have remained stable (2 years of follow-up). A literature search of the PubMed/Medline databases was performed using the search terms ["disseminated choroid plexus papilloma" OR "choroid plexus papilloma" OR "metastatic choroid plexus papilloma"] up to March 2021. Articles were then screened for similar patient radiographic presentation and histological diagnosis. To mitigate publication bias, referenced articles were utilized to identify other case reports and case series. DISCUSSION/CONCLUSION: We describe a rare case of a lateral ventricle CPP with widespread leptomeningeal dissemination causing acute obstructive hydrocephalus and compressive myelopathy requiring cerebrospinal fluid diversion and intracranial resection followed by thoracic spine decompression. This case report serves to broaden knowledge of disseminated CPP and to encourage complete neuro-axis imaging for choroid plexus tumors. Additionally, we propose a naming paradigm refinement that includes radiographic characteristics.

Paediatric atypical choroid plexus papilloma: is adjuvant therapy necessary?

INTRODUCTION: Choroid Plexus Tumours (CPTs) account for 1-4% of all brain tumours in children. Atypical choroid plexus papillomas (aCPPs) are a subset of these tumours, defined over a decade ago, yet no consensus exists on the optimal approach to their management. METHODS: We conducted a retrospective analysis of all patients treated for CPTs at the Hospital for Sick Children between January 1, 2000, and December 31, 2018, and focused on patients with aCPP. Data extracted from the patient records for analysis included: demographic and clinical features, radiological imaging, surgical and adjuvant therapies, key pathological features, immunohistochemical staining for TP53 and tumour karyotype. Six of seven aCPP samples were profiled using Illumina HumanMethylationEPIC arrays and the top 10,000 most variably methylated probes were visualized using tSNE. Copy number inferencing was also performed. RESULTS: Twenty-nine patients were diagnosed with CPT, seven of whom had a diagnosis of aCPP as confirmed by histological review. Methylation profiling demonstrated that aCPPs clustered with both choroid plexus papillomas (CPPs) and choroid plexus carcinomas (CPCs). Complete resection of the tumour was pursued in all cases of aCPP and no patient received adjuvant therapy. All aCPP patients were alive at last follow up. CONCLUSIONS: This limited case series suggests that paediatric aCPP can be successfully managed with surgical resection alone, followed by a 'watch and wait' approach thus avoiding adjuvant therapies. A deeper understanding of the biology of aCPP is required to identify objective markers which can help provide robust risk stratification and inform treatment strategies.

Pediatric choroid plexus papilloma arising from the cerebellopontine angle: systematic review with illustrative case.

INTRODUCTION: Choroid plexus tumors are uncommon intraventricular tumors that develop from the choroid plexus of the central nervous system. Choroid plexus papillomas arising from the cerebellopontine angle have been reported to almost exclusively occur in adults and are rarely found in children. METHODS: We report a systematic review conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines of SCOPUS and PubMed databases for case reports and case series of choroid plexus papillomas arising in the cerebellopontine angle in the pediatric population and discuss clinical presentation, imaging features, management options, and outcomes. We also report a case managed at our center. RESULTS: Ten cases of pediatric choroid plexus papillomas arising in the cerebellopontine angle were identified from the systematic review in addition to the case reported here, resulting in a total of eleven cases. The patients' median age was 8 years with a slight female sex predilection (1.2:1). Patients most commonly presented with headache, cerebellar signs, and cranial nerve palsies with median duration of symptoms at 4 months. All patients underwent surgical treatment with majority achieving gross total excision. No deaths were reported at median follow-up of 12 months. Complete neurologic recovery was attained in seven cases while partial recovery was seen in two cases. CONCLUSION: Choroid plexus papillomas found in the cerebellopontine angle in the pediatric population are extremely rare but they should be considered in the differential diagnosis. Complete surgical resection is the mainstay of treatment with excellent outcomes achievable in majority of patients.

Multimodality characteristics of multifocal choroid plexus carcinoma with bilateral calvarial defects in a dog.

An 8-year-old male intact miniature poodle presented for blindness, obtundation, tetraparesis, and vestibular signs. Magnetic resonance imaging, radiography, and ultrasound revealed a left piriform lobe lesion, right cerebellar and left brainstem lesions, and hydrocephalus and bilateral calvarial defects. Histopathology confirmed a choroid plexus carcinoma with meningeal and intraventricular metastases. The calvarial defect did not show evidence of necrosis, osteoclastic resorption, inflammation or neoplastic infiltration, reflecting a quiescent calvarial atrophy or dysplasia. These novel findings supported inclusion of bone atrophy secondary to chronic increased intracranial pressure as a differential diagnosis for large calvarial defects in dogs with choroid plexus carcinoma.

Infratentorial choroid plexus tumors in children.

OBJECTIVE: Choroid plexus tumors (CPTs) are rare pediatric intracranial neoplasms, and mostly occur in the lateral ventricle. CPTs located in the infratentorial location are considered to be rare in the pediatric population. We present a series of eight patients treated in the last decade at our institution focusing on clinical presentations and their outcome after excision. METHODS: We performed an institutional retrospective review of patients who underwent surgical resection of infratentorial CPTs during the period from 2008 to 2017. Patients' charts were reviewed for demographic data, clinical presentation, surgical treatment, and follow-up. RESULTS: There were eight patients (6 females and 2 males), with mean age for the cohort at presentation was 9.0 years. They represent 75% of 12 CPTs of all locations treated at the same period in our institution. These 8 infratentorial CPTs were in the fourth ventricle in seven, and in the cerebellopontine angle (CPA) in one. Seven patients had choroid plexus papillomas (WHO grade I) and 1 had an atypical choroid plexus papilloma (WHO grade II). Gross total resection was attempted in all patients. However, two of 3 patients with fourth ventricle floor invasion had subtotal resection with a thin layer of tumor left on the floor. The remaining 6 had a gross total resection. Six patients with preoperative hydrocephalus had a perioperative external ventricular drainage but none required permanent shunting after tumor resection. None showed recurrence/tumor progression without adjuvant therapy during the follow-up period of 20 months to 11 years. CONCLUSION: Infratentorial dominance among pediatric CPTs in this series contradicts previous reports. Infratentorial CPTs are amenable to surgical resection. Unresected small residuals due to invasion to the fourth ventricle floor showed no regrowth during 2 to 3 years follow-up without adjuvant therapy. However, these patients with incomplete resection need watchful observations.

Transventricular Migration of Choroid Plexus Carcinoma Causing an Intraoperative Conundrum: A Case Report with a Review of the Literature.

Migrating intracranial tumors are extremely rare occurrences in the neurosurgery literature. Introduction of any factor causing disequilibrium in cerebrospinal fluid circulation and pressure can potentially precipitate transventricular migration of pedunculated intraventricular lesions. The identification of such factors, prior to excision of intraventricular pedunculated tumors, is imperative to avoid intraoperative mismanagement. We report an extremely rare case of transventricular migration of a choroid plexus carcinoma in an infant, possibly precipitated by a ventriculoperitoneal (VP) shunt on the opposite side. This resulted in intraoperative confusion and a subsequent re-exploration of the opposite side for excision of the tumor. The literature provided only two similar occurrences in the past; however, in both cases, the migration was within the same ventricle and was documented prior to definitive resection. We report the first instance of transventricular migration of a tumor to the opposite ventricle following VP shunt which resulted in a negative intraoperative finding requiring a subsequent re-intervention on the opposite side. We believe that for any pedunculated intraventricular lesion, where an emergency management of hydrocephalus takes priority, a repeat neuroimaging is a must prior to definitive resection.

Water-Filled Vesicles of Choroid Plexus Tumors.

OBJECTIVE: Choroid plexus cysts are the most common neuro-epithelial cysts. METHODS: The authors describe 2 cases. The first case is a 1-year-old child presenting with hydrocephalus and cyst of the choroid plexus. The child was treated with endoscopic fenestration of the cysts. RESULTS: The histological examination of the cyst wall was consistent with choroid epithelium and water-filled vesicles. The second case is a 63 year old male with a highly vascularized tumor extending to choroid plexus. A quaductus Silvius was obstructed by the tumor. The histopathologic examination of choroid plexus showed a low number, water-vesicles. CONCLUSIONS: According to our knowledge, there are no previous reports of water-filled vesicles with choroid plexus cyst causing hydrocephalus. The first case is a good example of over secretion of cerebrospinal fluid (CSF) with the water-filled vesicle. The second case with low number of water filled vesicle shows that the cause of hydrocephalus is not over production of CSF, it is blockage of the CSF pathway in Aquaductus Silvius by the tumor itself. These 2 cases are illustrative and more importantly highlight the need to study for water-filled vesicles in these kind of cases.

Choroid plexus cysts-antenatal course and postnatal outcome in a tertiary hospital in North India.

PURPOSE: To assess the gestational course and postnatal outcome of antenatally diagnosed choroid plexus cysts. METHODS: From January 2015 to October 2017, mothers carrying foetuses with choroid plexus cysts (CPCs) were followed up prospectively till delivery, and subsequent postnatal assessment of all the babies was done. Progress of the lesions was monitored during pregnancy with ultrasound (USG) scans and postnatally analysed with clinical assessment and USG examination of the cranium. RESULTS: A total of 67 mothers of antenatally diagnosed CPCs were referred to the Paediatric Surgery Unit for opinion. Mean gestational age at the time of diagnosis was 19 ± 2.1 weeks (17-28 weeks) while mean age of the mothers at the time of referral was 26 ± 3.3 years (19-35 years). Sixty four mothers have undergone repeat antenatal scans after the diagnosis, and the CPCs disappeared completely in 60 (93.8%) of them. The CPCs persisted but reduced in size in 2 (4.1%), and the other 2 have been lost to follow-up. Thirty eight patients (56.7%) have unilateral CPCs. Mean size of cysts is 6.08 ± 3.0 mm (2.4­14.8 mm). One foetus, in which the CPC disappeared antenatally, developed it again on the postnatal scans, but is doing well on follow-up. Thirteen babies (19.4%) have other associated congenital malformations as well. CONCLUSIONS: CPCs may involve one or both ventricles and disappear in approximately 95% of the cases, mostly within 2 months from the diagnosis. The size of the cyst has no relation to its rate of disappearance. Postnatal persistence of CPCs is uncommon and the neurological sequel is unlikely; hence, prospective parents should be reassured accordingly.

Rare Case of Hemorrhagic Atypical Choroid Plexus Papilloma of Fourth Ventricle in Adult: A Diagnostic Dilemma.

Choroid plexus papillomas are highly vascular tumors, and such tumors causing subarachnoid hemorrhage have been reported in literature. Similarly, few articles have reported atypical fourth ventricular choroid plexus tumors in adults. However, such an atypical tumor presenting with grossly hemorrhagic transformation without any acute symptoms could not be found in the literature.

Hypertensive nonobstructive hydrocephalus as main magnetic resonance imaging feature in a dog with disseminated choroid plexus carcinomatosis.

Obstructive or nonobstructive hypertensive hydrocephalus is reported in choroid plexus tumors. Choroid plexus tumors typically present as T2-weighted hyperintense intraventricular masses with occasional cerebrospinal fluid-drop metastasis. Acquired neoplastic nonobstructive hydrocephalus without visible mass lesion in magnetic resonance imaging is not reported in dogs. A 4.5-year-old Rhodesian Ridgeback presented with reduced mental status, unilaterally absent pupillary light reflex, and neck pain. Magnetic resonance imaging revealed a nonobstructive hydrocephalus and widened lumbar subarachnoid space with no evidence of a primary mass lesion. Postmortem examination confirmed a disseminated choroid plexus tumor affecting the ependyma and choroid plexi of all ventricles and the cerebral and lumbar subarachnoid space. Disseminated choroid plexus carcinomatosis should be considered as a possible cause of hypertensive hydrocephalus even in absence of a primary mass.

Isolated Lumbar Atypical Choroid Plexus Papilloma: A Case Report.

AIM: To report the first case of an isolated lumbar grade II atypical choroid plexus papilloma (CPP). CASE REPORT: A 42-year-old man was admitted to the hospital because of back and leg pain. No urinary or rectal dysfunction was detected. Lumbar magnetic resonance imaging (MRI) showed a well-circumscribed, contrast-enhancing, intradural extramedullary mass at L2-3. He underwent L2 and L3 partial laminectomies for tumor resection and complete resection was achieved without causing neurological deficit. Histopathologic examination of the tumor resulted in a diagnosis of grade II atypical CPP. The Ki-67 staining index was 7%. No lesion was detected on postoperative craniospinal MRI. CONCLUSION: Isolated lumbar atypical CPP in the lumbar region has not been previously reported. In the presence of a single spinal lesion, the diagnosis of CPP should be considered. Unlike metastatic and synchronous tumors, the pathogenesis of isolated choroid plexus tumors within the spinal canal has not been explained.

Infantile Choroid Plexus Papilloma with Multiple Peritumoral Cysts.

Infantile choroid plexus papilloma (CPP) associated with multiple peritumoral cysts is a rare variant of CPP, and clinical course and optimal management are largely unknown. A 9-month-old boy presented with a large solid tumor in the left lateral ventricle associated with multiple peritumoral cysts, arachnoid cysts, and hydrocephalus containing xanthochromic fluid with high protein content. Shrinkage of these cysts and resolution of hydrocephalus were achieved after total resection of the hypervascular solid part of the tumor. Histological examination confirmed the solid part of the tumor as CPP and showed that the wall of the peritumoral cysts consisted of reactive gliosis without neoplastic cells. Follow-up magnetic resonance imaging 12 months after surgery revealed that these cysts remained stable. CPP with nonenhancing peritumoral cysts can be managed by resection of only the solid part of the tumor without permanent cerebrospinal fluid diversion.