Choroid plexus tumors in children less than 36 months: the Canadian Pediatric Brain Tumor Consortium (CPBTC) experience

The composition of choroid plexus tumor research: a bibliometric analysis of the 100 most impactful studies to date

PURPOSE

Choroid plexus tumors (CPT) are relatively rare CNS tumors that primarily occur in children. They are classified as low-grade choroid plexus papilloma, including atypical ones, and high-grade choroid plexus carcinoma based on histological characteristics. There has been extensive academic research regarding these complex tumors. The goal of this work was to identify the 100 most-cited articles pertaining to CPTs in order to better understand the most impactful studies to date.

METHODS

In August 2023, Elsevier's Scopus database was searched for the 100 most-cited articles about CPT. To look for trends, articles were classified as either basic science or clinical, and the earliest 50 articles were separated from the latest 50 articles and then were compared. Various bibliometric parameters were summarized and compared using Pearson's chi-square exact test and Wilcoxon rank sum test/Mann-Whitney U test.

RESULTS

The 100 most-cited articles were published between 1955 and 2016 in 53 different scientific journals, originating from 16 distinct countries. Over 75% of the articles were clinical in nature, and overall mean (range) values were as follows: citation count 78.5 (42-371), citation rate per year 3.4 (0.9-12), number of authors 6.2 (1-28). Newer articles had statistically higher citation rate (P < 0.01) and number of authors (P < 0.01) compared to their older counterparts. Additionally, while there was no significant difference in article focus (P = 0.64), there was a difference in study design (P < 0.01).

CONCLUSION

This study used citation number as a surrogate for article impact and identified the 100 most-cited CPT articles. New mutational analyses have allowed for further subgrouping and positive trends in collaboration shine hope for improvement in treatment outcomes and long-term survival.

Management of Choroid Plexus Tumors and the Benefit of Preoperative Embolization in Pediatric Patients: Report of 46 Cases from a Single Institution

OBJECTIVE

Optimal choroid plexus tumor (CPT) treatment involves gross total resection; however, intraoperative hemorrhage risk remains significant given tumor vascularity. This study describes pediatric CPT management and identifies patients most likely to benefit from preoperative embolization.

METHODS

CPTs resected from 1997 to 2021 were included. The characteristics of embolized patients were compared to nonembolized patients; nonembolized patients were further stratified based on open vascular control-pedicle feeder ligation versus no pedicle ligation prior to tumor debulking. Statistical analyses identified factors associated with estimated blood loss (EBL), transfusion, length of stay, and complications.

RESULTS

Among the 46 CPT cases identified, 98% achieved gross total resection, and 15% received embolization. Embolized patients were younger, smaller, and had larger tumors compared to nonembolized patients (median: 0.8 vs. 2.1 years; 9.3 vs. 14.4 kg; 91.08 vs. 5.5 cm3). Transfused patients were similarly younger and smaller (P < 0.05) than nontransfused patients. Among nonembolized patients, open vascular control was achieved in smaller tumors (<13 cm3) with significantly lower EBL (P = 0.002). Higher EBL was observed in patients with larger tumors, hydrocephalus, transependymal edema, vomiting, lethargy, and developmental regression (all P < 0.05). Patients with lethargy had longer hospital stays and a higher likelihood of postoperative complications (P < 0.05). There were no significant differences in complication rates between the embolization and nonembolization groups.

CONCLUSIONS

Despite higher surgical risk profiles, embolized patients had similar complication rates and postoperative hydrocephalus management as nonembolized patients. Embolization was particularly beneficial in patients at high risk for surgical morbidity, such as those <2 years, weighing <10 kg, and with a tumor volume >15 cm3.

Clinical utility of DNA methylation profiling for choroid plexus tumors

Background

Choroid plexus tumors (CPTs) are rare, potentially aggressive CNS tumors with defined histologic criteria for grading. In recent years, several patients within our practice have demonstrated discordance between the histologic diagnosis and clinical behavior. DNA methylation profiling has emerged as a potential diagnostic adjunct for aiding the clinical approach.

Methods

We reviewed the clinical and pathologic data of all CPTs diagnosed at Boston Children's Hospital from 1995 to 2023. All cases with available material (38/48) underwent DNA methylation profiling at NIH/NCI, and the classifier results were correlated with the WHO histologic grade and patient outcomes. Survival information was analyzed using Kaplan-Meier curves.

Results

There was good correlation (11/12, 92%) between methylation class and WHO histologic grade for choroid plexus carcinomas (CPC); one histologic CPC grouped with choroid plexus papilloma (CPP) group pediatric (P). Five CPPs grouped with methylation class CPC (5/17, 29%). In the group of atypical CPPs (n = 9), there were two that grouped with methylation class CPC. Survival analysis showed utility of methylation classes in the prediction of biologic behavior.

Conclusions

Results indicated that methylation profiling may serve as a valuable tool in the clinical decision-making process for patients with CPTs, providing additional prognostic information compared to WHO histologic grade alone. The value of methylation array analysis is particularly important given the lack of consensus on treatment regimens for CPTs.

Immunotherapy for Pediatric Brain and Spine Tumors: Current State and Future Directions

BACKGROUND

Brain tumors are the most common solid tumors and the leading cause of cancer-related deaths in children. Incidence in the USA has been on the rise for the last 2 decades. While therapeutic advances in diagnosis and treatment have improved survival and quality of life in many children, prognosis remains poor and current treatments have significant long-term sequelae.

SUMMARY

There is a substantial need for the development of new therapeutic approaches, and since the introduction of immunotherapy by immune checkpoint inhibitors, there has been an exponential increase in clinical trials to adopt these and other immunotherapy approaches in children with brain tumors. In this review, we summarize the current immunotherapy landscape for various pediatric brain tumor types including choroid plexus tumors, embryonal tumors (medulloblastoma, AT/RT, PNETs), ependymoma, germ cell tumors, gliomas, glioneuronal and neuronal tumors, and mesenchymal tumors. We discuss the latest clinical trials and noteworthy preclinical studies to treat these pediatric brain tumors using checkpoint inhibitors, cellular therapies (CAR-T, NK, T cell), oncolytic virotherapy, radioimmunotherapy, tumor vaccines, immunomodulators, and other targeted therapies.

KEY MESSAGES

The current landscape for immunotherapy in pediatric brain tumors is still emerging, but results in certain tumors have been promising. In the age of targeted therapy, genetic tumor profiling, and many ongoing clinical trials, immunotherapy will likely become an increasingly effective tool in the neuro-oncologist armamentarium.

Use of Tranexamic Acid for Elective Resection of Intracranial Neoplasms: A Systematic Review

BACKGROUND

As an established antifibrinolytic agent, tranexamic acid (TXA) has garnered widespread use during surgery to limit intraoperative blood loss. In the field of neurosurgery, TXA is often introduced in cases of traumatic brain injury or elective spine surgeries; however, its role during elective cranial surgeries is not well established. We report a systematic review of the use of TXA in elective surgical resection of intracranial neoplasms.

METHODS

We performed this systematic review following PRISMA guidelines to identify studies investigating the use of TXA in elective neurosurgical resection of intracranial neoplasms. Variables extracted included patient demographics, surgical indications, type of surgery performed, TXA dose and route of administration, operative duration, blood loss, transfusion rate, postoperative hemoglobin level, and complications.

RESULTS

After careful screening, 4 articles (consisting of 682 patients) met our inclusion/exclusion criteria. The studies included 2 prospective cohort studies, 1 retrospective cohort study, and 1 case series. A χ² test of pooled data demonstrated that patients administered TXA had a significantly decreased need for blood transfusions during surgery (odds ratio, 0.6273; 95% confidence interval, 0.4254-0.9251; P = 0.018). Mean total blood loss was 821.9 mL in the TXA group and 1099.0 mL in the control group across the studies. There was no significant difference in postoperative hemoglobin levels, with a mean of 11.4 g/dL in both the TXA and control groups.

CONCLUSIONS

These results support the use of intraoperative TXA in tumor resection. However, its role in tumor resection has been less well investigated compared with its use in other areas of neurosurgery.

Final results of the Choroid Plexus Tumor study CPT-SIOP-2000

Introduction

Standards for chemotherapy against choroid plexus tumors (CPT) have not yet been established.

Methods

CPT-SIOP-2000 (NCT00500890) was an international registry for all CPT nesting a chemotherapy randomization for high-risk CPT with Carboplatin/Etoposide/Vincristine (CarbEV) versus Cyclophosphamide/Etoposide/Vincristine (CycEV). Patients older than three years were recommended to receive irradiation: focal fields for non-metastatic CPC, incompletely resected atypical choroid plexus papilloma (APP) or metastatic choroid plexus papilloma (CPP); craniospinal fields for metastatic CPC/APP and non-responsive CPC. High risk was defined as choroid plexus carcinoma (CPC), incompletely resected APP, and all metastatic CPT. From 2000 until 2010, 158 CPT patients from 23 countries were enrolled.

Results

For randomized CPC, the 5/10 year progression free survival (PFS) of patients on CarbEV (n = 20) were 62%/47%, respectively, compared to 27%/18%, on CycEV (n = 15), (intention-to-treat, HR 2.6, p = 0.032). Within the registry, histological grading was the most influential prognostic factor: for CPP (n = 55) the 5/10 year overall survival (OS) and the event free survival (EFS) probabilities were 100%/97% and 92%/92%, respectively; for APP (n = 49) 96%/96% and 76%/76%, respectively; and for CPC (n = 54) 65%/51% and 41%/39%, respectively. Without irradiation, 12 out of 33 patients with CPC younger than three years were alive for a median of 8.52 years. Extent of surgery and metastases were not independent prognosticators.

Conclusions

Chemotherapy for Choroid Plexus Carcinoma is feasible and effective. CarbEV is superior to CycEV. A subset of CPC can be cured without irradiation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11060-021-03942-0.

Case Report: Reversible Hyperglycemia Following Rapamycin Treatment for Atypical Choroid Plexus Papilloma in an Infant

In this study, atypical choroid plexus papilloma was treated with high-dose rapamycin for 17 days preoperatively in an infant. Rapamycin significantly reduced the blood supply to the tumor while reducing the tumor volume, and most of the tumor was resected successfully. However, the infant developed hyperglycemia related to the rapamycin dose, which was effectively controlled by adjusting the dose and applying insulin.

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.

Preoperative Devascularization of Choroid Plexus Tumors: Specific Issues about Anatomy and Embolization Technique

(1) Background: Surgical treatment of choroid plexus tumors is challenging, burdened by a notable risk of bleeding. Neoadjuvant chemotherapy and preoperative embolization have been attempted, with encouraging results; however, the consensus on these procedures is lacking. (2) Methods: We present a case of a 10-month-old girl who underwent preoperative embolization of a hemorrhagic choroid plexus carcinoma of the lateral ventricle via the anterior choroidal artery, followed by total resection. (3) Results: The endovascular procedure was successfully completed, despite the rectification of the anterior choroidal artery associated with the absence of flow proximal to the plexal point. Minimal bleeding was observed during resection and the patient remained neurologically intact. (4) Conclusions: The time from entrance to exit in the anterior choroidal artery should be monitored and regarded as a potential 'occlusion time' in this specific group of patients. Nevertheless, our case supports the feasibility and effectiveness of preoperative embolization of a choroid plexus carcinoma of the lateral ventricle via the anterior choroidal artery, without complications. Furthermore, we suggest the use of a fast-embolic agent, such as N-butyl cyanoacrylate glue, as the preferred agent for this specific pathology and patient population.

Management of choroid plexus tumours: A comprehensive study from a tertiary hospital

OBJECTIVE

Choroid plexus tumours (CPT) are rare intraventricular tumours representing less than 0.5 % of brain tumours. The tumour is commonly located in the supratentorial region, but the location varies depending on the age. We present our experience of managing these tumours in a tertiary hospital.

METHODS

Retrospectively, we reviewed our operative database and recruited 80 cases of CPT who underwent surgical treatment in our institute from 1995 to 2018. We analysed the factors affecting the outcome and the perioperative complications of the choroid plexus tumour.

RESULTS

A total of 80 choroid plexus tumours were recruited in our retrospective review, of which 44 were choroid plexus papilloma (CPP), 13 were atypical choroid plexus tumours (ACPP), 23 were choroid plexus carcinomas (CPC). The mean age was 16.75 (SD 16.71) in the overall cohort. Males were found to be predominant in all tumour groups (M/F: 46/34). Headache was the most common symptom (52.5 %). Hydrocephalus was seen in 53.8 % of cases. The median overall survival was 89.88 months. Gross total resection was achieved in 62.5 % cases (n = 50/80), and near-total resection in 27. 5 % cases (n = 22/80). The median overall survival was 89.88 months. The median overall survival for CPP, ACPP, CPC was 106.83, 37.37, 36.19 months, respectively. Median Event-free survival was 65.83 months. A Cox regression analysis of predictors of overall survival of atypical CPP and CPC was done, in which age, sex, location, size, the extent of the resection, and complications were considered. The extent of the resection (p = 0.01) and the size (p = 0.02) were related to overall survival CONCLUSION: CPT's are the rare intraventricular tumours, which requires aggressive resection strategies. The extent of resection offers survival benefit based on the histological grades.

Outcome and molecular analysis of young children with choroid plexus carcinoma treated with non-myeloablative therapy: results from the SJYC07 trial

Background

Choroid plexus carcinoma (CPC) is a rare and aggressive tumor of infancy without a clear treatment strategy. This study describes the outcomes of children with CPC treated on the multi-institutional phase 2 SJYC07 trial and reports on the significance of clinical and molecular characteristics.

Methods

Eligible children <3 years-old with CPC were postoperatively stratified to intermediate-risk (IR) stratum if disease was localized or high-risk (HR) stratum, if metastatic. All received high-dose methotrexate-containing induction chemotherapy. IR-stratum patients received focal irradiation as consolidation whereas HR-stratum patients received additional chemotherapy. Consolidation was followed by oral antiangiogenic maintenance regimen. Survival rates and potential prognostic factors were analyzed.

Results

Thirteen patients (median age: 1.41 years, range: 0.21-2.93) were enrolled; 5 IR, 8 HR. Gross-total resection or near-total resection was achieved in ten patients and subtotal resection in 3. Seven patients had TP53-mutant tumors, including 4 who were germline carriers. Five patients experienced progression and died of disease; 8 (including 5 HR) are alive without progression. The 5-year progression-free survival (PFS) and overall survival rates were 61.5 ± 13.5% and 68.4 ± 13.1%. Patients with TP53-wild-type tumors had a 5-year PFS of 100% as compared to 28.6 ± 17.1% for TP53-mutant tumors (P = .012). Extent of resection, metastatic status, and use of radiation therapy were not significantly associated with survival.

Conclusions

Non-myeloablative high-dose methotrexate-containing therapy with maximal surgical resection resulted in long-term PFS in more than half of patients with CPC. TP53-mutational status was the only significant prognostic variable and should form the basis of risk-stratification in future trials.

Clinical Features and Prognostic Risk Factors of Choroid Plexus Tumors in Children

Background:

Decision-making concerning the treatment of choroid plexus tumor (CPT) in pediatric patients remains a topic of considerable debate. The aim of this work was to describe clinical features and prognostic risk factors of CPT in the pediatric population and to provide theoretical opinions regarding clinical decisions for CPT.

Methods:

The data of 96 patients with CPT and younger than 14 years were retrospectively analyzed. Clinical characteristics such as pathological type of CPTs, rate and severity of hydrocephalus, treatment and outcome, and recurrence were investigated. For categorical variables, the Pearson's Chi-square test was performed. The Mann–Whitney U-test was used for comparisons between nonnormally distributed parameters. Log-rank test was used for progression-free survival (PFS).

Results:

The study included 70 choroid plexus papilloma (CPP) cases, 17 atypical choroid plexus papilloma (aCPP) cases, and 9 choroid plexus carcinoma (CPC) cases. Compared with patients with CPP or aCPP, patients with CPC had a shorter disease course (median: CPP, 4 months; aCPP, 2 months; CPC, 1 month; H: 23.5, P < 0.001), higher rate of acute hydrocephalus (CPP, 27.1%; aCPP, 52.9%; CPC, 77.8%; χ² = 10.9, P < 0.05), and lower incidence of cure rate (CPP, 85.7%; aCPP, 70.5%; CPC, 33.3%; χ² = 13.5, P < 0.05). The severity of hydrocephalus with tumor in the lateral or third ventricle was significantly higher than that with tumors in the fourth ventricle (severe hydrocephalus: lateral ventricle, 51.7%; third ventricle, 47.0%; fourth ventricle, 11.1%; χ² = 26.0, P < 0.001). Patients with gross total surgical resection had no better PFS than those with partial resection because of the use of adjuvant therapy in the latter (χ² = 4.0, P > 0.05). Patients with CPC experienced shorter time for recurrence than those with CPP or aCPP (χ² = 40.1, P < 0.0001).

Conclusions:

Our results indicated that CPP in the fourth ventricle could trigger serious clinical symptoms at an early stage, requiring early intervention. Adjuvant treatment might be necessary for patients with partially resected CPP, aCPP, and CPC to achieve a favorable outcome.

Pediatric choroid plexus carcinoma: Biologically and clinically in need of new perspectives

Choroid plexus (CP) carcinoma is a rare pediatric brain neoplasm. Recent studies have highlighted the potential of genome-wide methylation and gene expression profiling to provide additional layers of information to improve tumor risk-stratification. There is a lack of data regarding the best therapy, and approaches have been heterogeneous. Despite multidisciplinary treatment approaches, the outcome remains guarded and treatments have been based on case series and expert opinions. In this study, we discuss the recent wealth of data regarding CP carcinoma molecular biology and current management. We also briefly highlight the remaining barriers to formulate the best treatment strategies, and future therapeutic potentials.

Establishing a Preclinical Multidisciplinary Board for Brain Tumors

Purpose: Curing all children with brain tumors will require an understanding of how each subtype responds to conventional treatments and how best to combine existing and novel therapies. It is extremely challenging to acquire this knowledge in the clinic alone, especially among patients with rare tumors. Therefore, we developed a preclinical brain tumor platform to test combinations of conventional and novel therapies in a manner that closely recapitulates clinic trials.Experimental Design: A multidisciplinary team was established to design and conduct neurosurgical, fractionated radiotherapy and chemotherapy studies, alone or in combination, in accurate mouse models of supratentorial ependymoma (SEP) subtypes and choroid plexus carcinoma (CPC). Extensive drug repurposing screens, pharmacokinetic, pharmacodynamic, and efficacy studies were used to triage active compounds for combination preclinical trials with "standard-of-care" surgery and radiotherapy.Results: Mouse models displayed distinct patterns of response to surgery, irradiation, and chemotherapy that varied with tumor subtype. Repurposing screens identified 3-hour infusions of gemcitabine as a relatively nontoxic and efficacious treatment of SEP and CPC. Combination neurosurgery, fractionated irradiation, and gemcitabine proved significantly more effective than surgery and irradiation alone, curing one half of all animals with aggressive forms of SEP.Conclusions: We report a comprehensive preclinical trial platform to assess the therapeutic activity of conventional and novel treatments among rare brain tumor subtypes. It also enables the development of complex, combination treatment regimens that should deliver optimal trial designs for clinical testing. Postirradiation gemcitabine infusion should be tested as new treatments of SEP and CPC. Clin Cancer Res; 24(7); 1654-66. ©2018 AACR.

Atypical choroid plexus papilloma: clinicopathological and neuroradiological features

Background Atypical choroid plexus papilloma (APP) is a rare, newly introduced entity with intermediate characteristics. To date, few reports have revealed the magnetic resonance (MR) findings. Purpose To analyze the clinicopathological and MR features of APP. Material and Methods The clinicopathological data and preoperative MR images of six patients with pathologically proven APP were retrospectively reviewed. The MR features including tumor location, contour, signal intensity, degree of enhancement, intratumoral cysts, and necrosis; and flow voids, borders, peritumoral edema, and associated hydrocephalus were analyzed. Results The APP were located in the ventricle (n = 4) and cerebellopontine angle (CPA, n = 2). Tumor dissemination along the spinal subarachnoid space was found in one patient. The tumors appeared as milt-lobulated (n = 5) or round mass (n = 1), with slightly heterogeneous signals (n = 5) or mixed signals (n = 1) on T1-weighted and T2-weighted images. Heterogeneous and strong enhancement were found in five cases on contrast-enhanced images. Three of four intraventricular tumors had a partly blurred border with ventricle wall. Four tumors had mild to moderate extent of surrounding edema signals. A slight hydrocephalus was seen in four patients. Incomplete capsule was seen in four tumors at surgery. Histopathologically, mild nuclear atypia was seen in all tumors with a mitotic rate of 2-5 per 10 high-power fields. Conclusion APP should be included in the differential diagnosis when an intraventricular or CPA tumor appearing as a multi-lobulated solid mass with slight heterogeneity, heterogeneous strong enhancement, partly blurred borders, mild to moderate peritumoral edema, or slight hydrocephalus are present.

Incidental choroid plexus papilloma in a child: A difficult decision

Background:

Choroid plexus tumors (CPT) in the pediatric population are usually discovered in symptomatic patients often with symptoms of increased intracranial pressure, with hydrocephalus as the most common presentation, along with seizures, subarachnoid hemorrhage, or focal neurological deficit. Most CPTs are found to be benign choroid plexus papillomas (CPP), whereas a small number are intermediate and malignant choroid plexus carcinomas (CPC). Total surgical resection is the established definitive treatment for symptomatic CPP.

Case Description:

We describe a young female who was found to have an incidental CPT during workup for recent head trauma without neurological deficits or hydrocephalus. She underwent a surgical operation to remove the tumor successful, with 1-year follow-up showing no recurrence and normal developmental milestones.

Conclusion:

This rare presentation of an asymptomatic CPT brings attention to the fact that there is no clear evidence for how or when to treat such patients. Because discovery of a CPT in an asymptomatic patient is uncommon, the treatment plan appears to be developed on a case-by-case basis. We hope to generate discussion for establishing an agreed upon treatment approach for CPTs in asymptomatic patients.

Pre-operative embolization of a choroid plexus carcinoma: review of the vascular anatomy

AIM

The purpose of this case is to highlight the benefits of preoperative embolization as well as to review the vascular anatomy that needs to be recognized in order to perform pre-operative embolization of choroid plexus tumors.

METHOD

We achieve this by presenting the case of a 12-month-old female who had symptoms of raised intracranial pressure. MRI demonstrated a large vividly enhancing mass centered within the atria of the right lateral ventricle associated with hydrocephalus in keeping with a choroid plexus tumor.

RESULT

Enlarged anterior and posterior choroidal arteries supplying the tumor were noted on the MRI scan. Pre-operative embolization was performed with NBCA glue via the anterior and posterior choroidal arteries. Subsequently, total surgical resection was achieved with only 200 cc of blood loss. Pathology confirmed a choroid plexus carcinoma.

CONCLUSION

Pre-operative embolization can be useful in minimizing blood loss during excision of choroid plexus tumors. It is important to understand the anatomy of the anterior and posterior choroidal arteries to perform embolization of these tumors safely.

Neoadjuvant chemotherapy reduces blood loss during the resection of pediatric choroid plexus carcinomas

OBJECT Choroid plexus carcinomas (CPCs) are rare brain tumors originating from the ventricular choroid plexus. They account for 2%-4% of all pediatric brain tumors and are most frequently seen in very young children. This pediatric proclivity, in combination with a marked vascularity, renders an aggressive resection a difficult and often dangerous endeavor. Blood losses of several total blood volumes in small children are not uncommon, sometimes forcing the neurosurgeon to abort the procedure, often leaving residual tumor. Great extent of tumor resection is an accepted beneficial factor for overall survival. Therefore, a second resection usually follows the administration of adjuvant chemotherapy. Second-look surgery appears to be associated with markedly decreased blood loss. Histological examination of specimens obtained at a second intervention shows decreased vascularity and fibrotic changes in tumor tissue. At the Hospital for Sick Children in Toronto, this empirical finding led to the strategy of neoadjuvant chemotherapy to minimize blood loss and maximize cytoreduction. The authors undertook this study to assess the potentially beneficial effect of neoadjuvant chemotherapy on blood loss during surgery for CPCs. METHODS In this retrospective cohort review, the demographic, clinical, and treatment parameters of 22 consecutive patients diagnosed with CPC are presented. All underwent surgical treatment at the Hospital for Sick Children from 1982 to 2013. Special attention was given to the impact of neoadjuvant chemotherapy on extent of resection and intraoperative blood loss. Extent of resection was calculated based on perioperative neuroimaging, and amount of blood loss was estimated based on transfusion parameters and perioperative changes in hematocrit. RESULTS Ten patients did not receive neoadjuvant chemotherapy, and 12 were treated with 2-5 cycles of ICE (ifosfamide, carboplatin, etoposide) chemotherapy in a neoadjuvant fashion. The 22 patients included in the study underwent a total of 37 tumor resection surgeries. In all of the cases in which neoadjuvant chemotherapy was used, at least a near-total resection (> 95% of tumor volume) was achieved. Patients who underwent gross-total resection had prolonged overall survival. Of the 37 resections, 18 were performed after chemotherapy. Mean blood loss in the neoadjuvant chemotherapy group was 22% of total estimated blood volume as opposed to 96% in patients without preoperative chemotherapy. CONCLUSIONS In children with CPC, the administration of neoadjuvant chemotherapy decreases intraoperative blood loss and increases extent of resection with a significant positive effect on overall survival.

Superior parietal lobule approach for choroid plexus papillomas without preoperative embolization in very young children

OBJECT Choroid plexus papillomas (CPPs) are rare neoplasms, often found in the atrium of the lateral ventricle of infants, and cause overproduction hydrocephalus. The extensive vascularity and medially located blood supply of these tumors, coupled with the young age of the patients, can make prevention of blood loss challenging. Preoperative embolization has been advocated to reduce blood loss and prevent the need for transfusion, but this mandates radiation exposure and the additional risks of vessel injury and stroke. For these reasons, the authors present their experience using the superior parietal lobule approach to CPPs of the atrium without adjunct therapy. METHODS A retrospective review was conducted of all children who presented to Columbia University/Morgan Stanley Children's Hospital of New York with a CPP in the atrium of the lateral ventricle and who underwent surgery using a superior parietal lobule approach without preoperative embolization. RESULTS Nine children were included, with a median age of 7 months. There were no perioperative complications or new neurological deficits. All patients had intraoperative blood loss of less than 100 ml, with a mean minimum hematocrit of 26.9% (range 19.6%-36.2%). No patients required a blood transfusion. The median follow-up was 39 months, during which time no patient demonstrated residual or recurrent tumor on MRI, nor did any have an increase in ventricular size or require CSF diversion. CONCLUSIONS The superior parietal lobule approach is safe and effective for very young children with CPPs in the atrium of the lateral ventricle. The results suggest that preoperative embolization is not essential to avoid transfusion or achieve overall good outcomes in these patients. This management strategy avoids radiation exposure and the additional risks associated with embolization.

The impact of surgical resection of giant supratentorial brain tumor in pediatric patients: safety and neurological outcome evaluated in 23 consecutive cases

OBJECTIVE

This study aims to evaluate the impact of gross total resection of giant supratentorial brain tumors (GSBT) on survival and neurological outcome in a consecutive single-center pediatric series.

METHODS

Clinical data of 23 patients under 18 years of age operated with GSBT (≥5 cm in diameter) were reviewed to determine epidemiological aspects, clinical presentation, associated factors, histopathological features, and outcome. Volumetric measurements were performed on magnetic resonance imaging or computed tomography scans obtained at the time of the initial surgical procedure.

RESULTS

The group included 23 patients (mean age 4.5 years). Signs and symptoms of raised intracranial pressure were present in 19 patients (82.6%). The most frequent tumor location was the parietal lobe in 19 patients (82.6%), and the mean tumor volume was 208 cm(3). Gross total or radical resection was achieved in all patients. Histopathological analysis revealed malignant brain tumors in 18 cases (78.2%). The most common neoplasm was choroid plexus carcinoma in seven (30.4 %). Mean intraoperative blood transfusion volume was 51.2 ml/kg. Chemotherapy and/or radiotherapy were performed as adjuvant treatment in 16 patients (69.5%). Mean length of follow-up was 36.7 months. Tumor malignancy grade significantly correlated with recurrence of the disease (P = 0.03) and death (P = 0.01), as opposed to tumor location, size, and extension to the ventricles.

CONCLUSIONS

Our clinical experience suggests that tumor mass reduction by en bloc surgery seems to be an effective approach in pediatric patients with GSBT, relieving symptoms related to raised intracranial pressure and providing a better response to adjuvant treatment.

Molecular characterization of choroid plexus tumors reveals novel clinically relevant subgroups

PURPOSE

To investigate molecular alterations in choroid plexus tumors (CPT) using a genome-wide high-throughput approach to identify diagnostic and prognostic signatures that will refine tumor stratification and guide therapeutic options.

EXPERIMENTAL DESIGN

One hundred CPTs were obtained from a multi-institutional tissue and clinical database. Copy-number (CN), DNA methylation, and gene expression signatures were assessed for 74, 36, and 40 samples, respectively. Molecular subgroups were correlated with clinical parameters and outcomes.

RESULTS

Unique molecular signatures distinguished choroid plexus carcinomas (CPC) from choroid plexus papillomas (CPP) and atypical choroid plexus papillomas (aCPP); however, no significantly distinct molecular alterations between CPPs and aCPPs were observed. Allele-specific CN analysis of CPCs revealed two novel subgroups according to DNA content: hypodiploid and hyperdiploid CPCs. Hyperdiploid CPCs exhibited recurrent acquired uniparental disomy events. Somatic mutations in TP53 were observed in 60% of CPCs. Investigating the number of mutated copies of p53 per sample revealed a high-risk group of patients with CPC carrying two copies of mutant p53, who exhibited poor 5-year event-free (EFS) and overall survival (OS) compared with patients with CPC carrying one copy of mutant p53 (OS: 14.3%, 95% confidence interval, 0.71%-46.5% vs. 66.7%, 28.2%-87.8%, respectively, P = 0.04; EFS: 0% vs. 44.4%, 13.6%-71.9%, respectively, P = 0.03). CPPs and aCPPs exhibited favorable survival.

DISCUSSION

Our data demonstrate that differences in CN, gene expression, and DNA methylation signatures distinguish CPCs from CPPs and aCPPs; however, molecular similarities among the papillomas suggest that these two histologic subgroups are indeed a single molecular entity. A greater number of copies of mutated TP53 were significantly associated to increased tumor aggressiveness and a worse survival outcome in CPCs. Collectively, these findings will facilitate stratified approaches to the clinical management of CPTs.

Pediatric choroid plexus tumors: epidemiology, treatments, and outcome analysis on 202 children from the SEER database

Choroid plexus papillomas (CPPs) and carcinomas (CPCs) are rare neoplasms that affect mostly children. Due to their rarity, their epidemiology and outcomes are incompletely understood. The National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) Program is a well-established population-based group of registries that collects and publishes cancer incidence and survival data representing approximately 28 % of the US population. SEER-STAT v8.1.2 was used to identify patients with ICD-O-3 codes for choroid plexus tumors in patients aged 0-19. Demographics, initial treatment, and follow-up data were collected. Statistical methods including Kaplan-Meier curves, log rank tests, and Cox proportional hazards regression were used to estimate associations between independent variables and survival. The SEER registries contained 107 CPPs (2004-2010) and 95 CPCs (1978-2010). Median follow-up was 38 and 40 months, respectively. More than 75 % of CPCs were diagnosed before the age of 5 years, versus 48 % for CPPs. Sixty-five percent of CPCs and 57 % of CPPs occurred in males. In both groups at least 90 % of children underwent surgical resection. Gross total resection (GTR) was achieved in 67.0 % of CPCs and 63.6 % of CPPs. Almost 17 % of CPCs were treated with radiation versus only 0.9 % of CPPs. More than 98 % of patients with CPP were alive at the last follow-up, versus 62 % of CPC patients. For CPC, surgery was significantly associated with increased overall survival, but contrary to previous reports, extent of surgical resection was not associated with survival. Age, sex, race, and radiation treatment also had no effect on survival. This report, using the SEER datasets, corroborates many findings of previous smaller studies on CPTs. CPC occurs in younger children, with a male predominance, and a much worse prognosis than CPP. As such, these tumors have been treated aggressively with high rates of GTR and radiation treatment. Despite these treatments, overall survival for CPC remains poor.

Imaging of brain tumors

Neuroimaging plays a crucial role in diagnosis of brain tumors and in the decision-making process for therapy. Functional imaging techniques can reflect cellular density (diffusion imaging), capillary density (perfusion techniques), and tissue biochemistry (magnetic resonance [MR] spectroscopy). In addition, cortical activation imaging (functional MR imaging) can identify various loci of eloquent cerebral cortical function. Combining these new tools can increase diagnostic specificity and confidence. Familiarity with conventional and advanced imaging findings facilitates accurate diagnosis, differentiation from other processes, and optimal patient treatment. This article is a practical synopsis of pathologic, clinical, and imaging spectra of most common brain tumors.

Use of tranexamic acid in infants undergoing choroid plexus papilloma surgery: a report of two cases

Choroid plexus papilloma (CPP) is a highly vascular tumor of infancy. Reducing blood loss is the key to successful surgical removal of CPPs. Tranexamic acid (TXA) is efficacious in reducing bleeding in craniofacial surgery for infants. This report demonstrates the potential utility of TXA for decreasing blood loss in the removal of vascular tumors in infants. We administered tranexamic acid to two infants with CPP during surgical removal to potentially aid hemostasis and therefore lessen intra-operative bleeding. Gross total surgical resection was accomplished; the patients were hemodynamically stable perioperatively, and the total calculated blood loss was minimal at <20% of the patients' total circulating blood volume. This is the first report of tranexamic acid administration for CPP surgery in children. TXA is an easily administered hemostatic agent and may merit further study as an agent to help reduce intra-operative blood loss in this vulnerable population.

Clinical outcome of pediatric choroid plexus tumors: retrospective analysis from a single institute

BACKGROUND

Choroid plexus tumor is a rare brain tumor with variable clinical features according to the histological grade. We reviewed the treatment outcome of 23 children, focusing on the biological behavior of the atypical choroid plexus papilloma (ACPP) and the current therapeutic strategy in choroid plexus carcinoma (CPC).

METHODS

The demographics, clinical features, surgical treatments, adjuvant therapies, and survival were reviewed.

RESULTS

The median age at diagnosis was 18 months--55 months for choroid plexus papilloma (CPP), 8 months for ACPP, and 15 months for CPC. Gross total resections were achieved in seven of eight patients with CPP, seven of seven with ACPP, and three of eight with CPC. Seven patients with CPC received chemotherapy. Four patients received high-dose chemotherapy (HDCT) and autologous peripheral blood stem cell transplantation (aPBSCT), and three among them have survived. Four patients with CPC received radiotherapy. One CPP patient and one CPC patient underwent radiosurgery. All CPP and ACPP patients have survived. The overall survival rate of the CPC patients was 62.5% in the first year and 42.9% in the second year. The progression-free survival rate of the CPC patients was 50% in the first year and 0% in the second year. Seven patients underwent permanent cerebrospinal fluid diversion surgery because of hydrocephalus or subdural effusion.

CONCLUSION

CPP and ACPP were surgically curable. Multi-modal treatments are necessary in the management of CPC with poor prognosis. HDCT and aPBSCT may be important to treat infants for whom radiotherapy is limited. Hydrocephalus and subdural effusion should be resolved with appropriate management.

Successful treatment of a recurrent choroid plexus carcinoma with surgery followed by high-dose chemotherapy and stem cell rescue

Choroid plexus carcinoma (CPC) is a rare central nervous system malignant tumor with a dismal prognosis, especially in the case of incomplete resection or recurrence. The authors report long-term survival of a 1-year-old patient with recurrent CPC and Li-Fraumeni syndrome with surgical resection and high-dose chemotherapy (HDC) consisting of single cycle of Busulfan and Thiotepa followed by autologous stem cell rescue without the use of radiation therapy. Remarkably the patient remains without evidence of recurrence 5 years after completion of therapy. Additional studies are necessary to determine the role of HDC and stem cell rescue in patients with recurrent CPC.

Optimized surgical approach to third ventricular choroid plexus papillomas of young children based on anatomical variations

BACKGROUND

Choroid plexus papilloma (CPP) in the third ventricle is a rare benign intracranial tumor.

METHODS

We report 3 pediatric cases of CPP in the third ventricle. The lesions were totally removed by a different surgical approach in each case.

RESULTS

When remarkable hydrocephalus is present, the transcortical approach is easier to perform, but may expose the patient to epilepsy and subdural effusion postoperatively. The transcallosal approach offers direct exposure of the ventricle system with minimal risk of cortical damage. The transcallosal-transforaminal approach with posterior enlargement of the foramen of Monro along the choroidal fissure provides a direct trajectory into the third ventricle through the natural cleft. The transcallosal-interforniceal approach does not depend on the size of the foramen of Monro, but it carries a risk for damage to the both fornices. The midline plane of the septum pellucidum and the forniceal columns in children are sometimes easily identifiable and separable, and in such cases the transcallosal-interforniceal approach appears to be a safe route for tumors extending to the posterior third ventricle. The interforniceal approach should be reserved for lesions that cannot be removed safely via the transforaminal approach.

CONCLUSIONS

Young children have a small total blood volume and fragile cardiovascular status. Therefore, it is critical to preserve the venous system and to ligate the feeding artery before extirpation of the tumor. The surgical approach to the third ventricular CPPs should be tailored to individual children based on tumor size, location, and vascularity.

Choroid plexus papilloma and Pierpont syndrome

The authors describe the case of a child who presented with hydrocephalus and phenotypic features characteristic of a multiple congenital anomalies/mental retardation syndrome. Dysmorphic facies, medial plantar lipomatosis, and developmental delay were observed in this case and are identical to documented findings of Pierpont syndrome diagnosed in 3 boys. This is the fourth case reported to date and is the first documented case of an oncological process- an intraventricular atypical choroid plexus papilloma tumor-found in association with Pierpont syndrome. Syndromes associated with choroid plexus papilloma are reviewed.

Choroid plexus tumors in children: a population-based study

BACKGROUND

Choroid plexus tumors are rare neoplasms that primarily occur in children. The use of the SEER (Surveillance, Epidemiology and End Results) database allows for the analysis of the relationship between prognostic factors and survival.

METHODS

We analyzed the SEER database to select pediatric patients (<18 years old) with histologically confirmed diagnoses of choroid plexus papillomas (CPP; WHO Grade 0), atypical CPP (WHO Grade I) and choroid plexus carcinomas (CPC; WHO grade III). In univariate and multivariate analysis, we analyzed the relationship between demographic (age, gender, race, date of diagnosis) and treatment factors (extent of surgical resection, use of adjuvant radiation) on survival.

RESULTS

Overall, 168 pediatric subjects with choroid plexus tumors were identified as follows: 75 cases of CPP, 12 cases of atypical CPP and 81 cases of CPC. The median follow-up time was 3.5 years for CPP and 7.7 years for CPC. The median age at diagnosis was 4 years for CPP (10-90th percentile 0-16 years) and 1 year for CPC (10-90th percentile 0-10 years). In univariate regression analysis, CPC histology (β = -3.2, 95% confidence interval, CI -4.8 to -1.5, p < 0.001) was significantly associated with younger age at diagnosis in comparison to CPP. The mean tumor size was 3.7 cm for CPP and 6.0 cm for CPC (p < 0.001). A higher-grade tumor was associated with significantly increased mortality (hazard ratio, HR = 28.90, 95% CI 3.94-211.83, p = 0.001). Overall survival at 5 years was 98.7% for CPP and 58.5% for CPC (p < 0.001). Among those patients with CPC, gross total resection (GTR) was associated with a significantly lower mortality (HR = 0.21, 95% CI 0.07-0.66, p = 0.007). Overall survival at 5 years was 70.9% after GTR, significantly better than 35.9% after subtotal resection (p = 0.012) and 30% after no surgery (p = 0.003). Radiation treatment was not found to confer a survival benefit in CPC. No demographic characteristics (age, sex, race, date of diagnosis) were significantly associated with mortality.

CONCLUSIONS

Analysis of a pediatric cohort of choroid plexus tumors in children in the SEER database shows that tumor grade is predictive of survival. In cases of CPC, the extent of surgical resection, especially GTR, is significantly associated with increased survival. Radiation did not confer survival benefit.

Preoperative embolisation of choroid plexus tumours in children: part I-does the reduction of perioperative blood loss affect the safety of subsequent surgery?

OBJECTIVE

Operative management of choroid plexus tumours is hindered by excessive bleeding and significant CSF production. Our aim was to assess whether the use of preoperative embolisation would increase the safety of surgery by reducing the perioperative blood loss and achieve higher rates of resection of the tumour.

METHODS

Between 1996 and 2009, 30 patients (mean age 2.25 years) with choroid plexus tumours (24 papillomas, 6 carcinomas) were treated. Fifteen of them underwent preoperative super-selective embolisation of the feeding vessels with histoacryl glue. The perioperative blood loss as a percentage of estimated blood volume loss (EBV) was recorded together with mortality and morbidity of the two groups (embolised, EMB+ vs. not, EMB-).

RESULTS

The embolisation was successful in 13/15 (86.6 %) patients. This manoeuvre rendered the tumour relatively avascular making the operative field "less hazardous" as reported by the surgeon. In addition, higher gross total resection rate was achieved (100 vs. 41 %; p = 0.001) at the first operative attempt in the EMB+ group. The percentage EBV loss was 96 % in EMB- group vs. 224 % in EMB+ group (p = 0.038).

CONCLUSION

Our observations with regards to preoperative embolisation of choroid plexus tumours show an acceptable safety profile for the endovascular technique. At the same time, it renders the operative treatment of the tumours safer by reducing perioperative blood loss resulting in a high gross total resection rate. In summary, we suggest that preoperative embolisation is a useful adjunct that should be considered prior to surgical resection in managing these patients.

[Tumors of the lateral ventricle in child: characteristics and specificities]

Tumors of the lateral ventricle are not as rare in children as in adults and present complex problems which are to be dealt with often in a context of emergency, on account of their large size and the risk of life-threatening bleeding in a small child. Their diagnostic features are different in children, especially in infants and even more so in the fetus. The main surgical problems are the risk of bleeding and of hydraulic complications. From an oncological perspective, the main tumor types are choroid plexus tumors, subependymal giant-cell astrocytoma, and low-grade gliomas. The developmental outcome of these patients is often poor, on account of severe intracranial hypertension and young age at diagnosis.