Atypical choroid plexus papilloma: clinical experience in the CPT-SIOP-2000 study

Imaging of supratentorial intraventricular masses in children:a pictorial review- part 1

PURPOSE

This article is the first in a two-part series designed to provide a comprehensive overview of the range of supratentorial intraventricular masses observed in children. Our primary objective is to discuss the diverse types of intraventricular masses that originate not only from cells within the choroid plexus but also from other sources.

METHODS

In this article, we review relevant epidemiological data, the current genetics/molecular classification as outlined in the fifth edition of the World Health Organization's Classification of tumours of the Central Nervous System and noteworthy imaging findings. We conduct an exhaustive analysis of primary choroid plexus tumours as well as other conditions such as choroid plexus hyperplasia, choroid plexus cyst, choroid plexus xanthogranuloma, atypical teratoid rhabdoid tumour, meningioma, arteriovenous malformation and metastasis.

RESULTS

We comprehensively evaluated each supratentorial intraventricular mass, providing an in-depth analysis of their unique clinical and histological characteristics. The fifth edition of the World Health Organization Classification of Tumours of the Central Nervous System introduces major modifications. These important changes could potentially have a profound impact on the management strategies and subsequent outcomes of these tumours.

CONCLUSION

Intraventricular masses in children can arise from various sources. Surgical intervention is key for certain supratentorial intraventricular masses in paediatric patients, with preoperative neuroimaging essential to decide the best treatment approach, surgical or otherwise, as some cases may not require surgery.

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.

Prognostic Factors and Nomogram for Choroid Plexus Tumors: A Population-Based Retrospective Surveillance, Epidemiology, and End Results Database Analysis

Background: Choroid plexus tumors (CPTs) are rare neoplasms found in the central nervous system, comprising 1% of all brain tumors. These tumors include choroid plexus papilloma (CPP), atypical choroid plexus papilloma (aCPP), and choroid plexus carcinoma (CPC). Although gross total resection for choroid plexus papillomas (CPPs) is associated with long-term survival, there is a scarcity of prospective data concerning the role and sequence of neoadjuvant therapy in treating aCPP and CPC. Methods: From the years 2000 to 2019, 679 patients with CPT were identified from the Surveillance, Epidemiology, and End Result (SEER) database. Among these patients, 456 patients had CPP, 75 patients had aCPP, and 142 patients had CPC. Univariate and multivariable Cox proportional hazard models were run to identify variables that had a significant impact on the primary endpoint of overall survival (OS). A predictive nomogram was built for patients with CPC to predict 5-year and 10-year survival probability. Results: Histology was a significant predictor of OS, with 5-year OS rates of 90, 79, and 61% for CPP, aCPP, and CPC, respectively. Older age and African American race were prognostic for worse OS for patients with CPP. Older age was also associated with reduced OS for patients with aCPP. American Indian/Alaskan Native race was linked to poorer OS for patients with CPC. Overall, treatment with gross total resection or subtotal resection had no difference in OS in patients with CPP or aCPP. Meanwhile, in patients with CPC, gross total resection (GTR) was associated with significantly better OS than subtotal resection (STR) only. However, there is no difference in OS between patients that receive GTR and patients that receive STR with adjuvant therapy. The nomogram for CPC considers types of treatments received. It demonstrates acceptable accuracy in estimating survival probability at 5-year and 10-year intervals, with a C-index of 0.608 (95% CI of 0.446 to 0.77). Conclusions: This is the largest study on CPT to date and highlights the optimal treatment strategies for these rare tumors. Overall, there is no difference in OS with GTR vs. STR in CPP or aCPP. Furthermore, OS is equivalent for CPC with GTR and STR plus adjuvant therapy.

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.

Choroid plexus tumors: A spectrum from benign to malignant

Choroid plexus tumors (CPT) are believed to originate from outgrowths of the choroid plexus. Despite their broad spectrum of symptoms, invasive nature, and prognosis, most CPTs typically exhibit similar presentations due to their relationship with the cerebral ventricles, as well as the mechanical obstruction and mass effect associated with their growth. In addition, these tumors mainly affect the pediatric population, further complicating the differentiation between benign and malignant subtypes. The World Health Organization classifies CPTs into three grades, namely, grades I, II, or III, based on their mitotic activity, which determine the benign or malignant nature of the tumors. CPTs classified by the World Health Organization (WHO) include choroid plexus papillomas (CPP), atypical CPPs (aCPP), and malignant choroid plexus carcinomas (CPC). Choroid plexus adenomas represent an additional category of benign CPTs not officially classified by the WHO. Despite the variations in histology, immunohistochemistry, imaging, treatment, and prognosis, CPTs cannot be reliably distinguished based solely on clinical presentation. Therefore, in this review, we aim to provide a comprehensive overview of each tumor subtype, along with the current management approach and emerging treatments.

Genomic profile of two Brazilian choroid plexus tumors by whole-exome sequencing

Choroid plexus tumors (CPTs) are rare intracranial neoplasms, representing <1% of all brain tumors, yet they represent 20% of first-year pediatric brain tumors. Although these tumors have been linked to TP53 germline mutations in the context of Li-Fraumeni syndrome, their somatic driver alterations remain poorly understood. In this study, we report two cases of lateral ventricle tumors: 3-yr-old male diagnosed with an atypical choroid plexus papilloma (aCPP), and a 6-mo-old female diagnosed with a choroid plexus carcinoma (CPC). We performed whole-exome sequencing of paired blood and tumor tissue in both patients, categorized somatic variants, and determined copy-number alterations. Our analysis revealed a tier II variant (Association for Molecular Pathology [AMP] criteria) in BRD1, a H3 and TP53 acetylation agent, in the aCPP. In addition, we detected copy-number gains on Chromosomes 12, 18, and 20 and copy-number losses on Chromosomes 13q and 22q (BRD1 locus) in this tumor. The CPC tumor had only a pathogenic germline TP53 variant, based on American College of Medical Genetics (ACMG) criteria, with a clinical and familiar history of Li-Fraumeni syndrome. The CPC patient presented loss of heterozygosity (LoH) of TP53 loci and hyperdiploid genome. Both tumors were microsatellite-stable. This is the first study performing whole-exome sequencing in Brazilian choroid plexus tumors, and in line with the literature, we corroborate the absence of recurrent somatic mutations in these tumors. Further studies with larger sample sizes are necessary to confirm our findings and better understand the underlying biology of these tumors.

Tumors of Choroid Plexus and Other Ventricular Tumors

Tumors arising inside the ventricular system are rare but represent a difficult diagnostic and therapeutic challenge. They usually are diagnosed when reaching a big volume and tend to affect young children. There is a wide broad of differential diagnoses with significant variability in anatomical aspects and tumor type. Differential diagnosis in tumor type includes choroid plexus tumors (papillomas and carcinomas), ependymomas, subependymomas, subependymal giant cell astrocytomas (SEGAs), central neurocytomas, meningiomas, and metastases. Choroid plexus tumors, ependymomas of the posterior fossa, and SEGAs are more likely to appear in childhood, whereas subependymomas, central neurocytomas, intraventricular meningiomas, and metastases are more frequent in adults. This chapter is predominantly focused on choroid plexus tumors and radiological and histological differential diagnosis. Treatment is discussed in the light of the modern acquisition in genetics and epigenetics of brain tumors.

Incidence and survival of choroid plexus tumors in the United States

Background

There are limited data available on incidence and survival of patients with choroid plexus tumors (CPT). This study provides the most current epidemiological analysis of choroid plexus tumors from 2004 to 2017 in the United States.

Methods

Data on 2013 patients with CPT were acquired from the Central Brain Tumor Registry of the United States in collaboration with the Centers for Disease Control and Prevention (CDC) and the National Cancer Institute, from 2004 to 2017. CPT cases were classified by the following pathological subtypes: choroid plexus papilloma (CPP), atypical choroid plexus papilloma (aCPP), and choroid plexus carcinoma (CPC). Frequencies and age-adjusted incidence rates (AAIR) per 100 000 and rate ratios per 100 000 (IRR) were reported for age, sex, race, and ethnicity for each pathological subtype with 95% confidence intervals (95% CI). Using CDC's National Program of Cancer Registries survival database, survival curves and hazard ratios (HRs) evaluated overall survival from 2001 to 2016.

Results

CPP had the highest overall incidence (AAIR: 0.034, 95% CI: 0.033-0.036), followed by CPC (AAIR: 0.008, 95% CI: 0.008-0.009) and aCPP (AAIR: 0.005, 95% CI: 0.005-0.006). Incidence was highest among children less than one year old among all subtypes (CPP AAIR: 0.278; aCPP AAIR: 0.140; CPC AAIR: 0.195), reducing as patients aged. Overall survival was worse among patients with CPC, being five times more likely to die compared to patients with CPP (HR: 5.23, 95% CI: 4.05-7.54, P < .001).

Conclusions

This analysis is the most current and comprehensive study in the US on the incidence and survival for CPT. Population based statistics provide critical information in understanding disease characteristics, which impact patient care and prognosis.

Prognostic Implication of DNA Methylation Signature in Atypical Choroid Plexus Papilloma With Intracranial Dissemination

An underestimation of pathologic diagnosis could be expected if disseminated choroid plexus tumors (CPTs) are diagnosed as lower grade tumors. Thus, molecular diagnosis using genome-wide DNA methylation profiling may be useful for clarifying the malignant potential of the tumor entity. Herein, we report a 2.7-year-old girl of pathologically atypical choroid plexus papilloma with intracranial dissemination. She was treated without radiotherapy and has been well, without recurrence for 32 months following the diagnosis. Subsequently, after a year from the diagnosis, T-stochastic neighbor embedding analysis was performed on methylation data of the case and compared with those of reference data of CPTs, revealing that the case was separated from the cluster of "Plexus tumor subclass pediatric B," which includes a majority of choroid plexus carcinomas with the worst prognosis of these entities, and was categorized into the cluster of "Plexus tumor subclass pediatric A" consisting of choroid plexus papilloma and atypical choroid plexus papillomas diagnosed pathologically. Our case indicates the clinical significance of molecular confirmation for diagnosis among CPTs, particularly lower grade tumors with dissemination.

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.

Primary intraventricular tumors - Imaging characteristics, post-treatment changes and relapses

Primary intraventricular neoplasms are rare tumors that originate from the ependymal or subependymal, septum pellucidum, choroid plexus and the supporting arachnoid tissue. Knowledge of the common locations of these tumors within the ventricular system, together with key imaging characteristics and presentation age, can significantly narrow the differential diagnosis. In 2016, the WHO reorganized the classification of several primary CNS tumors by combining histopathological and molecular data. This study highlights the imaging characteristics, histopathological and molecular data, treatment strategies and post-treatment changes of primary intraventricular tumors. Molecular-based diagnosis can not only aid in patient stratification and personalized treatment, but it can also provide prognostic and predictive value independent of WHO classification.

Atypical choroid plexus papilloma: A case report

We presents a rare case of a 15-year-old female who suffered atypical choroid plexus papilloma, which was accidental discovery due to head trauma. We gives a detailed description of its histological morphology and summarizes its clinical, pathological and prognostic characteristics, which is helpful for clinicians and pathologists to have a better understanding of this new disease.

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.

Long-Term Outcome After Surgical Resection of a Spinal Choroid Plexus Tumor in a Dog

A 6 yr old castrated male Clumber spaniel was referred for evaluation of acute paraplegia. MRI of the thoracolumbar spine demonstrated an intradural-extramedullary mass lesion at the level of T12 and extradural spinal cord compression at L1-L2. A hemilaminectomy was performed to achieve gross total resection of the mass lesion and removal of extruded disc material. A diagnosis of spinal choroid plexus tumor (CPT) and intervertebral disc extrusion was made. At 4 mo postoperatively, MRI demonstrated a mass lesion at the right lateral aperture of the fourth ventricle. Spinal drop metastasis from a primary intracranial CPT was suspected. The dog was ambulating independently and neurologically normal at that time. At 17 mo postoperatively, a third MRI was performed owing to decreased postural reactions in both hind limbs and vision loss in the right eye, and it demonstrated an increase in size of the intracranial mass lesion. These two additional MRI studies of the entire central nervous system showed no other metastatic lesions nor any evidence of local recurrence. At 25 mo postoperatively, the dog died at home. This is the first case report of surgical intervention and antemortem histopathological diagnosis of a spinal CPT in a dog.

The genetic landscape of choroid plexus tumors in children and adults

BACKGROUND

Choroid plexus tumors (CPTs) are intraventricular brain tumors predominantly arising in children but also affecting adults. In most cases, driver mutations have not been identified, although there are reports of frequent chromosome-wide copy-number alterations and TP53 mutations, especially in choroid plexus carcinomas (CPCs).

METHODS

DNA methylation profiling and RNA-sequencing was performed in a series of 47 CPTs. Samples comprised 35 choroid plexus papillomas (CPPs), 6 atypical choroid plexus papillomas (aCPPs) and 6 CPCs plus three recurrences thereof. Targeted TP53 and TERT promotor sequencing was performed in all samples. Whole exome sequencing (WES) and linked-read whole genome sequencing (WGS) was performed in 25 and 4 samples, respectively.

RESULTS

Tumors comprised the molecular subgroups "pediatric A" (N=11), "pediatric B" (N=12) and "adult" (N=27). Copy-number alterations mainly represented whole-chromosomal alterations with subgroup-specific enrichments (gains of Chr1, 2 and 21q in "pediatric B" and gains of Chr5 and 9 and loss of Chr21q in "adult"). RNA sequencing yielded a novel CCDC47-PRKCA fusion transcript in one adult choroid plexus papilloma patient with aggressive clinical course; an underlying Chr17 inversion was demonstrated by linked-read WGS. WES and targeted sequencing showed TP53 mutations in 7/47 CPTs (15%), five of which were children. On the contrary, TERT promoter mutations were encountered in 7/28 adult patients (25%) and associated with shorter progression-free survival (log-rank test, p=0.015).

CONCLUSION

Pediatric CPTs lack recurrent driver alterations except for TP53, whereas CPTs in adults show TERT promoter mutations or a novel CCDC47-PRKCA gene fusion, being associated with a more unfavorable clinical course.

Intracranial Choroid Plexus Carcinomas: Report of 11 Cases from a Single Institution

BACKGROUND

Choroid plexus carcinoma is a central nervous system tumor pathologically corresponding to World Health Organization grade III. Choroid plexus carcinoma mainly affects pediatric patients with a poor prognosis. Due to its rarity, standardized treatment has not yet been outlined.

METHODS

We retrospectively analyzed 11 patients with histopathologically diagnosed choroid plexus carcinoma between January 2008 and December 2016. They were treated with surgical resection with or without adjuvant therapies. The clinical profiles and outcomes were analyzed.

RESULTS

The mean age at diagnosis was 16.0 years (median, 7.0 years; range, 4 months to ∼59 years). Gross total resection was achieved in 9 cases, and subtotal resection in 2 cases. Seven patients received adjuvant radiotherapy, and 2 patients underwent chemotherapy. The mean overall survival was 34.8 months, and the mean progression-free survival was 24.5 months. During the follow-up period, 4 patients succumbed to central nervous system dissemination of choroid plexus carcinoma including 2 patients with malignant transformation from atypical choroid plexus papilloma to choroid plexus carcinoma and 1 patient treated with the combined chemotherapy protocol.

CONCLUSIONS

In this study, we described the clinicoradiologic characteristics of choroid plexus carcinomas. Surgical resection is the mainstream treatment. Due to the paucity of clinical evidence, the standard regimen of adjuvant therapies still needs further research.

Suboccipital Craniotomy and C1 Laminectomy for Atypical Choroid Plexus Papilloma

Atypical choroid plexus papilloma is a rare pediatric brain tumor that has distinct clinical and pathologic features. In this case, we highlight the diagnosis and management of this rare disease. The details of case positioning and execution are discussed. The case review is utilized as an overview of histopathologic findings, to discuss clinical features of the disease, and to highlight areas warranting further investigation. In particular, we provide insight into the typical clinical course post-treatment.

Aggresomes predict poor outcomes and implicate proteostasis in the pathogenesis of pediatric choroid plexus tumors

Purpose

Protein misfolding and aggregation result in proteotoxic stress and underlie the pathogenesis of many diseases. To overcome proteotoxicity, cells compartmentalize misfolded and aggregated proteins in different inclusion bodies. The aggresome is a paranuclear inclusion body that functions as a storage compartment for misfolded proteins. Choroid plexus tumors (CPTs) are rare neoplasms comprised of three pathological subgroups. The underlying mechanisms of their pathogenesis remain unclear. This study aims to elucidate the prognostic role and the biological effects of aggresomes in pediatric CPTs.

Methods

We examined the presence of aggresomes in 42 patient-derived tumor tissues by immunohistochemistry and we identified their impact on patients’ outcomes. We then investigated the proteogenomics signature associated with aggresomes using whole-genome DNA methylation and proteomic analysis to define their role in the pathogenesis of pediatric CPTs.

Results

Aggresomes were detected in 64.2% of samples and were distributed among different pathological and molecular subgroups. The presence of aggresomes with different percentages was correlated with patients’ outcomes. The ≥ 25% cutoff had the most significant impact on overall and event-free survival (p-value < 0.001) compared to the pathological and the molecular stratifications.

Conclusions

These results support the role of aggresome as a novel prognostic molecular marker for pediatric CPTs that was comparable to the molecular classification in segregating samples into two distinct subgroups, and to the pathological stratification in the prediction of patients’ outcomes. Moreover, the proteogenomic signature of CPTs displayed altered protein homeostasis, manifested by enrichment in processes related to protein quality control.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11060-020-03694-3.

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.

Pediatric atypical choroid plexus papilloma: Clinical features and diagnosis

OBJECTIVE

Atypical choroid plexus papilloma (aCPP) is a newly introduced subtype of choroid plexus tumors (CPTs) defined by the World Health Organization (WHO) in 2007 and is characterized by intermediate characteristics between choroid plexus papilloma (CPP) and choroid plexus carcinoma (CPC). Currently, the available data describing the clinical features of aCPP in children are limited.

METHODS

We performed a retrospective review of 24 pediatric patients with CPTs in our institute and focused on the clinical, radiological and histopathological features of 9 patients with aCPP.

RESULTS

The median age of aCPP patients was 12 (3-144) months, which was younger than the age of CPP patients (36 (5-132) months, P < 0.05). Of the 9 aCPPs, there were 4 cases of giant masses in the cerebral hemisphere, which was significantly higher than that in CPPs (44.4 % vs 0.0 %, P < 0.05). According to MRI analysis, cysts and necrosis (66.7 % vs 16.7 %, P < 0.05), peritumoral edema (55.6 % vs 8.3 %, P < 0.05) and blurred borders (55.6 % vs 8.3 %, P < 0.05) were more common in aCPPs than in CPPs. T1WI isointense signals were mainly observed in aCPPs and CPPs (aCPP66.7 % vs CPP58.3 %, P >0.05), while T2WI slightly low signals were more common in CPPs (CPP41.7 % vs aCPP0%, P < 0.05); moreover, the tumor volume of aCPPs was significantly larger than that of CPPs (aCPP78.3 cm3 vs 8.4 cm3, P < 0.05). For the DWI sequence scans, isointense signals were more common in aCPPs (aCPP77.8 %>CPP25.0 %, P < 0.05), while slightly low signals were more common in CPPs (CPP58.3 %>aCPP0%, P < 0.05). Both aCPPs and CPPs mainly showed homogeneously strong enhancement (aCPP66.7 % vs CPP91.7 %, P > 0.05). Interestingly, 1 aCPP showed annular enhancement. For the pathological and immunohistochemical studies, the Ki67 proliferation index was significantly higher in aCPPs than in CPPs (13 % vs 6%, P < 0.05), and the S-100(+)/Vim(+)/Syn(+) positive rate was higher in aCPPs (58.3 % vs 11.1 %, P < 0.05).

CONCLUSIONS

aCPP shows some distinctive clinical features compared with CPP, such as younger age, larger tumor size, more frequent necrosis and peritumoral edema, blurred borders, slightly low signals on T2WI and isointense signals on DWI, and a higher S-100(+)/Vim(+)/Syn(+) positive rate, which may provide more valuable evidence for differential diagnosis and clinical decisions surrounding aCPP.

Role of available adjuvant therapies following surgical resection of atypical choroid plexus papilloma-a systematic review and pooled analysis

Background

Atypical choroid plexus papilloma is a recently introduced entity with intermediate pathological characteristics. These tumors are relatively rare and the optimal management of these tumors is a matter of debate. Therefore, we performed a systematic review and pooled analysis about the effects of adjuvant therapies on outcome measures of these patients. We also compared these effects on totally and partially resected tumors and pediatric and adult populations.

Methods

A systematic search of 3 databases based on inclusion/exclusion criteria was performed. Data extraction was separately performed by 2 authors, and the summarized data were presented in the form of tables. Pooled estimates of different outcome measures were calculated for each adjuvant therapy and presented separately for studies with pediatric, adult, or mixed populations.

Results

A review of 14 included studies consisting of 144 patients revealed the effect of adjuvant treatment on reduction of tumor recurrence, metastasis, and reoperation rates and increasing survival rates in patients with subtotal tumor resection. This advantage was not seen in the case of gross total tumor resection. Almost all outcome measures were more favorable in the pediatric population.

Conclusions

It can be concluded that whenever gross total resection is not feasible, the implementation of adjuvant therapy can improve the outcome and prognosis. In other cases, it should be decided on an individual basis. Also, more aggressive behavior and higher rates of recurrence and mortality in the adult population suggest the consideration of more aggressive adjuvant treatments for adult patients.

Endoplasmic Reticulum Calcium Pumps and Tumor Cell Differentiation

Endoplasmic reticulum (ER) calcium homeostasis plays an essential role in cellular calcium signaling, intra-ER protein chaperoning and maturation, as well as in the interaction of the ER with other organelles. Calcium is accumulated in the ER by sarco/endoplasmic reticulum calcium ATPases (SERCA enzymes) that generate by active, ATP-dependent transport, a several thousand-fold calcium ion concentration gradient between the cytosol (low nanomolar) and the ER lumen (high micromolar). SERCA enzymes are coded by three genes that by alternative splicing give rise to several isoforms, which can display isoform-specific calcium transport characteristics. SERCA expression levels and isoenzyme composition vary according to cell type, and this constitutes a mechanism whereby ER calcium homeostasis is adapted to the signaling and metabolic needs of the cell, depending on its phenotype, its state of activation and differentiation. As reviewed here, in several normal epithelial cell types including bronchial, mammary, gastric, colonic and choroid plexus epithelium, as well as in mature cells of hematopoietic origin such as pumps are simultaneously expressed, whereas in corresponding tumors and leukemias SERCA3 expression is selectively down-regulated. SERCA3 expression is restored during the pharmacologically induced differentiation of various cancer and leukemia cell types. SERCA3 is a useful marker for the study of cell differentiation, and the loss of SERCA3 expression constitutes a previously unrecognized example of the remodeling of calcium homeostasis in tumors.

Epigenetics impacts upon prognosis and clinical management of choroid plexus tumors

PURPOSE

Choroid plexus tumors comprise of choroid plexus papilloma (CPP, WHO grade I), atypical choroid plexus papilloma (aCPP, WHO grade II) and choroid plexus carcinoma (CPC, WHO grade III). Molecular events driving the majority of choroid plexus tumors remain poorly understood. Recently, DNA methylation profiling has revealed different epigenetic subgroups.

METHODS

Comprehensive review of epigenetic profiles of choroid plexus tumors in the context of histopathological, genetic, and clinical features. DNA methylation profiling segregates choroid plexus tumors into three distinct epigenetic subgroups: supratentorial pediatric low-risk choroid plexus tumors (CPP and aCPP), infratentorial adult low-risk choroid plexus tumors (CPP and aCPP), and supratentorial pediatric high-risk choroid plexus tumors (CPP and aCPP and CPC). Epigenetic subgrouping provides additional prognostic information in comparison to histopathological grading.

CONCLUSIONS

Epigenetic profiling of choroid plexus tumors can be used for the identification of patients at risk of recurrence and is expected to play a role for treatment stratification and patient management in the context of future clinical trials.

Uncommon low-grade brain tumors

The 2016 World Health Organization (WHO) classification of primary central nervous system (CNS) tumors includes numerous uncommon (representing ≤1% of tumors) low-grade (grades I-II) brain neoplasms with varying clinical behaviors and outcomes. Generally, gross tumor or maximal safe resection is the primary treatment. Adjuvant treatments, though their exact role is unknown, may be considered individually based on pathological subtypes and a proper assessment of risks and benefits. Targetable mutations such as BRAF (proto-oncogene B-Raf), TRAIL (tumor necrosis factor apoptosis inducing ligand), and PDGFR (platelet derived growth factor receptor) have promising roles in future management.

Next generation DNA sequencing of atypical choroid plexus papilloma of brain: Identification of novel mutations in a female patient by Ion Proton

Choroid plexus papilloma (CPP) is a rare benign tumor of the central nervous system that is usually confined to the cerebral ventricles. According to the World Health Organization, CPP corresponds to a grade I atypical CPP (a-CPP); however, it can become more aggressive and reach grade II, which can rarely undergo malignant transformation into a choroid plexus carcinoma (grade III). To the best of our knowledge, identification of these tumors mutations by next generation DNA sequencing (NGS) has not been yet reported. In the present study, NGS analysis of an a-CPP case was performed. Data were analyzed using Advaita Bioinformatics i-VariantGuide and Ion Reporter 5.6 programs. The results from NGS identified 12 novel missense mutations in the following genes: NOTCH1, ATM, STK36, MAGI1, DST, RECQL4, NUMA1, THBS1, MYH11, MALT1, SMARCA4 and CDH20. The PolyPhen score of six variants viz., DST, RECQL4, NUMA1, THBS1, MYHI1 and SMARCA4 were high, which suggested these variants represents pathogenic variants. Two novel insertions that caused frameshift were also found. Furthermore, two novel nonsense mutations and 14 novel intronic variants were identified in this tumor. The novel missense mutation detected in ATM gene was situated in c.5808A>T; p. (Leu1936Phe) in exon 39, and a known ATM mutation was in c.5948A>G; p. (Asn1983Ser). These novel mutations had not been reported in previous database. Subsequently, the quality statistics of these variants, including allele coverage, allele ratio, P-value, Phred quality score, sequencing coverage, PolyPhen score and alleles frequency was performed. For all variants, P-value was highly significant and the Phred quality score was high. In addition, the results from sequencing coverage demonstrated that 97.02% reads were on target and that 97.88% amplicons had at least 500 reads. These findings may serve at determining new strategies to distinguish the types of choroid plexus tumor, and at developing novel targeted therapies. Development of NGS technologies in the Kingdom of Saudi Arabia may be used in molecular pathology laboratories.

Perinatal (fetal and neonatal) choroid plexus tumors: a review

INTRODUCTION

The object of this review is to describe the choroid plexus tumors (CPTs) occurring in the fetus and neonate with regard to clinical presentation, location, pathology, treatment, and outcome.

MATERIALS AND METHODS

Case histories and clinical outcomes were reviewed from 93 cases of fetal and neonatal tumors obtained from the literature and our own institutional experience from 1980 to 2016.

RESULTS

Choroid plexus papilloma (CPP) is the most common tumor followed by choroid plexus carcinoma (CPC) and atypical choroid plexus papilloma (ACPP). Hydrocephalus and macrocephaly are the presenting features for all three tumors. The lateral ventricles are the main site of tumor origin followed by the third and fourth ventricles, respectively. CPTs of the fetus are detected most often near the end of the third trimester of pregnancy by fetal ultrasound. The extent of surgical resection plays an important role in the treatment and outcome. In spite of excellent survival, which is especially true in the case of CPP, surgical resection may carry significant risks in an immature baby. Given the neonatal low blood volume and increased vascularity of the tumors, there is potential risk for hemorrhage. Although advances in neurosurgical techniques have led to a greater degree of complete surgical resections, survival for the perinatal CPC group remains low even with multimodality therapies.

CONCLUSION

Perinatal CPTs have variable overall survivals depending on degree of surgical resection and tumor biology. An increased understanding of the molecular features of these tumors may lead to improved therapies and ultimately survival.

Management of choroid plexus tumors-an institutional experience

Background

Choroid plexus tumors are rare entities. Resection is the mainstay of treatment in grade I and grade II tumors and adjuvant treatment is usually reserved for the less frequent choroid plexus carcinoma (CPC). Outcome is not only related to their histological grade but also dependent on their size, location, and presence of often multifactorial disturbances of cerebrospinal fluid (CSF) circulation.

Methods

Retrospective analysis of 36 consecutive patients operated on a choroid plexus tumor at our institution in a mixed pediatric and adult population between 1991 and 2016.

Results

Twenty-one CPP, 11 atypical choroid plexus papillomas (aCPP), and four CPC were encountered in 17 children and 19 adults. Regardless of histological grading, gross-total resection (GTR) could be achieved in 91.7% of patients. Tumor recurrence (25.0%) was significantly associated with histological grading (p = 0.004), subtotal resection (p = 0.002), and intraoperatively evident zones of tumor infiltration (p = 0.001). Adjuvant therapy was performed in 19.4% of patients, mainly diagnosed with CPC. The 5-year overall survival rate was 95.2% for CPP and 100.0% for both aCPP and CPC. Survival was related to the extent of resection (p = 0.001), tumor progression (p = 0.04), and the presence of leptomeningeal metastases (p = 0.002). Even after resection, either ventricular or subdural shunting was required in 25.0% of patients.

Conclusions

We could confirm that GTR is crucial for treatment of choroid plexus tumors. Parenchymal tumor infiltration as detected intraoperatively was associated with the extent of resection and not limited to CPC. CSF disturbances mandating treatment may persist after resection.

Choroid Plexus Papilloma of the Fourth Ventricle: A Pediatric Patient

Choroid plexus papilloma is a low-frequency entity in both the adult and pediatric populations. Its clinical presentation is very variable as it depends on its location and length. We must always do the differential diagnosis between papilloma and other intraventricular pathologies. This article is about a case report of a pediatric patient with a Choroid plexus papilloma located in the fourth ventricle, a location that is atypical for the pediatric population.

Vanishing diffuse leptomeningeal contrast enhancement in an infant with choroid plexus papilloma

Choroid plexus tumors (CPT) can present in the baseline magnetic resonance imaging (MRI) with lesions compatible with leptomeningeal dissemination. Therapeutic strategy in this condition is controversial. We present a case of an infant with CPP and significant diffuse leptomeningeal contrast enhancement at diagnosis, which spontaneously resolved after removal of the primary tumor. In these challenging cases, several aspects, such as histopathological/molecular diagnosis and close radiological follow-up, should be taken into account to avoid unnecessary treatments.

Choroid Plexus Carcinoma in Adults: Two Case Reports

Choroid plexus tumors are uncommon brain tumors that primarily occur in children. Most of these tumors originate from the intraventricular area, and the most common clinicalpresentation is increased intracranial pressure. Dissemination through the cerebrospinal fluid space is the inevitable natural course of the disease. Here, we present 2 rare cases of adult choroid plexus carcinoma (CPC), each with distinct clinical presentation and progression. The first case was a 40-year-old male who presented with multiple intraventricular masses. After surgical biopsy, radiation and intrathecal chemotherapy failed to elicit any response. The patient progressed with spinal cord dissemination and expired 1 year later. The second case presented with visual disturbance, and brain MRI revealed a large ovoid juxtaventricular mass with peritumoral edema. This 49-year-old female patient underwent craniotomy for what was thought to be a high-grade glioma; however, the mass was connected to the choroid plexus at the operative field. Her pathology specimen was diagnosed as CPC, and adjuvant systemic chemotherapy was administered. She has now been free of recurrence for 10 months. The description of the presentation and progression of these rare adult-onset CPC provides insight for the diagnosis and treatment of other rare instances of choroid plexus tumors.

ENDOSCOPIC ASSISTED, TRANSFONTANELLE EXCISION OF A LARGE THIRD VENTRICULAR ATYPICAL CHOROID PLEXUS PAPILLOMA IN AN INFANT

Choroid plexus papillomas are rare benign tumours, which are found in both adult and paediatric age groups. The 'atypical' histological subclass is rarer still. The commonest site of occurrence is in the lateral ventricles; rare locations are the cerebellopontine angle and the third ventricle. The goal of care is a gross total excision of the tumour. The histologic subtype determines further adjuvant care given to the patient. The outcome of the care of these patients depends on the histological grade, extent of surgical resection adjuvant care. We present a case of a 12 week-old infant with obstructive hydrocephalus, secondary to a third ventricular atypical choroid plexus papilloma. He had a 'two-staged' resection of the choroid plexus papilloma, using an endoscopic access via the right Kocher's point in the right anterior fontanelle, in the same position as that proposed for access in endoscopic third ventriculostomy because of the observed sutural diastasis. Histology confirmed an atypical choroid plexus papilloma. He made progressive recovery post-surgery but unfortunately there has been default with follow-up clinic visits.

Widely Metastatic Choroid Plexus Carcinoma Associated with Novel TP53 Somatic Mutation

BACKGROUND

Choroid plexus carcinoma (CPC) is a rare, malignant tumor occurring more commonly in children than adults. This case report describes the clinical course of a 3-year-old boy with a rare case of metastatic CPC with a novel TP53 mutation.

CASE DESCRIPTION

A 3-year-old boy presented with postconcussive symptoms after a fall. Computed tomography and magnetic resonance imaging revealed lesions in the suprasellar cistern, left lateral ventricle, and cauda equina. The tumor was diagnosed as choroid plexus carcinoma with a novel TP53 V216M somatic mutation. The patient underwent resection of the left lateral ventricle lesion.

CONCLUSION

We describe a case of CPC with highly metastatic characteristics and a novel TP53 mutation. Our report implicates TP53 in the pathogenesis of pediatric CPC, and we emphasize that CPC in children should prompt careful consideration of TP53 status to inform prognosis and clinical treatment.

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.

Glomeruloid Microvascular Proliferation, Desmoplasia, and High Proliferative Index as Potential Indicators of High Grade Canine Choroid Plexus Tumors

Choroid plexus tumors (CPT) are intraventricular neoplasms accounting for 10% of all primary central nervous system tumors in dogs. They are frequently classified according to the human WHO classification into choroid plexus papilloma (CPP, grade I), atypical CPP (aCPP, grade II), and choroid plexus carcinoma (CPC, grade III). Histological features observed in canine CPT such as increased vascular density (IVD) and glomeruloid microvascular proliferation (GMVP) are not part of the WHO classification. This multi-centric study aimed to investigate tumor-associated vascular hyperplasia in dogs by determining the prevalence of GMVP and IVD in 52 canine CPT and their association with tumor grade. In addition, the expression of angiogenic factors was assessed by immunohistochemistry in 25 tumors to investigate the pathogenesis of tumor-associated vascular hyperplasia. Based on the classical histological hallmarks, this study of 52 CPT identified 22 (42%) CPP (grade I) and 30 of (58%) CPC (grade III). GMVP was more prevalent in CPC (13/30; 43%) than CPP (1/22; 4%), whereas IVD occurred to a similar extent in CPP and CPC. Desmoplasia was more common in CPC (19/30; 63%) than CPP (2/22; 9%), and similarly, the proliferative index (PI) of neoplastic epithelium was significantly higher in CPC (5.14%) than CPP (0.94%). The majority of CPT expressed platelet-derived growth factor (PDGF), PDGFRα, PDGFRβ, and vascular endothelial growth factor (VEGF) irrespective of tumor grade or tumor-associated vascular hyperplasia. These results suggest that tumor-associated GMVP, desmoplasia, and PI may serve as histological indicators of malignancy in CPT.

Atypical choroid plexus papilloma: spontaneous resolution of diffuse leptomeningeal contrast enhancement after primary tumor removal in 2 pediatric cases

Atypical choroid plexus papillomas can metastasize in the form of leptomeningeal seeding. Postoperative chemotherapy is the recommended first-line treatment when gross-total removal is not achieved or in cases of disseminated disease. Here the authors report on 2 children with atypical choroid plexus papillomas and MRI findings of diffuse leptomeningeal enhancement at diagnosis, later presenting with spontaneous resolution of the leptomeningeal involvement after removal of the primary lesions. Observations in this report expand our knowledge about the natural history and biological behavior of these tumors and highlight the role of close neuroimaging surveillance in the management of atypical choroid plexus papillomas in cases with MRI evidence of diffuse leptomeningeal enhancement at presentation.

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.

Choroid Plexus Papillomas of the Cerebellopontine Angle

OBJECTIVE

Choroid plexus papillomas (CPPs) of the cerebellopontine angle (CPA) are extremely rare. We present a series of 21 cases operated on in the last 7 years at our institution.

METHODS

During the period from January 2008 to October 2015, we encountered 102 histologically established cases of CPPs, of which 21 were located in the CPA region. Clinical profiles, radiologic features, surgical procedures, intraoperative findings, and outcomes were extracted from the patient records and neuroimaging data.

RESULTS

The 21 CPPs in the CPA region accounted for 20.5% of all CPPs. Two of the tumors occurred in pediatric patients. Tumor size was 2.5-4.7 cm. The rate of calcification was higher in the CPPs in the CPA region. Peritumoral cysts and cysts with small nodules were observed in our cases. A far lateral suboccipital approach was chosen for CPPs protruding inferiorly into the foramen magnum region (n = 14), and a suboccipital retrosigmoid approach was chosen for the other tumors. Total resection was achieved in 18 patients, and subtotal resection was achieved in 3 patients. During the follow-up period, only 1 patient experienced recurrence 32 months after the first operation. The recurrence turned out to be an atypical CPP.

CONCLUSIONS

CPPs in the CPA region cannot be easily differentiated from other tumors preoperatively. Cysts and calcifications appear on neuroimaging. CPPs in the CPA region usually protrude inferiorly into the foramen magnum region. As much tumor should be removed as possible to avoid recurrence and malignant transition.

Preclinical studies of 5-fluoro-2'-deoxycytidine and tetrahydrouridine in pediatric brain tumors

Chemotherapies active in preclinical studies frequently fail in the clinic due to lack of efficacy, which limits progress for rare cancers since only small numbers of patients are available for clinical trials. Thus, a preclinical drug development pipeline was developed to prioritize potentially active regimens for pediatric brain tumors spanning from in vitro drug screening, through intracranial and intra-tumoral pharmacokinetics to in vivo efficacy studies. Here, as an example of the pipeline, data are presented for the combination of 5-fluoro-2'-deoxycytidine and tetrahydrouridine in three pediatric brain tumor models. The in vitro activity of nine novel therapies was tested against tumor spheres derived from faithful mouse models of Group 3 medulloblastoma, ependymoma, and choroid plexus carcinoma. Agents with the greatest in vitro potency were then subjected to a comprehensive series of in vivo pharmacokinetic (PK) and pharmacodynamic (PD) studies culminating in preclinical efficacy trials in mice harboring brain tumors. The nucleoside analog 5-fluoro-2'-deoxycytidine (FdCyd) markedly reduced the proliferation in vitro of all three brain tumor cell types at nanomolar concentrations. Detailed intracranial PK studies confirmed that systemically administered FdCyd exceeded concentrations in brain tumors necessary to inhibit tumor cell proliferation, but no tumor displayed a significant in vivo therapeutic response. Despite promising in vitro activity and in vivo PK properties, FdCyd is unlikely to be an effective treatment of pediatric brain tumors, and therefore was deprioritized for the clinic. Our comprehensive and integrated preclinical drug development pipeline should reduce the attrition of drugs in clinical trials.

Choroid Plexus Tumors: Experience of 10 Cases with Special References to Adult Cases

Choroid plexus tumors (CPTs) are rare intraventricular neoplasms accounting for about 0.3–0.6% of all intracranial tumors. This retrospective study on CPTs presents clinico-pathological features and management strategies based on a 20-year single-institutional experience. This series included 10 consecutive patients with pathologically proven CPTs; 5 choroid plexus papillomas (CPPs), 3 atypical CPPs (ACPPs), and 2 choroid plexus carcinomas (CPCs). Their clinical, radiological, and histopathological features as well as management including follow-up studies were reviewed. The patients included five males and five females, aging from 0 years to 61 years with median of 28 years. The affected site was lateral ventricle in two adults and fourth ventricle in eight patients; four children and four adults. The most common symptoms were gait disturbance and memory disturbance. All the patients underwent craniotomy with total, subtotal, and partial removals achieved in 50%, 40%, and 10% of the patients, respectively. The occurrence of the high grade subtypes was 50% in both the adult and pediatric groups. The Ki-67/MIB-1 index increased across the three histological subtypes, from CPP to ACPP and then to CPC. Adjuvant therapy was administered in three patients. The two patients (one adult and one child) with CPC died of whole central nervous system dissemination. At a median of 62-month follow-up, the other eight patients were alive, with only one patient having recurrence and reoperation. The results demonstrate that gross total resection is usually curative for CPP and ACPP, and adjuvant chemoradiotherapy would be required for CPC and incompletely resected ACPP.

Extraventricular Intraparenchymal Choroid Plexus Tumors in Cerebral Hemisphere: A Series of 6 Cases

OBJECTIVE

Extraventricular intraparenchymal choroid plexus tumors (CPTs) in the cerebral hemisphere are extremely rare. The aim of this study was to investigate the clinical characteristics, radiologic findings, and surgical outcomes of this atypical type of CPT.

METHODS

The study comprised 6 patients with pathologically proven extraventricular intraparenchymal CPTs who were surgically treated at Qilu Hospital of Shandong University. The PubMed database was searched for similar cases published before January 2015, and these cases were reviewed.

RESULTS

Patients were 5 (83.3%) men and 1 (16.7%) woman with an average age of 46.5 years. Symptoms and signs of CPT were usually associated with increased intracranial pressure and invasion of functional areas by tumor. Magnetic resonance imaging commonly demonstrated a contrast-enhancing intraparenchymal mass with cysts; hydrocephalus was not observed in any cases. Subtotal resection and gross total resection were achieved in 1 (16.7%) and 5 (83.3%) cases, respectively. There were 3 cases (50.0%) of choroid plexus papilloma, 2 cases (33.3%) of atypical choroid plexus papilloma, and 1 case (16.7%) not otherwise specified. There was a low incidence of postoperative complications, and surgical outcomes of CPTs were satisfactory.

CONCLUSIONS

In contrast to typical lesions, extraventricular intraparenchymal CPTs in the cerebral hemisphere are rarely associated with hydrocephalus. Magnetic resonance imaging features are key in preoperative diagnosis; nevertheless, it is difficult to distinguish this atypical type of CPT from other lesions. Surgical removal of the tumor is safe and efficacious.

The role of chemotherapy and surgical removal in the treatment of Choroid Plexus carcinomas and atypical papillomas

INTRODUCTION

We performed a retrospective study on clinical assessment, tumor location, radiological imaging, histopathological characteristics, and therapeutic management of 7 patients affected by choroid plexus carcinoma (CPC) or atypical choroid plexus papilloma (ACPP) who have been observed in the last 12 years.

METHODS

Four patients fulfilled the criteria for classification as ACPP and three cases as CPC. The median age of the patients at the diagnosis was 42 months (range 3-190 months). Except one older patient (15 years old), all patients were younger than 3 years of age. In all patients affected by ACPP, a total surgical resection was achieved. Two children relapsed 12 and 8 months following radical removal. Both of them underwent adjuvant chemotherapy (carboplatin, cyclophosphamide, etoposide, doxorubicin, and methotrexate); a complete remission was maintained in all cases. In all three patients with CPC, it was impossible to achieve complete resection at first surgery. The response to chemotherapy was variable: in one case, it was complete with complete remission following 6 months; in one case, it was partial with reduction on volume (the patient underwent second-look surgery with complete resection); in the third case, there was no response and the patient progressed and finally died with metastatic disease, 8 months after chemotherapy was started. For children with CPC, the OS was 75% at 6 years.

RESULTS

In our series, surgery associated with chemotherapy led to long-term survival in 4/4 patients affected by ACPP and 2/3 patients affected by CPC. Clinical results achieved in our series confirm that our therapeutic regimen is feasible and efficient as a possible adjuvant treatment for both CPC and ACPP. It also suggests that surgery has a pivotal role in the management of most children affected by CPTs.