Ependymoma: an update

Patterns of Extraneural Metastases in Children With Ependymoma

Ependymomas account for 10% of all malignant pediatric central nervous system tumors. Standard therapy includes maximal safe surgical resection, followed by focal radiation. Despite the aggressive therapy, progression-free survival is poor. Most ependymoma relapses occur locally at the original tumor site. Extraneural presentations of ependymoma are extremely rare, and no standard of care treatment exists. We present a single-institution case series of 3 patients who experienced extraneural relapses of supratentorial ependymoma and describe their treatment and outcome. These cases of extraneural relapse highlight the possible modes of extraneural spread, including hematogenous, lymphatic, and microscopic seeding through surgical drains and shunts. In addition, they illustrate the increase in histologic grade and mutational burden that may occur at the time of relapse. These cases illustrate the role of aggressive, individualized treatment interventions using a combination of surgery, radiation, and chemotherapy.

The Positive Impact of a Chemotherapeutic Approach on Relapse Ependymoma or WHO Grade III Anaplastic Ependymoma: Report of a Rare Case

Children with recurrent ependymoma have a poor prognosis. Reirradiation has been proposed as an effective treatment for relapsed ependymoma. In this report, we present the case of a 14-year-old male child with a World Health Organization (WHO) grade III relapse ependymoma, emphasizing the imaging feature that helps differentiate the relapse ependymoma, which is a rarer condition in children. Being able to determine this tumor by its imaging appearance is important to risk stratify patient management decisions. The survival rate of ependymoma is usually five years, but in this case, we present a 14-year-old male child alive with reirradiation and chemotherapy management. The prognosis of the patient after undergoing treatment was good.

Extra-Neural Metastases of Late Recurrent Myxopapillary Ependymoma to Left Lumbar Paravertebral Muscles: Case Report and Review of the Literature

Ependymomas are commonly classified as low-grade tumors, although they may harbor a malignant behavior characterized by distant neural dissemination and spinal drop metastasis. Extra-CNS ependymoma metastases are extremely rare and only few cases have been reported in the lung, lymph nodes, pleura, mediastinum, liver, bone, and diaphragmatic, abdominal, and pelvic muscles. A review of the literature yielded 14 other case reports metastasizing outside the central nervous system, but to our knowledge, no studies describe metastasis in the paravertebral muscles. Herein, we report the case of a 39-year-old patient with a paraspinal muscles metastasis from a myxopapillary ependymoma. The neoplasm was surgically excised and histologically and molecularly analyzed. Both the analyses were consistent with the diagnosis of muscle metastases of myxopapillary ependymoma. The here-presented case report is first case in the literature of a paraspinal muscles metastasis of myxopapillary ependymoma.

An Insight into Pathophysiological Features and Therapeutic Advances on Ependymoma

Simple Summary

Although biological information and the molecular classification of ependymoma have been studied, the treatment systems for ependymoma are still insufficient. In addition, because the disease occurs infrequently, it is difficult to obtain sufficient data to conduct large-scale or randomized clinical trials. Therefore, this study is intended to emphasize the importance of understanding its pathological characteristics and prognosis as well as developing treatments for ependymoma through multilateral studies.

Abstract

Glial cells comprise the non-sensory parts of the central nervous system as well as the peripheral nervous system. Glial cells, also known as neuroglia, constitute a significant portion of the mammalian nervous system and can be viewed simply as a matrix of neural cells. Despite being the “Nervenkitt” or “glue of the nerves”, they aptly serve multiple roles, including neuron repair, myelin sheath formation, and cerebrospinal fluid circulation. Ependymal cells are one of four kinds of glial cells that exert distinct functions. Tumorigenesis of a glial cell is termed a glioma, and in the case of an ependymal cell, it is called an ependymoma. Among the various gliomas, an ependymoma in children is one of the more challenging brain tumors to cure. Children are afflicted more severely by ependymal tumors than adults. It has appeared from several surveys that ependymoma comprises approximately six to ten percent of all tumors in children. Presently, the surgical removal of the tumor is considered a standard treatment for ependymomas. It has been conspicuously evident that a combination of irradiation therapy and surgery is much more efficacious in treating ependymomas. The main purpose of this review is to present the importance of both a deep understanding and ongoing research into histopathological features and prognoses of ependymomas to ensure that effective diagnostic methods and treatments can be developed.

Phase 2 Study of Pomalidomide (CC-4047) Monotherapy for Children and Young Adults With Recurrent or Progressive Primary Brain Tumors

Introduction

Treatment of recurrent primary pediatric brain tumors remains a major challenge, with most children succumbing to their disease. We conducted a prospective phase 2 study investigating the safety and efficacy of pomalidomide (POM) in children and young adults with recurrent and progressive primary brain tumors.

Methods

Patients with recurrent and progressive high-grade glioma (HGG), diffuse intrinsic pontine glioma (DIPG), ependymoma, or medulloblastoma received POM 2.6 mg/m²/day (the recommended phase 2 dose [RP2D]) on days 1-21 of a 28-day cycle. A Simon's Optimal 2-stage design was used to determine efficacy. Primary endpoints included objective response (OR) and long-term stable disease (LTSD) rates. Secondary endpoints included duration of response, progression-free survival (PFS), overall survival (OS), and safety.

Results

46 patients were evaluable for response (HGG, n = 19; DIPG, ependymoma, and medulloblastoma, n = 9 each). Two patients with HGG achieved OR or LTSD (10.5% [95% CI, 1.3%-33.1%]; 1 partial response and 1 LTSD) and 1 patient with ependymoma had LTSD (11.1% [95% CI, 0.3%-48.2%]). There were no ORs or LTSD in the DIPG or medulloblastoma cohorts. The median PFS for patients with HGG, DIPG, ependymoma, and medulloblastoma was 7.86, 11.29, 8.43, and 8.43 weeks, respectively. Median OS was 5.06, 3.78, 12.02, and 11.60 months, respectively. Neutropenia was the most common grade 3/4 adverse event.

Conclusions

Treatment with POM monotherapy did not meet the primary measure of success in any cohort. Future studies are needed to evaluate if POM would show efficacy in tumors with specific molecular signatures or in combination with other anticancer agents.

Clinical Trial Registration

ClinicalTrials.gov, identifier NCT03257631; EudraCT, identifier 2016-002903-25.

The role of sex genotype in paediatric CNS tumour incidence and survival

PURPOSE

Evidence exists, in CNS germinomas and medulloblastomas (MB), that patient sex significantly influences incidence and outcome. The role of sex genotype in other paediatric CNS tumours remains unclear. This study sought to examine the role of sex genotype in CNS tumour incidence and overall survival (OS).

METHODS

Age-adjusted incidence and OS rates were collected from the Surveillance Epidemiology and End Result (SEER) registry between 2000 and 2011 for common paediatric (<=19 years) CNS tumours: pilocytic astrocytoma (PA), anaplastic astrocytoma, glioblastoma (GBM), medulloblastoma, supratentorial CNS embryonal tumour, ependymoma, and germinoma. All patients with histologically confirmed, ICD-03 coded, first tumours, were included. Kaplan-Meier and Cox regression analyses were used to calculate hazard ratios (HR).

RESULTS

The total cases are as follows: males=3018 and females=2276. Highest incidence was seen in PA (n=2103). GBM displayed the worst OS, whilst PA displayed the best. Higher incidence was observed in males for all tumours, except PA. Females with ependymoma had significantly better OS compared to males, whereas males with germinomas had better OS compared to females. Females <1 year with AA had better OS than males. Increasing age significantly improved male and female survival in ependymoma and medulloblastoma.

CONCLUSION

Interrogating population-based registries such as SEER minimises bias and provides credible data. Observed differences in incidence and OS between the sexes for different paediatric CNS tumours provide useful prognostic information for clinicians. Sex genotype was a significant independent prognostic factor in ependymomas and germinomas. Further investigation of possible epigenetic and hormonal differences may provide sex-specific vulnerabilities that may be exploitable for targeted therapy.

A retrospective analysis of recurrent pediatric ependymoma reveals extremely poor survival and ineffectiveness of current treatments across central nervous system locations and molecular subgroups

BACKGROUND

Relapse occurs in 50% of pediatric ependymoma cases and has poor prognosis. Few studies have investigated the clinical progress of relapsed disease, and treatment lacks a standardized approach.

METHODS AND MATERIALS

We analyzed 302 pediatric ependymoma cases. Tumor, demographic, and treatment variables were investigated for association with relapse risk, time to recurrence, and survival after relapse. DNA methylation profiling was performed for 135/302 cases, and predominant subgroups were EPN_PFA (n = 95) and EPN_RELA (n = 24). Chromosome 1q status was ascertained for 185/302 cases by fluorescent in-situ hybridization (FISH), multiplex ligation-dependent probe amplification (MLPA), and DNA methylation profiles.

RESULTS

Sixty-two percent of cases relapsed, with a median of two recurrences with no difference between posterior fossa and supratentorial locations (66% vs 55% relapse rate). One hundred seventeen (38%) cases relapsed within two years and five (2%) beyond 10 years. The late relapses were clinically heterogeneous. Tumor grade and treatment affected risk and time to relapse variably across subgroups. After relapse, surgery and irradiation delayed disease progression with a minimal impact on survival across the entire cohort. In the EPN_PFA and EPN_RELA groups, 1q gain was independently associated with relapse risk (subhazard ratio [SHR] 4.307, P = 0.027 and SHR 1.982, P = 0.010, respectively) while EPN_PFA had increased relapse risk compared with EPN_RELA (SHR = 0.394, P = 0.018).

CONCLUSIONS

Recurrent pediatric ependymoma is an aggressive disease with poor outcomes, for which current treatments are inadequate. We report that chromosome 1q gain increases relapse risk in common molecular subgroups in children but a deeper understanding of the underlying biology at relapse and novel therapeutic approaches are urgently needed.

Supratentorial pediatric cortical ependymomas: a comprehensive retrospective study

Pediatric cortical ependymomas (CEs) are rare; the clinical features and optimal treatment remain ill-defined. We aimed to clarify the clinical characteristics and outcome of pediatric CEs based on institutional series and literature review. Thirteen children with CEs from our department were included in the present study. Furthermore, a search of English language peer-reviewed articles yielded 43 patients with CEs. The clinical data, treatment, and outcome were retrospectively reviewed and statistically analyzed. Our institutional series consisted of nine males and four females. The literature review yielded 56 pediatric CE cases (including ours) for further analysis. Of these 56 cases, frontal lobe (n = 19, 41.3%) was the most common location and most of the tumors were located in the right hemisphere (n = 27, 58.7%). Seizures (n = 23, 41.1%) were the most frequent preoperative symptoms. Thirty patients (n = 30, 53.6%) were WHO grade II. Five continuous patients in our series screened for C11orf95-RELA fusion and all the patients (100%) were RELA fusion positive. Fourteen (26.4%) patients experienced tumor recurrence and 4 (7.5%) patients died during the follow-up. Multivariate survival analysis depicted extent of surgery resection was the only prognostic factor for PFS and patient with gross total resection (P = 0.037, HR 3.682, 95% CI 1.082-13.79) had longer PFS. Furthermore, Log-rank testing for Kaplan-Meier survival analysis showed the extent of surgery resection (P = 0.007) was the only prognostic factor for OS. Pediatric CEs are rare, commonly seen in frontal lobe and right hemisphere. Seizures are the most common symptoms. They may have higher rate of RELA fusions, but favorable outcome. A low incidence of anaplastic histology has been depicted. Gross total resection is significantly associated with longer PFS and OS. Careful follow-up is necessary because the tumors may progress.

Anaplastic ependymoma metastases though a ventriculoperitoneal shunt

Ependymomas are rare glial tumors that comprise 10% of intracranial pediatric malignancies. Primary central nervous system malignancies can rarely metastasize extracranially. When metastases occur, it usually does so in the setting of surgical manipulation of the central nervous system and can spread through the blood, lymph, or artificial means, for example, a ventriculoperitoneal shunt. We describe the presentation and progression of an 18-month-old boy diagnosed with an ependymoma. Initially managed with surgery, radiation, and ventriculoperitoneal shunt placement for symptomatic hydrocephalus, the tumor later recurred with drop metastasis to the thoracic spinal cord. The patient subsequently developed extensive metastases within the abdominal cavity, which were seeded through a ventriculoperitoneal shunt. We present a case of a rare complication of intra-abdominal tumor seeding and carcinomatosis from an intracranial ependymoma through a ventriculoperitoneal shunt. This is a rare presentation of a possible complication, which requires awareness of both surgeons and radiologists.

An application of the Toronto Childhood Cancer Stage Guidelines in three population-based cancer registries: The case of central nervous tumors

BACKGROUND

Cancer stage is a determinant of survival of childhood central nervous system (CNS) cancers and could help the interpretation of survival variability among countries. Consensus guidelines to stage childhood malignancies in population cancer registries ("Toronto Childhood Cancer Stage Guidelines") have been recently proposed with the goal of data comparability. Indeed, stage is not systematically recorded in all registries and, when it is, different classification systems are used. We applied the Toronto Childhood Cancer Stage Guidelines to CNS cancer cases of three population-based cancer registries with the aim of evaluating the feasibility of staging this type of cancer and the critical points in the classification of CNS tumors.

PROCEDURES

The Toronto Childhood Cancer Stage Guidelines were applied to 175 CNS patients, diagnosed from January 1, 2002 to December 31, 2014 in three cancer registries in Italy, and the percentage of cases that could be staged was assessed.

RESULTS

One hundred eight of 126 (86%) medulloblastomas and other embryonal CNS cancers and 22 of 49 (45%) ependymomas were staged. Using these guidelines, survival of children with localized tumors could be discriminated from that of children with metastatic disease.

CONCLUSIONS

The use of the Toronto Childhood Cancer Stage Guidelines is feasible for staging medulloblastoma in Italian population-based cancer registries, whereas it is more difficult for ependymomas. In Italy, cerebrospinal fluid examination, one of the decisive tests to stage CNS tumors, is not routinely performed as a first-line diagnosis procedure in ependymoma pediatric patients. A similar exercise by a larger number of cancer registries in different countries could suggest improvements in the childhood cancer staging system.

Intracranial ependymomas: molecular insights and translation to treatment

Ependymomas are primary central nervous system tumors (CNS), arising within the posterior fossa and supratentorial regions of the brain, and in the spine. Over the last decade, research has resulted in substantial insights into the molecular characteristics of ependymomas, and significant advances have been made in the establishment of a molecular classification system. Ependymomas both within and between the three CNS regions in which they arise, have been shown to contain distinct genetic, epigenetic and cytogenic aberrations, with at least three molecularly distinct subgroups identified within each region. However, these advances in molecular characterization have yet to be translated into clinical practice, with the standard treatment for ependymoma patients largely unchanged. This review summarizes the advances made in the molecular characterization of intracranial ependymomas, outlines the progress made in establishing preclinical models and proposes strategies for moving toward subgroup-specific preclinical investigations and treatment.

Low-dose Actinomycin-D treatment re-establishes the tumoursuppressive function of P53 in RELA-positive ependymoma

Ependymomas in children can arise throughout all compartments of the central nervous system (CNS). Highly malignant paediatric ependymoma subtypes are Group A tumours of the posterior fossa (PF-EPN-A) and RELA-fusion positive (ST-EPN-RELA) tumours in the supratentorial compartment. It was repeatedly reported in smaller series that accumulation of p53 is frequently observed in ependymomas and that immunohistochemical staining correlates with poor clinical outcome, while TP53 mutations are rare. Our TP53 mutation analysis of 130 primary ependymomas identified a mutation rate of only 3%. Immunohistochemical analysis of 398 ependymomas confirmed previous results correlating the accumulation of p53 with inferior outcome. Among the p53-positive ependymomas, the vast majority exhibited a RELA fusion leading to the hypothesis that p53 inactivation might be linked to RELA positivity.

In order to assess the potential of p53 reactivation through MDM2 inhibition in ependymoma, we evaluated the effects of Actinomycin-D and Nutlin-3 treatment in two preclinical ependymoma models representing the high-risk subtypes PF-EPN-A and ST-EPN-RELA. The IC-50 of the agent as determined by metabolic activity assays was in the lower nano-molar range (0.2–0.7 nM). Transcriptome analyses of high-dose (100 nM), low-dose (5 nM) and non-treated cells revealed re-expression of p53 dependent genes including p53 upregulated modulator of apoptosis (PUMA) after low-dose treatment. At the protein level, we validated the Actinomycin-D induced upregulation of PUMA, and of p53 interaction partners MDM2 and p21. Proapoptotic effects of low-dose application of the agent were confirmed by flow cytometry. Thus, Actinomycin-D could constitute a promising therapeutic option for ST-EPN-RELA ependymoma patients, whose tumours frequently exhibit p53 inactivation.

Nonclinical Profile of BLZ-100, a Tumor-Targeting Fluorescent Imaging Agent

BLZ-100 is a single intravenous use, fluorescent imaging agent that labels tumor tissue to enable more complete and precise surgical resection. It is composed of a chlorotoxin peptide covalently bound to the near-infrared fluorophore indocyanine green. BLZ-100 is in clinical development for intraoperative visualization of human tumors. The nonclinical safety and pharmacokinetic (PK) profile of BLZ-100 was evaluated in mice, rats, canines, and nonhuman primates (NHP). Single bolus intravenous administration of BLZ-100 was well tolerated, and no adverse changes were observed in cardiovascular safety pharmacology, PK, and toxicology studies in rats and NHP. The single-dose no-observed-adverse-effect-levels (NOAELs) were 7 mg (28 mg/kg) in rats and 60 mg (20 mg/kg) in NHP, corresponding to peak concentration values of 89 400 and 436 000 ng/mL and area-under-the-curve exposure values of 130 000 and 1 240 000 h·ng/mL, respectively. Based on a human imaging dose of 3 mg, dose safety margins are >100 for rat and monkey. BLZ-100 produced hypersensitivity reactions in canine imaging studies (lethargy, pruritus, swollen muzzle, etc). The severity of the reactions was not dose related. In a follow-up study in dogs, plasma histamine concentrations were increased 5 to 60 minutes after BLZ-100 injection; this coincided with signs of hypersensitivity, supporting the conclusion that the reactions were histamine based. Hypersensitivity reactions were not observed in other species or in BLZ-100 human clinical studies conducted to date. The combined imaging, safety pharmacology, PK, and toxicology studies contributed to an extensive initial nonclinical profile for BLZ-100, supporting first-in-human clinical trials.

Cerebellar Mutism Syndrome following Midline Posterior Fossa Tumor Resection in Children: An Institutional Experience

Aim:

Cerebellar mutism (CM) syndrome is a well-known and annoying complication of posterior fossa surgery in the pediatric age group. Risk factors such as the type of tumor, size, involvement of posterior fossa structures and hydrocephalus, and postoperative cerebellar swelling for CM were investigated in this study.

Materials and Methods:

A consecutive series of 33 children with midline posterior fossa tumors were operated at the SMS Medical College and Hospital, Department of Neurosurgery, Jaipur India, between September 2015 and December 2016. Their speech and neuroradiological studies were systematically analyzed both preoperatively and postoperatively.

Results:

CM syndrome (CMS) developed in six children (18.18%) in the early postoperative period. The pre- and post-operative irritability, medulloblastoma histology, maximum size more than 45 mm, involvement of superior cerebellar peduncles, and vermian incision were significant single independent risk factors. In addition, male gender also associated with a higher risk for CMS. The latency for the development of mutism ranged from 1 to 12 days (mean 3.5 days). The speech returned to normal in all patients. All cases with CMS accompanied by cerebellar ataxia.

Conclusion:

The medulloblastoma, irritability, maximum size more than 45 mm, involvement of superior cerebellar peduncles, and vermian incision were significant single independent risk factors for postoperative pediatric CMS. Mutism after posterior fossa tumor resection is also accompanied with ataxia. CM usually has a self-limiting course and a favorable prognosis.

Consensus paper on post-operative pediatric cerebellar mutism syndrome: the Iceland Delphi results

INTRODUCTION

Confusion has surrounded the description of post-operative mutism and associated morbidity in pediatric patients with cerebellar tumors for years. The heterogeneity of definitions and diagnostic features has hampered research progress within the field, and to date, no international guidelines exist on diagnosis, prevention, treatment, or follow-up of this debilitating condition. An international group of clinicians and researchers from multiple relevant disciplines recently formed a cohesive panel to formulate a new working definition and agree upon standardized methods for diagnosis and follow-up.

METHODS

Consensus was obtained using the modified nominal group technique, involving four rounds of online Delphi questionnaires interspersed with a structured consensus conference with lectures, group work, and open discussion sessions.

RESULTS

A new, proposed definition of "post-operative pediatric CMS" was formed, preliminary recommendations for diagnostic and follow-up procedures were created, two working groups on a new scoring scale and risk prediction and prevention were established, and areas were identified where further information is needed.

DISCUSSION

The consensus process was motivated by desire to further research and improve quality of life for pediatric brain tumor patients. The Delphi rounds identified relevant topics and established basic agreement, while face-to-face engagement helped resolve matters of conflict and refine terminology. The new definition is intended to provide a more solid foundation for future clinical and research work. It is thought as a consensus for moving forward and hopefully paves the way to developing a standard approach to this challenging problem with the advent of better scoring methods and ultimate goal of reducing the risk of CMS.

Preclinical Validation of the Utility of BLZ-100 in Providing Fluorescence Contrast for Imaging Spontaneous Solid Tumors

There is a need in surgical oncology for contrast agents that can enable real-time intraoperative visualization of solid tumors that can enable complete resections while sparing normal surrounding tissues. The Tumor Paint agent BLZ-100 is a peptide-fluorophore conjugate that can specifically bind solid tumors and fluoresce in the near-infrared range, minimizing light scatter and signal attenuation. In this study, we provide a preclinical proof of concept for use of this imaging contrast agent as administered before surgery to dogs with a variety of naturally occurring spontaneous tumors. Imaging was performed on excised tissues as well as intraoperatively in a subset of cases. Actionable contrast was achieved between tumor tissue and surrounding normal tissues in adenocarcinomas, squamous cell carcinomas, mast cell tumors, and soft tissue sarcomas. Subcutaneous soft tissue sarcomas were labeled with the highest fluorescence intensity and greatest tumor-to-background signal ratio. Our results establish a foundation that rationalizes clinical studies in humans with soft tissue sarcoma, an indication with a notably high unmet need.

Pre-B-cell leukemia homeobox interacting protein 1 is overexpressed in astrocytoma and promotes tumor cell growth and migration

BACKGROUND

Glial brain tumors cause considerable mortality and morbidity in children and adults. Innovative targets for therapy are needed to improve survival and reduce long-term sequelae. The aim of this study was to find a candidate tumor-promoting protein, abundantly expressed in tumor cells but not in normal brain tissues, as a potential target for therapy.

METHODS

In silico proteomics and genomics, immunohistochemistry, and immunofluorescence microscopy validation were performed. RNA interference was used to ascertain the functional role of the overexpressed candidate target protein.

RESULTS

In silico proteomics and genomics revealed pre-B-cell leukemia homeobox (PBX) interacting protein 1 (PBXIP1) overexpression in adult and childhood high-grade glioma and ependymoma compared with normal brain. PBXIP1 is a PBX-family interacting microtubule-binding protein with a putative role in migration and proliferation of cancer cells. Immunohistochemical studies in glial tumors validated PBXIP1 expression in astrocytoma and ependymoma but not in oligodendroglioma. RNAi-mediated PBXIP1-knockdown in glioblastoma cell lines strongly reduced proliferation and migration and induced morphological changes, indicating that PBXIP1 knockdown decreases glioma cell viability and motility through rearrangements of the actin cytoskeleton. Furthermore, expression of PBXIP1 was observed in radial glia and astrocytic progenitor cells in human fetal tissues, suggesting that PBXIP1 is an astroglial progenitor cell marker during human embryonic development.

CONCLUSION

PBXIP1 is a novel protein overexpressed in astrocytoma and ependymoma, involved in tumor cell proliferation and migration, that warrants further exploration as a novel therapeutic target in these tumors.

Immunohistochemical expression of cyclin D1 is higher in supratentorial ependymomas and predicts relapses in gross total resection cases

Ependymomas are tumors of the CNS. Although cyclin D1 overexpression has been related to several cancers, its prognostic value in ependymomas has not yet been fully established. We evaluated cyclin D1 expression by an immunohistochemistry analysis of 149 samples of ependymomas, including some relapses, corresponding to 121 patients. Eighty-one patients were adults, 60 were intracranial cases and 92 tumors were grade II. Gross total resection (GTR) was achieved in 62% of cases, and relapse was confirmed in 41.4% of cases. Cyclin D1 protein expression was analyzed by immunohistochemistry and scored with a labeling index (LI) calculated as the percentage of positively stained cells by intensity. We also analyzed expression of CCND1 and NOTCH1 in 33 samples of ependymoma by quantitative real-time PCR. A correlation between cyclin D1 LI score and anaplastic cases (P < 0.001), supratentorial location (P < 0.001) and age (P = 0.001) were observed. A stratified analysis demonstrated that cyclin D1 protein expression was strong in tumors with a supratentorial location, independent of the histological grade or age. Relapse was more frequent in cases with a higher cyclin D1 LI score (P = 0.046), and correlation with progression-free survival was observed in cases with GTR (P = 0.002). Only spinal canal tumor location and GTR were suggestive markers of PFS in multivarite analyses. Higher expression levels were observed in anaplastic cases for CCND1 (P = 0.002), in supratentorial cases for CCND1 (P = 0.008) and NOTCH1 (P = 0.011). There were correlations between the cyclin D1 mRNA and protein expression levels (P < 0.0001) and between CCND1 and NOTCH1 expression levels (P = 0.003). Higher cyclin D1 LI was predominant in supratentorial location and predict relapse in GTR cases. Cyclin D1 could be used as an immunohistochemical marker to guide follow-up and treatment in these cases.

Telomerase inhibition abolishes the tumorigenicity of pediatric ependymoma tumor-initiating cells

Pediatric ependymomas are highly recurrent tumors resistant to conventional chemotherapy. Telomerase, a ribonucleoprotein critical in permitting limitless replication, has been found to be critically important for the maintenance of tumor-initiating cells (TICs). These TICs are chemoresistant, repopulate the tumor from which they are identified, and are drivers of recurrence in numerous cancers. In this study, telomerase enzymatic activity was directly measured and inhibited to assess the therapeutic potential of targeting telomerase. Telomerase repeat amplification protocol (TRAP) (n = 36) and C-circle assay/telomere FISH/ATRX staining (n = 76) were performed on primary ependymomas to determine the prevalence and prognostic potential of telomerase activity or alternative lengthening of telomeres (ALT) as telomere maintenance mechanisms, respectively. Imetelstat, a phase 2 telomerase inhibitor, was used to elucidate the effect of telomerase inhibition on proliferation and tumorigenicity in established cell lines (BXD-1425EPN, R254), a primary TIC line (E520) and xenograft models of pediatric ependymoma. Over 60 % of pediatric ependymomas were found to rely on telomerase activity to maintain telomeres, while no ependymomas showed evidence of ALT. Children with telomerase-active tumors had reduced 5-year progression-free survival (29 ± 11 vs 64 ± 18 %; p = 0.03) and overall survival (58 ± 12 vs 83 ± 15 %; p = 0.05) rates compared to those with tumors lacking telomerase activity. Imetelstat inhibited proliferation and self-renewal by shortening telomeres and inducing senescence in vitro. In vivo, Imetelstat significantly reduced subcutaneous xenograft growth by 40 % (p = 0.03) and completely abolished the tumorigenicity of pediatric ependymoma TICs in an orthotopic xenograft model. Telomerase inhibition represents a promising therapeutic approach for telomerase-active pediatric ependymomas found to characterize high-risk ependymomas.

Genomic characterization of ependymomas reveals 6q loss as the most common aberration

Ependymomas are rare tumors of the central nervous system (CNS). They are classified based on tumor histology and grade, but the prognostic value of the WHO grading system remains controversial. Treatment is mainly surgical and by radiation. An improved knowledge of ependymoma biology is important to elucidate the pathogenesis, to improve classification schemes, and to identify novel potential treatment targets. Only 113 ependymoma karyotypes with chromosome aberrations are registered in the Mitelman database. We present the first study of ependymoma genomes combining karyotyping and high resolution comparative genomic hybridization (HR-CGH). Nineteen tumor samples were collected from three pediatric and 15 adult patients treated at Oslo University Hospital between 2005 and 2012. Histological diagnoses included subependymoma and myxopapillary ependymoma (WHO grade I), ependymoma (WHO grade II) and anaplastic ependymoma (WHO grade III). Four tumors were intraspinal and 15 were intracranial. Seventeen samples were successfully karyotyped, HR-CGH analysis was undertaken on 17 samples, and 15 of 19 tumors were analyzed using both methods. Twelve tumors had karyotypic abnormalities, mostly gains or losses of whole chromosomes. Structural rearrangements were found in four tumors, in two of which 2p23 was identified as a breakpoint region. Twelve tumors displayed genomic imbalances by HR-CGH analysis with loss of material at 6q as the most common. 6q loss, which was detected by one or both methods in seven of 12 (58%) abnormal tumors, and 5p gain (observed in five tumors; 42%) were the most common genomic aberrations in this series.

Kinetics of porphyrin fluorescence accumulation in pediatric brain tumor cells incubated in 5-aminolevulinic acid

BACKGROUND

Fluorescence-guided surgery with 5-aminolevulinic acid (5-ALA) enables more complete resections of tumors in adults. 5-ALA elicits accumulation of fluorescent porphyrins in various cancerous tissues, which can be visualized using a modified neurosurgical microscope with blue light. Although this technique is well established in adults, it has not been investigated systematically in pediatric brain tumors. Specifically, it is unknown how quickly, how long, and to what extent various pediatric tumors accumulate fluorescence. The purpose of this study was to determine utility and time course of 5-ALA-induced fluorescence in typical pediatric brain tumors in vitro.

METHODS

Cell cultures of medulloblastoma [DAOY and UW228], cPNET [PFSK] atypical teratoid rhabdoid tumor [BT16] and ependymoma [RES196] were incubated with 5-ALA for either 60 minutes or continuously. Porphyrin fluorescence intensities were determined using a fluorescence-activated cell sorter (FACS) after 1, 3, 6, 9, 12 and 24 hours. C6 and U87 cells served as controls.

RESULTS

All pediatric brain tumor cell lines displayed fluorescence compared to their respective controls without 5-ALA (p < 0.05). Sixty minutes of incubation resulted in peaks between 3 and 6 hours, whereas continuous incubation resulted in peaks at 12 hours or beyond. 60 minute incubation peak levels were between 52 and 91 % of maxima achieved with continuous incubation. Accumulation and clearance varied between cell types.

CONCLUSIONS

We demonstrate that 5-ALA exposure of cell lines derived from typical pediatric central nervous system (CNS) tumors induces accumulation of fluorescent porphyrins. Differences in uptake and clearance indicate that different application modes may be necessary for fluorescence-guided resection, depending on tumor type.

Extraneural metastasis of an ependymoma: a rare occurrence

Extraneural metastases of ependymoma are very rare, and have been reported in the lungs, lymph nodes, pleura, mediastinum, liver, diaphragmatic muscle, and bone. We describe the radiological findings of pathologically proven lung metastases from an anaplastic ependymoma. The tumor which arose in the posterior fossa was first diagnosed in 2007 when first surgical resection was performed outside our institute. Multiple operations were performed after that due to tumor relapse. Multiple lung nodules were discovered incidentally during a VP shunt survey. Biopsy from the lung nodules displayed identical histomorphology to the primary brain tumor.

Outcome of infants and young children with newly diagnosed ependymoma treated on the "Head Start" III prospective clinical trial

This study investigates the outcome of children <10 years old with newly-diagnosed ependymoma treated on the prospective multinational "Head Start" III clinical trial. Between April 2004 and July 2009, 19 children with newly-diagnosed ependymoma were enrolled. All children were to receive five induction chemotherapy cycles followed by one consolidation cycle of myelo-ablative chemotherapy and autologous hematopoietic cell rescue. Children between 6 and 10 years of age or with residual tumor prior to consolidation were to receive irradiation thereafter. Median age of 19 children (8 female) was 20 months at diagnosis. Median follow up was 44 months. The primary site was infratentorial in 11 and supratentorial in 8 patients. Gross total resection was achieved in 10 patients. After induction chemotherapy, all three supratentorial ependymoma patients with residual disease achieved a complete response (CR), while only one of six infratentorial patients with residual disease achieved CR. Three infratentorial patients developed progressive disease during induction chemotherapy. All four infratentorial patients with residual disease who underwent autologous hematopoietic cell transplant, failed to achieve CR. Four patients received focal irradiation following chemotherapy. The 3-year event free survival (EFS) and overall survival (OS) for supratentorial ependymoma were 86 ± 13 % and 100 % respectively. The 3-year EFS and OS for infratentorial ependymoma were 27 ± 13 % and 73 ± 13 % respectively. The role of intensive induction and consolidation chemotherapy in deferring irradiation should be investigated further in children with supratentorial ependymoma with residual disease following surgery. This approach appears ineffective in children with infratentorial ependymoma in the absence of irradiation.

Extraneural ependymoma: distant bone, lung, liver, and lymph node metastases following bevacizumab

Extraneural metastases of ependymoma are rare, and have been reported in the lungs, lymph nodes, pleura, mediastinum, liver, diaphragmatic muscle, and bone. We report a case of anaplastic ependymoma with distant metastases to the vertebral bones, lungs, liver, and lymph nodes following treatment with bevacizumab. Recent research has hypothesized that angiogenic tumors may develop means of resistance to antiangiogenic therapies, and some evidence suggests potential for antiangiogenic therapies to promote additional means for cancer spread. Nevertheless, antiangiogenic therapies continue to demonstrate potential as potent therapies for the treatment of many cancers, and should continue to be researched for future uses.

Role of platelet derived growth factor receptor (PDGFR) over-expression and angiogenesis in ependymoma

New molecularly targeted therapies are needed for childhood ependymoma. Angiogenesis and the PDGFR pathway could be potential therapeutic targets. This study aimed to screen ependymomas for the expression and clinicopathological correlates of angiogenic factors and potential therapeutic targets including VEGFR, endoglin (CD105), CD34, CD31, c-Kit, PDGFR-α and PDGFR-β. Immunohistochemistry for angiogenesis factors and PDGFR-α and β was performed in 24 archival tumor samples from children and adults treated for ependymoma at our institution. CD31 density, CD105 density and pericyte coverage index (PCI) were calculated. These findings were correlated with clinical outcome. VEGFR2 was overexpressed in tumor cells in only one out of 24 cases, but was found overexpressed in the vessels in 6 cases. PDGFR-α and β were found to be over-expressed in the ependymoma tumor cells in seven out of 24 cases (29.2 %). CD31 density, CD105 density and PCI did not correlate with expression of PDGFRs. Overexpression of PDGFR-α and β in tumor cells and overexpression of PDGFR-α in tumor endothelium had prognostic significance and this was maintained in multivariate analysis for overexpression of PDGFR-α in tumor cells (2 year progression free survival was 16.7 ± 15.2 for cases with overexpression of PDGFR-α in the tumor vs. 74.5 ± 15.2 for those with low/no expression, hazard ratio = 5.78, p = 0.04). A number of angiogenic factors are expressed in ependymoma tumor cells and tumor endothelium. Preliminary evidence suggests that the expression of PDGFRs could have a prognostic significance in ependymoma. This data suggests that PDGFRs should be further evaluated as targets using novel PDGFR inhibitors.

Prognostic factors and treatment options for paediatric ependymomas

The aim of this study was to determine factors of prognostic relevance for paediatric ependymomas, and evaluate the efficacy of treatment modalities. This is a retrospective study of 43 patients with ependymoma (<18 years) who underwent a combination of surgical excision, chemotherapy, and/or radiotherapy treatment at The Prince of Wales Cancer Centre between 1969 and 2009. Statistical analysis was performed to assess the prognostic relevance of various parameters affecting the two-year and five-year overall survival (OS) and progression-free survival (PFS). The five-year OS and PFS were 50.3% and 44.8% respectively (median follow-up 50 months). Eighteen patients (41.9%) experienced tumour recurrence: 13 had a local recurrence (LR) and five had both LR and distant recurrence. On univariate analysis, a more favourable prognosis in terms of both OS and PFS was evident for supratentorial tumours compared to infratentorial tumours (OS p=0.007, PFS p=0.045), stereotactic radiosurgery/ fractionated stereotactic radiotherapy compared to craniospinal irradiation or local posterior fossa/local brain±boost radiotherapy modalities (OS p=0.047, PFS p=0.031), total radiotherapy dose >50 Gy compared to ≤50 Gy (OS p=0.008, PFS p=0.005), and in patients with no tumour recurrence compared to those with recurrence (OS p=0.03, PFS p<0.001). Although not statistically significant, a more favourable multivariate outcome was evident in patients who underwent complete surgical resection. Chemotherapy treatment and histopathological grade, however, were not relevant to prognosis. This study supports the need to pursue more aggressive treatment for infratentorial and/or recurrent tumours. Ideal treatment involves maximal surgical resection, followed by adjuvant radiotherapy (>50 Gy).

Pediatric neuro-oncology: current status and future directions

Tumors of the central nervous system (CNS) are the most common solid malignancies in childhood and are the leading cause of cancer-related death in this age group. While an ongoing improvement in overall prognosis has been achieved in the last few decades, current therapeutic approaches still confer significant morbidities, especially for the very young. The traditional strategies of surgery, radiotherapy and conventional cytotoxic chemotherapy need to be further refined while newer approaches, including molecularly targeted agents, hold the promise of better responses, improved outcomes and reduced toxicities. This article discusses treatment standards, the focus of current clinical investigations and the future promise of novel, biologically based approaches for the most common pediatric CNS tumors: primitive neuroectodermal tumors including medulloblastomas, ependymomas and astrocytomas (both low-grade and high-grade glioma).

Supratentorial ependymoma in children: to observe or to treat following gross total resection?

BACKGROUND

The standard treatment for ependymoma is surgical resection followed by postoperative irradiation to the local site. The role of radiation therapy in completely resected supratentorial ependymoma has been questioned over the past two decades.

PROCEDURE

Retrospective review of the medical records of all consecutively diagnosed supratentorial ependymoma patients at Children's Hospital Los Angeles between January 1999 and December 2009.

RESULTS

Ten patients (three females) were included. The median age at presentation was 5.6 years (range 1.8-15.6 years). Reviewed histology was anaplastic ependymoma in seven patients and cellular ependymoma in three patients. Gross total resection was achieved in six patients; five were observed and one received chemotherapy. In the four patients who underwent subtotal resection, one was observed, two received local irradiation and one received irradiation and chemotherapy. The median length of follow up was 43 (range 22-81) months. Four relapses were observed; two patients who underwent initial gross total resection. All patients who underwent gross total resection were alive at the time of preparation of this article. The 5-year progression-free and overall survival rates were 53 ± 19% and 86 ± 13% respectively.

CONCLUSIONS

Radiation therapy was avoided in five patients following gross total resection, four of whom had anaplastic histology. In some children with completely resected supratentorial ependymoma, surgery alone may be an acceptable treatment option.

Copy number gain of 1q25 predicts poor progression-free survival for pediatric intracranial ependymomas and enables patient risk stratification: a prospective European clinical trial cohort analysis on behalf of the Children's Cancer Leukaemia Group (CCLG), Societe Francaise d'Oncologie Pediatrique (SFOP), and International Society for Pediatric Oncology (SIOP)

PURPOSE

The high incidence of recurrence and unpredictable clinical outcome for pediatric ependymoma reflect the imprecision of current therapeutic staging and need for novel risk stratification markers. We therefore evaluated 1q25 gain across three age- and treatment-defined European clinical trial cohorts of pediatric intracranial ependymoma.

EXPERIMENTAL DESIGN

Frequency of 1q gain was assessed across 48 ependymomas (42 primary, 6 recurrent) using Affymetrix 500K single-nucleotide polymorphism arrays. Gain of 1q25 was then evaluated by interphase FISH across 189 tumors treated on the Children's Cancer Leukaemia Group/International Society for Pediatric Oncology (SIOP) CNS9204 (n = 60) and BBSFOP (n = 65) adjuvant chemotherapy trials, or with primary postoperative radiotherapy (SIOP CNS9904/RT, n = 64). Results were correlated with clinical, histologic, and survival data.

RESULTS

Gain of 1q was the most frequent imbalance in primary (7/42, 17%) and recurrent ependymomas (2/6, 33%). Gain of 1q25 was an independent predictor of tumor progression across the pooled trial cohort [HR = 2.55; 95% confidence interval (CI): 1.56-4.16; P = 0.0002] and both CNS9204 (HR = 4.03; 95% CI: 1.88-8.63) and BBSFOP (HR = 3.10; 95% CI: 1.22-7.86) groups. The only clinical variable associated with adverse outcome was incomplete tumor resection. Integrating tumor resectability with 1q25 status enabled stratification of cases into disease progression risk groups for all three trial cohorts.

CONCLUSIONS

This is the first study to validate a prognostic genomic marker for childhood ependymoma across independent trial groups. 1q25 gain predicts disease progression and can contribute to patient risk stratification. We advocate the prospective evaluation of 1q25 gain as an adverse marker in future international clinical trials.

Pediatric infratentorial ependymoma: prognostic significance of anaplastic histology

Pediatric infratentorial ependymomas are difficult to cure. Despite the availability of advanced therapeutic modalities for brain tumors, total surgical resection remains the most important prognostic factor. Recently, histological grade emerged as an independent prognostic factor for intracranial ependymoma. We retrospectively reviewed the treatment outcome of 33 pediatric patients with infratentorial ependymoma. Progression-free survival (PFS) and overall survival (OS) rates were calculated and relevant prognostic factors were analyzed. Fourteen patients (42%) were under the age of 3 at diagnosis. Gross total resection was achieved in 16 patients (49%). Anaplastic histology was found in 13 patients (39%). Adjuvant therapies were delayed until progression in 12 patients (36%). Actuarial PFS rates were 64% in the first year and 29% in the fifth year. Actuarial OS rates were 91% in the first year and 71% in the fifth year. On univariate analysis, brainstem invasion (P = 0.047), anaplastic histology (P = 0.004), higher mitotic count (P = 0.001), and higher Ki-67 index (P = 0.004) were significantly related to a shorter PFS. Gross total resection (P = 0.029) and a greater age at diagnosis (P = 0.033) were significantly related to a longer PFS. On multivariate analysis, anaplastic histology alone was significantly related to a shorter PFS (P = 0.023). Gross total resection (P = 0.039) was significantly related to a longer overall survival (OS) on multivariate analysis. Anaplastic histology and gross total resection were the most important clinical factors affecting PFS and OS, respectively. Anaplastic histology, mitotic count, and Ki-67 index can be used as universal and easily available prognostic parameters in infratentorial ependymomas.

Posterior fossa ependymomas: a tale of two subtypes

Ependymomas are common childhood brain tumors, but little is known about their underlying biology. In this issue of Cancer Cell, Witt et al. present that posterior fossa ependymomas comprise two distinct molecular subtypes, each with unique gene expression signatures, different levels of genomic instability, and different prognosis.

Epigenetic mechanisms regulating neural development and pediatric brain tumor formation

Pediatric brain tumors are the leading cause of cancer-related death in children, and among them, embryonal tumors represent the largest group with an associated poor prognosis and long-term morbidity for survivors. The field of cancer epigenetics has emerged recently as an important area of investigation and causation of a variety of neoplasms, and is defined as alterations in gene expression without changes in DNA sequence. The best studied epigenetic modifications are DNA methylation, histone modifications, and RNA-based mechanisms. These modifications play an important role in normal development and differentiation but their dysregulation can lead to altered gene function and cancer. In this review the authors describe the mechanisms of normal epigenetic regulation, how they interplay in neuroembryogenesis, and how these can cause brain tumors in children when dysregulated. The potential use of epigenetic markers to design more effective treatment strategies for children with malignant brain tumors is also discussed.

Inhibin B and anti-Müllerian hormone as markers of gonadal function after treatment for medulloblastoma or posterior fossa ependymoma during childhood

OBJECTIVE

To evaluate the roles of hypothalamic-pituitary and spinal irradiations and chemotherapy in gonadal deficiency after treatment for medulloblastoma or posterior fossa ependymoma by measuring levels of plasma inhibin B and antimüllerian hormone (AMH).

STUDY DESIGN

A total of 34 boys and 22 girls were classified as having normal levels of plasma follicle-stimulating hormone (FSH; <9 IU/L), or abnormal levels of FSH (>9 IU/L) and luteinizing hormone (LH; <5 or >5 IUL).

RESULTS

Two boys had partial gonadotropin deficiency, combined with testicular deficiency in one boy. Six boys had increased levels of FSH, indicating tubular deficiency, combined with Leydig cell deficiency in 5 boys. The 7 boys with inhibin B levels <100 ng/mL included the one with combined deficiencies and the 6 with testicular deficiency. Puberty did not progress in 7 girls; 3 had gonadotropin deficiency, combined with ovarian deficiency in one, and 4 had increased FSH levels, indicating ovarian deficiency. Inhibin B and AMH levels were low in the girl with combined deficiencies, in the 4 girls with ovarian deficiency, and in 4 girls with normal clinical-biological ovarian function, including 2 who underwent ovarian transposition before irradiation.

CONCLUSION

The plasma concentrations of inhibin B and AMH are useful means of detecting primary gonad deficiency in patients with no increase in their plasma gonadotropin levels because of radiation-induced gonadotropin deficiency.

Apurinic/apyrimidinic endonuclease is inversely associated with response to radiotherapy in pediatric ependymoma

Apurinic/apyrimidinic endonuclease (Ap endo) is a key DNA repair activity that confers radiation resistance in human cells. Here we examined the association between Ap endo activity and response to radiotherapy in pediatric ependymomas, tumors for which treatment options are limited and survival rates are only about 50%. We assayed Ap endo activity in 36 ependymomas and expression of Ape1/Ref-1, the predominant Ap endo activity in humans, in 44 tumors by immunostaining. Cox proportional hazards regression models were used to analyze the association of activity or expression with progression-free survival or with overall survival. Activity varied 13-fold and was not associated with tumor or patient characteristics. In univariate models with Ap endo activity entered as a continuous variable, the hazard ratio for progression increased by a factor of 2.18 for every 0.01 unit increase in activity (p ≤ 0.003) in 24 grade II ependymomas. Risk for death increased by a factor of 1.89 (p ≤ 0.02) in the same population. The fraction of Ape1/Ref-1 immunopositive cells varied widely within individual tumors and was not associated with either progression-free or with overall survival. Suppressing Ap endo activity in pediatric ependymoma cells significantly increased radiation sensitivity, suggesting that the association of activity with radiation response reflected, at least in part, repair of radiation-induced DNA lesions. Our data indicate that Ap endo activity is predictive of outcome following radiotherapy, and suggest that Ape1/Ref-1 promotes radiation resistance in pediatric ependymomas. Our findings support the use of inhibitors of Ap endo activity to overcome resistance.

[Magnetic resonance imaging of infratentorial anaplastic ependymoma in children]

OBJECTIVE

To show the main findings for anaplastic ependymoma on MRI.

MATERIAL AND METHODS

We reviewed all patients diagnosed with anaplastic ependymoma at our tertiary hospital during a six-year period. We recorded the MRI findings for this type of tumor (on conventional sequences following the protocol for the study of CNS tumors, diffusion-weighted imaging, contrast-enhanced sequences, and MR spectroscopy).

RESULTS

Our series comprises seven children with infratentorial anaplastic ependymoma. We found no definitive characteristics to distinguish between grade II and grade III tumors before histology, as none of the lesions had spread to the cerebrospinal fluid at diagnosis or showed increased restriction in the diffusion-weighted sequence.

CONCLUSIONS

The MRI characteristics cannot definitively distinguish between grade II ependymomas and anaplastic grade III ependymomas. Only a few details about diffusion and dissemination to the cerebrospinal fluid, if present, can distinguish between these types at imaging.

Language outcomes following risk-adapted treatments for tumors located within the posterior fossa

The language skills of 4 children treated for tumors involving the cerebellum and/or fourth ventricle with risk-adapted treatments were compared, as a group, with performance of a group of control children (n = 20). The language skills of the individual cases were also profiled. At the group level, language skill failed to differentiate the 2 groups of children. At an individual level, however, only 1 of the 4 children treated with risk-adapted treatments presented with intact language skills. Variable language profiles were identified in the remaining 3 children. The presence of hydrocephaly was a consistent factor in reduced language outcomes. The findings highlight the importance of prospective language monitoring.

Immunohistochemical expression of cell cycle/apoptosis regulators and epidermal growth factor receptor in pediatric intracranial ependymomas

Intracranial ependymomas are the third most common primary brain tumor in children. We set out to investigate the expression of p-53, p-27, bcl-2, and epidermal growth factor receptor in 13 pediatric infratentorial ependymomas, in correlation with Ki-67/ MIB-1 proliferation index and prognosis. The median progression-free survival was 37.5 months, and the 5-year overall survival was 50%. There was a statistically significant higher expression of Ki-67 and p-53 index in anaplastic tumors. There was also a higher expression of p-27, bcl-2, and epidermal growth factor receptor in anaplastic tumors, but the difference was not statistical significant. No significant correlation was found between overall survival and level of expression of Ki-67, p-53, p-27, bcl-2, and epidermal growth factor receptor. Epidermal growth factor receptor detection in a considerable number of ependymomas probably reflects its role in the neoplastic transformation and can serve as a therapeutic target.

Isolated extracranial recurrence of anaplastic ependymoma

Anaplastic ependymoma is a malignant glial tumor thought to arise from radial glial cells of the ventricular zone. Because ependymoma is frequently encountered within ventricular spaces, they are prone to leptomeningeal dissemination. Metastatic extracranial ependymoma has been reported, but in the context of progressive intracranial disease. We report on a boy who developed isolated extracranial recurrence of his anaplastic ependymoma, initially at the scalp and later metastases to cervical lymph nodes. The location of tumor recurrence proximate to the surgical site suggested surgical seeding. This case demonstrates an unusual site of recurrence of anaplastic ependymoma and highlights a previously underappreciated surgical complication.

Intracranial metastatic disease rarely involves the pituitary: retrospective analysis of 935 metastases in 155 patients and review of the literature

We present a case report of a patient recently treated at our institution for an isolated non-small cell lung cancer metastatic lesion to the sella, report the lack of involvement of the pituitary gland in a large single-institution series of treated intracranial parenchymal metastases, and review the pertinent literature. We reviewed cranial imaging studies (CT and MRI) for 935 metastases in 155 patients treated at our institution over the previous 3 years for intracranial metastatic disease. Special attention was paid to the skull base to document the presence of any metastatic disease involving the pituitary gland, infundibular stalk, sella turcica (including anterior and posterior clinoids), or diaphragm sellae. We found no other involvement of the pituitary gland or other sellar structures by metastatic disease in this series. Intracranial metastatic disease rarely involves the pituitary gland and infundibular stalk parenchyma, suggesting that this structure may be safely omitted from the treatment field during WBRT and prophylactic cranial irradiation (PCI). This treatment approach should reduce the late sequelae of treatment to this critical organ.