Ependymomas of the spinal region in adults: Clinical and pathological features and MYCN expression levels in spinal ependymomas and myxopapillary ependymomas

BACKGROUND

Ependymomas (EPNs) of the spinal region are a heterogeneous group of tumors that account for 17.6 % in adults. Four types have been recognized: subependymoma, spinal ependymoma (Sp-EPN), myxopapillary ependymoma (MPE), and Sp-EPN-MYCN amplified, each with distinct histopathological and molecular features.

METHODS

This study investigated the clinical and pathological characteristics and MYCN expression levels of 35 Sp-EPN and MPE cases diagnosed at a tertiary university hospital over a decade-long period.

RESULTS

Twenty-five cases were Sp-EPN and 10 cases were MPE, and were graded as WHO grade 2, except for 1 Sp-EPN case with grade 3 features. The most common symptoms were lower back pain and difficulty in walking. Radiology showed different tumor sizes and locations along the spinal cord, with MPEs exclusively in the lumbosacral region. Surgery was the main treatment, and gross total resection was achieved in all cases except for one. Immunohistochemistry showed low Ki-67 proliferation indices in all cases, and no MYCN expression. During follow-up, 3 (8.6 %) cases recurred and/or metastasized and 5 cases (14.3 %) died. No significant difference was found in disease-free survival or overall survival between Sp-EPN and MPE cases. However, 3 cases with grade 2 histology demonstrated recurrence and/or metastasis, despite the lack of MYCN expression.

CONCLUSION

Our results underscore the multifactorial nature of tumor aggressiveness in EPNs of the spinal region. This study enhances our knowledge of the clinical and pathological features of Sp-EPNs and MPEs and highlights the need for better diagnostic and prognostic markers in these rare tumors.

MYCN immunohistochemistry as surrogate marker for MYCN-amplified spinal ependymomas

MYCN (master regulator of cell cycle entry and proliferative metabolism) gene amplification defines a molecular subgroup of spinal cord ependymomas that show high-grade morphology and aggressive behavior. Demonstration of MYCN amplification by DNA methylation or fluorescence-in situ hybridization (FISH) is required for diagnosis. We aimed to (i) assess prevalence and clinicopathological features of MYCN-amplified spinal ependymomas and (ii) evaluate utility of immunohistochemistry (IHC) for MYCN protein as a surrogate for molecular testing. A combined retrospective-prospective study spanning 8 years was designed during which all spinal cord ependymomas with adequate tissue were subjected to MYCN FISH and MYCN IHC. Among 77 spinal cord ependymomas included, MYCN amplification was identified in 4 samples from 3 patients (3/74, 4%) including two (1st and 2nd recurrences) from the same patient. All patients were adults (median age at diagnosis of 32 years) including two females and one male. The index tumors were located in thoracic (n = 2) and lumbar (n = 1) spinal cord. One of the female patients had neurofibromatosis type 2 (NF2). All four tumors showed anaplastic histology. Diffuse expression of MYCN protein was seen in all four MYCN-amplified samples but in none of the non-amplified cases, thus showing 100% concordance with FISH results. On follow-up, the NF2 patient developed widespread spinal dissemination while another developed recurrence proximal to the site of previous excision. To conclude, MYCN-amplified spinal ependymomas are rare tumors, accounting for ~ 4% of spinal cord ependymomas. Within the limitation of small sample size, MYCN IHC showed excellent concordance with MYCN gene amplification.

Strong OLIG2 expression in supratentorial ependymoma, ZFTA fusion-positive: A potential diagnostic pitfall

Ependymomas (EPN) are central nervous system neoplasms that exhibit an ependymal phenotype. In particular, supratentorial EPN (ST-EPN) must be differentiated from more aggressive entities such as glioblastoma, IDH-wildtype. This task is frequently addressed with the use of immunohistochemistry coupled with clinical presentation and morphological features. Here we describe the case of a young adult presenting with migraine-like symptoms and a temporoinsular-based expansile mass that was first diagnosed as a GBM, mostly based on strong and diffuse oligodendrocyte transcription factor 2 (OLIG2) expression. Molecular characterization revealed a ZFTA::RELA fusion, supporting the diagnosis of ST-EPN, ZFTA fusion-positive. OLIG2 expression is rarely reported in tumors other than GBM and oligodendrocyte-lineage committed neoplasms. The patient was treated with radiotherapy and temozolomide after surgery and was alive and well at follow-up. This report illustrates the need to assess immunostains within a broader clinical, morphological and molecular context to avoid premature exclusion of important differential diagnoses.

Lateral-type posterior fossa ependymomas in pediatric population

BACKGROUND

Lateral-type posterior fossa ependymomas are a well-defined subtype of tumours both clinically and pathologically, with a poor prognosis. Their incidence is low and surgical management is challenging. The objective of the present work is to review our series of lateral-tye posterior fossa ependymomas and compare our results with those of previous series.

METHODS

Among 30 cases of ependymoma operated in our paediatric department in the last ten years, we identified seven cases of lateral-type posterior fossa ependymomas. We then performed a retrospective, descriptive study.

RESULTS

Mean age of our patients was 3.75 years. 6 cases presented with hydrocephalus. Mean tumour volume at diagnosis was 61 cc. A complete resection was achieved in six cases and a near-total resection in one patient. 5 patients transiently required a gastrostomy and a tracheostomy. Mean follow-up was 58 months. One case progressed along this period and eventually died. 4 cases of hydrocephalus required a ventriculoperitoneal CSF shunt and two were managed with a third ventriculostomy. At last follow-up 4 patients carried a normal life and two displayed a mild restriction according to Lansky´s scale.

CONCLUSIONS

The aim of surgical treatment in lateral-type posterior fossa ependymomas is complete resection. Neurological deficits associated to lower cranial nerve dysfunction are common but transient. Deeper genetic characterization of these tumours may identify risk factors that guide stratification of adjuvant therapies.

Pediatric spinal ependymoma with chromothripsis of chromosome 6: a case report and review of the literature

BACKGROUND

Ependymomas are the third most common central nervous system tumor in the pediatric population; however, spinal ependymomas in children are rare. Ependymomas affecting the spinal cord most frequently occur in adults of 20-40 years of age. The current World Health Organization classification system for ependymomas is now composed of ten different entities based on histopathology, location, and molecular studies, with evidence that the new classification system more accurately predicts clinical outcomes.

CASE PRESENTATION

We present the case of a 16-year-old Caucasian female patient with a history of type 2 neurofibromatosis with multiple schwannomas, meningioma, and spinal ependymoma. Chromosome analysis of the harvested spinal ependymoma tumor sample revealed a 46,XX,-6,+7,-22,+mar[16]/46,XX[4] karyotype. Subsequent OncoScan microarray analysis of the formalin-fixed paraffin-embedded tumor sample confirmed + 7, -22 and clarified that the marker chromosome represents chromothripsis of the entire chromosome 6 with more than 100 breakpoints. Fluorescent in situ hybridization and microarray analysis showed no evidence of MYCN amplification. The final integrated pathology diagnosis was spinal ependymoma (central nervous system World Health Organization grade 2 with no MYCN amplification.

CONCLUSION

This case adds to the existing literature of pediatric patients with spinal ependymomas and expands the cytogenetic findings that may be seen in patients with this tumor type. This case also highlights the value of cytogenetics and microarray analysis in solid tumors to provide a more accurate molecular diagnosis.

Association of early surgery and absence of ataxia with full recovery after spinal intramedullary ependymoma resection

OBJECTIVE

Spinal intramedullary ependymomas (IEs) represent a well-defined tumor entity usually warranting resection. Factors that determine full long-term neurological recovery after resection are seldomly reported on in larger clinical series. In this study, the authors aimed to highlight the neurological outcome of patients with IEs after resection, with a focus on full neurological recovery, and to explore possible risk factors for the absence of neurological amelioration to an optimal function after surgical treatment.

METHODS

A single-center retrospective analysis of all patients undergoing surgery for IEs between 2007 and 2021 was performed. Data collection included patient demographics, symptoms, clinical findings, histopathological diagnosis, surgical procedures, complications, and neurological outcome. Patients harboring a favorable outcome (modified McCormick Scale [mMS] grade of I) were compared with patients with a less favorable outcome (mMS grade ≥ II) at the final follow-up.

RESULTS

In total, 72 patients with a histologically diagnosed IE were included. IEs in those patients (41 males, 31 females; median age 51 [IQR 40-59] years) mostly occurred in the cervical (n = 40, 56%) or thoracic (n = 23, 32%) spine. Upon admission, motor deficits or gait deficits (mMS grade ≥ II) were present in 29 patients (40%), with a median mMS grade of II (IQR I-II). Gross-total resection was achieved in 60 patients (90%), and the rate of surgical complications was 7%. Histopathologically, 67 tumors (93%) were classified as WHO grade 2 ependymomas, 3 (4%) as WHO grade 1 subependymomas, and 2 (3%) as WHO grade 3 anaplastic ependymomas. After a mean follow-up of 863 ± 479 days, 37 patients (51%) had a fully preserved neurological function and 62 patients (86%) demonstrated an mMS grade of I or II. Comparison of favorable with unfavorable outcomes revealed an association of early surgery (within a year after symptom onset), the absence of ataxia or gait disorders, and a low mMS grade with full neurological recovery at the final follow-up. A subgroup of patients (n = 15, 21%) had nonresolving deterioration at the final follow-up, with no significant differences in relevant variables compared with the rest of the cohort.

CONCLUSIONS

The data presented solidify the role of early surgery in the management of spinal IEs, especially in patients with mild neurological deficits. Furthermore, the presence of gait disturbance or ataxia confers a higher risk of incomplete long-term recovery after spinal ependymoma resection. Because a distinct subgroup of patients had nonresolving deterioration, even when presenting with an uneventful history, further analyses into this subgroup of patients are required.

When a dermatopathologist encounters the ultra-rare: A case series of superficial soft tissue/cutaneous myxopapillary ependymomas

Myxopapillary ependymoma (MPE) is an uncommon variant of ependymoma, almost exclusively seen in conus medullaris or filum terminale. MPE can be diagnostically challenging, especially when arising extra-axially. Here we report 5 cases of superficial soft tissue/cutaneous MPE, identified across three tertiary institutions. All patients were female and three of them (3/5, 60%) were children (median age 11 years, range 6-58 years). The tumors presented as slow-growing masses of the sacrococcygeal subcutaneous soft tissues, occasionally identified after minor trauma and clinically favored to be pilonidal sinuses. Imaging showed no neuraxis connection. Macroscopically, tumors were well-circumscribed, lobulated, and solid and microscopically they exhibited typical histopathology of MPE, at least focally. Two of the tumors (2/5, 40%) showed predominantly solid or trabecular architecture with greater cellular pleomorphism, scattered giant cells, and increased mitotic activity. All tumors (5/5, 100%) showed strong diffuse immunohistochemical expression of GFAP. One tumor clustered at the category "ependymoma, myxopapillary" by methylome analysis. Two patients (2/5, 40%) had local recurrence at 8 and 30 months after the initial surgery. No patients developed metastases during the follow-up period (median 60 months, range 6-116 months). Since a subset of extra-axial MPEs behaves more aggressively, timely and accurate diagnosis is of paramount importance.

Association Between Urbanicity and Outcomes Among Patients with Spinal Cord Ependymomas in the United States

BACKGROUND

Spinal cord ependymomas (SCEs) represent the most common intramedullary spinal cord tumors among adults. Research shows that access to neurosurgical care and patient outcomes can be greatly influenced by patient location. This study investigates the association between the outcomes of patients with SCE in metropolitan and nonmetropolitan areas.

METHODS

Cases of SCE between 2004 and 2019 were identified within the Central Brain Tumor Registry of the United States, a combined dataset including the Centers for Disease Control and Prevention's National Program of Cancer Registries and National Cancer Institute's Surveillance, Epidemiology, and End Results Program data. Multivariable logistic regression models were constructed to evaluate the association between urbanicity and SCE treatment, adjusted for age at diagnosis, sex, race and ethnicity. Survival data was available from 42 National Program of Cancer Registries (excluding Kansas and Minnesota, for which county data are unavailable), and Cox proportional hazard models were used to understand the effect of surgical treatment, county urbanicity, age at diagnosis, and the interaction effect between age at diagnosis and surgery, on the survival time of patients.

RESULTS

Overall, 7577 patients were identified, with 6454 (85%) residing in metropolitan and 1223 (15%) in nonmetropolitan counties. Metropolitan and nonmetropolitan counties had different age, sex, and race/ethnicity compositions; however, demographics were not associated with differences in the type of surgery received when stratified by urbanicity. Irrespective of metropolitan status, individuals who were American Indian/Alaska Native non-Hispanic and Hispanic (all races) were associated with reduced odds of receiving surgery. Individuals who were Black non-Hispanic and Hispanic were associated with increased odds of receiving comprehensive treatment. Diagnosis of SCE at later ages was linked with elevated mortality (hazard ratio = 4.85, P < 0.001). Gross total resection was associated with reduced risk of death (hazard ratio = 0.37, P = 0.004), and age did not interact with gross total resection to influence risk of death.

CONCLUSIONS

The relationship between patients' residential location and access to neurosurgical care is critical to ensuring equitable distribution of care. This study represents an important step in delineating areas of existing disparities.

The role of surgery in recurrent ependymomas

OBJECTIVE

The role of surgery in recurrent ependymomas and its contribution to the outcome are not well defined. While gross-total resection (GTR) has shown benefit in newly diagnosed patients with improvement in progression-free survival (PFS), its impact after recurrence is not known. Its role in distant relapses or multiple local recurrences is similarly less well understood. The objective of this study was to investigate whether GTR could prolong survival after recurrence.

METHODS

In this paper, the authors identified patients with ependymomas who underwent surgery at Texas Children's Hospital for recurrent ependymomas between December 2000 and December 2021. Surgical treatment was stratified as GTR, subtotal resection (STR), or a biopsy. Kaplan-Meier analysis was performed for PFS and overall survival (OS), and the log-rank test was used to assess statistical significance. The Cox regression model was used for multivariable analysis.

RESULTS

Forty children were identified with a first ependymoma recurrence and follow-up data were collected. The median age was 5.46 years (95% CI 4.52-6.39 years) with a mean follow-up of 3.92 years (95% CI 2.42-5.42 years). In 26 patients (65%), the original tumor was located in the infratentorial space. Twenty-nine patients (72.5%) presented with local recurrence. Within this group, the 5-year PFS rates for the GTR and STR groups were 40.1% and 26.8%, respectively. The 5- and 10-year OS rates were 58.3% and 50% in the GTR group and 51% and 16.7% in the STR group, respectively. Fifteen patients presented with a second recurrence. The 5-year PFS and OS rates in patients who had GTR after a second recurrence were 33% and 50%, respectively.

CONCLUSIONS

GTR of local recurrent ependymomas can result in long-term survival in first and second recurrences. Further and larger studies are necessary to elucidate the role of surgery in distal recurrences.

Sacral ependymoma presents 20 years after initial posterior fossa lesion

Posterior fossa ependymomas (PFEs) are designated histologically as low-grade neoplasms. Despite being characterised as benign, cases of metastasis have been reported only a few times with the patients concurrently diagnosed with the primary tumour. Interval drop metastasis or spontaneous second distal tumours are extremely rare and, in most cases, are diagnosed within a few months of primary tumour resection. Here, we report a patient with a grade 2 paediatric PFE exhibiting a 20-year interval to a second sacral ependymoma. The patient was initially diagnosed with a PFE at the age of 10 years and underwent tumour resection and postoperative radiotherapy. In their late 20s, the patient presented with basilar artery occlusion complicated by life-threatening epistaxis. Post-thrombolysis, the patient presented with a large sacral grade 1 myxopapillary ependymoma with cauda equina syndrome-like symptoms. Here, we present a rare case of two ependymomas with a 20-year interval in the same patient with compounding comorbidities.

Optimizing biomarkers for accurate ependymoma diagnosis, prognostication, and stratification within International Clinical Trials: A BIOMECA study

BACKGROUND

Accurate identification of brain tumor molecular subgroups is increasingly important. We aimed to establish the most accurate and reproducible ependymoma subgroup biomarker detection techniques, across 147 cases from International Society of Pediatric Oncology (SIOP) Ependymoma II trial participants, enrolled in the pan-European "Biomarkers of Ependymoma in Children and Adolescents (BIOMECA)" study.

METHODS

Across 6 European BIOMECA laboratories, we evaluated epigenetic profiling (DNA methylation array); immunohistochemistry (IHC) for nuclear p65-RELA, H3K27me3, and Tenascin-C; copy number analysis via fluorescent in situ hybridization (FISH) and MLPA (1q, CDKN2A), and MIP and DNA methylation array (genome-wide copy number evaluation); analysis of ZFTA- and YAP1-fusions by RT-PCR and sequencing, Nanostring and break-apart FISH.

RESULTS

DNA Methylation profiling classified 65.3% (n = 96/147) of cases as EPN-PFA and 15% (n = 22/147) as ST-ZFTA fusion-positive. Immunohistochemical loss of H3K27me3 was a reproducible and accurate surrogate marker for EPN-PFA (sensitivity 99%-100% across 3 centers). IHC for p65-RELA, FISH, and RNA-based analyses effectively identified ZFTA- and YAP-fused supratentorial ependymomas. Detection of 1q gain using FISH exhibited only 57% inter-center concordance and low sensitivity and specificity while MIP, MLPA, and DNA methylation-based approaches demonstrated greater accuracy.

CONCLUSIONS

We confirm, in a prospective trial cohort, that H3K27me3 immunohistochemistry is a robust EPN-PFA biomarker. Tenascin-C should be abandoned as a PFA marker. DNA methylation and MIP arrays are effective tools for copy number analysis of 1q gain, 6q, and CDKN2A loss while FISH is inadequate. Fusion detection was successful, but rare novel fusions need more extensive technologies. Finally, we propose test sets to guide future diagnostic approaches.

Survival analysis and prognostic factors in posterior fossa ependymomas in children and adolescents

OBJECTIVE

In this study, the authors aimed to analyze the overall survival (OS) and progression-free survival (PFS) of patients younger than 18 years of age who were diagnosed with posterior fossa ependymomas, and to identify prognostic factors such as the degree of resection, tumor topography, and involvement of the lesion in the hindbrain.

METHODS

The authors performed a retrospective cohort study of patients younger than 18 years of age, treated beginning in 2000, with a diagnosis of posterior fossa ependymoma. Ependymomas were separated into three groups: tumors restricted to the fourth ventricle, tumors inside the fourth ventricle and exiting from the foramen of Luschka, and tumors inside the fourth ventricle and completely surrounding the hindbrain. Furthermore, the tumors were classified by molecular group using the staining method for H3K27me3. Statistical analysis was performed using Kaplan-Meier survival curves, with p < 0.05 considered statistically significant.

RESULTS

Of 1693 patients who underwent surgical treatment between January 2000 and May 2021, 55 patients who met the inclusion criteria were included. The median age at diagnosis was 2.98 years. The median OS was 44 months, and the survival rates at 1, 5, and 10 years were 92.5%, 49.1%, and 38.3%, respectively. The cases were assigned to two posterior fossa ependymoma molecular groups: 35 (63.6%) cases to group A and 8 (14.5%) to group B. The median ages in groups A and B were 2.94 and 2.85 years and the median OS values were 44 and 38 months, respectively (p = 0.9245). Statistical analysis was performed on multiple variables, including age, sex, histological grade, Ki-67 expression, tumor volume, extent of resection, and adjuvant therapies. The median PFS of patients with dorsal-only involvement was 28 months; for dorsolateral involvement, it was 15 months; and for total involvement, it was 9.5 months (p = 0.0464). No statistically significant difference was found for OS. There was a statistically significant difference between the proportion of patients in whom gross-total resection was achieved in the dorsal-only involvement group (73.1%, 19/26) and those in the total involvement group (0%, 0/6) (p = 0.0019).

CONCLUSIONS

This study confirmed that the extent of resection has an impact on OS and PFS. The authors found that adjuvant radiotherapy resulted in a higher OS but did not prevent progression, that the pattern of involvement of the brainstem in the tumor at diagnosis could elicit important information regarding the patient's prognosis regarding PFS, and that the total involvement of the rhombencephalon impaired the gross-total resection of these tumors.

[Classification and Diagnostics of Pediatric Brain Tumors]

In childhood and young adulthood, a wide variety of brain tumors, such as medulloblastoma and ependymoma, frequently occur. Moreover, high- or low-grade diffuse gliomas, commonly found in adults, also emerge. Recent genomic research has revealed numerous molecular and genetic features of pediatric brain tumors. These molecular and genetic findings have been incorporated into the latest 2021 World Health Organization Classification of Tumors of the Central Nervous System(WHO CNS 5). WHO CNS 5 introduces separate classifications for adult- and pediatric-type diffuse gliomas, which were conventionally diagnosed using the same criteria. Classifying these adult- and pediatric-type gliomas using histopathological properties alone is challenging. Therefore, molecular diagnostics utilizing diverse molecular and genetic information, including variants, copy number alterations, structural abnormalities, and DNA methylation profiles, are imperative. Many molecular and genetic characteristics have been elucidated in the WHO CNS 5. Molecular diagnostics and classification are essential for accurately categorizing pediatric brain tumors, and the significance of molecular and genetic information will continue to grow.

Latest classification of ependymoma in the molecular era and advances in its treatment: a review

Ependymoma is a rare central nervous system (CNS) tumour occurring in all age groups and is one of the most common paediatric malignant brain tumours. Unlike other malignant brain tumours, ependymomas have few identified point mutations and genetic and epigenetic features. With advances in molecular understanding, the latest 2021 World Health Organization (WHO) classification of CNS tumours divided ependymomas into 10 diagnostic categories based on the histology, molecular information and location; this accurately reflected the prognosis and biology of this tumour. Although maximal surgical resection followed by radiotherapy is considered the standard treatment method, and chemotherapy is considered ineffective, the validation of the role of these treatment modalities continues. Although the rarity and long-term clinical course of ependymoma make designing and conducting prospective clinical trials challenging, knowledge is steadily accumulating and progress is being made. Much of the clinical knowledge obtained from clinical trials to date was based on the previous histology-based WHO classifications, and the addition of new molecular information may lead to more complex treatment strategies. Therefore, this review presents the latest findings on the molecular classification of ependymomas and advances in its treatment.

Adult intracranial ependymoma-relevance of DNA methylation profiling for diagnosis, prognosis, and treatment

BACKGROUND

A methylation-based classification of ependymoma has recently found broad application. However, the diagnostic advantage and implications for treatment decisions remain unclear. Here, we retrospectively evaluate the impact of surgery and radiotherapy on outcome after molecular reclassification of adult intracranial ependymomas.

METHODS

Tumors diagnosed as intracranial ependymomas from 170 adult patients collected from 8 diagnostic institutions were subjected to DNA methylation profiling. Molecular classes, patient characteristics, and treatment were correlated with progression-free survival (PFS).

RESULTS

The classifier indicated an ependymal tumor in 73.5%, a different tumor entity in 10.6%, and non-classifiable tumors in 15.9% of cases, respectively. The most prevalent molecular classes were posterior fossa ependymoma group B (EPN-PFB, 32.9%), posterior fossa subependymoma (PF-SE, 25.9%), and supratentorial ZFTA fusion-positive ependymoma (EPN-ZFTA, 11.2%). With a median follow-up of 60.0 months, the 5- and 10-year-PFS rates were 64.5% and 41.8% for EPN-PFB, 67.4% and 45.2% for PF-SE, and 60.3% and 60.3% for EPN-ZFTA. In EPN-PFB, but not in other molecular classes, gross total resection (GTR) (P = .009) and postoperative radiotherapy (P = .007) were significantly associated with improved PFS in multivariable analysis. Histological tumor grading (WHO 2 vs. 3) was not a predictor of the prognosis within molecularly defined ependymoma classes.

CONCLUSIONS

DNA methylation profiling improves diagnostic accuracy and risk stratification in adult intracranial ependymoma. The molecular class of PF-SE is unexpectedly prevalent among adult tumors with ependymoma histology and relapsed as frequently as EPN-PFB, despite the supposed benign nature. GTR and radiotherapy may represent key factors in determining the outcome of EPN-PFB patients.

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.

Ependymomas in Children and Adults

Ependymomas account for approximately 5% of all CNS tumors in adults and around 10% in the pediatric population. Contrary to traditional theories supporting that ependymomas arise from ependymal cells, recent studies propose radial glial cells as the cells of origin. In adults, half of the ependymomas arise in the spinal cord, whereas in the pediatric population, almost 90% of ependymomas are located intracranially. Most of the ependymomas are usually low-grade tumors except anaplastic variants and some cases of RELA-fusion-positive ependymomas, a molecular variant consisting the most recent addition to the 2016 World Health Organization (WHO) classification. Of note, the recently described molecular classification of ependymomas into nine distinct subgroups appears to be of greater clinical utility and prognostic value compared to the traditional histopathological classification, and parts of it are expected to be adopted by the WHO in the near future. Clinical manifestations depend on the location of the tumor with infratentorial ependymomas presenting with acute hydrocephalus. Gross total resection should be the goal of treatment. The prognostic factors of patients with ependymomas include age, grade, and location of the tumor, with children with intracranial, anaplastic ependymomas having the worst prognosis. In general, the 5-year overall survival of patients with ependymomas is around 60-70%.

[Pediatric Posterior Fossa Tumors]

Posterior fossa tumors tend to entail obstructive hydrocephalus, and urges initiating prompt treatment. Prevalent pathologies include medulloblastoma, ependymoma, pilocytic astrocytoma, and atypical teratoid/rhabdoid tumor(AT/RT). In most cases, maximal safe resection is related to better prognosis. In some cases of ependymoma and AT/RT with high vascularity, second-look surgery with neoadjuvant chemotherapy is effective. The treatment strategy should be tailored according to each tumor.

Extra-Axial supratentorial anaplastic ependymoma: Unusual location of an aggressive tumor, A case report

INTRODUCTION

Ependymomas are more common in the pediatric population, in whom they are commonly infratentorial. Extra axial location of a supratentorial ependymoma is extremely rare.

DIAGNOSIS

Radiologically these tumors are often misdiagnosed as meningioma or other extra axial lesions owing to their unusual location and lack of any pathognomonic features. Hence, histopathological examination becomes imperative for proper evaluation and an adequate diagnosis.

CASE

Herein we report a case of a supratentorial extra axial anaplastic ependymoma misdiagnosed as a metastatic tumor on radiological examination and mimicking meningioma intra operatively, located in the frontal and temporal region in a 20 year old man.

Overview of recent advances in the classification of ependymomas in WHO CNS5 classification: Simplified approach to their integrated diagnosis

Ependymomas can arise along the entire neuraxis; however, they possess site-specific unique molecular alterations and a methylome pattern which is directly related with the prognostic outcomes. Since 2016, when the updated fourth edition of World Health Organization (WHO) classification of tumors of the central nervous system was published, it has been emphasized to classify ependymomas by anatomic site and molecular signatures associated genetic alterations so that classification of the disease reflects its underlying biology. In continuation, the fifth edition of the WHO classification of CNS tumors introduces major changes, including site-specific molecular profiles as the basis of classifying ependymomas. Furthermore, an integrated tier system of reporting is recommended for better clinical correlation and predicting outcomes. WHO grading can still be included in a specific tier, along with molecular markers.

Ependymoma: Evaluation and Management Updates

PURPOSE OF REVIEW

To review state of art and relevant advances in the molecular genetics and management of ependymomas of children and adults.

RECENT FINDINGS

Ependymomas may occur either in the brain or in the spinal cord. Compared with intracranial ependymomas, spinal ependymomas are less frequent and exhibit a better prognosis. The new WHO classification of CNS tumors of 2021 has subdivided ependymomas into different histomolecular subgroups with different outcome. The majority of studies have shown a major impact of extent of resection; thus, a complete resection must be performed, whenever possible, at first surgery or at reoperation. Conformal radiotherapy is recommended for grade 3 or incompletely resected grade II tumors. Proton therapy is increasingly employed especially in children to reduce the risk of neurocognitive and endocrine sequelae. Craniospinal irradiation is reserved for metastatic disease. Chemotherapy is not useful as primary treatment and is commonly employed as salvage treatment for patients failing surgery and radiotherapy. Standard treatments are still the mainstay of treatment: the discovery of new druggable pathways will hopefully increase the therapeutic armamentarium in the near future.

Orbital Ependymoma

Orbital ependymomas are rare in the orbit and usually occur secondary to extracerebral extension of an intraventricular ependymoma. The authors present a rare case of orbital ependymoma in a 74-year-old female. The patient was initially diagnosed with intraventricular ependymoma at the age of 13 years that required multiple repeat craniotomies for tumor recurrence. She then developed progressive tumor growth with extension into the bilateral frontal lobes and orbit. The orbital involvement produced binocular diplopia, epiphora, and globe distortion with compressive optic neuropathy. To the authors knowledge, this is the first such report in the English language ophthalmic literature.

TTF-1: A Well-Favored Addition to the Immunohistochemistry Armamentarium as a Diagnostic Marker of SEGA

BACKGROUND

Subependymal giant cell astrocytoma (SEGA) is a World Health Organization grade 1 neoplasm, which, due to its dubious morphologic features, may be misdiagnosed as a high-grade tumor at times. This tumor shows binary immunoexpression including both glial and neural markers, leading to a state of diagnostic quandary. Recent evidences have surmised the diagnostic utility of thyroid transcription factor 1 (TTF-1), spurring us to study the practicality of this marker in distinguishing SEGAs from its mimics.

METHODS

In this study, TTF-1 immunohistochemistry using clone 8G7G3/1 (1:50) was performed in 38 cases of SEGA, 30 cases of central neurocytoma, 10 cases each of intraventricular glioblastoma and ependymoma, and 5 cases of cortical tubers. Additionally, serine/threonine-protein kinase B-Raf (BRAFV600E) mutation, a common genetic alteration in pediatric low-grade-glial tumors with neuronal-differentiation, was analyzed using Ventana immunohistochemistry platform.

RESULTS

TTF-1 immunopositivity was seen in all 38 cases (100%) of SEGAs, with 20 cases (52.6%) showing diffuse (>50% of tumor area) expression while focal (<50%) immunopositivity was seen in 18 cases (47.3%). None of the cases demonstrated serine/threonine-protein kinase B-Raf immunolabeling. Barring 2 cases of neurocytoma (6.6%), all other cases including ependymoma, glioblastoma, and cortical tubers were immunonegative for TTF-1.

CONCLUSIONS

The congruous finding of TTF-1 expression in SEGA and cells of the developing neuroepithelium in the medial ganglionic eminence hint toward a primogenitor cell with neoplastic potential in the presence of impelling factors.

Clinical Image of a Spinal Ependymoma Discovered 8 Years after Initial Misdiagnosis as an Idiopathic Syringomyelia

With the increasing frequency of neuroimaging, incidental intramedullary cavities are diagnosed more frequently. We present a case of asymptomatic incidental intramedullary cervical cavity diagnosed as an idiopathic syringomyelia as initial magnetic resonance imaging (MRI) showed an isolated cystic image without contrasted component. The patient had no subsequent MRI follow-up, but eventually showed symptoms 8 years later. By this stage of the disease, the MRI appearance had changed, showing a solid and enhanced component. The patient underwent surgical resection and histopathology concluded a papillary ependymoma (grade 2). This case illustrates how asymptomatic intramedullary cavities may hide an underlying tumoral process and why these cavities should not be considered as idiopathic syringomyelia by default, except after prolonged MRI follow-up.

Subcutaneous sacrococcygeal myxopapillary ependymoma misdiagnosed as pilonidal disease

Ependymomas are neoplasms which arise from the radial glial cells, which many recent studies have proposed are neural stem cells. Extracranial ependymomas are rare. We present the case report and supporting multimedia of a 37-year-old man who presented with a painless intergluteal swelling which was diagnosed clinically as a pilonidal cyst. However, on excision, he was found to have a subcutaneous sacrococcygeal myxopapillary ependymoma based on histological findings. His management and follow-up are presented and discussed. Given the rare nature of this condition, there is a lack of published guidelines on management and follow-up protocols. Supporting evidence is limited to sporadic case reports. This case highlights the diagnostic challenges and management strategies adopted supported by the best available evidence.

Primary mediastinal ependymoma: A case report and literature review

RATIONALE

Ependymomas are neuroepithelial tumors that typically occur in the central nervous system. Ependymomas arising in the mediastinum are exceedingly rare, with only approximately 9 isolated cases reported in the literature to date.

PATIENT CONCERNS

A 35-year-old woman was referred to our hospital with complaints of progressive back pain for 3 months. Physical examination revealed decreased breathing sounds and tenderness. Contrast-enhanced computed tomography showed a soft tissue mass with heterogeneous enhancement in the right posterior mediastinum.

DIAGNOSES

The diagnosis of primary mediastinal ependymomas (PMEs) was confirmed by postoperative histopathologic examination.

INTERVENTIONS AND OUTCOMES

The patient underwent surgical resection of the tumor and experienced local recurrence with neck metastasis 2 years postoperatively. She underwent reoperation for the recurrent tumors and received postoperative radiotherapy and adjuvant chemotherapy. Two years later, the patient is doing well, with no evidence of tumor progression or recurrence.

LESSONS

Since PMEs are exceedingly rare, treatment options are limited. Surgical resection seems to be the mainstay of treatment. Further evidence-based studies are required to prove the benefit of radiotherapy and chemotherapy in the treatment of PMEs.

Myxopapillary ependymoma of cauda equina presented with communicating hydrocephalus and papilloedema: A case report

We reported a case of cauda equina myxopapillary ependymoma in a patient who presented with atypical history of progressive blurring of vision. Ophthalmology examination revealed relative afferent pupillary defect, binasal hemianopia and papilloedema. This case report serves as a reminder that the intraspinal tumour could be a cause of papilloedema, despite rare, should be considered in a hydrocephalus patient who presented with no intracranial pathology and minimal spinal symptoms.

Newly Diagnosed Metastatic Intracranial Ependymoma in Children: Frequency, Molecular Characteristics, Treatment, and Outcome in the Prospective HIT Series

BACKGROUND

Data on frequency, clinical presentation, and outcome of primary metastatic intracranial ependymoma in children are scarce.

PATIENTS AND METHODS

Prospective data on patients younger than 21 years with metastatic intracranial ependymoma at first diagnosis, registered from 2001 to 2014 in the HIT-2000 trial and the HIT-2000 Interim Registry, were analyzed.

RESULTS

Of 453 registered patients with intracranial ependymoma and central neuropathology review, initial staging included spinal magnetic resonance imaging in all patients and lumbar cerebrospinal fluid (CSF) analysis in 402 patients. Ten patients (2.2%) had metastatic disease, including three with microscopic CSF positivity only (M1 metastasis stage, 0.7% of patients with CSF staging). Location of the primary tumor was supratentorial in four patients (all supratentorial RELA-fused ependymoma [ST-EPN-RELA]) and within the posterior fossa in five patients (posterior fossa ependymoma type A [PF-EPN-A], n = 4; posterior fossa ependymoma not further classifiable, n = 1), and multifocal in one patient.All four patients with ST-EPN-RELA were alive in first or second complete remission (CR) 7.5-12.3 years after diagnosis. All four patients with macroscopic metastases of posterior fossa or multifocal ependymoma died. Three patients with initial M1 stage (ST-EPN-RELA, n = 1; PF-EPN-A, n = 2) received chemotherapy and local irradiation and were alive in second or third CR 3.0-9.7 years after diagnosis. Progression-free and overall survival of the entire cohort at 5 years was 13% (±6%), and 58% (±16%), respectively.

CONCLUSION

Primary metastatic disease is rare in children with intracranial ependymoma. Prognosis may depend on molecular subgroup and extent of dissemination, and relevance of CSF analysis for initial staging remains to be clarified.

IMPLICATIONS FOR PRACTICE

Childhood ependymoma presenting with metastasis at first diagnosis is very rare with a frequency of 2.4% in this population-based, well-characterized cohort. Detection of microscopic metastases in the cerebrospinal fluid was extremely rare, and impact on prognosis and respective treatment decision on irradiation field remains unclear. Initial metastatic presentation occurs in both supratentorial RELA-fused ependymoma and posterior fossa ependymoma. Prognosis may differ according to extent of metastasis and biological subgroup, with poor prognosis in diffusely spread metastatic posterior fossa ependymoma even after combination therapy with both intensive chemotherapy and craniospinal irradiation, which may help to guide individual therapeutic decisions for future patients.

Diagnosis and rehabilitation of a pregnant woman with spinal cord disorder due to spinal cord tumor

Introduction

Spinal cord tumors are a rare cause of spinal cord disorder (SCD). Early diagnosis can be challenging, especially in patient populations with other potential etiologies for back pain, such as pregnant women.

Case presentation

A 28-year-old female presented at 8 weeks gestation with thoracic back pain initially diagnosed as gestational low back pain. Her symptoms progressed to lower extremity weakness. After diagnosis and resection of a spinal cord ependymoma, we collaborated with the inpatient interdisciplinary team to devise a rehabilitation program focused on minimizing pregnancy-related complications and optimizing care of a newborn in the setting of a new paraplegia.

Discussion

Providers should not assume all pregnant women with low back pain have gestational back pain, as it can be due to more insidious causes. The rehabilitation course for women who develop an SCD during gestation should be carefully tailored toward their pre- and post-natal care and with the education of how the disorder can affect pregnancy and parenting.

Charcot-Marie-Tooth 1A concurrent with anaplastic ependymoma in a toddler: when an acute event unmasks a chronic condition

Gogou M, Pavlidou E, Pavlou E, Papageorgiou T, Tragiannidis A, Giannopoulos A, Hatzipantelis E. Charcot-Marie -Tooth 1A concurrent with anaplastic ependymoma in a toddler: when an acute event unmasks a chronic condition. Turk J Pediatr 2019; 61: 428-430. We report a 14-month-old toddler admitted to the Pediatric Oncology Department after surgical resection of supratentorial anaplastic ependymoma. The child was treated with International Society of Pediatric Oncology Ependymoma II 2015 chemotherapy protocol (vincristine, carboplatin, cisplatin, cyclophosphamide and methotrexate). At the end of the first cycle the child presented with symptoms such as unsteadiness and ataxic gait along with decreased motor and sensory action potentials of the limbs. As the father of the child was diagnosed with Charcot-Marie-Tooth 1A disease, a genetic analysis of the PMP22 gene was performed confirming the diagnosis of Charcot- Marie-Tooth 1A in the child, too. This case gently reminds the possibility of vincristine-induced neurotoxicity and underscores the significance of an appropriate neurological assessment before vincristine initiation.

EANO guidelines for the diagnosis and treatment of ependymal tumors

Ependymal tumors are rare CNS tumors and may occur at any age, but their proportion among primary brain tumors is highest in children and young adults. Thus, the level of evidence of diagnostic and therapeutic interventions is higher in the pediatric compared with the adult patient population.The diagnosis and disease staging is performed by craniospinal MRI. Tumor classification is achieved by histological and molecular diagnostic assessment of tissue specimens according to the World Health Organization (WHO) classification 2016. Surgery is the crucial initial treatment in both children and adults. In pediatric patients with intracranial ependymomas of WHO grades II or III, surgery is followed by local radiotherapy regardless of residual tumor volume. In adults, radiotherapy is employed in patients with anaplastic ependymoma WHO grade III, and in case of incomplete resection of WHO grade II ependymoma. Chemotherapy alone is reserved for young children <12 months and for adults with recurrent disease when further surgery and irradiation are no longer feasible. A gross total resection is the mainstay of treatment in spinal ependymomas, and radiotherapy is reserved for incompletely resected tumors. Nine subgroups of ependymal tumors across different anatomical compartments (supratentorial, posterior fossa, spinal) and patient ages have been identified with distinct genetic and epigenetic alterations, and with distinct outcomes. These findings may lead to more precise diagnostic and prognostic assessments, molecular subgroup-adapted therapies, and eventually new recommendations pending validation in prospective studies.

Supratentorial extraventricular ependymomas: A retrospective study focused on long-term outcomes and prognostic factors

OBJECTIVE

Supratentorial extraventricular ependymomas are relatively rare. Long-term outcomes and prognostic factor for this rare tumor have not been well established. The purpose of this study was to demonstrateprogression-freesurvival(PFS),overallsurvival(OS), and prognostic factors of such tumor.

PATIENTS AND METHODS

Fifty-five patients with supratentorial extraventricular ependymomas from our hospital were included in this study. Epidemiological characteristics, clinical features, treatment,long-term outcomes, and prognostic factors for PFS and OS were reviewed retrospectively.

RESULTS

The patients consisted of 30 males and 25 females with mean age of 30.0 ± 23.6 years (range, 1-74 years). Twenty-nine tumors were located in the right hemisphere, and 26 in the left side. The 2 most common tumor locations were the frontal (n = 19; 35%) and parietal lobe (n = 11; 20%). All patients underwent surgical resection. Gross-total resection (GTR) was achieved in 42 cases (76%) and subtotal resection (STR) was performed in 13 patients (24%). According to the WHO classification system, 38 tumors (69%) were Grade III (anaplastic ependymoma), and 17 (31%) were Grade II (ependymoma). Three-,5-, and 10 year PFS rates were 60%, 49%, and 36%, respectively. Three-,5-, and 10 year OS rates were 79%, 64%, and 49%, respectively. EOR and tumor grade were identified as prognostic factors for PFS and OS on univariate analysis, multivariate analysis, and Kaplan-Meierlog-rank testing. Subtotal resection (STR) predicted a worse PFS (HR = 4.808; 95%, 1.942-11.905; P = .001) and OS (HR = 5.650; 95%, 2.114-15.152; P = .001). WHO Grade III tumors also had worse PFS (HR = 3.922; 95%, 1.429-18.182; P = .012) and OS (HR = 6.329; 95%, 1.328-30.303; P = 0.021). For patients with tumor recurrence, reoperation was significant prognostic factors for OS (HR = 2.091; 95%, 0.939-4.654; p = .000). Age, sex, tumor side, and postoperativeradiotherapy were not prognostic factors for PFS and OS.

CONCLUSIONS

Most supratentorial extraventricular ependymomas are WHO grade III tumors. STRandWHO Grade III pathology predicted worse PFS and OS. Gross-total resection remains the optimal treatment for patients with supratentorial extraventricular ependymoma. Reoperation should be considered first in cases of recurrence. The role of postoperative radiotherapy as an adjuvant treatment for supratentorial extraventricular ependymoma needs further investigation.

You're the Flight Surgeon

McCoy RP. You're the flight surgeon: myxopapillary ependymoma. Aersop Med Hum Perform. 2017; 88(10):970-973.

The Clinical Features and Surgical Outcomes of Spinal Cord Tanycytic Ependymomas: A Report of 40 Cases

OBJECTIVE

Spinal cord tanycytic ependymomas (TEs) rarely are reported because of extremely low incidence. Understanding of this disease is therefore poor. The aim of this study was to analyze the incidence and clinical, radiologic, pathologic, and prognostic features of spinal cord TEs.

METHODS

Approximately 4000 spinal cord tumors were resected surgically in Beijing Tiantan Hospital between April 2009 and May 2016. We identified all cases of pathologically proved TEs among these patients.

RESULTS

TEs accounted for approximately 1% of spinal cord tumors (40 of an estimated 4000). Patients with TE were a mean age of 40.0 years and had no significant sex preference (21 male and 19 female). The median diameter of the maximal tumor was 54.2 mm (range, 16-153 mm). The mean preoperative Japanese Orthopedic Association (JOA) score was 13.0. Radiologically, 47.5% (19/40) cases showed poorly defined tumor border, and 40% (16/40) of them showed preoperative syringomyelia. Gross total resection was achieved in 30 cases, subtotal resection in 8, and partial resection in 2. At the time of discharge, JOA score and neurologic function showed improvement in 26 cases (65%), no change in 12 cases (30%), and worsening in 2 cases (5%). At a median follow-up of 43 months (range, 7-101 months), 1- and 5-year progression-free survival rates were 100.0% and 97.5%, respectively. Only one patient had tumor recurrence which was found 30 months after surgery. No patient died of tumor recurrence. At the latest follow-up, JOA score showed improvement in 30 cases (75%), no change in 8 cases (20%), and worsening in 2 cases (5%). Univariate analysis revealed that tumor size and preoperative JOA score were significantly associated with the short-term outcomes. Meanwhile, age ≥40 years, tumor size ≥50 mm, non-gross total resection, and preoperative JOA score <14 were significantly associated with an increased risk of worsened long-term outcomes. Poorly defined tumor border and preoperative JOA score <14 significantly limited the extent of tumor resection.

CONCLUSIONS

Spinal cord TE is a rare subtype of ependymomas with low recurrence. Long-term survival can be expected, although poorly defined tumor border is an independent predictor of long-term outcomes. Microsurgical treatment of spinal cord TEs remains a formidable challenge due to the poorly defined border and critical neurovascular structures encasement. It is unnecessary for radical tumor resection at the cost of severe neurologic deficits.

Integrating Tenascin-C protein expression and 1q25 copy number status in pediatric intracranial ependymoma prognostication: A new model for risk stratification

PURPOSE

Despite multimodal therapy, prognosis of pediatric intracranial ependymomas remains poor with a 5-year survival rate below 70% and frequent late deaths.

EXPERIMENTAL DESIGN

This multicentric European study evaluated putative prognostic biomarkers. Tenascin-C (TNC) immunohistochemical expression and copy number status of 1q25 were retained for a pooled analysis of 5 independent cohorts. The prognostic value of TNC and 1q25 on the overall survival (OS) was assessed using a Cox model adjusted to age at diagnosis, tumor location, WHO grade, extent of resection, radiotherapy and stratified by cohort. Stratification on a predictor that did not satisfy the proportional hazards assumption was considered. Model performance was evaluated and an internal-external cross validation was performed.

RESULTS

Among complete cases with 5-year median follow-up (n = 470; 131 deaths), TNC and 1q25 gain were significantly associated with age at diagnosis and posterior fossa tumor location. 1q25 status added independent prognostic value for death beyond the classical variables with a hazard ratio (HR) = 2.19 95%CI = [1.29; 3.76] (p = 0.004), while TNC prognostic relation was tumor location-dependent with HR = 2.19 95%CI = [1.29; 3.76] (p = 0.004) in posterior fossa and HR = 0.64 [0.28; 1.48] (p = 0.295) in supratentorial (interaction p value = 0.015). The derived prognostic score identified 3 different robust risk groups. The omission of upfront RT was not associated with OS for good and intermediate prognostic groups while the absence of upfront RT was negatively associated with OS in the poor risk group.

CONCLUSION

Integrated TNC expression and 1q25 status are useful to better stratify patients and to eventually adapt treatment regimens in pediatric intracranial ependymoma.

Anaplastic Ependymoma With Ganglionic Differentiation: Report of a Rare Case and Implications in Diagnosis

Ependymomas are glial neoplasms with rare cases exhibiting neuronal differentiation. We describe a case of spinal anaplastic ependymoma with ganglionic differentiation in a 28-year-old woman. The ganglionic component was labeled by synaptophysin, whereas the rest of the tumor showed features of an anaplastic ependymoma. Stem cell marker MELK was noted to stain both the neoplastic ependymal and ganglionic components, possibly suggesting a stem cell/progenitor origin for the tumor with subsequent divergent differentiation.

MRI-detection rate and incidence of lumbar bleeding sources in 190 patients with non-aneurysmal SAH

BACKGROUND

Up to 15% of all spontaneous subarachnoid hemorrhages (SAH) have a non-aneurysmal SAH (NASAH). The evaluation of SAH patients with negative digital subtraction angiography (DSA) is sometimes a diagnostic challenge. Our goal in this study was to reassess the yield of standard MR-imaging of the complete spinal axis to rule out spinal bleeding sources in patients with NASAH.

METHODS

We retrospectively analyzed the spinal MRI findings in 190 patients with spontaneous NASAH, containing perimesencephalic (PM) and non-perimesencephalic (NPM) SAH, diagnosed by computer tomography (CT) and/or lumbar puncture (LP), and negative 2nd DSA.

RESULTS

190 NASAH patients were included in the study, divided into PM-SAH (n = 87; 46%) and NPM-SAH (n = 103; 54%). Overall, 23 (22%) patients had a CT negative SAH, diagnosed by positive LP. MR-imaging of the spinal axis detected two patients with lumbar ependymoma (n = 2; 1,05%). Both patients complained of radicular sciatic pain. The detection rate raised up to 25%, if only patients with radicular sciatic pain received an MRI.

CONCLUSION

Routine radiological investigation of the complete spinal axis in NASAH patients is expensive and can not be recommended for standard procedure. However, patients with clinical signs of low-back/sciatic pain should be worked up for a spinal pathology.

Pediatric Ependymoma

Over the past 150 years since Virchow's initial characterization of ependymoma, incredible efforts have been made in the classification of these tumors and in the care of pediatric patients with this disease. While the advent of modern neurosurgery and the optimization of radiation have provided significant gains, a more complex but incomplete picture of pediatric ependymomas has begun to form through a combination of international collaborations and detailed genetic and histologic characterizations. This review includes and synthesizes the clinical understanding of pediatric ependymoma and their developing molecular insight into what is truly a family of malignancies in which distinct members require different surgical approaches, radiation plans, and targeted therapies.

Genomics and epigenetics: A study of ependymomas in pediatric patients

OBJECTIVE

We identify chromosomal alterations, the methylation pattern and gene expression changes in pediatric ependymomas.

METHODS

CGH microarray, methylation and gene expression were performed through the Agilent platform. The results were analyzed with the software MatLab, MapViewer, DAVID, GeneCards and Hippie.

RESULTS

Amplification was found in 14q32.33, 2p22.3 and 8p22, and deletion was found in 8p11.23-p11.22 and 1q21.3. We observed 42.387 CpG islands with changes in their methylation pattern, in which we found 272 genes involved in signaling pathways related to carcinogenesis. We found 481 genes with altered expression. The genes IMMT, JHDMD1D, ASAH1, ZWINT, IPO7, GNAO1 and CISD3 were found to be altered among the three levels.

CONCLUSION

The 2p22.3, 8p11.23-p11.22 and 14q32.33 regions were identified as the most important; the changes in the methylation pattern related to cell cycle and cancer genes occurred in MIB2, FGF18 and ITIH5. The IPO7, GNAO1 and ASAH1 genes may play a major role in ependymoma development.

Pediatric thalamic tumors in the MRI era: a Canadian perspective

BACKGROUND

Thalamic gliomas are rare. The natural history is unpredictable, and the optimal management of these tumors in children is poorly defined. The aim was to identify outcomes, prognostic factors, and response to various modalities of treatment in a relatively large population of pediatric thalamic tumors from many centers within a fairly homogeneous health care system.

METHODS

We performed a Canadian multicenter retrospective review of pediatric thalamic tumors presenting during the MRI era (1989-2012). Radiology and pathology were reviewed by central independent reviewers. Paraffin shavings for RNA extraction were taken and tested for fusion events involving KIAA1549:BRAF. Tumors were classified as unilateral or bithalamic based on their origin on imaging. Univariate and multivariate analyses on factors influencing survival were performed.

RESULTS

Seventy-two thalamic tumors were identified from 11 institutions. Females represented 53% of the study population, and the mean age at presentation was 8.9 years. Sixty-two tumors were unilateral and 10 bithalamic. Unilateral tumors had a greater propensity to grow inferiorly towards the brainstem. These tumors were predominantly low grade in comparison to bithalamic tumors which were high-grade astrocytomas. The 5-year overall survival was 61 ± 13% for unithalamic tumors compared to 37 ± 32% for bithalamic tumors (p = 0.097). Multivariate analysis indicated tumor grade as the only significant prognostic factor for unithalamic tumors. Six unilateral tumors, all low grade, were BRAF fusion positive.

CONCLUSION

Unilateral and bilateral thalamic tumors behave differently. Surgical resection is an appropriate treatment option in unilateral tumors, most of which are low grade, but outcome is not related to extent of resection (EOR). Bilateral thalamic tumors have a poorer prognosis, but the occasional patient does remarkably well. The efficacy of chemotherapy and radiotherapy has not been clearly demonstrated. Novel therapeutic approaches are required to improve the prognosis for malignant unilateral thalamic tumors and bilateral thalamic tumors.

Ependymoma: a heterogeneous tumor of uncertain origin and limited therapeutic options

Ependymomas are tumors that typically occur with an age-based site preference, with adults harboring supratentorial and spinal tumors and pediatric tumors being mainly in the posterior fossa. Despite their similar histologic appearance, the prognosis varies significantly by age and tumor location, with a better prognosis in increasing age. The mainstay of treatment remains surgical excision with or without radiation therapy as the tumor biology is poorly understood and chemotherapy is generally considered to be ineffective. More recently, molecular biology data have increased our understanding of the genetic and epigenetic changes that drive these tumors, but still it will take a lot of effort to find effective chemotherapeutic regimens. Currently, we are trying to define a subset of tumors, for which radiation therapy can be avoided.

[Subcutaneous myxopapillary ependymoma]

Subcutaneous myxopapillary ependymoma is a very rare entity, and to our knowledge this is the first published case from Denmark. A previously healthy 32-year-old male presented with subcutaneous swelling and tenderness located at the top of the intergluteal cleft. The circular soft tumour, measuring 1.7 × 1.7 × 1.2 cm, was removed surgically. After histopathological examination with several immunohistochemical and special stainings, the diagnosis surprisingly was subcutaneous myxopapillary ependymoma. The tumour was removed with free margins and no metastases were found on follow-up CT- and MRI scans.

Posterior fossa tumors in children: developmental anatomy and diagnostic imaging

INTRODUCTION

Modern understanding of the relation between the mutated cancer stem cell and its site of origin and of its interaction with the tissue environment is enhancing the importance of developmental anatomy in the diagnostic assessment of posterior fossa tumors in children. The aim of this review is to show how MR imaging can improve on the exact identification of the tumors in the brainstem and in the vicinity of the fourth ventricle in children, using both structural imaging data and a precise topographical assessment guided by the developmental anatomy.

RESULTS

The development of the hindbrain results from complex processes of brainstem segmentation, ventro-dorsal patterning, multiple germinative zones, and diverse migration pathways of the neural progenitors. Depending on their origin in the brainstem, gliomas may be infiltrative or not, as well as overwhelmingly malignant (pons), or mostly benign (cervicomedullary, medullo-pontine tegmental, gliomas of the cerebellar peduncles). In the vicinity of the fourth ventricles, the prognosis of the medulloblastomas (MB) correlates the molecular subtyping as well as the site of origin: WNT MB develop from the Wnt-expressing lower rhombic lip and have a good prognosis; SHH MB develop from the Shh-modulated cerebellar cortex with an intermediate prognosis (dependent on age); recurrences are local mostly. The poor prognosis group 3 MB is radiologically heterogeneous: some tumors present classic features but are juxtaventricular (rather than intraventricular); others have highly malignant features with a small principal tumor and an early dissemination. Group 4 MB has classic features, but characteristically usually does not enhance; dissemination is common. Although there is as yet no clear molecular subgrouping of the ependymomas, their sites of origin and their development can be clearly categorized, as most develop in an exophytic way from the ventricular surface of the medulla in clearly specific locations: the obex region with expansion in the cistern magna, or the lateral recess region with expansion in the CPA and prepontine cisterns (cerebellar ependymomas, and still more intra-brainstem ependymomas are rare). Finally, almost all cerebellar gliomas are pilocytic astrocytomas.

CONCLUSIONS

A developmental and anatomic approach to the posterior fossa tumors in children (together with diffusion imaging data) provides a reliable pre-surgical identification of the tumor and of its aggressiveness.

Incidence and survival of childhood central nervous system tumors: A report of the regional registry of childhood cancers in Auvergne-Limousin

INTRODUCTION

Central nervous system tumors (CNST) are the most lethal of solid tumors in childhood cancer.

PATIENTS AND METHODS

We report incidence and survival data for all CNST (International Classification of Diseases for Oncology third edition, category III or Xa) recorded in children under 15 years of age by the Auvergne-Limousin cancer registry for the period 1986-2009.

RESULTS

Annual incidence of all CNST was 3.27 per 100,000 and the male to female ratio was 0.95. Over 45.0% of CNST were glial. Astrocytomas (36.2%) showed the highest incidence for each age group except between 1 and 4 years where embryonal tumors were more common. For all CNST, no significant variation in incidence over time was observed for the evaluated period of 23 years (annual percent change: -0.4%, 95% CI, [-2.8-2.1]). Globally, 5 years overall survival was 67% [59-73] and had increased by more than 16% between 1986-1999 and 2000-2009, mainly due to better survival for astrocytomas, other gliomas, ependymomas and choroid plexus tumors (P=0.01).

CONCLUSION

We report that the incidence of CNST in Auvergne-Limousin is similar to that in the literature and did not increase between 1986 and 2009. In addition, 5 years overall survival increased after 1999, especially for surgically treatable tumors.