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.

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.

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.

Outcomes following management of relapsed pediatric posterior fossa ependymoma in the molecular era.

PURPOSE: The overall survival and prognostic factors for children with multiply recurrent posterior fossa ependymoma are not well understood. We aimed to assess prognostic factors associated with survival for relapsed pediatric posterior fossa ependymoma. METHODS: An institutional database was queried for children with a primary diagnosis of posterior fossa ependymoma from 2000 to 2019. Kaplan-Meier survival analysis and Cox-proportional hazard regression were used to assess the relationship between treatment factors and overall survival. RESULTS: There were 60 patients identified; molecular subtype was available for 56, of which 49 (87.5%) were PF-A and 7 (12.5%) were PF-B. Relapse occurred in 29 patients (48%) at a mean time of 24 months following primary resection. Median 50% survival was 12.3 years for all patients and 3.3 years following diagnosis of first relapsed disease. GTR was associated with significantly improved survival following primary resection (HR 0.373, 95% CI 0.14-0.96). Presence of recurrent disease was significantly associated with worse survival (p < 0.0001). At recurrent disease diagnosis, disseminated disease was a negative prognostic factor (HR 11.0 95% CI 2.7-44) while GTR at first relapse was associated with improved survival HR 0.215 (95% CI: 0.048-0.96, p = 0.044). Beyond first relapse, the impact of GTR was not significant on survival, though surgery compared to no surgery was favorable with HR 0.155 (95% CI: 0.04-0.59). CONCLUSIONS: Disseminated disease at recurrence and extent of resection for first relapsed disease were important prognostic factors. Surgery compared to no surgery was associated with improved survival for the multiply recurrent ependymoma cohort.

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.

A review of primary central nervous system neoplasms of cats.

Primary central nervous system (CNS) neoplasms are uncommonly diagnosed in cats. The majority of primary feline CNS neoplasms described in the veterinary literature consist of meningioma and glioma occurring mainly in the brain and less often in the spinal cord. Although most neoplasms can be diagnosed based on routine histologic evaluation, less typical tumors need to be further characterized using immunohistochemistry. This review compiles the relevant information about the most common primary CNS neoplasms of cats available in the veterinary literature, aiming to serve as a converging source of information for the topic.

[Pediatric Intracranial Ependymoma - Recommendations for First-Line Treatment from the German HIT-MED study group]. / Kinder und Jugendliche mit intrakraniellem Ependymom ­ Empfehlungen der HIT-MED-Studiengruppe der GPOH zur Erstlinientherapie.

Biological subtypes of ependymoma (EPN) have been introduced by the recent WHO classification and appear to have great impact on the clinical course, but have not yet found their way into clinical risk stratification. Further, the overall unfavorable prognosis underlines the fact that current therapeutic strategies need further evaluation for improvement. To date, there is no international consensus regarding first-line treatment for children with intracranial EPN. Extent of resection is known to be the most important clinical risk factor, leading to the consensus that consequent evaluation for re-surgery of postoperative residual tumor needs to have highest priority. Furthermore, efficacy of local irradiation is unquestioned and recommended for patients aged>1 year. In contrast, efficacy of chemotherapy is still under discussion. The European trial SIOP Ependymoma II aims at evaluating efficacy of different chemotherapy elements, leading to the recommendation to include German patients. The BIOMECA study, as biological accompanying study, aims at identifying new prognostic parameters. These results might help to develop targeted therapies for unfavorable biological subtypes. For patient who are not qualified for inclusion into the interventional strata, the HIT-MED Guidance 5.2 provides specific recommendations. This article is meant as an overview of national guidelines regarding diagnostics and treatment as well as of treatment according to the SIOP Ependymoma II trial protocol.

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%.

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.

Fahr's disease associated with anaplastic ependymoma: a case report and review of the literature.

Fahr's disease, also known as familial idiopathic basal ganglia calcification or bilateral strio-pallido-dentate calcinosis, is a rare entity characterized by abnormal vascular calcium depositionin the thalamus, basal ganglia, cerebral cortex and the dentate nuclei of the cerebellum. Intracranial ependymomas comprise approximately 2% to 9% of all neuroepithelial tumors. It is reported that supratentorial ependymoma constitute 30% to 50% of all intracranial ependymal tumors. Among supratentorial ependymomas, approximately 50% of them are located extraventricular and demonstrate no relationship with the ventricularsystem.The association of brain tumor with Fahr's disease is a rare entity and has been reported several times before. Whereas, to best our knowledge, the association of Fahr's disease and supratentorial anaplastic ependymoma is described in the present study for the first time.

[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.

[Verification of the diagnosis of supratentorial ependymomas by real-time PCR]. / Verifikatsiya diagnoza supratentorial'nykh ependimom metodom PTsR v rezhime real'nogo vremeni.

BACKGROUND: Differential diagnosis of supratentorial ependymomas is of particular difficulty in neurooncology due to nonspecific clinical and radiographic findings, a rare seen «classic¼ morphological picture, and a nonspecific immunophenotype. Thanks to molecular genetic methods, in particular real-time PCR, it has become possible to verify supratentorial ependymomas and identify their molecular group, on which further prognosis depends. OBJECTIVE: To develop a set of molecular genetic tests based on real-time PCR to verify supratentorial ependymomas. MATERIAL AND METHODS: 56 tissue samples were collected from patients with supratentorial ependymomas, WHO Grade II, and anaplastic ependymomas, WHO Grade III. We developed primers and fluorescent TaqMan probes for real-time PCR analysis to detect the ZFTA::RELA, ZFTA::MAML2, ZFTA::NCOA2, ZFTA::MAML3, YAP1::MAMLD1, and YAP1::FAM118B gene fusions. For immunohistochemical analysis, monoclonal rabbit anti-NF-kb p65 antibodies (HUABIO, China) were used, the study was carried out on AutostainerLink 48 immunostainer (DAKO, Denmark). RESULTS: Real-time PCR was able to verify the diagnosis for 69.9% (n=39) of samples and classify them into molecular groups of ZFTA- or YAP1-positive supratentorial ependymomas. Immunohistochemically it was possible to verify 58% (n=29) ependymomas. CONCLUSION: Diagnosis by real-time PCR is a relatively fast, accessible and easily interpreted method that allows verification of the molecular group in 70% of cases of supratentorial ependymomas without the use of additional methods.

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.

Ependymal Tumors.

Ependymomas (EPN) are commonly encountered brain tumors in the pediatric population. They may arise in the supratentorial compartment, posterior fossa and spinal cord. Histopathologic grading of EPN has always been challenging with poor interobserver reproducibility and lack of correlation between histologic grade and patient outcomes. Recent studies have highlighted that, despite histopathological similarities among variants of EPN at different anatomical sites, they possess site-specific genetic and epigenetic alterations, transcriptional profiles and DNA copy number variations. This has led to a molecular and location-based classification for EPN which has been adopted by the World Health Organization Classification of Central Nervous System Tumors and more accurately risk-stratifies patients than histopathologic grading alone. Given the complexity of this evolving field, the purpose of this paper is to offer a practical approach to the diagnosis of EPN, including the selection of the most appropriate molecular surrogate immunohistochemical stains, basic molecular studies and more sophisticated techniques if needed. The goal is to reach a rapid, sound diagnosis, providing essential information regarding prognosis and guiding clinical decision-making.

Extraventricular site indicates higher grade but better prognosis in adult supratentorial ependymomas: a 14-year single-center retrospective cohort.

Supratentorial extraventricular ependymoma (STEE) and supratentorial intraventricular ependymoma (STIE) are two subsets of supratentorial ependymoma (SE). These two subsets have similar gene features and only differ in original sites: STEE occurs in the brain parenchyma, and STIE is located in ventricles and surrounded by cerebral spinal fluid. The present study aims to depict the diversities of these two subsets and elucidate the potential effects of the anatomic site on the tumor with the same type, grade, and molecular features. Sixty-six consecutive adult SE patients from 2008 to 2021 were enrolled in our study. Clinical data, pathological features, and long-term outcomes were analyzed retrospectively. Results demonstrated that adult STEE presented with a higher proportion of WHO grade 3 (P = .028) and higher Ki-67 index (≥10%) (P = .019) compared to adult STIE. Survival analysis demonstrated that patients of grade 3 STEE exhibited a significantly longer overall survival (OS) than patients of grade 3 STIE (median OS, 24.4 months vs. 13.0 months; P = .004). Grade 2 (hazard ratio (HR) = 0.217; P < .001) and gross total resection (GTR) (HR = 0.156; P < .001) were identified as favorable prognostic factors for all adult SE. The STEE was also associated with a lesser hazard of death for patients of grade 3 on multivariate analysis (HR = 0.263; P = .047). These findings suggested that the extraventricular site was an indicator for higher grade and better prognosis in adult supratentorial ependymoma.

Squash cytology of clear cell meningioma: Report of a case.

Clear cell meningioma (CCM) is a rare histological variant of meningioma. It is commonly located at the cerebellopontine angle and the spine particularly around the cauda equina. Squash cytology finding of meningioma is well-established, however there is sparse literature available on squash cytology of CCM. Here we describe a case of CCM occurring in the lumbar spine in a young woman. Initially, on squash cytology a diagnosis of a low grade glioma favouring an ependymoma was considered. Eventually histopathological examination along with immunohistochemistry helped us reach the diagnosis of a CCM. In this article we discuss the cytomorphology of CCM along with its cytological differentials and the hurdles to an accurate diagnosis.

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.

Ependymoma: an epidemiological perspective from a low- and middle-income country.

OBJECTIVE: To enumerate the burden of ependymoma in our region and identify the demographic, tumoural, surgical, clinical characteristics, and outcomes of patients diagnosed with ependymoma. METHODS: This retrospective cross-sectional study included patients admitted under neurosurgical service between January 1 and December 31, 2019. The inclusion criterion for the study was a histopathological diagnosis of the brain lesion. The experience of the ependymal brain tumours observed at the 32 participating sites in Pakistan is presented. RESULTS: A total of 2750 patients with brain tumours were seen in 2019 at our centres of whom 58(2.1%) had a histopathological diagnosis of ependymoma. The median age at diagnosis was nine (IQR= 4.5-24.5) years. The median time to surgery from date of radiological diagnosis was 38.5 (IQR= 4-93.8) days. The median KPS score at presentation was 70 (IQR= 60-80), and post-surgery was 90 (IQR= 70-100), showing an average increase of 20. Our population's overall mortality rate for ependymoma was 31.1%, with the 30-day mortality rate being 2.2% (lower than the 4.5% on average for all brain tumours in our cohort). CONCLUSIONS: Ependymomas were predominantly found in the paediatric population in the presented cohort. While gender distribution and histopathological grading seemed to follow international trends, this study had a much higher mortality rate and a much lower gross total resection rate than centres in high-income countries.

[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.

Ependymomas.

Ependymal neoplasms are a heterogenous group of neoplasms arising from the progenitors of the cells lining the ventricular system and the spinal central canal. During the last few years, significant novel data concerning oncogenesis, molecular characteristics and clinical correlations of these tumours have been collected, with a strong relevance for their pathological classification. The recently published 5th edition of WHO Classification of Central Nervous System Tumours integrates this novel knowledge and represents a substantial update compared to the previous edition. Concerning supratentorial ependymomas, the previous RELA fusion-positive ependymoma has been renamed into ZFTA fusion-positive and the novel YAP1 fusion-positive ependymoma subtype has been added. Posterior fossa ependymomas should now be allocated either to the Type A or Type B subtypes based on molecular profiling or using the H3 K27me3 immunohistochemical surrogate. Regarding spinal ependymomas, a novel subtype has been added based on a distinctive molecular trait, presence of MYCN amplification, and on the unfavourable outcome. Finally, myxopapillary ependymoma is now classified as a grade 2 tumour in accordance with its overall prognosis which mirrors that of conventional spinal ependymomas. The aim of this review is to present these changes and summarize the current diagnostic framework of ependymal tumours, according to the most recent updates.