A Single-center Experience of Radiotherapy in Pediatric Ewing Sarcoma/Primitive Neuroectodermal Tumor of the Chest Wall.

AIM: To evaluate the treatment results, prognostic parameters, and treatment-related toxicity in patients with Ewing sarcoma (ES)/primitive neuroectodermal tumor (PNET) of the chest wall who underwent surgery, chemotherapy, and radiotherapy (RT) in a tertiary referral center. METHODS: The data of 24 patients under 18 years of age with a histologic diagnosis of ES/PNET in the chest wall that received RT in our department between February 2003 and July 2020 were retrospectively evaluated. RT was applied to the primary site±whole involved chest wall and to the whole lung in patients with lung metastasis. RESULTS: The median age was 8.5 years (range: 1.5 to 17 y), 15 (63%) patients were female and 9 were male (37%). The tumor localization was extrathoracic in 18 (75%) and intrathoracic in 6 (25%) patients. Mediastinal lymph node and distant metastasis (DM) was present in 5 (21%) and 4 (16%) cases at diagnosis, respectively. The median follow-up after RT was 47 months (range: 11 to 162 mo). The 2-year and 5-year overall survival, event-free survival, local recurrence-free survival, and pleural recurrence-free survival were 83% and 48%, 48% and 42%, 74% and 48%, and 61% and 52%, respectively. The overall local control rate was 83% and the pleural control rate was 67%. RT was well tolerated, with 1 case of grade 3 acute dermatitis and 1 case of grade 3 subacute radiation pneumonitis. Late toxicity was observed in 3 (13%) cases. CONCLUSION: Long-term survival can be achieved with extended-field RT even in patients with ES/PNET of the chest wall with DM. The low toxicity rates allow us to draw the conclusion that RT with modern techniques is an effective and safe treatment modality for these patients.

Intraocular medulloepithelioma clinical features and management of 11 cases.

AIMS: To describe the clinical features, imaging characteristics, histopathology, treatment and outcomes of intraocular medulloepithelioma. METHODS: Medical records of 11 patients with clinically or histopathologically confirmed medulloepithelioma were retrieved and reviewed. Clinical features, diagnostic challenges, imaging characteristics, management, histopathology and prognosis were assessed. RESULTS: The median age of the patients at initial diagnosis was 4 years, with the most common manifestations being leukocoria (five eyes), loss of vision (four eyes), ocular pain (one eye) and ophthalmic screening (one eye). The clinical signs include a grey-white ciliary body lesion, cataract or lens subluxation, secondary glaucoma and evident cysts. The ultrasound biomicroscopy (UBM) imaging most commonly displays ciliary body mass with intratumoural cysts (nine eyes). Three patients underwent surgery for cataract or glaucoma while the tumours were incidentally found. Two of the three patients managed by eye preserve treatments eventually required enucleation because of local tumour recurrence or phthisis. One patient treated with intra-arterial chemotherapy and cryotherapy had successful tumour regression and globe salvage. CONCLUSIONS: Initial misdiagnosis, delay in diagnosis and subsequent misdirected management is not uncommon in medulloepithelioma. The presence of multiple cysts in the tumour and retrolental neoplastic cyclitic membrane detected by UBM can offer certain information. Selective intra-arterial melphalan may prevent further tumour growth, but longer follow-up is necessary until treatment efficacy is fully evaluated.

Intraocular medulloepithelioma: an unusual and challenging entity in paediatric population.

Intraocular medulloepithelioma is a rare, congenital tumour of the non-pigmented ciliary epithelium. It most frequently arises from the ciliary body but can also have its origin from the retina, iris and optic nerve. The age when lesion first appears is typically around 2-10 years. Nearly 50-60% of patients having this lesion may also have secondary features such as cataract and neovascular glaucoma. Those with extrascleral medulloepithelioma are at risk for metastasis. Systemic correlation of the tumour with pleuropulmonary blastoma/DICER1 gene is reported in the literature. Here, we report a case of a 15 years old boy with one year history of right eye proptosis and painful red right eye along with decreased vision for one week. He was assessed and operated for cataract elsewhere three years back. The ophthalmology team managed him for endophthalmitis with intravenous antibiotics, followed by 2 sessions of cryotherapy and finally an enucleation of right eye was performed due to severe pain and no vision in the involved eye. His left eye, general physical examination and systemic evaluation were normal. Histopathology revealed the diagnosis of 'malignant teratoid medulloepithelioma'. Therefore, evaluation of systemic associations for DICER1 gene mutations was performed by the oncology team. For high risk feature of scleral invasion on histopathology, he was treated with chemotherapy. Since the tumour is of rare occurrence; an international expert team with vast research experience in PPB/DICER1 associated tumours was also contacted. He was registered in International PPB/DICER1 registry where a detailed central radiology and pathology review was performed. Genetic counseling and surveillance plan was also suggested by the international registry.

Embryonal tumor with multilayered rosettes: Post-treatment maturation and implications for future therapy.

BACKGROUND: Embryonal tumor with multilayered rosettes (ETMR) is a deadly grade IV pediatric brain tumor. Despite an intensive multimodal treatment approach that includes surgical resection, high-dose chemotherapy, and radiotherapy, the progression-free survival at 5 years is less than 30%. CASE: We report a case of long-term survival in a 5-month old female with a large mass in the posterior fossa, diagnosed as ETMR, which subsequently underwent treatment-induced maturation. Prior to chemotherapy, histopathology revealed an abundance of highly proliferative, undifferentiated cells and multilayered rosette structures. Conversely, post-treatment histopathology revealed cell populations that differentiated into neuronal and ganglionic phenotypes. At 5-year follow-up, the patient remains progression-free. CONCLUSION: This finding contributes to the few reports to date of post-treatment differentiation/maturation of ETMR cell populations, with an implication for less cytotoxic therapeutic interventions aimed at differentiation.

Epigenetic age acceleration among survivors of pediatric medulloblastoma and primitive neuroectodermal tumor.

Survivors of childhood central nervous system (CNS) tumors experience early-onset aging-related phenotypes. DNA methylation (DNAm) age is an emerging epigenetic biomarker of physiologic age and may be predictive of chronic health conditions in long-term survivors. This report describes the course of epigenetic age acceleration using post-diagnosis blood samples (median: 3.9 years post-diagnosis; range: 0.04-15.96) from 83 survivors of pediatric CNS tumors. Epigenetic age acceleration was detected in 72% of patients, with an average difference between chronologic and DNAm age of 2.58 years (95% CI: 1.75-3.41, p < 0.001). Time from diagnosis to sample collection correlated with the magnitude of epigenetic age acceleration.

The prognostic factors of Ewing sarcoma/peripheral primitive neuroectodermal tumor: A retrospective analysis of 67 patients at a single center.

To investigate the characteristics and factors that impact the prognosis of Ewing sarcoma/peripheral primitive neuroectodermal tumor (ES/pPNET) patients. We retrospectively analyzed ES/pPNET patients diagnosed at our hospital from January 2011 to December 2020. We used 1-way analysis of variance to investigate whether the age differences between different subgroups were statistically significant and used the Kaplan-Meier method and Cox regression model for the survival analysis. Of the 67 included patients, 13 had central nervous system PNET, and 54 had ES/pPNET. The median survival time of the 54 ES/pPNET patients was 18 months; the 1-year, 3-year and 5-year progression-free survival rates were 37.0% and 9.3% and 1.9%, respectively; and the 1-year, 3-year and 5-year overall survival (OS) rates were 66.7%, 27.8%, and 7.4%, respectively. The 1-way analysis of variance results showed no statistically significant age difference between the different subgroups (P = .127 between the central nervous system PNET and ES/pPNET groups, P = .764 between different subgroups within the ES/pPNET group). The univariate survival analysis showed that metastasis at diagnosis and the treatment method were independent factors affecting the OS rate of ES/pPNET patient (P = .003 and 0.000, respectively). The multivariate survival analysis also showed that the treatment method and metastasis at diagnosis were related factors affecting OS (P = .025 and 0.001, respectively). The prognosis of patients with primitive neuroectodermal tumors is poor. The treatment method and metastasis at the time of diagnosis influences ES/pPNET patient survival time, but there is no significant tumor site-dependent correlation with patient age or sex.

[Embryonal tumor with multilayered rosettes (ETMR): case report and literature review]. / Embrional'naya opukhol' s mnogosloinymi rozetkami (embryonal tumor with multilayered rosettes ­ ETMR): sluchai iz praktiki i obzor literatury.

Embryonal tumor with multilayered rosettes (ETMR) is a rare and highly malignant brain tumor that develops in children younger 4 years old. This neoplasm is characterized by extremely aggressive course, low sensitivity to chemotherapy and radiotherapy. Thanks to the progress of pathologists, diagnosis of ETMR is now available using immunohistochemical examination with LIN28A and SALL4 antibodies. Moreover, detection of microRNA amplification in the 19q13.42 locus by fluorescent hybridization in situ allows an unmistakable diagnosis.The authors describe clinical course and treatment outcome in a 2-year-old patient with a giant tumor of the right parietotemporal region. Postoperative histological examination verified ETMR. Despite adjuvant treatment, we observed fast progression of disease and unfavorable outcome after 5 months. Case report is supplemented by literature review. CONCLUSION: ETMR is very rare and poorly understood neoplasm. The authors present a giant hemispheric ETMR in a 2-year-old boy with an extremely aggressive course of disease. Despite the advances in diagnosis and treatment of CNS tumors in children, there are currently more questions than answers regarding ETMR. Pooled analysis of all available data with large-scale studies is needed. It is necessary to emphasize an exceptional role of each clinical case for global study of this tumor. Timely adjuvant/neoadjuvant therapy in highly specialized centers is also essential.

Primary Ewing's sarcoma (ES)/peripheral primitive neuroectodermal tumor (pPNET) of the tongue in a child: A case report.

Ewing's sarcoma (ES) and primitive neuroectodermal tumor (PNET) are high grade malignant small round cell tumors presenting in both skeletal and extraskeletal anatomic locations. Actually, they are the same entity showing varying degrees of neuroectodermal differentiation. Very few cases of peripheral PNET (pPNET) of the tongue was reported in medical literature. Here, we first report a case of primary extraskeletal ES/pPNET in the tongue of a 9-years old girl. The result of immunohistochemical analysis showed the membranous positive for CD99 and Vimentin. The girl underwent radical surgical treatment and received six cycles of OPEC regimen adjuvantchemotherapy without radiotherapy, and now she is remaining tumor-free survival. The individual comprehensive therapy shows a good curative effect.

Extracranial medulloepithelioma: a review of the literature.

PURPOSE: Medulloepithelioma is a rare, malignant tumor that typically arises in the periventricular region of the cerebral hemispheres or the ciliary body of the eye. Even rarer still is the extracranial manifestation of medulloepithelioma with only 12 cases reported to date. Our purpose is to report a case of an intradural, extra-medullary medulloepithelioma and review the limited literature about diagnosis and treatment of this extremely rare pathology. METHODS: PubMed was queried using search terms "peripheral medulloepithelioma" and "pre-sacral medulloepithelioma." Medulloepitheliomas which were intraocular or occurred in reproductive organs were excluded. Patients' age, sex, the symptomatic period prior to diagnosis, primary tumor site, stage, treatment regimen, pathologic description, and survival outcomes were collected. RESULTS: We present a case of extracranial medulloepithelioma in an 8-year-old male. Morphology of the neoplasm was representative of medulloepithelioma but there was no amplification of C19MC. Additionally, the neoplasm stained positive for CD99. Twelve other cases of extracranial medulloepithelioma were found in literature review. CONCLUSIONS: The rarity of extracranial medulloepithelioma makes for a challenging diagnosis. Designing an optimal treatment strategy is difficult because of a scarcity of cases and wide variety in locations and treatments. Our case provides an example of treatment including resection, intense induction chemotherapy, consolidation with high-dose chemotherapy and stem cell rescue, craniospinal proton radiation therapy, and metronomic chemotherapy.

Primary Ewing sarcoma of the kidney: A series of four cases.

INTRODUCTION: Ewing sarcoma (ES), the neuroectodermal derived tumour typically occurs in the bone and soft tissue of children and young adults. Primary ES of the kidney is strikingly rare and only a few cases and small case series have been documented. Due to the highly aggressive nature of this neoplasm, distinction from other morphological mimickers is truly indispensable in terms of treatment and prognosis. Here we describe the clinicopathological features of four cases of primary ES of the kidney with special emphasis on one case having extensive neural differentiation postneo- adjuvant chemotherapy (NACT). Extensive neural differentiation in renal ES has not been documented to date. CASE SERIES: Four patients (age range from 15-35 years) had kidney mass and multiple distant metastases at first presentation. Primary diagnosis of Ewing sarcoma was rendered by histopathology with the help of immunohistochemistry on core biopsy material. Tumour cells in all cases showed diffuse membranous CD99, nuclear FLI-1 and NKX2.2. Two of the patients had undergone radical nephrectomy followed by combination chemotherapy. Another two patients were first treated with neo-adjuvant chemotherapy (NACT) followed by radical nephrectomy. In one of them, histopathological examination of nephrectomy specimens revealed extensive neural differentiation. The adrenal gland was free in all four cases. The follow-up period was 12 -24 months. Three patients had survived and one of them became disease-free. CONCLUSION: Primary ES of the kidney is a rare and lethal entity. Due to overwhelming rarity, chemotherapy protocol has not been standardised and followed as ES in bone/soft tissue. Histopathological confirmation and prompt initiation of treatment may improve patient survival and outcome.

PRINCIPLES OF DIAGNOSIS AND TREATMENT OF ASKIN'S TUMOR IN CHILDREN: CASE REPORT.

The aim of the study was to show principles of diagnosis and treatment of Askin's tumor in children. Diagnostic procedures include physical examination, chest X-ray, CT scan and PET CT, morphological, histological and immunohistochemical examinations, cytogenetic study. Primitive neuroectodermal tumors belong to the group of low differentiated, overly aggressive neoplasms, originating from cells of the parasympathetic autonomic nervous system. Patient F., 9 years old, first consulted by pediatric oncologist in 2014 with complaints of volume formation in the chest on the right side which progressively increases. Diagnosis: PNEP (primitive neuroectodermal tumor) of the soft tissues of the chest on the right side in the 4th intercostal space along the midclavicular line T2aN0M0, stage 2a, standard risk group. We've shown results of diagnostical process, treatment and it's result in our patient. Patients who have received combination therapy, including chemotherapy, surgical removal of the tumor and radiation therapy, have better prognostic results. However, relapses often occur that require more aggressive treatment with high-dose chemotherapy, monoclonal antibodies, and bone marrow transplantation.

Congenital primary primitive neuroectodermal tumor of the orbit in a newborn.

INTRODUCTION: Primitive neuroectodermal tumors arise from the progenitor cells of the neural crest, in the central nervous system or other peripheral locations. CASE PRESENTATION: We report a rare case of a congenital malignant tumor, diagnosed as a primary orbital primitive neuroectodermal tumor on histopathological examination. CONCLUSION: Multidisciplinary management with adjuvant chemotherapy needed for the management of these cases.

Primary EWS/PNET of the lung with TP53 germline and SKT11 somatic mutation: A case report and review of the literature.

Primary pulmonary EWS/PNET is extremely rare. This report describes a 20 year-old man with primary pulmonary EWS/PNET with TP53 germline and SKT11 somatic mutation. After four neoadjuvant chemotherapy cycles (VAC with alternating IE) combined with anlotinib, a left pneumonectomy was performed. Maintenance anlotinib monotherapy was then continued with no sign of recurrence to date. It is suggested that before the treatment and prognosis of children or young adults with primary EWS/PNET of the lung that consideration should be given to genetic testing.

Primary primitive neuroectodermal tumour of the kidney in adults: Experience of managing 12 cases with systematic review and pooled analysis of literature.

INTRODUCTION: Primitive neuroectodermal tumor (PNET) of the kidney is unusual in adults. These tumours are diagnosed mainly on histopathology and that too sometimes has limitations. With this study, we aimed to review our clinical and histopathological data of patients with renal PNET and reviewing the world literature. METHODS: In this retrospective study, we reviewed our database from January 2006 to July 2018 to include all the cases of primary PNET of the kidney. We also performed systematic literature search to identify all the relevant series on renal PNET. RESULTS: A total of 12 patients including 5 men and 7 women were managed during the above mentioned period. Out of these 7 patients, 2 patients had metastasis at diagnosis, one had locally advanced disease, 6 underwent radical nephrectomy, 5 patients received adjuvant chemotherapy (two currently receiving) and only 1 patient received adjuvant radiotherapy (RT). On Immunohistochemistry (IHC), CD99 and FLI1 were positive in all the patients. Median survival was 10 months. In our review 10 studies were included, 38.6% of the patients had metastatic disease and 10.7% had locally advanced disease at diagnosis. Overall mean survival was 33.75 months. CD99 and FLI1 were positive in 94.3% and 78.5%, respectively. CONCLUSION: PNET remains a pathological diagnosis and IHC has important place in diagnosis of PNET. Locally advanced and metastatic disease is common at diagnosis leading to overall poor survival.

Therapeutic implications of improved molecular diagnostics for rare CNS embryonal tumor entities: results of an international, retrospective study.

BACKGROUND: Only few data are available on treatment-associated behavior of distinct rare CNS embryonal tumor entities previously treated as "CNS-primitive neuroectodermal tumors" (CNS-PNET). Respective data on specific entities, including CNS neuroblastoma, FOXR2 activated (CNS NB-FOXR2), and embryonal tumors with multilayered rosettes (ETMR) are needed for development of differentiated treatment strategies. METHODS: Within this retrospective, international study, tumor samples of clinically well-annotated patients with the original diagnosis of CNS-PNET were analyzed using DNA methylation arrays (n = 307). Additional cases (n = 66) with DNA methylation pattern of CNS NB-FOXR2 were included irrespective of initial histological diagnosis. Pooled clinical data (n = 292) were descriptively analyzed. RESULTS: DNA methylation profiling of "CNS-PNET" classified 58 (19%) cases as ETMR, 57 (19%) as high-grade glioma (HGG), 36 (12%) as CNS NB-FOXR2, and 89(29%) cases were classified into 18 other entities. Sixty-seven (22%) cases did not show DNA methylation patterns similar to established CNS tumor reference classes. Best treatment results were achieved for CNS NB-FOXR2 patients (5-year PFS: 63% ± 7%, OS: 85% ± 5%, n = 63), with 35/42 progression-free survivors after upfront craniospinal irradiation (CSI) and chemotherapy. The worst outcome was seen for ETMR and HGG patients with 5-year PFS of 18% ± 6% and 22% ± 7%, and 5-year OS of 24% ± 6% and 25% ± 7%, respectively. CONCLUSION: The historically reported poor outcome of CNS-PNET patients becomes highly variable when tumors are molecularly classified based on DNA methylation profiling. Patients with CNS NB-FOXR2 responded well to current treatments and a standard-risk CSI-based regimen may be prospectively evaluated. The poor outcome of ETMR across applied treatment strategies substantiates the necessity for evaluation of novel treatments.

Clinicopathological characteristics and outcomes in embryonal tumor with multilayered rosettes: A decade long experience from a tertiary care centre in North India.

BACKGROUND: Embryonal tumor with multilayered rosettes (ETMR) are a heterogenous group clinically, pathologically and topographically. Due to limited cases, data regarding its molecular genetics, pathology and prognostic factors is evolving. We retrospectively analysed our cohort of ETMR over last decade in order to study their clinicopathological characteristics and outcome. METHODS: Our cohort consisted of patients diagnosed with Embryonal tumor with abundant neuropil and true rosettes (ETANTR)/Ependymoblastoma (EBL)/ Medulloepithelioma (MEPL) over the past decade. Clinical details, including outcome and imaging data was retrieved. Histological analysis including immunohistochemical work-up was performed. RESULTS: Cohort included 15 patients with age range between 1 and 28 years and M:F ratio of 1.5:1. Supratentorial location predominated in comparison to tumors arising in posterior fossa. ETANTR and EBL patterns were equally distributed (40% each), followed by one case each of mixed pattern (EBL + ETANTR), MEPL and embryonal tumor, unclassified. All tumors readily expressed LIN 28A and INI-1 was retained. Recurrence with evidence of glial and rhabdoid differentiation was noted in a single patient 9 months following resection. Follow-up period ranged from 1 to 31 months, with overall median survival of 6.4 months. Eight patients were planned for adjuvant treatment following surgery, of which only four could complete it. All patients, except for one, succumbed to the disease. CONCLUSIONS: ETMR have a heterogenous morphology and gathers ETANTR, EBL, MEPL within its spectrum. Following treatment, the recurrent tumor may feature glial/rhabdoid differentiation. LIN28A is expressed in all cases, however should be interpreted in context of histology. Prognosis of ETMR remains dismal despite multimodal therapy.

Renal Primitive Neuroectodermal Tumor With Inferior Vena Cava Thrombus: Case Series and Literature Review of a Rare but Challenging Entity.

OBJECTIVE: To investigate the clinicopathological characteristics, treatments, and prognosis of patients with renal primitive neuroectodermal ectodermal tumors (rPNETs) with inferior vena cava (IVC) tumor thrombus. PATIENTS AND METHODS: We retrospectively reviewed 6 patients with rPNETs and IVC tumor thrombus between January 2005 and December 2019, and identified 39 published cases through a literature review. The clinicopathological characteristics, treatments, and survival data were analyzed. RESULTS: The median patient age patients was 26 years, and the male to female ratio was approximately 1:1. The average tumor diameter was 12.5 cm. Seventeen patients (37.8%) showed metastasis at diagnosis. Forty-three cases (95.6%) were managed with surgical resection, and 35 (77.8%) received adjuvant chemotherapy after surgery. Follow-up data were available for 41 patients (median follow-up, 10 months; range, 4.5-13.0). The median overall survival (OS) and median progression-free survival (PFS) were both 30.0 months. Patients who received adjuvant chemotherapy had better PFS than those who underwent surgery only (30.0 months [95% confidence interval [CI], 4.3-55.7] vs 5.0 months [95% CI, 1.0-9.0]; P = .036). In terms of OS, however, the difference between the 2 groups was not significant (30.0 months [95% CI, 8.4-52.6] vs 7.0 months [95% CI, 4.5-9.5]; P = .244). CONCLUSIONS: rPNET with IVCTT is an extremely rare entity that mostly occurs in young adults. Although multidisciplinary treatment is used, the prognosis of this disease remains unclear. RN with IVC tumor thrombectomy is a challenging procedure requiring vascular management techniques and experience. Adjuvant chemotherapy contributes to improved PFS, but not OS. Thus, early diagnosis and treatment play a key role in improving prognosis.

Embryonal tumors with multilayered rosettes: A tertiary care centre experience.

BACKGROUND: Embryonal tumors with multilayered rosettes (ETMR) is an extremely rare and highly aggressive tumor. It includes three distinct entities i.e, embryonal tumor with abundant neuropil and true rosettes (ETANTR), ependymoblastoma (EBL) and medulloepithelioma (MEPL). Here, we present our institutional experience of seven ETMR cases treated over a period of five years. MATERIALS AND METHODS: Patients' records from 2015 to 2019 were reviewed manually and electronically to retrieve the data. Clinicopathological and outcome details of ETMR cases were entered in a predesigned proforma. RESULTS: A total of seven cases of ETMR were registered from 2015 to 2019 with a median age at presentation of four years (range 3-7 years). All patients underwent surgery. However, only three patients completed the planned adjuvant treatment, comprising of focal radiotherapy (RT) alone, craniospinal irradiation (CSI) alone and CSI followed by six cycles of chemotherapy in one patient each respectively. Two patients commenced CSI but deteriorated during RT and thereafter needed best supportive care. Two patients could not be started on any adjuvant treatment. Unfortunately, six patients succumbed to their disease within one year of their diagnosis. Only one patient who received both CSI and adjuvant chemotherapy is alive at 15 months of diagnosis. CONCLUSION: ETMR is a rare and aggressive entity. Majority of the patients die within one year of the diagnosis despite multimodality treatment.

Treatment and Outcomes for Central Nervous System Tumors in Australian Adolescents and Young Adults: A Population-Based National Study.

Purpose: While central nervous system (CNS) tumors account for only 10% of adolescent and young adult (AYA) cancers, they are the leading cause of cancer death in this age group. Using national data for Australia, we describe the presentation, treatment, and survival for AYAs diagnosed with CNS tumors. Methods: A population-based study of 15-24 year-olds diagnosed with CNS tumors (low- and high-grade glioma [LGG, HGG], medulloblastoma [MB], primitive neuroectodermal tumors [PNET], ependymoma [EP]) or other (e.g., low-grade neuronal tumor) between 2007 and 2012. Clinical details were extracted from hospital medical records for each patient. Treatment centers were classified as pediatric or adult services. Results: Two hundred seventy-five patients (129 LGG, 77 HGG, 23 MB, 10 PNET, 19 EP, 17 other) were identified, with 17% treated at pediatric hospitals. Symptoms (headache [53%], nausea [31%]) were present for a median of 3 weeks before consulting a health professional. Of LGG patients, 15% had radiotherapy (RT) and 12% chemotherapy (CT). Of HGG patients, 81% had RT and 75% CT. All MB and PNET were managed with surgery, and 74% of MB and 80% of PNET had both RT and CT. Treatment did not differ by treatment center type. Five-year survival for LGG and EP was over 80%, but was 42% for HGG and 20% for PNET. Conclusions: This national, population-based study indicates similar treatment for AYA patients with CNS tumors between pediatric and adult services. Poor outcomes for HGG and PNET patients highlight the need for clinical trials of novel approaches for these tumors.