UNASSIGNED: Ewing sarcoma (ES), a rare malignancy, comprises whatever the age, 4-15% of all primary bone tumors. It represents 1% of all malignant tumors in children and is the fourth most common bone malignancy after myeloma, osteosarcoma, and chondrosarcoma.
UNASSIGNED: A 12-year-old boy came to the Oral Surgery Department of Bretonneau Hospital referred by his dentist with a rapidly evolving swelling in the left mandibula for 6 weeks, which was initially diagnosed as a facial cellulitis. Cone beam computed tomography (CBCT) showed a poorly defined, expansile, and osteolytic tumor on the left side of the mandible. Clinical and radiographic findings were in favor of an aggressive primitive bone tumor. A mandibular biopsy under general anesthesia was performed in the Department of Surgical Oncology at Institut Curie in Paris, revealing an ES.
UNASSIGNED: Mandibular ES can mimic dental infections when swelling is the main clinical manifestation, which can lead to a delayed diagnosis. A correlation between clinical, radiological, histopathological, and immunohistochemical with cytogenetics is needed to confirm the diagnosis. Moreover, smaller tumors have better survival.Dentists must therefore be aware of the clinical signs of ES in order to quickly refer patients to a specialized department.
UNASSIGNED: Bellut N, Lutz CM, Lesnik M, et al. Ewing\'s Sarcoma of Mandible: A Case Report with Review of Literature. Int J Clin Pediatr Dent 2024;17(2):187-190.

BACKGROUND: Multidrug chemotherapy for Ewing sarcoma can lead to severe myelosuppression. We proposed two clinical questions (CQ): CQ #1, \"Does primary prophylaxis with G-CSF benefit chemotherapy for Ewing sarcoma?\" and CQ #2, \"Does G-CSF-based intensified chemotherapy improve Ewing sarcoma treatment outcomes?\".
METHODS: A comprehensive literature search was conducted in PubMed, Cochrane Library, and Ichushi web databases, including English and Japanese articles published from 1990 to 2019. Two reviewers assessed the extracted papers and analyzed overall survival (OS), febrile neutropenia (FN) incidence, infection-related mortality, quality of life (QOL), and pain.
RESULTS: Twenty-five English and five Japanese articles were identified for CQ #1. After screening, a cohort study of vincristine, ifosfamide, doxorubicin, and etoposide chemotherapy with 851 patients was selected. Incidence of FN was 60.8% with G-CSF and 65.8% without; statistical tests were not conducted. Data on OS, infection-related mortality, QOL, or pain was unavailable. Consequently, CQ #1 was redefined as a future research question. As for CQ #2, we found two English and five Japanese papers, of which one high-quality randomized controlled trial on G-CSF use in intensified chemotherapy was included. This trial showed trends toward lower mortality and a significant increase in event-free survival for 2-week interval regimen with the G-CSF primary prophylactic use compared with 3-week interval.
CONCLUSIONS: This review indicated that G-CSF\'s efficacy as primary prophylaxis in Ewing sarcoma, except in children, is uncertain despite its common use. This review tentatively endorses intensified chemotherapy with G-CSF primary prophylaxis for Ewing sarcoma.

Periosteal Ewing sarcoma (ES) is an exceedingly rare topographic subtype of the ES. To our knowledge, only 60 patients have been reported in the medical English language literature. It predominantly affects men in the second decade of life and arises in the long tubular bone diaphysis. PES rarely develops distant metastases. We report two patients of this rare ES location that were found on the distal tibial shaft and proximal femoral diaphysis of a 21-year-old man and an 8-year-old boy, respectively. Both patients were treated with neoadjuvant chemotherapy, wide resection, and adjuvant chemotherapy. One of our patients had lung metastases at the time of diagnosis and died 5 years later. The other patient presented intramedullary humeral bone metastasis 19 years after diagnosis. There has been no evidence of disease in the 26 years of follow-up. Close follow-up of periosteal ES is recommended because distant metastases may exceptionally occur, even several years after diagnosis.

Ewing\'s Sarcoma (ES) is an rare, small round-cell sarcoma that predominantly occurs in children and young adults, with both skeletal and extraskeletal manifestations. However, pancreatic ES, due to its rarity, is infrequently featured in scholarly literature, with only a scant 43 reported instances. Our study describes a case of pancreatic ES in an 8-year-old boy who was found to have an abdominal mass. Following an exhaustive examination, the boy was diagnosed with a neoplasm in the pancreatic head and underwent a complex surgical procedure encompassing pancreatoduodenectomy and partial transverse colectomy. Immunohistochemical assays confirmed the neoplastic cells\' positivity for Cluster of Differentiation 99(CD99), Vimentin, and NK2 Homeobox 2(NKX2.2), while genomic testing identified an EWSR1-FLI1(Ewing Sarcoma Breakpoint Region 1-Friend Leukemia Integration 1) gene fusion. This led to a conclusive diagnosis of pancreatic Ewing\'s Sarcoma. The patient underwent seven cycles of adjuvant chemotherapy, alternating between VDC (Vincristine, Doxorubicin, Cyclophosphamide) and IE (Ifosfamide, Etoposide) tri-weekly, but did not undergo radiotherapy. At present, the patient remains neoplasm-free. Through our case analysis and comprehensive review of the existing literature, we aim to underscore th rarity of pancreatic Ewing\'s sarcoma and to highlight the efficacy of our individualized therapeutic approach.

Peripheral neuroectodermal tumors (PNET), or Ewing sarcoma, are tumors that generally develop in bone; extraskeletal locations are rare. Renal PNETs are rare and are characterized by an aggressive clinical course and a poor prognosis. We report the case of a young patient who presented with abdominal and lumbar pain with a palpable abdominal mass. The imaging was in favor of a huge renal tumor, and the histological analysis allowed the diagnosis of a renal PNET. The therapeutic attitude was multimodal, including surgery and chemotherapy, allowing complete remission and a favorable outcome.

Ewing sarcoma (ES) usually arises from long bones and affects the head and neck region in only 1%-4% of cases. We reported clinical, radiographic, cytomorphologic, and histomorphologic findings of the ES in the mandible, because of its rarity and radiologically misinterpreted as a parotid gland tumor. A 26-year-old male patient presented with a history of painfull cheek swelling. On magnetic resonance imaging, a mass measuring 50 × 48 × 45 mm was found eroding mandible and pushing back the parotid gland. Aspiration cytology was performed with suspicion of parotid gland tumor. Small, nucleated cells with nuclear indentation, inconspicuous nucleoli, and occasionally rosette-like arrangement were observed. Neuroendocrine immune markers were positive on cell block. It was diagnosed as small round cell neoplasm with neuroendocrine differentiation and biopsy was suggested. The differential diagnosis considered soft tissue and parotid gland tumors. The small round cell tumor morphology was seen on biopsy specimen and immunostaining was applied. The diagnosis for this case was ES of the mandible. ES of the mandible is unusual. Although the histogenesis is still unknown, various cells have been proposed as cells of origin namely, endothelial, hematopoietic, fibroblastic, mesenchymal stem cells or neural derived mesenchymal stem cells. Small cell morphology, CD99, CD56, neuron specific enolase, and synaptophysin expressions confirmed the diagnosis of ES. The differentiation of the ES from other small cell tumors may be difficult and requires awareness for histological and immunohistochemical features. It should be kept in mind that the diagnosis can be challenging due to uncommon locations and radiological misinterpreted.

BACKGROUND: Spinal cord tumors present a challenge in diagnosis and treatment due to their varied histopathological characteristics. While Ewing sarcoma is a rare malignant tumor typically originating from skeletal bone, cases of primary intradural extraskeletal Ewing sarcoma are exceptionally rare. The similarity of its presentation to other spinal tumors further complicates its identification and management.
METHODS: We report a case of a 58-year-old Palestinian male with intradural extraskeletal lumbar Ewing sarcoma. The patient initially presented with lower back pain and bilateral S1 radiculopathy, with more severe symptoms on the left side. Magnetic resonance imaging revealed a 7 cm oval-shaped mass with homogeneous contrast enhancement, obstructing the spinal canal from L3/L4 to L5/S1 levels. Initially, a myxopapillary ependymoma was suspected, but the patient\'s sensory and motor functions suddenly deteriorated during hospitalization. Repeat magnetic resonance imaging indicated heterogeneous contrast enhancement, indicating acute intratumoral hemorrhage. Consequently, the patient underwent emergent L3-L5 laminotomy, with successful gross total resection of the tumor. Histopathological and immunohistochemical analyses confirmed the diagnosis of intradural extraskeletal Ewing sarcoma. Adjuvant therapy was administered to minimize the risk of local recurrence or distant metastasis. A systematic review of relevant literature, along with retrospective analysis of medical records, operative reports, radiological studies, and histopathological findings of similar cases, was also conducted.
CONCLUSIONS: Intradural extraskeletal Ewing sarcoma is an infrequently encountered condition in adult patients, emphasizing the importance of considering it in the differential diagnosis of spinal tumors. Surgeons must possess a comprehensive understanding of this rare entity to ensure accurate staging and optimal management, particularly in the early stages when prompt intervention may improve prognosis.

BACKGROUND: Patients with high-risk or metastatic Ewing sarcoma (ES) and rhabdomyosarcoma (RMS) have a guarded prognosis. High-dose chemotherapy (HDT) with autologous stem cell transplant (ASCT) has been evaluated as a treatment option to improve outcomes. However, survival benefits remain unclear, and treatment is associated with severe toxicities.
METHODS: A systematic review was conducted, using the population, intervention, comparison outcome (PICO) model, to evaluate whether utilization of HDT/ASCT impacts the outcome of patients with ES and RMS compared to standard chemotherapy alone, as part of first line treatment or in the relapse setting. Medline, Embase and Cochrane Central were queried for publications from 1990 to October 2022 that evaluated event-free survival (EFS), overall survival (OS), and toxicities. Each study was screened by two independent reviewers for suitability. A qualitative synthesis of the results was performed.
RESULTS: Of 1,172 unique studies screened, 41 studies were eligible for inclusion with 29 studies considering ES, 10 studies considering RMS and 2 studies considering both. In ES patients with high-risk localised disease who received HDT/ASCT after VIDE chemotherapy, consolidation with melphalan-based HDT/ASCT as first line therapy conveyed an EFS and OS benefit over standard chemotherapy consolidation. Efficacy of HDT/ASCT using a VDC/IE backbone, which is now standard care, has not been established. Survival benefits are not confirmed for ES patients with metastatic disease at initial diagnosis. For relapsed/refractory ES, four retrospective studies report improvement in outcomes with HDT/ASCT with the greatest evidence in patients who demonstrate a treatment response before HDT, and in patients under the age of 14. In RMS, there is no proven survival benefit of HDT/ASCT in primary localised, metastatic or relapsed disease.
CONCLUSIONS: Prospective randomised trials are required to determine the utility of HDT/ASCT in ES and RMS. Selected patients with relapsed ES could be considered for HDT/ASCT.

UNASSIGNED: Renal Ewing sarcoma is an aggressive and rare malignancy affecting children and adolescents. Limited data on its management contribute to uncertainties in treatment.
UNASSIGNED: We present two pediatric cases of renal Ewing sarcoma. Both cases emphasize the significance of accurate diagnosis, multimodal treatment, and long-term follow-up in achieving favorable outcomes. Accurate diagnosis of renal Ewing sarcoma is crucial for effective management. Multimodal treatment involving neoadjuvant chemotherapy, surgical resection and staging with lymph node sampling, and chemotherapy continuation has shown promising results in our cases. Long-term follow-up is essential for monitoring disease progression and ensuring optimal outcomes.
UNASSIGNED: There is limited data published about these renal tumors, especially in the pediatric population, and most studies lack long-term follow-up, with uncertain management due to limited data. This data will add to the newer, multimodal approach and form the basis for future meta-analysis to help formulate guidelines for upcoming international meetings. Continued research efforts are necessary to optimize strategies and improve the prognosis for pediatric patients with renal Ewing sarcoma.

Karthik DhandapaniEwing sarcoma arises in both bones (most common) and soft tissues and it commonly affects young adults. The tumor is composed of small round cells showing positivity for CD99 and FLI1 on immunohistochemistry (IHC). We describe ganglion cell differentiation post-chemotherapy in Ewing sarcoma which is a rare phenomenon. A 13-year-old girl presented with a chest wall mass. On biopsy correlating with IHC, the diagnosis was rendered as Ewing sarcoma. She underwent neoadjuvant chemotherapy followed by resection of the tumor. On microscopic evaluation, the tumor showed prominent ganglionic differentiation with expression of neuronal markers. Although maturation post-chemotherapy is an established finding with better prognosis in other primitive pediatric tumors, such neural differentiation is rare with only a few case reports in Ewing sarcoma both post- and pre-chemotherapy. Clinical significance and prognosis of such differentiation which appear to be better are not yet established and needs to be elucidated.