Ewing Sarcoma Research Articles

CAR T cells redirected to B7-H3 for pediatric solid tumors: Current status and future perspectives

Despite intensive therapies, pediatric patients with relapsed or refractory solid tumors have poor outcomes and need novel treatments. Immune therapies offer an alternative to conventional treatment options but require the identification of differentially expressed antigens to direct antitumor activity to sites of disease. B7-H3 (CD276) is an immune regulatory protein that is expressed in a range of malignancies and has limited expression in normal tissues. B7-H3 is highly expressed in pediatric solid tumors including osteosarcoma, rhabdomyosarcoma, Ewing sarcoma, Wilms tumor, neuroblastoma, and many rare tumors. In this article we review B7-H3-targeted chimeric antigen receptor (B7-H3-CAR) T cell therapies for pediatric solid tumors, reporting preclinical development strategies and outlining the landscape of active pediatric clinical trials. We identify challenges to the success of CAR T cell therapy for solid tumors including localizing to and penetrating solid tumor sites, evading the hostile tumor microenvironment, supporting T cell expansion and persistence, and avoiding intrinsic tumor resistance. We highlight strategies to overcome these challenges and enhance the effect of B7-H3-CAR T cells, including advanced CAR T cell design and incorporation of combination therapies.

Factors Influencing the Outcome of Patients with Primary Ewing Sarcoma of the Sacrum.

Ewing sarcoma (EwS) is a rare and highly malignant bone tumor primarily affecting children, adolescents, and young adults. The pelvis, trunk, and lower extremities are the most common sites, while EwS of the sacrum as a primary site is very rare, and only few studies focusing on this location are published. Due to the anatomical condition, local treatment is challenging in sacral malignancies. We analyzed factors that might influence the outcome of patients suffering from sacral EwS. We retrospectively analyzed data of the GPOH EURO-E.W.I.N.G 99 trial and the EWING 2008 trial, with a cohort of 124 patients with localized or metastatic sacral EwS. The study endpoints were overall survival (OS) and event-free survival (EFS). OS and EFS were calculated using the Kaplan-Meier method, and univariate comparisons were estimated using the log-rank test. Hazard ratios (HRs) with respective 95% confidence intervals (CIs) were estimated in a multivariable Cox regression model. The presence of metastases (3y-EFS: 0.33 vs. 0.68; P < 0.001; HR = 3.4, 95% CI 1.7 to 6.6; 3y-OS: 0.48 vs. 0.85; P < 0.001; HR = 4.23, 95% CI 1.8 to 9.7), large tumor volume (≥200 ml) (3y-EFS: 0.36 vs. 0.69; P=0.02; HR = 2.1, 95% CI 1.1 to 4.0; 3y-OS: 0.42 vs. 0.73; P=0.04; HR = 2.1, 95% CI 1.03 to 4.5), and age ≥18 years (3y-EFS: 0.41 vs. 0.60; P=0.02; HR = 2.6, 95% CI 1.3 to 5.2; 3y-OS: 0.294 vs. 0.59; P=0.01; HR = 2.92, 95% CI 1.29 to 6.6) were revealed as adverse prognostic factors. Young age seems to positively influence patients` survival, especially in patients with primary metastatic disease. In this context, our results support other studies, stating that older age has a negative impact on survival. Tumor volume, metastases, and the type of local therapy modality have an impact on the outcome of sacral EwS. Level of evidence: Level 2. This trial is registered with NCT00020566 and NCT00987636.

Insights into Molecular Diversity within the FUS/EWS/TAF15 Protein Family: Unraveling Phase Separation of the N-Terminal Low-Complexity Domain from RNA-Binding Protein EWS.

The FET protein family, comprising FUS, EWS, and TAF15, plays crucial roles in mRNA maturation, transcriptional regulation, and DNA damage response. Clinically, they are linked to Ewing family tumors and neurodegenerative diseases such as amyotrophic lateral sclerosis. The fusion protein EWS::FLI1, the causative mutation of Ewing sarcoma, arises from a genomic translocation that fuses a portion of the low-complexity domain (LCD) of EWS (EWSLCD) with the DNA binding domain of the ETS transcription factor FLI1. This fusion protein modifies transcriptional programs and disrupts native EWS functions, such as splicing. The exact role of the intrinsically disordered EWSLCD remains a topic of active investigation, but its ability to phase separate and form biomolecular condensates is believed to be central to EWS::FLI1's oncogenic properties. Here, we used paramagnetic relaxation enhancement NMR, microscopy, and all-atom molecular dynamics (MD) simulations to better understand the self-association and phase separation tendencies of the EWSLCD. Our NMR data and mutational analysis suggest that a higher density and proximity of tyrosine residues amplify the likelihood of condensate formation. MD simulations revealed that the tyrosine-rich termini exhibit compact conformations with unique contact networks and provided critical input on the relationship between contacts formed within a single molecule (intramolecular) and inside the condensed phase (intermolecular). These findings enhance our understanding of FET proteins' condensate-forming capabilities and underline differences between EWS, FUS, and TAF15.

Recommender-based bone tumour classification with radiographs—a link to the past

ObjectivesTo develop an algorithm to link undiagnosed patients to previous patient histories based on radiographs, and simultaneous classification of multiple bone tumours to enable early and specific diagnosis.Materials and methodsFor this retrospective study, data from 2000 to 2021 were curated from our database by two orthopaedic surgeons, a radiologist and a data scientist. Patients with complete clinical and pre-therapy radiographic data were eligible. To ensure feasibility, the ten most frequent primary tumour entities, confirmed histologically or by tumour board decision, were included. We implemented a ResNet and transformer model to establish baseline results. Our method extracts image features using deep learning and then clusters the k most similar images to the target image using a hash-based nearest-neighbour recommender approach that performs simultaneous classification by majority voting. The results were evaluated with precision-at-k, accuracy, precision and recall. Discrete parameters were described by incidence and percentage ratios. For continuous parameters, based on a normality test, respective statistical measures were calculated.ResultsIncluded were data from 809 patients (1792 radiographs; mean age 33.73 ± 18.65, range 3–89 years; 443 men), with Osteochondroma (28.31%) and Ewing sarcoma (1.11%) as the most and least common entities, respectively. The dataset was split into training (80%) and test subsets (20%). For k = 3, our model achieved the highest mean accuracy, precision and recall (92.86%, 92.86% and 34.08%), significantly outperforming state-of-the-art models (54.10%, 55.57%, 19.85% and 62.80%, 61.33%, 23.05%).ConclusionOur novel approach surpasses current models in tumour classification and links to past patient data, leveraging expert insights.Clinical relevance statementThe proposed algorithm could serve as a vital support tool for clinicians and general practitioners with limited experience in bone tumour classification by identifying similar cases and classifying bone tumour entities.Key Points• Addressed accurate bone tumour classification using radiographic features.• Model achieved 92.86%, 92.86% and 34.08% mean accuracy, precision and recall, respectively, significantly surpassing state-of-the-art models.• Enhanced diagnosis by integrating prior expert patient assessments.Graphical abstract

Primary extraskeletal intradural Ewing sarcoma with acute hemorrhage: a case report and review of the literature

BackgroundSpinal 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.Case presentationWe 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.ConclusionsIntradural 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.

Operative treatment of pulmonary primitive neuroectodermal tumor: a case report and literature review

BackgroundPulmonary primitive neuroectodermal tumor (PNET), a member of the Ewing sarcoma family of tumors, is a rare malignancy that is associated with a grim prognosis. To date, fewer than 30 cases of pulmonary PNET have been reported. In this case report, we present the clinical details of a 12-year-old girl with pulmonary PNET who underwent surgical treatment. We also conducted an analysis and summary of other relevant studies and the surgical outcomes.Case presentationIn May 2018, a 12-year-old girl was admitted with symptoms of cough and blood-tinged phlegm. A computed tomography scan revealed a large mass, measuring 12.9 cm × 8.1 cm, in the right middle and lower lungs. A percutaneous lung biopsy confirmed poorly differentiated tumor cells with a nested growth pattern. Immunohistochemical staining demonstrated positive expression of CD99, CD56, Vimentin, and Synaptophysin. The patient was diagnosed with pulmonary PNET. Following three cycles of neoadjuvant chemotherapy, a substantial reduction in tumor volume was observed. Subsequently, the patient underwent a surgical procedure involving pneumonectomy and partial resection of the left atrium with the assistance of cardiopulmonary bypass. The patient was discharged 37 days after surgery. During a three-year follow-up period, she exhibited no signs of tumor recurrence and has successfully returned to school.ConclusionsThis case highlights the successful management of an advanced PNET with neoadjuvant chemotherapy, pneumonectomy, and partial resection of the left atrium employing cardiopulmonary bypass. The patient remained disease-free after three years. Our analysis of surgically treated cases indicates that neoadjuvant chemotherapy can contribute to improved prognoses for PNET patients. It is crucial to emphasize that complete surgical excision remains the cornerstone of treatment, underscoring the importance of surgeons considering radical surgical approaches whenever feasible for patients with pulmonary PNETs.

Use of Vacuum-Assisted Closure to Reduce the Likelihood of Wound Complications After Limb-Sparing Resection of Pediatric Primary Bone Sarcomas of the Femur

BackgroundLimb-sparing surgery is the standard of care for primary bone tumors. However, such procedures are associated with high rates of wound complications, specifically in lower-extremity surgeries. Therefore, identifying and implementing interventions to minimize the likelihood of wound complications after limb-sparing resection of the lower extremity is crucial. MethodsPatients who underwent limb-sparing osteosarcoma or Ewing sarcoma resection during a 7-year period at a single institution were retrospectively reviewed. Data were collected on 39 patients who underwent limb-sparing resection of the femur. Patient demographics, tumor characteristics, and perioperative and postoperative data were extracted and analyzed. Patients who underwent resection before April 2017 received conventional postoperative incision dressings. Starting in April 2017, patients received vacuum-assisted closure (VAC) with the 3 M™ Prevena VAC system after surgical closure. Eighteen patients received conventional postoperative incision dressing, and 21 received incisional wound VAC. A wound complication was defined as any Clavien-Dindo classification greater than 0 within a 28-day postoperative period. ResultsPatients who received postoperative incisional wound VAC had lower rates of wound complications than those who received conventional incision dressings (14% vs. 50%; p = 0.035). Additionally, patients in whom wound complications developed had a longer average hospital stay than those without wound complications (5 days vs. 4 days; p = 0.029). ConclusionsWound complications prolong the hospital stay and can delay adjuvant chemotherapy for bone tumors. The use of postoperative incisional wound VAC is associated with less likelihood of wound complications and should be considered in any high-risk surgical closure. Level of EvidenceLevel III Treatment Study.

Use of pedicled flaps after oncologic resections in pediatric patients.

The aim of this study is to review the indications of pedicled flaps and analyze the results.A observational retrospective study of under 18-year-old oncology patients who required reconstructive surgery with pedicled flaps between 2011 and 2022 was performed. Demographic and clinical variables, indications, complications, and outcomes were collected.236 patients were reviewed and 13 met inclusion criteria, eight girls and five boys (mean age: 10.6years). Indications were Ewing's sarcoma (5), osteosarcoma (5), neuroblastoma, desmoid tumor, and neurofibroma. Preoperative PET-CT, MRI and bone scintigraphy were performed. The flaps were used on costal and extremity reconstruction: latissimus dorsi (5), pectoralis (2), medial gastrocnemius (2), combined latissimus dorsi, trapezius and serratus muscle, biceps femoris, fascio-neuro-cutaneous saphenous and cutaneous advancement-rotation. Two were performed on allograft and eight on prosthesis. All allowed immediate and complete closure. Six patients received intraoperative radiotherapy. One flap infection and two vascular complications were reported, a total necrosis, which required a new flap, and a partial necrosis, treated with a local plasty. Chemotherapy was resumed after 21days (15-31). Mean follow-up time was 5.34years.Flaps are an effective therapeutic option allowing reconstruction of large defects after pediatric oncologic surgeries. The most frequent complication was vascular.

Use of modern three-dimensional imaging models to guide surgical planning for local control of pediatric extracranial solid tumors.

In complex pediatric surgical oncology, surgical planning is contingent upon data gathered from preoperative imaging. Three-dimensional (3D) modeling and printing has been shown to be beneficial for adult presurgical planning, though pediatric literature is less robust. The study reviews our institutional experience with the use of 3D image segmentation and printed models in approaching resection of extracranial solid tumors in children. This is a single institutional series from 2021 to 2023. Models were based on computed tomography and magnetic resonance imaging studies, optimized for 3D imaging. The feasibility and creation of the models is reviewed, including specific techniques, software, and printing materials from our institution. Clinical implications for surgical planning are also described, along with detailed preoperative and intraoperative images. 3D modeling and printing was performed for four pediatric patients diagnosed with extracranial solid tumors. Diagnoses included Ewing sarcoma, hepatoblastoma, synovial sarcoma, and osteosarcoma. No intraoperative complications or discrepancies with the preoperative 3D-printed model were noted. No evidence of local recurrence was identified in any patient thus far. Our institutional series demonstrates a wide spectrum of clinical application for 3D modeling and printing technology within pediatric surgical oncology. This technology may aid in surgical planning for both resection and reconstruction, can be applied to a diverse breadth of diagnoses, and may potentially augment patient and/or family education about their condition.

Prognostic value of PRR11 and immune cell infiltration in Ewing sarcoma.

Ewing's sarcoma (ES) is the second most common bone and soft tissue malignancy in children and adolescents with a poor prognosis. The identification of genes with prognostic value may contribute to the prediction and treatment of this disease. The GSE17679, GSE68776, GSE63155, and GSE63156 datasets were downloaded from the Gene Expression Omnibus database and qualified. Prognostic value of differentially expressed genes (DEGs) between the normal and tumor groups and immune cell infiltration were explored by several algorithms. A prognostic model was established and validated. Finally, functional analyses of the DEGs were performed. Proline rich 11 (PRR11) and mast cell infiltration were noted as the key indicators for the prognosis of ES. Kaplan-Meier and scatter plots for the training and two validation sets showed that patients in the low-PRR11 expression group were associated with better outcomes than those in the high-PRR11 expression group. The concordance indices and calibration analyses of the prognostic model indicated good predictive accuracy in the training and validation sets. The area under the curve values obtained through the receiver operating characteristic analysis for 1-, 3-, 5-year prediction were ≥ 0.75 in the three cohorts, suggesting satisfactory sensitivity and specificity of the model. Decision curve analyses suggested that patients could benefit more from the model than the other strategies. Functional analyses suggested that DEGs were mainly clustered in the cell cycle pathway. PRR11 and mast cell infiltration are potential prognostic indicators in ES. PRR11 possibly affects the prognosis of patients with ES through the cell cycle pathway.

Impact of the COVID-19 pandemic on the demographic and disease burden of pediatric malignant solid tumors in China: a single-center, cross-sectional study.

With the development of the novel coronavirus disease 2019 (COVID-19), China implemented measures in an attempt to control the infection rate. We conducted a single-center, cross-sectional study to ascertain the impact of the COVID-19 pandemic on the equitable availability of medical resources for children diagnosed with malignant solid tumors in China. Data on the demographics, clinical characteristics, and medical expenses of 876 patients diagnosed with neuroblastoma, rhabdomyosarcoma (RMS), Wilms tumor, hepatoblastoma (HB), Ewing sarcoma (ES), and central nervous system (CNS) tumors from 2019 to 2021, during the COVID-19 pandemic, were retrospectively collected from the National Center for Children's Health. The Pearson χ2 test and Mann-Whitney test were performed to analyze the differences among variables. Except for the regional origin of children with tumors during the epidemic, no significant differences were found in the demographic or clinical characteristics of patients at initial diagnosis. The number of patients from northern China and northeastern China who attended Beijing Children's Hospital (BCH) increased after the outbreak of COVID-19 (P=0.001). There was no significant alteration observed in the frequency of hospitalizations per individual per annum (P=0.641) or the mean expense incurred per individual per hospitalization (P=0.361). In addition, the medical insurance coverage rate of real-time settlement increased year by year. After the COVID-19 outbreak, the origin of patients with solid tumor who visited BCH was concentrated in the northern region of China. COVID-19 had no impact on the other demographic factors, clinical characteristics, or economic burden of patients with pediatric malignant solid tumors.

Complete pathological response of pelvic Ewing sarcoma in adult female—a case report

Complete pathological response of pelvic Ewing sarcoma in adult female—a case report

The effect of albumin to alkaline phosphatase ratio on survival in patients with metastatic bone sarcomas

Objective: To investigate the effect of albumin to alkaline phosphatase ratio (AALPR) at survival in patients with metastatic bone sarcomas.&#x0D; Patients and Methods: 60 patients with metastatic bone sarcomas were included in the study. The relationship between AALPR before chemotherapy and overal survival (OS) and progression free survival (PFS) was evaluated with Cox regression multivariate analysis.&#x0D; Results: Of the patients in the study, 25 (58.3%) were osteosarcoma, 16 (26.7%) Ewing's sarcoma, 5 (8.3%) chondrosarcoma and 4 (6.7%) giant cell bone tumor. AALPR was 0.039 obtained in ROC analysis. The median PFS and OS at AALPR ≥ 0.039 group was statistically significantly higher than the group with

Machine Learning–Supported Diagnosis of Small Blue Round Cell Sarcomas Using Targeted RNA Sequencing

Small blue round cell sarcomas (SBRCSs) are a heterogeneous group of tumors with overlapping morphologic features but markedly varying prognosis. They are characterized by distinct chromosomal alterations, particularly rearrangements leading to gene fusions, whose detection currently represents the most reliable diagnostic marker. Ewing sarcomas (ESs) are the most common SBRCSs, defined by gene fusions involving EWSR1 and transcription factors of the ETS gene family, while the most frequent non-EWSR1-rearranged SBRCSs harbor a CIC rearrangement. Unfortunately, the identification of CIC::DUX4 translocation events, the most common CIC rearrangement, is challenging with current methods. Here, a machine-learning approach to support SBRCS diagnosis relying on gene expression profiles measured via targeted sequencing is presented. The analyses on a curated cohort of 69 soft tissue tumors (STT) showed markedly distinct expression patterns for SBRCS subgroups. A random forest (RF) classifier trained on ES and CIC-rearranged cases predicted probabilities of being CIC-rearranged > 0.9 for CIC-rearranged-like sarcomas and < 0.6 for other SBRCS. Testing on a retrospective cohort of 1335 routine diagnostic cases identified 15 candidate CIC-rearranged tumors with a probability > 0.75, all of which supported by expert histopathological reassessment. Furthermore, the multi-gene RF classifier appeared advantageous over using high ETV4 expression alone, previously proposed as surrogate to identify CIC rearrangement. Taken together, the expression-based classifier can offer valuable support for SBRCS pathological diagnosis.

The development and external validation of a web-based nomogram for predicting overall survival with Ewing sarcoma in children.

Ewing sarcoma remains the second most prevalent primary aggressive bone tumor in teens and young adults. The aim of our study was to develop and validate a web-based nomogram to predict the overall survival for Ewing sarcoma in children. A total of 698 patients, with 640 cases from the Surveillance, Epidemiology, and End Results (the training set) and 58 cases (the external validation set), were included in this study. Cox analyses were carried out to determine the independent prognostic indicators, which were further included to establish a web-based nomogram. The predictive abilities were tested through the concordance index, calibration curve, decision curve analysis, and area under the receiver operating characteristic curve. As suggested by univariate and multivariate Cox analyses, age, primary site, tumor size, metastasis stage (M stage), and chemotherapy were included as the independent predictive variables. The area under the receiver operating characteristic curve values, calibration curves, concordance index, and decision curve analysis from training and validation groups suggested the model has great clinical applications. We developed a convenient and precise web-based nomogram to evaluate overall survival for Ewing sarcoma in children. The application of this nomogram would assist physicians and patients in making decisions.

Precise single column resection and reconstruction with femoral head plus total hip replacement for primary malignant peri-acetabulum tumors

To evaluate whether single acetabular column can be reserved and the effect of reconstruction with femoral head plus total hip replacement (THR) for primary malignant peri-acetabulum tumors. From 2007 to 2015, nineteen patients with primary malignant peri-acetabulum tumors were enrolled. All cases underwent single column resection with clear surgical margins. Ten of the 19 tumor’s resections were assisted by computer navigation. Femoral heads were applied to reconstruct anterior or posterior column defects; THR was used for joint reconstruction. The surgical safety, oncologic outcome and prosthesis survivorship and function were evaluated by regular follow-up. The average follow-up period was 65.9 months. Surgical margins contained wide resection in 12 cases and marginal resection in 7 cases. One patient with Ewing's sarcoma died 14 months postoperative due to lung metastasis. One case with chondrosarcoma had recurrence. One prosthesis was removed due to infection. The average MusculoSkeletal Tumor Society (MSTS) function score was 83.7%. Due to the relative small number of cases, there was no significant difference in the recurrence rate and prosthesis failure rate between the navigation group and non-navigation group. Single column resection and reconstruction with femoral head autograft plus THR is an effective, safe method with less complication rate and better functional outcome for patients with peri-acetabular tumors.

Fusion of old and new: Employing touch imprint slides for next generation sequencing in solid tumors.

Cytomorphological evaluation of tissue touch imprints during rapid on-site evaluation or intraoperative pathology consultation has crucial value. However, literature on their utility for molecular testing is limited. In this study, we emphasize a further benefit of touch imprint slides and scrutinize our institutional experience on their use in molecular testing, specifically next generation sequencing (NGS). NGS-based reports (2019-2023) of Koç University Hospital were retrospectively analyzed and circumstances in which sequencing was conducted on touch imprint slides were retrieved (n = 18). Type/location of the biopsy, diagnosis, results, and quality metrics were recorded. Touch imprints were addressed when they harbored more neoplastic cells compared with permanent biopsies, when suboptimal fixation mitigated deoxyribonucleic acid/ribonucleic acid (DNA/RNA) yield in resections or when the sample was obtained from bone and required decalcification. Diagnoses were diverse, namely non-small-cell lung cancer, gastric adenocarcinoma, glial tumor, Ewing sarcoma, and carcinoma of unknown primary. The percentage of tumor cells on slides stretched between 15% and 70%. Molecular findings ranged from KRAS mutations to TRIM1::NTRK2 and EWSR::FLI1 fusions. For five cases, sequencing did not yield any alteration, one study was not completed because it did not yield high-quality RNA. Touch imprint slides provide a reliable alternative, especially when neoplastic cells are scarce in permanent biopsies or decalcification deters nucleic acid quality. Based on our experience, we suggest making touch imprints on a routine basis, especially for every bone biopsy. Once digitally scanned duplicates are made, original slides can be safely used for DNA-/RNA-based molecular studies.

Small cell osteosarcoma versus fusion-driven round cell sarcomas of bone: retrospective clinical, radiological, pathological, and (epi)genetic comparison with clinical implications.

Small cell osteosarcoma (SCOS), a variant of conventional high-grade osteosarcoma (COS), may mimic fusion-driven round cell sarcomas (FDRCS) by overlapping clinico-radiological and histomorphological/immunohistochemical characteristics, hampering accurate diagnosis and consequently proper therapy. We retrospectively analyzed decalcified formalin-fixed paraffin-embedded (FFPE) samples of 18 bone tumors primarily diagnosed as SCOS by methylation profiling, fusion gene analysis, and immunohistochemistry.In eight cases, the diagnosis of SCOS was maintained, and in 10 cases it was changed into FDRCS, including three Ewing sarcomas (EWSR1::FLI1 in two cases and no identified fusion gene in the third case), two sarcomas with BCOR alterations (KMT2D::BCOR, CCNB3::BCOR, respectively), three mesenchymal chondrosarcomas (HEY1::NCOA2 in two cases and one case with insufficient RNA quality), and two sclerosing epithelioid fibrosarcomas (FUS::CREBL3 and EWSR1 rearrangement, respectively).Histologically, SCOS usually possessed more pleomorphic cells in contrast to the FDRCS showing mainly monomorphic cellular features. However, osteoid was seen in the latter tumors as well, often associated with slight pleomorphism. Also, the immunohistochemical profile (CD99, SATB2, and BCOR) overlapped.Clinically and radiologically, similarities between SCOS and FDRCS were observed, with by imaging only minimal presence or lack of (mineralized) osteoid in most of the SCOSs.In conclusion, discrimination of SCOS, epigenetically related to COS, versus FDRCS of bone can be challenging but is important due to different biology and therefore therapeutic strategies. Methylation profiling is a reliable and robust diagnostic test especially on decalcified FFPE material. Subsequent fusion gene analysis and/or use of specific immunohistochemical surrogate markers can be used to substantiate the diagnosis.

Acute Lymphoblastic Leukemia (ALL) as a secondary malignancy in adolescent patient after completion of Ewing's sarcoma chemotherapy: a case report

OBJECTIVE: To report an adolescent patient who was diagnosed with Acute lymphoblastic leukemia (ALL) after completing Ewing sarcoma (ES) therapy. CASE: A 14 years old girl complained of left crusis tumor since 4 months before hospitalized. Tumor biopsy showed a round cell tumor, as well as immunohistochemistry which showed a positive CD99, consistent with ES. The patient had received 14 cycles chemotherapy for 7 months with regimens vincristine 1.5 mg/m2, cyclophosfamide 1200 mg/m2, dactinomycin 0.5 mg/m2, and doxorubicin 30 mg/m2. Between chemotherapy, patient also was given granulocyte colony-stimulating factor several times. Pasien also undergo 31 times radiation therapy with total 31x1.8 Gy (55.8 Gy). Two months after last chemotherapy for Ewing sarcoma, she was admitted again with prolonged fever, and pallor.Laboratorium showed leukocytosis (88.86x103uL), monocytosis (41%), severe neutropenia (0.39x103uL), severe normochromic normocytic anemia (4,3 g/dL), severe thrombocytopenia (4x103uL), reticulocytopenia (0,46%), with lymphoblast in peripheral blood smear. Bone marrow aspiration result showed lymphoblast infiltration 60% with heterogen morphology, no cluster cell non hematopoetic in bone marrow, consisten with acute lymphoblastic leukemia (ALL-L2) suspected secondary malignancy from Ewing’s Sarcoma. Patient underwent chemotherapy for high risk ALL at induction phase with combination of vincristin, daunorubicin, L-asparginase, metotrexate high dose, prednison, and 6-mercaptopurine. After completing induction phase, the patient’s condition get worsening and later died. CONCLUSION: ES survivors are at significant risk for secondary malignancies. Leukimia is one of which the most common secondary malignancies. Young children are particularly susceptible to the mutagenic effects of both chemotherapy and radiotherapy, as proven by several studies.

Sonographic features of sternal pseudotumour in children

AbstractIntroductionSternal pseudotumour is an important but rare entity thought to be an inflammatory, non‐neoplastic lesion that can mimic tumours. The purpose of this paper was to illustrate the imaging features of this lesion to avoid unnecessary investigations.MethodsThe clinical notes and imaging features of four patients with a diagnosis of sternal pseudotumour were reviewed over a period from February 2016 to July 2019.ResultsAll patients were afebrile with no history of trauma. The median age at presentation was 12.5 months. The median length of symptoms prior to presentation was 3.5 days. One patient had a mildly elevated C‐reactive protein. Chest radiographs showed a pre‐sternal soft‐tissue mass, with or without osseous destruction of the subjacent sternum. Ultrasound showed a heterogeneous, hypoechoic pre‐sternal soft‐tissue mass with variable internal vascularity with extension between sternal ossification centres. CT and MRI showed an enhancing dumbbell‐shaped lesion with a pre‐sternal and retro‐sternal soft‐tissue component. The median time to complete resolution was 3 months. One patient had a biopsy that showed chronic inflammation and fibrosis.DiscussionThese lesions present in young children typically with a 1‐ to 2‐week history of a focal 2‐ to 4‐cm swelling over the sternum. The aetiology is unknown but may be on the basis of a yet‐to‐be identified pathogen. Inflammatory markers and cultures are normal or mildly elevated. Important differential considerations include sternal osteomyelitis or neoplastic causes such as Ewing sarcoma, rhabdomyosarcoma, Langerhans cell histiocytosis and infantile fibrosarcoma.ConclusionSternal pseudotumor is a rare but important entity to be aware of to avoid unnecessary invasive biopsy or further investigations. Our suggestion is that this is a ‘Don't touch’ lesion that requires close short‐interval follow‐up at a surgical outpatient clinic and with ultrasound until resolution.