Skeletal Ewing Sarcoma Research Articles

An unusual cystic presentation of pelvic skeletal Ewing sarcoma: a case series.

Ewing sarcoma (ES) is the second mostcommon primarymalignant bone tumour in children and adolescents. About 14.5% of primary malignancies develop in pelvic bones, wherethey typically have worse prognoses than extremity or acral sarcomas. It usually presents with aggressive features onradiology scans, but may also present with different radiological characteristics. In this series, we describe rare appearancesof pelvic skeletal Ewing sarcoma, with large extraosseous cystic component on imaging, defined by the presence of fluid-filledspaces in the extraosseous tumour lesion, which distinguishes it from the solid nature of conventional ES. We report3 cases of cystic presentation of ES, with imaging features supporting diagnosis of a primary malignant bone tumourarising from the superior pubic ramus with associated massive intrapelvic solid and cystic mass. CT-guided biopsy provideddiagnosis of ES, with large intrapelvic soft tissue and cystic component. These patients underwent neo-adjuvantchemotherapy and proton beam therapy with significant reduction in size of the solid components, while the cysticcomponents remained relatively unchanged. Two patients underwent surgical resection of the tumour (navigated P3internal hemipelvectomy and hemipelvis P2/P3 resection, respectively), and one patient died while on treatment. In both whounderwent surgery, histology showed ES with margins clear and more than 99% of treatment-induced necrosis. To theauthors' knowledge, this unusual presentation of pelvic ES is described for the first time in the literature as a case series,with particular reference to atypical extraosseous cystic changes, along with the clinical and radiological characteristics,and their treatment.

Ewing sarcoma: a tumor with an uncanny predilection for uncommon sites

Ewing sarcoma is one of the most common bone tumors diagnosed in pediatric age group second only to osteosarcoma. The tumor is known to involve most commonly pelvic bones and long bones while extra-skeletal Ewing sarcoma accounts for 15%. Ewing sarcoma of other sites like scapula, clavicle, hands, and feet are quite rare, accounting for only 3-5%. To determine the epidemiological profile of Ewing sarcoma of unusual sites treated in our department including age at diagnosis, site of origin and mode of management along with survival data. Details of Ewing sarcoma patients reported our department in last 9 years were collected and data was analysed. We report a total of 20 cases of Ewing sarcoma in last 9 years with 4 (20%) extra skeletal Ewing sarcoma arising from soft tissues of extremities and 30% from rare sites (3 scapula, 1 clavicle, 1 phalanx, 1 calcaneum). All patients were operated after 4-7 cycles of chemotherapy with 66% limb salvage rate. With an average necrosis of 40%, with a median follow up of 36 months, the overall survival of the group was found to be 77.7%. Ewing sarcoma is one of the rare tumors of bone and soft tissue with the predilection for unusual sites, with reasonable survival outcomes in localized disease. Though scapula, clavicle, hands and feet are rare sites for Ewing sarcoma, they accounted for 30% in our department, possibly because of the referral patterns.

Transcriptomic and immunophenotypic characterization of two cases of adamantinoma-like Ewing sarcoma of the thyroid gland.

Adamantinoma-like Ewing sarcoma (ALES) is a rare aggressive malignancy occasionally diagnosed in the thyroid gland. ALES shows basaloid cytomorphology, expresses keratins, p63, p40, frequently CD99, and harbours the t(11;22) EWSR1::FLI1 translocation. There is debate on whether ALES resembles more sarcoma or carcinoma. We performed RNA sequencing from two ALES cases and compared findings with skeletal Ewing's sarcomas and nonneoplastic thyroid tissue. ALES was investigated by in situ hybridization (ISH) for high-risk human papillomavirus (HPV) DNA and immunohistochemistry for the following antigens: keratin 7, keratin 20, keratin 5, keratins (AE1/AE3 and CAM5.2), CD45, CD20, CD5, CD99, chromogranin, synaptophysin, calcitonin, thyroglobulin, PAX8, TTF1, S100, p40, p63, p16, NUT, desmin, ER, FLI1, INI1, and myogenin. An uncommon EWSR1::FLI transcript withretained EWSR1 exon 8 was detected in both ALES cases. Regulators of EWSR1::FLI1 splicing (HNRNPH1, SUPT6H, SF3B1) necessary for production of a functional fusion oncoprotein, as well as 53 genes (including TNNT1, NKX2.2) activated downstream to the EWSR1::FLI1 cascade, were overexpressed. Eighty-six genes were uniquely overexpressed in ALES, most of which were related to squamous differentiation. Immunohistochemically, ALES strongly expressed keratins 5, AE1/AE3 and CAM5.2, p63, p40, p16, and focally CD99. INI1 was retained. The remaining immunostains and HPV DNA ISH were negative. Comparative transcriptomic profiling reveals overlapping features of ALES with skeletal Ewing's sarcoma and an epithelial carcinoma, as evidenced by immunohistochemical expression of keratin 5, p63, p40, CD99, the transcriptome profile, and detection of EWSR1::FLI1 fusion transcript by RNA sequencing.

3D vs. 2D MRI radiomics in skeletal Ewing sarcoma: Feature reproducibility and preliminary machine learning analysis on neoadjuvant chemotherapy response prediction.

The extent of response to neoadjuvant chemotherapy predicts survival in Ewing sarcoma. This study focuses on MRI radiomics of skeletal Ewing sarcoma and aims to investigate feature reproducibility and machine learning prediction of response to neoadjuvant chemotherapy. This retrospective study included thirty patients with biopsy-proven skeletal Ewing sarcoma, who were treated with neoadjuvant chemotherapy before surgery at two tertiary sarcoma centres. 7 patients were poor responders and 23 were good responders based on pathological assessment of the surgical specimen. On pre-treatment T1-weighted and T2-weighted MRI, 2D and 3D tumour segmentations were manually performed. Features were extracted from original and wavelet-transformed images. Feature reproducibility was assessed through small geometrical transformations of the regions of interest mimicking multiple manual delineations, and intraclass correlation coefficient >0.75 defined feature reproducibility. Feature selection also consisted of collinearity and significance analysis. After class balancing in the training cohort, three machine learning classifiers were trained and tested on unseen data using hold-out cross-validation. 1303 (77%) 3D and 620 (65%) 2D radiomic features were reproducible. 4 3D and 4 2D features passed feature selection. Logistic regression built upon 3D features achieved the best performance with 85% accuracy (AUC=0.9) in predicting response to neoadjuvant chemotherapy. Compared to 2D approach, 3D MRI radiomics of Ewing sarcoma had superior reproducibility and higher accuracy in predicting response to neoadjuvant chemotherapy, particularly when using logistic regression classifier.

Ewing's Sarcoma of the Gastrointestinal Tract—A Case Series

Ewing's sarcoma is a neoplasm of the undifferentiated small round cells, which generally affects the bone and deep soft tissues of children and adolescents. Extraskeletal Ewing's sarcomas are less common than skeletal Ewing's sarcoma with the most common sites being chest wall, retroperitoneal space, lower extremities, paravertebral region, and gluteal region. Primary Ewing's sarcoma of the gastrointestinal tract is rare. The rarity of cases, lack of specific literature, or guidelines for treatment and varying presentations make these cases challenging to diagnose and to treat. In this series, we share our experience from a tertiary cancer care center in South India. By our knowledge, this is the first case series in literature sharing the experience from a single center in treating four cases of gastrointestinal Ewing's sarcoma.

A CASE OF EXTRASKELETAL EWING'S SARCOMA IN THE RETROPERITONEUM

A 23-year-old man was admitted to our hospital with a huge pelvic tumor. MRI showed a tumor mixed with a solid component and polycystic cyst with maximum diameter of about 20 cm. Percutaneous tumor needle biopsy was performed and diagnosis was Ewing sarcoma. At that time, operation is extremely difficult, so the neoadjuvant chemotherapy with ifosfamide, etoposide, Adriamycin, and vincristine were administered. After 6 courses, MRI showed tumor reduction to maximum diameter of 10 cm. We planned tumor resection with total cystectomy for radical resection, but we also tried to preserve bladder considering the young age and quality of life. Although the bladder was partially resected, tumor resection was succeeded without removing surrounding organs. Histopathological examination revealed viable cells remained, but more than 95% was disappeared and the surgical margins were negative. Here we report a case of extra skeletal Ewing sarcoma in the retroperitoneum that was treated with chemotherapy and surgery without scarifying surrounding organs.

Outcomes of extra-skeletal versus skeletal Ewing sarcoma patients treated with standard chemotherapy protocol.

11027 Background: Extra-skeletal ewing sarcomas (ES) are rare, and data on outcomes following standard ES chemotherapy protocols are very limited. Methods: We retrospectively collected data on skeletal and extra-skeletal ES patients who presented with localized disease from January, 2006 to June, 2018. Disease and treatment characteristics were compared between the two groups by the chi-square test. Overall survival (OS) and local recurrence free survival (LRFS) were estimated by the Kaplan-Meier method and compared by the Log-rank test. Results: A total of 120 patients were included. Twenty-nine (24%) had extra-skeletal and 91 (76%) had skeletal ES. Location was in the extremity in 51 (43%) and non-extremity in 69 (57%). For extra-skeletal ES, tumors originated from soft tissue in 23 (79%), and viscera in 6 (21%). All patients received standard vincristine, doxorubicin, and cyclophosphamide alternating with ifosfamide and etoposide (VDC-IE), with a plan for local control at week 12 of the protocol. Local control was by surgery in 76 (63%) and radiotherapy in 44 (37%). At a median follow up of 38 months, there was no difference in 5-year OS between extra-skeletal and skeletal ES patients (67% and 70% respectively, p = 0.96). Patients with visceral ES had inferior 5-year OS compared to all others (soft-tissue extra-skeletal and skeletal ES); 33% vs. 72%; p = 0.013. Resectability rate was not different between extra-skeletal and skeletal ES patients (54% and 69% respectively, p= 0.11). Furthermore, among patients who underwent surgery, there was no difference between extra-skeletal and skeletal ES patients in R0 resection rate (86% and 89% respectively, p= 0.52) and poor ( < 90%) tumor necrosis rate (62% and 46% respectively, p= 0.31). However, more local recurrences (28% vs. 10%, p= 0.034) and inferior 5-year LRFS (74% vs. 83%; p = 0.042) were observed in the extra-skeletal group, although more extra-skeletal patients received adjuvant radiotherapy; 11 (73%) vs. 21 (36%), p = 0.01. Conclusions: Patients with localized extra-skeletal ES have OS outcomes that are comparable to skeletal ES treated with standard VDC-IE chemotherapy. However, extra-skeletal ES patients are at significantly higher risk of local recurrence.

Comparison of clinical features and outcomes in patients with extraskeletal vs skeletal Ewing sarcoma: an SEER database analysis of 3,178 cases.

BackgroundThe clinicopathological characteristics, outcomes and prognostic factors of primary extraskeletal Ewing sarcoma (EES) remained insufficiently explored. We aimed to examine these aspects and compared the same with skeletal Ewing sarcoma (SES).Patients and methodsWe identified Ewing sarcoma, peripheral primitive neuroectodermal tumors or Askin tumor patients who were registered in the Surveillance, Epidemiology, and End Results database from 1973 to 2014. Clinicopathological features were assessed by using Fisher’s exact tests. Cancer-specific survival (CSS) and overall survival (OS) were estimated by using the Kaplan–Meier method and the Cox proportional hazards model. Prognostic factors were identified by multivariate Cox regression analysis.ResultsThe age of patients with EES was diagnosed to be higher and they were more likely to be female (46.1% vs 36.2%; P<0.001), have tumor <10 cm (49.8% vs 35.4%; P<0.001), have regional node involvement (5.4% vs 1.0%; P<0.001) and receive surgery (69.1% vs 53.8%; P<0.001) compared to patients with skeletal tumors. Metastatic status did not differ by origin. Kaplan–Meier analysis showed that the origin had significant difference in CSS and OS among patients aged 0–19 years and with metastatic stage at presentation, but not in patients aged 20–39, ≥40 years and with no-metastatic stage. A Cox multivariable model controlling for differences between groups confirmed inferior survival for patients with EES. Age, tumor size, tumor stage and surgery were the most important factors significantly influencing both CSS and OS in the EES and SES patients. Race, year of diagnosis and tumor site were associated with CSS and OS among patients with SES, but failed in EES.ConclusionThe clinicopathological characteristics, outcomes and prognostic factors differed among patients with EES compared to patients with SES. Extraskeletal origin was an unfavorable prognostic factor.

Personalized genomic analysis based on circulating tumor cells of extra-skeletal Ewing sarcoma of the uterus: A case report of a 16-year-old Korean female.

A 16-year-old female with Ewing sarcoma, a very rare disease with poor prognosis in women, was admitted to the hospital with abdominal pain. Diagnostic laparotomy revealed the Ewing sarcoma originating from the extramural uterus. Histological examination yielded positive test results for CD99, vimentin, S-100, eosin 5-maleimide and periodic acid-Shiff. EWS-FLI1 type 1 translocation was confirmed. Fibroblast growth factor receptor (FGFR) 4 (c.1162G> A) and HRas proto-oncogene (HRAS; c.182A> G) mutations were also detected. At eight months following complete remission, pelvic lymph node metastasis was confirmed. Epithelial cell adhesion molecule-positive circulating tumor cells (CTCs) were detected in liquid biopsy. FGFR3 (c.1948A> G) and FGFR4 (c.1162G> A) mutations were found in the CTCs. FGFR4 (c.1162G> A) and HRAS (c.182A> G) mutations were confirmed in cell-free circulating tumor DNA. A sequence of EWSR1 gene was also confirmed in the CTCs. To the best of our knowledge, this is the first report of skeletal Ewing sarcoma being detected using multiple noninvasive diagnostic methods to observe genetic translocation and mutation in blood CTCs. It may be used to monitor the therapeutic effect of cancer or predict prognosis. Therefore, liquid biopsy is expected to serve a pivotal role in ultra-precise medicine in the future.

Extraskeletal versus Skeletal Ewing Sarcoma in the adult population: Controversies in care

Background and ObjectivesA lack of consensus exists on the prognosis of extraskeletal Ewing sarcoma (EES) relative to its skeletal (ES) counterpart in adults. This study sought to characterize outcome differences between the two diagnoses. MethodsFrom 2004 to 2014, the NCDB identified 2,660 Ewing Sarcoma patients. Cox proportional hazards regression analysis was used to identify risk factors for overall survival (OS). ResultsEES patients were older, more likely to be female, and have smaller tumors. Among patients with ES, 4.0% received no treatment, 2.5% received local therapy only (surgery and/or radiation), 16.8% received chemotherapy only, while 52.2% received combination therapy (local and chemotherapy), and 17.0% recieived triple therapy (surgery, radiation and chemotherapy). Among patients with EES, 4.3% recived no treatment, 5.6% received local therapy only, 15.6% received chemotherapy only, while 47.0% received combination therapy, and 21.6% received triple therapy. No difference in OS was observed between the two groups (P = 0.816). Factors independently associated with OS for ES included age (HR = 1.26, P = 0.01), Charlson-Deyo Score (CDS) ≥2 (HR = 3.66, P < 0.001), combination therapy (HR = 0.39, P < 0.001) and triple therapy (HR = 0.34, P < 0.001). For EES, factors for OS were age (HR = 1.52, P < 0.001), CDS ≥2 (HR = 1.90, P = 0.02), combination therapy (HR = 0.44, P < 0.001), triple therapy (HR = 0.34, P < 0.001) and PNET histology (HR = 1.33, P = 0.02). ConclusionsDemographic, histological, and treatment characteristics differ between adult patients diagnosed with ES and ESS. However, survival and independent predictors of survival are consistent between the two diagnoses.

Non-metastatic Ewing's sarcoma family of tumors of bone in adolescents and adults: prognostic factors and clinical outcome-single institution results.

There is limited data regarding outcomes of Ewing's sarcoma family of tumors in adolescents and adults compared with the same tumors in childhood. The aim of the study was to analyze prognostic factors and treatment results in a cohort of adolescents and adults with non-metastatic skeletal Ewing's sarcoma family of tumors. From 1992-2008, 90 adolescents and adults with Ewing's sarcoma family of tumors of the bone were referred to our institution. Sixty-five (72%) non-metastatic patients with analyzable data and treated in our institution were retrospectively evaluated. All patients were treated with alternated chemotherapy regimens administered every 3 weeks. The local treatment modality was selected according to tumor and patient characteristics. The median age was 21 years (range, 13-50). Most patients (74%) were >17 years of age. Forty-six percent of the tumors were located in the extremities. Local therapy was surgery in 45 patients and radiotherapy alone in 19 patients. Twenty-one patients received preoperative and 13 patients postoperative radiotherapy. Median follow-up was 43 months (range, 7-167). The 5-year event-free and overall survival rates for all patients were 44% and 49%, respectively. On univariate survival analysis, event-free and overall survival were worse for patients >17 years of age, tumor size >8 cm in diameter, an axial location, positive surgical margins, and poor histopathological response (<90% necrosis). Age, tumor site and tumor size on event-free and overall survival remained significant on multivariate analysis. We identified age, tumor size, and tumor site as independent prognostic factors, in accord with the Western literature. These patients require novel treatment modalities.

Extraskeletal and Skeletal Ewing Sarcoma Family of Tumours in Adults: A Clinico Radiological Review of 50 Cases

This review describes the imaging characteristics of Ewing sarcoma family of tumours ESFT exclusively in an adult population The magnetic resonance imaging MRI and computed tomography CT appearances in adult patients with ESFT is described The imaging characteristics in this largest case series of adult ESFT reported so far were similar to those reported in the paediatric ESFT Our incidence of extra skeletal ESFT of is the highest reported so far in the adult population and is higher than the reported incidence of in the paediatric and adolescent population MRI was found to be superior to CT scan in identifying tumour involvement of the bone marrow and in delineating the soft tissue involvement due to its multi planar imaging capability

Treatment outcomes of Japanese patients with Ewing sarcoma: differences between skeletal and extraskeletal Ewing sarcoma.

The incidence of Ewing sarcoma is lower in non-Caucasian populations, compared with Caucasian populations, for unknown reasons. Most studies from western countries have reported improvement in outcomes following multi-agent chemotherapy, with no difference in outcome between skeletal and extraskeletal Ewing sarcoma. However, there are few studies of Ewing sarcoma in non-Caucasian populations, with especially few comparing outcomes between skeletal and extraskeletal Ewing sarcoma. Thus, the purpose of this study is to determine whether the outcomes and prognostic factors of Ewing sarcoma in the Japanese population are similar to those in Caucasian populations and to determine whether skeletal and extraskeletal Ewing sarcoma have similar outcomes in Japanese patients. We retrospectively evaluated the outcomes of 74 Japanese patients with Ewing sarcoma treated between 1981 and 2011 from the Osaka University Orthopaedic Oncology Group. Extraskeletal Ewing sarcoma, tumors in the extremities, localized disease at presentation and diagnosis after 2000 were significantly associated with a favorable outcome. Among patients with localized disease at presentation, a significantly better outcome was observed for those with extraskeletal Ewing sarcoma, those who underwent a VDC/IE based or VAIA chemotherapy protocol, and those who were diagnosed after 2000. In the multivariable analyses, extraskeletal Ewing sarcoma was an independent predictor of increased overall survival among all patients and the subset of patients with localized disease. The outcome of patients with Ewing sarcoma in Japan has improved in the last decade. The outcomes and prognostic factors are similar for Japanese and Caucasian patients, though in this series of Japanese patients, a better prognosis was observed for patients with extraskeletal rather than skeletal Ewing sarcoma.

Congenital Ewing's Sarcoma/Primitive Neuroectodermal Tumor of the Upper Extremity.

Dear Editor, The patient was a female newborn, 3200 g in weight, 50 Cm in length, who presented at birth with a firm mass on the left upper arm, measuring 25 × 16 × 45 mm in size. Physical examination revealed a non-movable mass with firm consistency and mild tenderness on the left upper arm. Family and maternal histories were unnoteworthy, and the laboratory examination was normal. An excisional biopsy of the mass was performed and the histopathological findings of the excised lesion were ES/PNET. Immunohistochemistry was positive for CD99, NSE, PCK, desmin, and negative for CK. In enhanced chest CT, abdominal ultrasonography, and whole body bone scan no evidence of abnormality or metastasis was detected. Bone marrow biopsy and further treatment were refused by her parents. Unfortunately, the sarcoma recurred one year later. Seven cycles of VIDE regimen (Vincristine 0.25 mg d1; Ifosfamide 500 mg d1-4; Doxorubicin 3.5 mg d1-4; Teniposide 50 mg d1, 25 mg d2-4) was administered. After radiation therapy (3040cGy/19 fractions, 6 MeV electrons), the patient underwent autologous stem cell transplantation and achieved a complete remission. Two years later, the patient came to our institution presenting with a subcutaneous mass near the area of surgical scar on the left upper arm. The ultraphonic revealed several hypoechoic nodules between the skin and subcutaneous fat layer on the left upper arm, the biggest one measured 15 × 5mm in size. X-ray (Panel A) showed no adjacent humerus destruction. Magnetic Resonance Imaging showed several nodules on the shallow surface of biceps muscle of the left arm with slight enhancement and marked swelling of the surrounding soft tissue (Panel B, C, arrow). Chest CT scan and whole body bone scan were normal. Subsequent excisional biopsies were performed on 18/11/2013, and the postoperative pathologic results were Ewing’s sarcoma. The patient was treated by a course of three-dimensional conformal radiotherapy (3D-CRT) after surgery. Dose of external irradiation was 4680cGy/26 fractions (6 MeV X-ray) in 30 days. The patient is alive 20 months after the second relapse. ES and PNET share common antigenic profiles, cytogenic aberrations and proto-oncogene expression which are derived from the same primordial bone marrow-derived mesenchymal stem cell (1). At the molecular level, ES/PNET is characterized by chromosomal translocations that fuse the EWSR1 gene to some members of the ETS family of transcription factors, being FLI1 the most frequently implicated [t (11; 22) (q24; q12)] (2). The incidence of these tumors in early childhood is rare, accounting for less than 10 cases per million each year (3), and the incidence in newborns is exceedingly rare. Wong et al reported 1975 patients with Ewing’s sarcoma, only 39 (2.0%) were diagnosed at < 12 months of age (4). ES/PNET with a slight male predominance occur predominantly in primarily white and Hispanic patients; however, these tumors are extremely rare in individuals of African or Asian origin (2). ES/PNET account for approximately 10% of primary malignant bone tumors and mainly affect the long bones (47%), pelvis or ribs (5). While 30% are seen in an extraskeletal location of the soft tissues, 5% occurred in extremities among these extraskeletal Ewing’s sarcomas (6, 7). Manifestation in extraskeletal location of the soft tissues of extremities rarely occurs and this would appear to be the first description of a congenital ES/PNET arising in the soft tissue of upper extremity. Multiagent systemic therapy for localized ES/PNET achieved a 5-year survival of approximatly 70 - 75% (8-10). The similarity in survival between older and younger patients with Ewing sarcoma was reported in literature (11). A study including 2202 ES/PNETs demonstrated that extraskeletal ES/PNETs have a superior prognosis compared with skeletal Ewing sarcoma. About 30 – 40% of patients suffer from recurrent tumors and have a very poor prognosis (12). The 5-year survival following recurrence of these patients is approximately 10 – 15%, while it was 7% for those whose disease recurred within 2 years (13). In our case of disease recurrence after surgery, the patient was treated with multiagent chemotherapy, stem cell transplantation and aggressive surgical treatment, and is still surviving.

Extraosseous Ewing Sarcoma: Diagnosis, Prognosis and Optimal Management

Extraosseous Ewing sarcomas (EESs) are rare tumours originating from soft tissues. Their clinical picture depends mainly on the primary site of the sarcoma. Patient characteristics and outcomes seem to be different in EES compared to patients with skeletal Ewing sarcoma, with implications for patient care and prognosis. However, multimodality therapeutic strategies are recommended for all types of the Ewing tumour family. The available diagnostic tools include ultrasonographic evaluation and computed tomography (CT) or magnetic resonance imaging as well as histopathologic and immunohistochemical tissue examination. Several histologic and genetic biomarkers have been established, although their utilization needs to be further tested by larger prospective studies. Regarding localized disease, the recommended treatment remains surgery. However, chemotherapy can be added to achieve improved survival, with neoadjuvant regimens showing more promising results than adjuvant regimens. Radiotherapy is an option to obtain local control, although its complications have reduced its utilization. In metastatic or recurrent disease, systematic chemotherapy improves survival.

Role of radiation in the treatment of non-metastatic osseous Ewing sarcoma.

Local control, either with surgery, radiation (RT) or both, is essential in the management of localised Ewing sarcoma; however, the relative role of RT remains controversial. Using the Surveillance, Epidemiology, and End Results database, 612 patients treated for non-metastatic skeletal Ewing sarcoma between the years 1988 and 2010 were identified. Median age and follow-up were 13 years (range: 0-21) and 56 months (range: 0-287), respectively. Five-year overall survival (OS) for the cohort was 74.4 ± 2.0%. Patients received surgery alone (51.3%), RT alone (21.6%) or both (27.1%). Patients with skeletal Ewing sarcoma had improved OS with surgery alone compared with other treatments. However, in subset analyses, RT was not inferior to surgery alone for appendicular (5-year OS: 80.0% vs. 79.3%), non-pelvic (84.3% vs. 79.9%) or localised disease (confined to cortex or periosteum; 79.7% vs. 80.6%). After controlling for stage and site, no increase in mortality was observed with RT versus surgery alone (hazard ratio = 0.77 (95% confidence interval: 0.49-1.19)). In regard to survival, RT did not appear to be inferior to surgery alone for most patients, particularly those with disease at favourable sites (localised, appendicular, non-pelvic). In select patients with Ewing sarcoma, RT may be an appropriate strategy for local control that does not necessarily compromise survival outcomes.

Survival of adolescents and young adults (AYAs) with skeletal Ewing sarcoma: A Dutch population-based study.

10530 Background: Ewing sarcoma is most prevalent among children and adolescents. Although increasing age in general is associated with poorer survival, little is known about survival in adolescent...

Diagnostic accuracy of 18F-FDG PET/CT for detecting recurrence in patients with primary skeletal Ewing sarcoma

To evaluate the diagnostic accuracy of (18)F-FDG PET/CT for detecting recurrence in patients with primary skeletal Ewing sarcoma. We retrospectively analysed data from 53 patients (age 20.1 ± 10.5 years, 39 male) who had undergone 71 (18)F-FDG PET/CT studies for suspected recurrence (52 studies) or for routine follow-up (19 studies) after primary therapy of skeletal Ewing sarcoma. (18)F-FDG PET/CT studies were evaluated qualitatively and quantitatively (maximum standardized uptake value, SUVmax) by two nuclear medicine physicians in consensus. Sensitivity, specificity, predictive values and accuracy were calculated on per study basis. Clinical/imaging follow-up (minimum 6 months) and/or histopathology (when available) were taken as the reference standard. Of the total of 71 (18)F-FDG PET/CT studies, 42 (59.1%) were positive for recurrence and 29 (40.9%) were negative for recurrence. Local recurrence was most common (38 studies) followed by bone metastasis (9 studies), and node and lung metastasis (2 studies each). Of the 71 studies, 38 were true-positive, 27 were true-negative, 4 were false-positive and 2 were false-negative. Overall per study based sensitivity was 95%, specificity was 87%, PPV was 90%, NPV was 93% and accuracy was 91.5%. No significant difference was found in the accuracy of PET/CT between the suspected recurrence group and the routine follow-up group (94% vs. 84%; P = 0.390). Overall mean lesion SUVmax was 7.8 ± 4.1 (range 1.9-17.2). No site-based difference was found in SUVmax. (18)F-FDG PET/CT demonstrates high diagnostic accuracy for detecting recurrence in patients with primary skeletal Ewing sarcoma, when it is suspected (clinically or on imaging) or during routine follow-up.

Primary Extraskeletal Ewing's Sarcoma of Nasal Cavity

Extra skeletal Ewing's Sarcoma (EES) of nasal cavity is a rare soft tissue tumor, morphologically similar to the commoner Ewing's sarcoma (ES) arising from bone. We report a case of EES of nasal cavity in a nine year old male who presented with nasal obstruction. Contrast enhanced CT scan showed mildly enhancing soft tissue attenuating mass. Histopathologically examination showed round cell tumor which was confirmed by special stain and immunohistochemistry. PAS showed positivity for intracellular glycogen, Immunohistochemistry showed positivity for MIC-2,CK,S-100,EMA.

Tumoral thrombosis of inferior vena cava and iliac veins resulting in unilateral lower limb edema in a young adult: A rare presentation of skeletal Ewing's sarcoma

Association of venous thromboembolic events (TEs) with malignancy is well known. Ewing's sarcoma usually presents as swelling at the primary site, however presenting as unilateral lower limb edema due to tumoral thrombosis of right iliac vein and IVC is a rare event. A 30-year-old male patient with extensive right lower limb swelling was admitted and imaging studies (plain film, ultrasonography, Doppler, computed tomography) revealed a mass arising from right iliac bone, adjoining sacrum and tumoral thrombosis of right iliac veins extending into inferior vena cava. Histopathological diagnosis was Ewing's sarcoma. Patient was treated successfully with chemotherapy and surgical embolectomy. So a young patient presenting with deep vein thrombosis should be investigated not only to establish any thrombophilic pre-disposition, but also let the clinician to suspect for any local malignancy. Treatment depends upon the proximal extent of tumoral thrombus. With advances in imaging and chemotherapeutic regimens early diagnosis is possible and appropriate treatment planning improves the prognosis. To our knowledge skeletal Ewing's sarcoma with bland thrombosis is a known entity however no such case with direct invasion of tumor into veins leading to tumoral venous thrombosis has been reported in medical literature.