Protocol for the Examination of Specimens From Pediatric and Adult Patients With Osseous and Extraosseous Ewing Sarcoma Family of Tumors, Including Peripheral Primitive Neuroectodermal Tumor and Ewing Sarcoma

Extraskeletal Ewing's sarcoma of the thigh with lung and bone metastasis: Case report

INTRODUCTION AND IMPORTANCE

Extraskeletal Ewing's sarcoma is an uncommon tumor with a devastating prognosis and a very high mortality rate, particularly in metastatic forms, it primarily affects young people mainly in the 2nd to 4th decades of life. It can affect different parts of the body, without a particular clinical presentation which delays diagnosis.

CASE PRESENTATION

12-year-old male patient presented with swelling over the left proximal thigh of 7 months duration associated with pain and limping. On physical examination, he had about 20 × 15 cm firm, tender, and erythematous proximal left thigh swelling that is fixed to the structures with an overlying scar.

CLINICAL DISCUSSION

Extra skeletal Ewing's sarcoma (EES) is a member of the Ewing Sarcoma Family of tumors. EES is a rare tumor with an incidence ranging from 0.1 to 0.4 per a million people. It presented with rapidly increasing swelling mainly over the soft tissue of the proximal thigh, pelvis, paravertebral region, chest wall, upper arm and shoulder. Age at presentation ranges 10 to 30 years with no gender preference. Imaging is crucial in the diagnosis, preoperative assessment, in staging and evaluation of treatment outcomes. Histopathology study is mandatory for the definitive diagnosis of EES among competitive differential diagnoses. The management of EES includes Surgery, chemotherapy and/or radiation therapy based on the stage of the disease.

CONCLUSION

EES is a rare tumor but it should be in the differential diagnosis of adolescent patients presented with soft tissue mass/swelling.

Clinicodemographic characteristics of extraosseous ewing sarcoma: A comparative meta-analysis of pediatric and adult patients

Background

Evidence suggests different presentation patterns and prognosis of extraosseous Ewing Sarcoma (EES) based on age. Thus, we carried out this study to test the difference between children and adult EES cases regarding clinicodemographic characteristics and prognosis.

Methods

A total of 4 databases were explored yielding 18 relevant studies for data synthesis. Outcomes included the comparison of demographic and clinical characteristics as well as prognosis between children and adults with EES. Log odds ratio (logOR) and its 95% confidence interval (CI) were pooled across studies. Statistical models/methods were selected based on heterogeneity.

Results

Our analysis included a total of 1261 children and 1256 adults. When we compared these two age categories, we did not observe a significant difference in the risk of developing EES [logOR = -0.13; 95% CI: -0.65: 0.39; I2 = 88.42%]. No significant differences regarding gender, tumor location, and size (≤5 vs. >5 cm), EWSR1 positivity, or management modality. We did not observe significant difference regarding clinical outcomes, such as 5-year overall survival and event-free survival, recurrence, mortality, no evidence of disease, and secondary metastasis.

Conclusions

Our findings highlight the absence of an association between the age category of patients and the incidence of EES, as well as its clinical outcomes.

Practical Management of Adult Ultra-Rare Primary Retroperitoneal Soft Tissue Sarcoma: A Focus on Perivascular Epithelioid Tumours and Extraosseous Ewing Sarcoma

With the exception of well-differentiated liposarcoma, dedifferentiated liposarcoma, leiomyosarcoma, solitary fibrous tumour, malignant peripheral nerve sheath tumour, and undifferentiated pleomorphic sarcoma, the majority of the ≈70 histologic subtypes of retroperitoneal sarcoma are defined as 'ultra-rare' sarcomas, with an incidence of ≤1-5/1,000,000 persons/year. For most of these ultra-rare RPS subtypes, diagnosis and treatment follows international guidelines for the management of more common RPS histologies, with en bloc surgical resection as the mainstay of curative treatment, and enrolment in clinical trials where possible. Because the treatment of RPS is heavily driven by histology, the surgeon must be familiar with specific issues related to the diagnosis and management of ultra-rare sarcoma subtypes. Expert radiological and surgeon reviews are required to differentiate similarly presenting tumours where surgery can be avoided (e.g., angiomyolipoma), or where upfront systemic therapy is indicated (e.g., extraosseous Ewing's sarcoma). Thus, the management of all retroperitoneal sarcomas should occur at a sarcoma referral centre, with a multidisciplinary team of experts dedicated to the surgical and medical management of these rare tumours. In this focused review, we highlight how diagnosis and management of the ultra-rare primary RPS histologies of malignant perivascular epithelioid cell tumour (PEComa), extraosseous Ewing sarcoma (EES), extraosseous osteosarcoma (EOS), and rhabdomyosarcoma (RMS) critically diverge from the management of more common RPS subtypes.

Ewing’s Sarcoma of the Breast in a Young Woman: A Case Report and Review of the Literature

Ewing’s Sarcoma Family Tumors (ESFT) include classic Ewing’s sarcoma of bone, extra-skeletal Ewing’s sarcoma (EES), malignant small cell tumor of the chest wall (Askin tumor), and soft tissue-based Peripheral Primitive Neuroectodermal tumors (pPNET). The t(11;22)(q24;q12) translocation is associated with 85% of tumors and leads to EWS-FLI-1 (Ewing’s Sarcoma–Friend Leukemia Integration-1) formation. This is a potent transforming gene that encodes a chimeric protein that plays a role in the genesis of Ewing’s Sarcoma and Primitive Neuroectodermal Tumors. The breast location of ESFT remains exceptional. The prognosis is among the poorest of all subtypes of breast cancer and even poorer than other extraosseous Ewing’s sarcomas. We describe the case report of a 23-year-old patient with a growing breast lump, who required an accurate and challenging diagnostic estimation and who ultimately resulted in a peripheral primary neuroectodermal tumor (pPNET). Through this case description and a brief narrative review of the literature, we aim to highlight the rarity of ESFT located in the breast. Histopathological confirmation is mandatory for all growing masses of the breast to reach a conclusive diagnosis and plan the correct treatment. Patients with rare diagnoses should always be centralized in breast units, conducting multidisciplinary meetings and, when necessary, the diagnosis should be shared through wider national or international registries.

Primary primitive neuroectodermal tumor of urinary bladder: a case report and literature review

Primary primitive neuroectodermal tumor (PNET) of the bladder is an extremely rare and highly aggressive neoplasm. We report a case of PNET of the urinary bladder associated with increased serum neuron-specific enolase (NSE) in the presence of relapse and metastasis. A 66-year-old male presented to our department due to painless gross hematuria. Computed tomographic urography (CTU) showed an intraluminal tumor in the anterior bladder wall. Biopsy revealed a malignant small round blue cell tumor. The patient denied radical cystectomy, and partial cystectomy was given together with resection of adjacent peritoneum. The patient was diagnosed with primary bladder PNET after pathological inspection with negative surgical margins. Additionally, he received 6 cycles of chemotherapy using etoposide and cisplatin (EP) regime, and showed recurrence and metastasis afterwards. Disease progression was seen after transurethral resection (TUR) of bladder tumor and radiotherapy. Pelvic and retroperitoneal metastasis triggered bilateral hydronephrosis, and then palliative treatment was given with bilateral percutaneous nephrostomy. Finally, he died 12 months after diagnosis. PNETs are highly aggressive tumors characterized by the expression of MIC2 and neural markers and the presence of EWS-FLI1 translocation. We recommend histologic, immunohistochemical, and cytogenetic analysis in all patients with small round blue cell bladder malignancy in order to rule out other small cell malignancies. Multimodal treatment, including surgery and adjuvant chemotherapy must be initiated. Patients aged ≤30 years underwent complete resection of tumor and standard chemotherapy showed a better prognosis, while those with metastasis, incomplete resection and inadequate response to chemotherapy showed poor prognosis. Moreover, an elevated NSE may indicate a poor prognosis.

Extraskeletal Ewing sarcoma: Diagnosis, management and prognosis

Extraskeletal Ewing sarcoma (EES) is a relatively uncommon primary tumor of the soft tissues, which accounts for 20-30% of all reported cases of ES. Being uncommon, all members of the ES family tumors are treated following the same general protocol of sarcoma tumors. The present review summarizes the diagnosis, management and prognosis of EES, focusing on the differences between the subtypes of ESS. The clinical features and imaging of EES are also discussed. Magnetic resonance imaging is the modality of choice for diagnostic imaging and local staging, while core-needle biopsy with pathological testing is used to obtain a definitive diagnosis. Although several oncology groups endorse that ES family of tumors should be treated with similar algorithm and protocols, some studies have demonstrated that surgery and radiotherapy may be used as a form of local control. However, further studies are required to conclude the optimum treatment option for EES.

EWSR1 fusion proteins mediate PAX7 expression in Ewing sarcoma

PAX7 is a paired-box transcription factor that is required for the developmental specification of adult skeletal muscle progenitors in mice. We previously demonstrated PAX7 expression as a marker of skeletal muscle differentiation in rhabdomyosarcoma. Here, using analyses of published whole-genome gene expression microarray data, we identify PAX7 as a gene with significantly increased expression in Ewing sarcoma in comparison to CIC-DUX4 round cell sarcoma. Analysis of PAX7 in a large cohort of 103 Ewing sarcoma cases by immunohistochemistry revealed expression in 99.0% of cases (102/103). PAX7 expression was noted in cases demonstrating three distinct Ewing sarcoma EWSR1 translocations involving FLI1, ERG, and NFATc2. No PAX7 expression was observed in any of 27 cases of CIC-DUX4 sarcoma by immunohistochemistry (0%; 0/27). Exploring the mechanism of PAX7 expression in Ewing sarcoma using curated RNA- and ChIP-sequencing data, we demonstrate that the EWSR1 fusion protein is required for PAX7 expression in Ewing sarcoma and identify a candidate EWSR1-FLI1-bound PAX7 enhancer that coincides with both a consensus GGAA repeat-containing binding site and a peak of regulatory H3K27 acetylation. Taken together, our findings provide mechanistic support for the utility of PAX7 immunohistochemistry in the diagnosis of Ewing sarcoma, while linking this sarcoma of uncertain histogenesis to a key transcriptional regulator of mammalian muscle progenitor cells.

Extraosseous Ewing sarcoma in the mesentery: the first report of cases in children

Extraosseous ewing sarcoma (EES) is a rare soft-tissue tumor usually found in the extremities or paraspinal region. We describe the case of a 4-year-old boy with a large cystic mass in the mesentery diagnosed as mesenteric lymphangioma preoperatively and as EES after partial resection and histopathological examination. EES in the mesentery is extremely rare, with only 2 reports described in the English literature. This represents the first report of EES in a child.

Gene expression profiling of peripheral blood cells: new insights into Ewing sarcoma biology and clinical applications

Ewing sarcoma (ES) is a group of highly aggressive small round cell tumors of bone or soft tissue with high metastatic potential and low cure rate. ES tumors are associated with a rapid osteolysis and necrosis. The currently accepted clinical prognostic parameters do not accurately predict survival of high-risk patients. Moreover, neither the subtype of EWS-FLI1/ERG in the tumor, nor the detection of fusion transcripts in the peripheral blood (PB) samples, has prognostic value in ES patients. We evaluated the prevalence of circulating tumor cells (CTCs) in 34 adult ES patients. Since CTCs were confirmed in only small subset of patients, we further explored the expression profiles of PB leukocytes using a panel of genes associated with immune system status and increased tumor invasiveness. Moreover, we analyzed the alterations of the routine blood tests in the examined cohort of patients and correlated our findings with the clinical outcome. A uniform decrease in ZAP70 expression in PB cells among all ES patients, as compared to healthy individuals, was observed. Monocytosis and the abnormal expression of CDH2 and CDT2 genes in the PB cells significantly correlated with poor prognosis in ES patients. Our study supports the previously proposed hypothesis of systemic nature of ES. Based on the PB cell expression profiles, we propose a mechanism by which immune system may be involved in intensification of osteoclastogenesis and disease progression in ES patients. Moreover, we demonstrate the prognostic value of molecular PB testing at the time of routine histopathological diagnosis.

Some general considerations about the clinicopathologic aspects of soft tissue tumors in children and adolescents

Soft tissue tumors in children and adolescents are an important group of neoplasms, pseudoneoplasms, and tumefactive malformations with some distinctive clinicopathologic, genetic, syndromic, and therapeutic implications. In addition to the basic pathologic examination, there is the availability of diagnostic adjuncts in various settings based upon the histopathologic features that facilitate and/or corroborate a diagnosis. Immunohistochemistry, cytogenetics, molecular genetics, and an ever-increasing array of new technologies are available to address specific diagnostic questions and even potential therapeutic strategies. This review focuses upon some of the unique aspects of soft tissue tumors in children, including the classification, approach to the diagnosis, grading, clinical and pathologic staging, therapy-related changes, pathogenesis, and risk factors.

Modern Diagnosis of Small Cell Malignancies of Children

Small cell malignancies of children constitute a continuing diagnostic challenge for surgical pathologists, although modern methods of ancillary diagnosis provide powerful tools that resolve most difficult cases. Current techniques range from identification of DNA alternations, including gene fusions, chromosome translocations, and genetic deletions, to recognition of characteristic patterns of protein expression, usually visualized with immunohistochemistry. In spite of these advances, recognition of key cellular and histologic features remains the keystone of diagnosis but requires adequately fixed and carefully stained histologic sections. Cytologic features now suffice for diagnosis if confirmed by appropriate testing. This article outlines key histologic features of pediatric small cell neoplasms and the algorithms that allow diagnostic confirmation and the initiation of appropriate therapy.

The efficient operation of the surgical pathology gross room

The gross room is the area where pathology specimens from operating rooms are transferred for pathology review and analysis, serving as the bridge between the treating physician and diagnostic surgical pathologist. Reaching the correct diagnosis for a specimen depends on the proper handling and processing of tissue transferred to this very busy area. We review here the basic function and management of the gross room including a brief discussion of common specimen types, biohazard exposure and safety, and collection of tissue for research.

Ewing sarcoma and primitive neuroectodermal tumor of the esophagus: report of a case and review of literature

This study presents a case of Ewing sarcoma and primitive neuroectodermal tumor arising in the esophagus of a 44-year-old woman who presented with progressive dysphagia. Imaging studies demonstrated a polypoid lesion in the esophagus. The tumor was characterized by corded and pseudopapillary architecture, cytologic monotony, and low proliferative activity. Immunohistochemical stains were positive for CD99, neuron-specific enolase, vimentin, cyclin D1, p53, and FLI1 gene product. Fluorescence in situ hybridization demonstrated a 22q12 translocation, associated with primitive neuroectodermal tumor in the tumor cells, whereas reverse transcription polymerase chain reaction conformed expression of Ewing sarcoma/FLI1 fusion transcript in the patient's bone marrow aspirate. Although this is a rare site for this type of tumor to occur, primitive neuroectodermal tumor should be considered in the differential diagnosis of mesenchymal tumors of the esophagus. Genetic analysis is crucial to establish the diagnosis and can be successfully performed on formalin-fixed, paraffin-embedded material and hematopoietic tissue.

The problems and promise of central pathology review: development of a standardized procedure for the Children's Oncology Group

The practice of central histopathologic review by expert pathologists has accompanied entry of patients onto multi-institutional therapeutic research protocols for the past half-century, and it is still a key component in the majority of therapeutic protocols conducted by the Children's Oncology Group (COG). Policies regarding pathology review have historically varied but have recently been standardized by the COG. Pretreatment central pathology review has been used to improve the accuracy of pathology data that is critical to the conduct of the study and to ensure that ineligible patients are not enrolled on a study. Pretreatment central review is unnecessary when there are established criteria for diagnosis, when institutions can uniformly apply these criteria, and when diagnoses are reliably reported. Pretreatment central review is appropriate when there are established diagnostic criteria and expert reviewers can consistently apply them but when institutional diagnoses show significant variability. It is inappropriate when there are no standard criteria or when variability exists among experts. Retrospective reviews (for example, those performed after protocol entry and treatment have occurred) historically have been used to verify institutional diagnoses and to record other features of tumors, prior to analysis of research questions. However, delayed reporting of discrepant diagnoses from retrospective reviews introduced obvious concerns regarding the appropriateness of treatment and exposed institutional pathologists and clinicians to significant professional risks. This article examines the historical usage and current status of the central pathology review process and the rationale and indications for its performance.

Small Round Cell Tumors of Bone

Context.—Primary small round cell tumors of the bone are a heterogeneous group of malignant neoplasms presenting predominantly in children and adolescents. They include Ewing sarcoma/peripheral neuroectodermal tumor or Ewing family tumors, lymphoma, mesenchymal chondrosarcoma, and small cell osteosarcoma. Even though they share many morphological similarities, their unique biological and genetic characteristics have provided substantial insights into the pathology of these diverse neoplasms.

Objective.—To provide an overview of the clinical, radiologic, pathologic, and genetic characteristics of these tumors along with a pertinent review of the literature.

Data Sources.—A literature search using PubMed and Ovid MEDLINE was performed, and data were obtained from various articles pertaining to clinicopathologic, biological, and genetic findings in these tumors. Additionally, findings from rare cases have been included from author's subspecialty experience.

Conclusion.—The diagnosis of small round cell tumors can be made accurately by applying clinicopathologic criteria, as well as a panel of immunohistochemical and genetic studies in appropriate cases. Molecular genetic studies may provide further insight into the biology, histogenesis, and prognosis of these tumors.

Primitive neuroectodermal tumor: rare, highly aggressive differential diagnosis in urologic malignancies

OBJECTIVES

Peripheral primitive neuroectodermal tumor (PNET) is a highly aggressive neoplasm belonging to the Ewing family of tumors. It is characterized by the expression of MIC2 and neural markers (eg, neuron-specific enolase, synaptophysin, S-100, vimentin, Leu-7), and the presence of the EWS-FLI1 translocation.

METHODS

We performed a MEDLINE search for PNET in urologic malignancies. Additionally, we report on 2 cases of renal and 1 case of bladder PNET. The data obtained by reviewing patients with renal PNET were analyzed using Kaplan-Meier analysis.

RESULTS

Renal PNET is diagnosed in young adults (median age 24 years). In contrast, the incidence of bladder PNET seems to be dependent on a defective immune mechanism. Patients often present with pain (84%), palpable tumor (60%), and hematuria (38%). The radiologic findings are uncharacteristic; therefore, the diagnosis should be based on the histologic and immunohistochemistry findings. Renal and bladder PNET are both often diagnosed at an advanced stage and, therefore, the prognosis is poor, despite aggressive multimodal treatment (surgery, polychemotherapy, radiotherapy). We identified palpable tumor masses (log-rank test, P = 0.0027) and synaptophysin expression (log-rank test, P = 0.0422) as prognostic unfavorable markers for renal PNET.

CONCLUSIONS

Renal PNET should be considered in young patients who present with the classic triad of renal cancer, hematuria, and pain and palpable tumor. Once PNET is diagnosed, multimodal treatment (radical surgery, multidrug chemotherapy, radiotherapy) must be initiated. Despite this, the prognosis is poor if distant metastases are present. Furthermore, palpable tumor masses and synaptophysin expression are associated with a shorter cancer-specific survival.

Pediatric undifferentiated sarcoma of the soft tissues: a clinicopathologic study

Pediatric undifferentiated soft tissue sarcomas represent a major challenge for pathologists and clinicians. The goal of this study was to identify cases that warranted this diagnosis by current standards of analysis and then determine if there are clinicopathological commonalities that may be useful for diagnosis, management, and prognosis. Eighteen potential patients were identified using the institutional pathology database. Three cases were reclassified as specific sarcomas, and 2 cases had insufficient material for molecular analysis, leaving 13 cases for pathological review and 12 patients for radiological and clinical review. There were 7 males and 6 females. The median age at diagnosis was 11 years (1 month to 16 years). Tumors commonly involved the trunk (7 of 13; 54%) and ranged in size from 1.7 to 14.5 cm (mean, 6.7 cm). Eleven patients received ifosfamide/etoposide chemotherapy and 4 received irradiation. Five-year event-free and overall survival (EFS and OS) rates were 54% and 74%, respectively. The predominant histological pattern was round to plump spindled cells forming sheets (9 of 13; 69%) and severe atypia was associated with decreased survival (P = 0.048). Immunohistochemistry showed positivity for vimentin (92%), CD117 (92%), and vascular endothelial growth factor (69%), and 8% to 23% showed focal positivity for epithelial, neural, or myogenic markers. Tumors were uniformly negative for translocations associated with pediatric sarcomas. The presence of certain common morphological and immunohistochemical features in the absence of specific molecular genetic abnormalities allows for a diagnosis of pediatric undifferentiated soft tissue sarcoma; however, whether this group of neoplasms forms a unique category of tumors or a common precursor pathway for a number of different sarcomas awaits further study.