EWSR1 fusions: Ewing sarcoma and beyond

Superficial Neurocristic FET::ETS Fusion Tumor: Expanding the Clinicopathological and Molecular Genetic Spectrum of a Recently Described Entity

Superficial neurocristic EWSR1::FLI1 fusion tumor is a very recently described, clinically indolent tumor of the skin and superficial soft tissues, which differs in essentially all ways from Ewing sarcoma, despite harboring an identical fusion event. The EWSR1 and FLI1 genes are members of the FET and ETS gene family, respectively, and very rare examples of Ewing sarcoma harbor alternative FET::ETS fusion events, such as EWSR1::ERG, FUS::FLI1, FUS::ERG, EWSR1::ETV4, and others. We report 5 new cases of this very rare entity, harboring in 3 cases alternative FET::ETS fusion events. The tumors occurred in 2 males and 3 females (median age, 14 years, range, 8-69 years) and presented as solitary dermal/subcutaneous masses of the thigh, foot, shoulder, arm, and back (median size, 1.8 cm; range, 1-2 cm). All patients underwent wide excisions; one received adjuvant chemotherapy. Clinical follow-up on 3 patients (median, 24 months; range, 18-31 months) showed all to be without disease. Morphologically, all tumors displayed typical features of this entity as described, with nests of cytologically bland, diffusely S100 protein/SOX10-positive round cells without mitotic activity, surrounded by fibrous bands containing spindled cells with similar nuclear features. The tumors also showed membranous CD99 (4/5) and nuclear NKX2.2 (3/3) expression. RNA sequencing (5 cases) demonstrated FUS::FLI1, FUS::ERG, EWSR1::FLI1, EWSR1::ERG, and a novel FUS::ETV5. Methylation profiling (4 cases) showed all to cluster with previously reported superficial neurocristic EWSR1::FLI1 fusion tumors and apart from conventional and "adamantinoma-like" Ewing sarcoma. Our findings confirm the distinctive clinicopathological features of this very rare, recently described entity and expand its molecular genetic spectrum. Reflecting on these findings, we propose modifying the name of this entity to "superficial neurocristic FET::ETS fusion tumor."

EWSR1: the promiscuous king of mesenchymal neoplasia

EWSR1 is the most commonly rearranged gene in mesenchymal neoplasia, and its myriad chimeric oncoproteins drive widely disparate neoplasms. Here, we survey selected EWSR1 rearrangements, including well-described EWSR1 fusions with CREB family members, ATF1 and CREB1, as well as fusions in emerging entities such as mesenchymal neoplasms with EWSR1::PATZ1 and EWSR1::NFATC2 fusions. We also discuss recent data demonstrating the imperfect specificity of EWSR1::WT1 and, possibly, EWSR1::FLI1 fusions.

Recent advances in molecular profiling of bone and soft tissue tumors

The molecular characterization of soft tissue and bone tumors is a rapidly evolving field that has changed the perspective of how these tumors are diagnosed today. Morphology and clinico-radiological context still represent the cornerstone of diagnostic considerations but are increasingly complemented by molecular data that aid in objectifying and confirming the classification. The spectrum of analyses comprises mutation or gene fusion specific immunohistochemical antibodies, fluorescence in situ hybridization, DNA and RNA sequencing as well as CpG methylation profiling. This article provides an overview of which tools are presently available to characterize bone and soft tissue neoplasms molecularly, what limitations should be considered, and what conclusions can be drawn from the individual findings.

Ewing Sarcoma of the Female Genital Tract: Clinicopathologic Analysis of 21 Cases With an Emphasis on the Differential Diagnosis of Gynecologic Round Cell, Spindle, and Epithelioid Neoplasms

Ewing sarcoma is an uncommon neoplasm considered in the differential diagnosis of tumors with "small round cell" morphology, but its occurrence in the gynecologic tract has only been sporadically documented. Herein, we describe the largest cohort of Ewing sarcoma localized to the female genital tract to date, and emphasize their clinicopathologic resemblance to more common gynecologic neoplasms. Ewing sarcoma (n=21) was retrospectively identified from 5 institutions. The average patient age was 35 (range 6-61) years. Tumor sites included uterus (n=8), cervix (n=4), vulva (n=5), vagina (n=1), broad ligament (n=1), inguinal area (n=1), and pelvis (n=1). Nine of 18 cases in which slides were available for review demonstrated only classic round cell morphology, with the remainder showing a variable combination and prominence of variant ovoid/spindle or epithelioid appearance. Tumors showed diffuse membranous reactivity for CD99 (20/20) and were positive for NKX2.2 (8/8, diffuse) and cyclin D1 (7/7, of which 3/7 were patchy/multifocal and 4/7 were diffuse). They were negative for ER (0/6) and CD10 (0/6). Three cases were initially diagnosed as endometrial stromal sarcomas. EWSR1 rearrangement was confirmed in 20/21 by fluorescence in situ hybridization (n=15) and/or sequencing (n=8). Of the eight tumors that underwent sequencing, 6 harbored FLI1 , 1 ERG, and 1 FEV as the fusion partner. Of 11 patients with available follow-up, 5 died of disease, 1 developed lung metastases and 5 are alive with no evidence of disease. Ewing sarcoma of the gynecologic tract is a rare, aggressive entity that shares some morphologic and immunohistochemical features with other more common gynecologic neoplasms. In addition to the typical round cell appearance, variant spindled/ovoid to epithelioid morphology may also be observed and should prompt consideration of this entity with appropriate immunohistochemical and/or molecular studies.

Fusion-driven cutaneous and superficial mesenchymal and adnexal tumors-A clinicopathologic and molecular study of 15 cases, including a novel case of ACTB::ZMIZ2-rearranged adnexal carcinoma

BACKGROUND

While the list of fusion-driven soft tissue neoplasms is expanding rapidly, their importance among cutaneous and superficial mesenchymal and adnexal neoplasms remains poorly understood. This challenge is especially evident in cases with ambiguous histopathology that are difficult to classify based on morphology.

AIMS

Our goal was to investigate the benefits of next-generation sequencing in diagnosing complex cutaneous neoplasms.

MATERIALS & METHODS

Departmental archives were searched for fusion-driven cutaneous neoplasms. Slides were retrieved and clinical information including follow-up was obtained.

RESULTS

Fifteen cases occurred in eight female and seven male patients, with a median age of 26 years (range: 1-83) at diagnosis. Tumors involved the extremities (9), scalp (5), and head and neck (1). Predominant features included myoepithelial (5), nested spindled with clear cytoplasm (2), atypical adnexal/squamoid (2), small round blue cell (2), cellular spindled (3), and fibrohistiocytic morphology (1). Most frequently encountered fusions involved EWSR1 (6) fused to ERG (1), FLI1 (1), CREB1 (2), CREM (1), PBX3 (1), followed by PLAG1 (4) with LIFR (2), TRPS1 (1) and CHCHD7. Additional fusions encountered were YAP1::NUTM1, EML4::ALK, SS18::SSX1 (2), and a novel fusion: ACTB::ZMIZ2. Integration of histologic features and molecular findings led to final diagnoses of primary cutaneous Ewing sarcoma (2), soft tissue myoepithelioma (4), cutaneous syncytial myoepithelioma (1), cutaneous adnexal carcinoma (1), porocarcinoma (1), inflammatory myofibroblastic tumor (1), synovial sarcoma (2), clear cell sarcoma (2), and angiomatoid fibrous histiocytoma (1).

DISCUSSION AND CONCLUSION

Our results show that fusion testing can be a helpful diagnostic tool, especially in cases with unusual or uncommon morphology in superficial sites. Furthermore, it can allow for the identification of potential therapeutic targets in some instances.

Back to the future! Selected bone and soft tissue neoplasms with shared genetic alterations but differing morphological and immunohistochemical phenotypes

Bone and soft tissue tumors (BST) are a highly heterogeneous group largely classified by their line of differentiation, based on their resemblance to their normal counterpart in adult tissue. Yet, rendering a specific diagnosis can be challenging, primarily due to their rarity and overlapping histopathologic features or clinical presentations. Over the past few decades, seemingly histogenetic-specific gene fusions/translocations and amplifications have been discovered, aiding in a more nuanced classification, leading to well-established objective diagnostic criteria and the development of specific surrogate ancillary tests targeting these genetic aberrations (e.g., immunohistochemistry). Ironically, the same research also has revealed that some specific tumor subtypes may be the result of differing and often multiple gene fusions/translocations, but, more interestingly, identical gene fusions may be present in more than one phenotypically and biologically distinct neoplasm, sometimes with entirely different clinical behavior. Prime examples include, EWSR1::ATF1 and, less commonly, EWSR1::CREB1 gene fusions present in both clear cell sarcoma, a malignant high-grade tumor with melanocytic differentiation, and angiomatoid fibrous histiocytoma, a mesenchymal neoplasm of intermediate malignancy with a generally indolent course. Similarly, MDM2 amplification, once deemed to be pathognomonic for atypical lipomatous tumor/well differentiated and dedifferentiated liposarcoma, has been documented in a range of additional distinct tumors, including low grade osteosarcomas (e.g. low grade central and surface parosteal) and high-grade intimal sarcomas, amongst others. Such findings reinforce the importance of careful attention to morphological and clinicoradiological features and correlation with molecular testing before rendering a specific diagnosis. Future classification systems in BST neoplasms cannot be solely based on molecular events and ideally will balance morphologic features with molecular analysis. Herein, we provide a narrative literature review of the more common BST neoplasms with shared genetic events but differing demographics, morphology, immunophenotype, and clinical behavior, re-emphasizing the importance of the hematoxylin and eosin slide and the "eye" of the practicing pathologist.

Recent advances in the investigation of fusion RNAs and their role in molecular pathology of cancer

Gene fusions have had a significant role in the development of various types of cancer, oftentimes involved in oncogenic activities through dysregulation of gene expression or signalling pathways. Some cancer-associated chromosomal translocations can undergo backsplicing, resulting in fusion-circular RNAs, a more stable isoform immune to RNase degradation. This stability makes fusion circular RNAs a promising diagnostic biomarker for cancer. While the detection of linear fusion RNAs and their function in certain cancers have been described in literature, fusion circular RNAs lag behind due to their low abundance in cancer cells. This review highlights current literature on the role of linear and circular fusion transcripts in cancer, tools currently available for detecting of these chimeric RNAs and their function and how they play a role in tumorigenesis.

Identification of Novel/Rare EWSR1 Fusion Partners in Undifferentiated Mesenchymal Neoplasms

Recurrent gene fusions (GFs) in translocated sarcomas are recognized as major oncogenic drivers of the disease, as well as diagnostic markers whose identification is necessary for differential diagnosis. EWSR1 is a 'promiscuous' gene that can fuse with many different partner genes, defining different entities among a broad range of mesenchymal neoplasms. Molecular testing of EWSR1 translocation traditionally relies on FISH assays with break-apart probes, which are unable to identify the fusion partner. Therefore, other ancillary molecular diagnostic modalities are being increasingly adopted for accurate classification of these neoplasms. Herein, we report three cases with rare GFs involving EWSR1 in undifferentiated mesenchymal neoplasms with uncertain differential diagnoses, using targeted RNA-seq and confirming with RT-PCR and Sanger sequencing. Two GFs involved hormone nuclear receptors as 3' partners, NR4A2 and RORB, which have not been previously reported. NR4A2 may functionally replace NR4A3, the usual 3' partner in extraskeletal myxoid chondrosarcoma. The third GF, EWSR1::BEND2, has previously been reported in a subtype of astroblastoma and other rare entities, including a single case of a soft-tissue tumor that we discuss in this work. In conclusion, our findings indicate that the catalogue of mesenchymal neoplasm-bearing EWSR1 fusions continues to grow, underscoring the value of using molecular ancillary techniques with higher diagnostic abilities in the routine clinical setting.

Sclerosing Odontogenic Carcinoma With a Prominent Clear Cell Component Mimicking Odontogenic Clear Cell Carcinoma: An Extremely Rare Case With a Fatal Clinical Outcome

Sclerosing odontogenic carcinoma (SOC) is an exceedingly rare odontogenic carcinoma known for its locally aggressive yet indolent behavior. There have been no reports of metastasis to distant organs, except a single case involving lymph node metastasis. This report details the case of a 49-year-old female who presented with a well-demarcated radiolucent lesion in the mandible, accompanied by root resorption and tooth displacement. Microscopically, the lesion exhibited a distinctive composition, with two distinct components: cords of epithelium embedded within an abundant collagenous stroma and solid nests of clear polygonal cells surrounded by hyalinized stroma. Notably, the tumor exhibited direct invasion into the submental muscles, accompanied by perineural and vascular invasion, as well as cortical bone loss. Additionally, the clear cells contained diastase-sensitive periodic acid-Schiff-positive granules. Immunohistochemically, the tumor cells displayed positivity for cytokeratin 19 and p63 while testing negative for myoepithelial markers. The Ki-67 index was measured at 23%. Importantly, neitherEWSR1 nor MAML2 rearrangements were detected through fluorescence in situ hybridization (FISH) analysis. Over several years, this patient experienced three instances of local recurrence; notably, four years after the initial surgery, fludeoxyglucose F18-positron emission tomography (18FDG-PET)/CT scans confirmed the presence of pulmonary metastasis. This case presents an unusual histological variation of SOC, marked by vascular invasion, and is notably the first documented case of a fatal outcome in this context.

The Incidence of Multiple Fusions in a Series of Pediatric Soft Tissue and Bone Tumors

BACKGROUND

Next generation sequencing (NGS) has increased the detection of fusion genes in cancer. NGS has found multiple fusions in single tumor samples; however, the incidence of this in pediatric soft tissue and bone tumors (PSTBTs) is not well documented. The aim of this study is to catalogue the incidence of multiple fusions in a series of PSTBTs, and apply a modified gene fusion classification system to determine clinical relevance.

METHODOLOGY

RNA from 78 bone and soft tissue tumors and 7 external quality assessment samples were sequenced and analyzed using recently-described Metafusion (MF) software and classified using a modification of previously-published schema for fusion classification into 3 tiers: 1, strong clinical significance; 2, potential clinical significance; and 3, unknown clinical significance.

RESULTS

One-hundred forty-five fusions were detected in 85 samples. Fifty-five samples (65%) had a single fusion and 30 (35%) had more than 1 fusion. No samples contained more than 1 tier 1 fusion. There were 40 tier 1 (28%), 36 tier 2 (24%), and 69 (48%) tier 3 fusions.

CONCLUSIONS

A significant percentage of PSTBTs harbor more than 1 fusion, and by applying a modified fusion classification scheme, the potential clinical relevance of such fusions can be determined.

Gene partners of the EWSR1 fusion may represent molecularly distinct entities

EWSR1 fusions are highly promiscuous and are associated with unique malignancies, clinical phenotypes, and molecular subtypes. However, rare fusion partners (RFP) of EWSR1 has not been well described. Here, we conducted a cross-sectional, retrospective study of 1,140 unique tumors harboring EWSR1 fusions. We identified 64 unique fusion partners. RFPs were identified more often in adults than children. Alterations in cell cycle control and DNA damage response genes as driving the differences between fusion partners. Potentially clinically actionable genomic variants were more prevalent in tumors harboring RFP than common fusions. While the data presented here is limited, tumors harboring RFP of EWSR1 may represent molecularly distinct entities and may benefit from further molecular testing to identify targeted therapeutic options.

Case report: The activity of multi-kinase VEGF inhibitor, Pazopanib, in metastatic undifferentiated round cell sarcomas harboring EWSR1::CREM fusion: clinicopathological series of two cases and literature review

Soft tissue sarcomas harboring EWSR1::CREM fusion are rare and challenging to treat. Pazopanib, a multi-tyrosine kinase inhibitor, is FDA-approved for advanced soft tissue sarcomas, but predictive biomarkers for its efficacy remain unidentified. We conducted a study on > 240,000 neoplasms submitted to Caris Life Sciences (Phoenix, AZ) to detect rearrangements using whole transcriptome sequencing. Two sarcoma-experienced, board-certified pathologists performed histological reviews, and treatment/outcome information was collected. Among the identified cases (n = 18), we observed a diverse range of sarcoma and other cancers, including an intracranial myxoid mesenchymal tumor, mesothelioma, hyalinizing clear cell carcinomas of the head and neck, clear cell sarcomas, and undifferentiated round cell sarcomas, as well as histologically malignant tumors with epithelioid morphology. Notably, two undifferentiated, metastatic, abdominal round cell sarcoma cases treated with pazopanib demonstrated significant sustained partial response and clinical benefit. To explore the genetic factors associated with the efficacy of pazopanib in these cases, next-generation sequencing and fluorescence in situ hybridization were analyzed for alterations in the tumors. The genomic analysis provided compelling evidence confirming the presence of EWSR1::CREM fusion in both cases, with no other pathogenic gene variants or copy number alterations detected. These cases demonstrate the potential of Pazopanib as a promising therapeutic option for patients with EWSR1::CREM fusion-positive soft tissue sarcomas, including metastatic undifferentiated round cell sarcomas. The sustained clinical benefit and partial responses observed in these cases warrant further research to validate these findings and explore the wider utility of Pazopanib in this rare and challenging subset of soft tissue sarcomas. Case studies: Case 1: A 49-year-old man presented with abdominal pain, weight loss, and chronic cough. A computed tomography (CT) of the chest, abdomen, and pelvis showed multiple lung nodules and masses and a right rectus mass that was biopsied and revealed an undifferentiated round cell sarcoma with a rare fusion EWSR1-CREM. No additional pathogenic gene variants or copy number alterations were detected. He received neoadjuvant chemotherapy with three cycles of Vincristine, Adriamycin, and Ifosfamide (VAI) and seven cycles of Vincristine/Irinotecan and Temodar (VIT). After cycle 7 of VIT, he had surgical resection of the abdominal mass and received radiation for lung metastasis. He completed 13 cycles of VIT after which he presented with progression of disease and switched to monotherapy with Pazopanib. At the time of this analysis he had stable disease for 28 months. Case 2: A 75-year-old woman presented with pelvic pain and new onset constipation. CT abdomen showed a large pelvic mass and intraperitoneal tumor spread. Exploratory laparotomy revealed a ruptured pelvic mass and a small bowel tumor. Both tumors were proved to be high-grade, poorly differentiated sarcoma. Genomic analysis demonstrated an EWSR1::CREM fusion but no other pathogenic gene variants or copy number alterations. She was treated initially for a primitive neuroectodermal tumor (PNET) with four cycles of Vincristine/Adriamycin/Cytoxan/Olaratumab but declined additional chemotherapy after progression. Two years later, she presented with recurrent abdominal mass and received one cycle of Temodar/Irinotecan, then she began Pozapanib and underwent palliative radiation to the entire pelvis. She has been on Pazopanib for 23 months with stable disease.

Predicting Molecular Subtype and Survival of Rhabdomyosarcoma Patients Using Deep Learning of H&E Images: A Report from the Children's Oncology Group

PURPOSE

Rhabdomyosarcoma (RMS) is an aggressive soft-tissue sarcoma, which primarily occurs in children and young adults. We previously reported specific genomic alterations in RMS, which strongly correlated with survival; however, predicting these mutations or high-risk disease at diagnosis remains a significant challenge. In this study, we utilized convolutional neural networks (CNN) to learn histologic features associated with driver mutations and outcome using hematoxylin and eosin (H&E) images of RMS.

EXPERIMENTAL DESIGN

Digital whole slide H&E images were collected from clinically annotated diagnostic tumor samples from 321 patients with RMS enrolled in Children's Oncology Group (COG) trials (1998-2017). Patches were extracted and fed into deep learning CNNs to learn features associated with mutations and relative event-free survival risk. The performance of the trained models was evaluated against independent test sample data (n = 136) or holdout test data.

RESULTS

The trained CNN could accurately classify alveolar RMS, a high-risk subtype associated with PAX3/7-FOXO1 fusion genes, with an ROC of 0.85 on an independent test dataset. CNN models trained on mutationally-annotated samples identified tumors with RAS pathway with a ROC of 0.67, and high-risk mutations in MYOD1 or TP53 with a ROC of 0.97 and 0.63, respectively. Remarkably, CNN models were superior in predicting event-free and overall survival compared with current molecular-clinical risk stratification.

CONCLUSIONS

This study demonstrates that high-risk features, including those associated with certain mutations, can be readily identified at diagnosis using deep learning. CNNs are a powerful tool for diagnostic and prognostic prediction of rhabdomyosarcoma, which will be tested in prospective COG clinical trials.

An EWSR1-EZHIP fusion in a cerebral hemisphere astroblastoma

Astroblastomas are considered extremely rare tumors and have not been formally graded. While gene mutations are used to diagnose these tumors, further research is needed for proper diagnosis and classification. This report presents a case of astroblastoma in a 44-year-old woman. A tumor was found to have histology consistent with astroblastoma, with no MN1 gene changes. Several mutations were present, and fusion of the EWSR1 and EZHIP genes was noted, which has never been reported before in the literature. Fusions of the EWSR1 gene could be characteristics of astroblastomas, in addition to MN1 alterations, and identification of these mutations could help in the diagnosis of these rare tumors.

Cutaneous Ewing Sarcoma Presenting as a Second Primary Malignancy in a Child

Ewing sarcoma is an EWS-ETS family member-driven malignancy that most commonly arises from bone. Cutaneous Ewing sarcoma is a rare variant which harbors an EWS-ETS family fusion but demonstrates an immunohistochemical staining pattern distinct from classic Ewing tumors. EWSR1 fluorescence in situ hybridization testing interpretation can be challenging in the setting of cutaneous Ewing sarcoma, making an integrated histologic and sequencing approach key for an accurate diagnosis. Here, we report a pediatric patient with a history of neuroblastoma treated with surgery only that developed a cutaneous nodule and was diagnosed with cutaneous Ewing sarcoma as a second primary cancer.

Fatal course of undetected Ewing-like sarcoma in a 9-year-old boy with uncharacteristic clinical presentation

A 9-year-old boy collapsed shortly after complaining of shortness of breath. Despite immediate resuscitation measures, the boy died. A few weeks earlier, he had received antibiotic treatment for respiratory infection. However, the post-mortem examination revealed an advanced tumor mass of the mediastinum with infiltration of vital structures, which was identified as a small blue round neoplasm with aspects of an extramedullary Ewing-like sarcoma by supplementary histological and immunohistochemical examinations.This dramatic clinical course of events shows that the possible presence of serious diseases should always be considered behind harmless symptoms, even in children.

Identification of Hub Genes Associated With the Development of Stomach Adenocarcinoma by Integrated Bioinformatics Analysis

Objective

This study was conducted in order to gain a better understanding of the molecular mechanisms of stomach adenocarcinoma (STAD), which is necessary to predict the prognosis of STAD and develop novel gene therapy strategies.

Methods

In this study, the gene expression profile of GSE118916 in the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas Program (TCGA) was used to explore the differential co-expression genes of STAD and normal tissues.

Results

A total of 407 STAD samples were collected, consisting of 375 from stomach adenocarcinoma tissues and 32 from normal tissues, as well as RNA-seq count data for 19,600 genes. Forty-two differentially expressed genes were screened by weighted gene co-expression network analysis (WGCNA) and differentially expressed gene analysis. According to the functional annotation analysis of the clusterProfiler R package, these genes were analyzed for GO function enrichment, digestion (biological process), tube bottom material membrane (cell component), and oxidoreductase activity (molecular function). The KEGG pathway was enriched in gastric acid secretion and chemical carcinogenesis. In addition, Cytoscape's cytoHubba plug-in was used to identify seven hub genes (EWSR1, ESR1, CLTC, PCMT1, TP53, HUWE1, and HDAC1) in a protein-protein interaction (PPI) network consisting of 7 nodes and 11 edges. Compared with normal tissues, CLTC and TP53 genes were upregulated in stomach adenocarcinoma (P < 0.05). TP53 was expressed differently in stages II and IV, EWSR1 was expressed differently in stages II and III, and ESR1 was expressed differently in stages I-III. Among the seven hub genes, Kaplan-Meier analysis and TCGG showed that the expression levels of HDAC1 and CLTC were significantly correlated with OS in patients with stomach adenocarcinoma (P < 0.05). GEPIA2 analysis showed that ESR1 expression was closely correlated with OS and DFS in gastric adenocarcinoma (P < 0.05). Then, the expression of the genes and their correlations were revealed by the R2 Platform (http://r2.amc.nl). Finally, we collected 18 pairs of gastric mucosal tissues from normal people and cancer tissues from patients with stomach adenocarcinoma. The expression levels of the above seven hub genes and their relative protein expression were detected by RT-PCR and immunohistochemistry (IHC). The results showed that the gene and protein expression levels in stomach adenocarcinoma tissues were increased than those in the normal group.

Conclusion

In summary, we believe that the identified hub genes were related to the occurrence of stomach adenocarcinoma, especially the expression of ESR1, HDAC1, and CLTC genes, which are related to the prognosis and overall survival of patients and may become the potential for the future diagnosis and treatment of STAD.

NPM1 is a Novel Therapeutic Target and Prognostic Biomarker for Ewing Sarcoma

Ewing sarcoma (ES) is a cancer that may originate from stem mesenchymal or neural crest cells and is highly prevalent in children and adolescents. In recent years, targeted therapies against immune-related genes have shown good efficacy in a variety of cancers. However, effective targets for immunotherapy in ES are yet to be developed. In our study, we first identified the immune-associated differential hub gene NPM1 by bioinformatics methods as a differentially expressed gene, and then validated it using real time-PCR and western blotting, and found that this gene is not only closely related to the immune infiltration in ES, but also can affect the proliferation and apoptosis of ES cells, and is closely related to the survival of patients. The results of our bioinformatic analysis showed that NPM1 can be a hub gene in ES and an immunotherapeutic target to reactivate immune infiltration in patients with ES. In addition, treatment with NPM1 promoted apoptosis and inhibited the proliferation of ES cells. The NPM1 inhibitor NSC348884 can induce apoptosis of ES cells in a dose-dependent manner and is expected to be a potential therapeutic agent for ES.

Locally advanced malignant solitary fibrous tumour successfully treated with conversion chemotherapy, operation and postoperative radiotherapy: a case report

Preoperative diagnosis of solitary fibrous tumour (SFT) may not provide a complete tumour picture and may be inaccurate. There is no standard treatment for locally advanced or metastasised malignant SFT (MSFT). Here, the case of a 17-year-old male patient with final pathology diagnosis of MSFT is reported. Preoperative biopsy pathology results suggested an Ewing sarcoma that was positive for CD99 antigen, vimentin, friend leukaemia integration 1 transcription factor, apoptosis regulator Bcl-2, and synaptophysin; and negative for CD34 antigen, S-100 protein (S-100), smooth muscle antigen, cytokeratin, and Wilms tumour 1 associated protein. The Ki67 positive rate was 8%, so the patient initially received eight cycles of conversion chemotherapy (vincristine, etoposide, ifosfamide and pirarubicin for one cycle, and vincristine, doxorubicin, and cyclophosphamide/ifosfamide and etoposide for 7 cycles in total). The tumour shrunk significantly and was surgically removed. The final pathology diagnosis was MSFT that was positive for CD99 and signal transducer and activator of transcription 6, and negative for CD34, tumour protein 63, S-100, desmin, and epithelial membrane antigen. Fluorescence in situ hybridization showed no gene translocation in EWS RNA binding protein 1, SS18 subunit of BAF chromatin remodelling complex or FUS RNA binding protein. The patient finally accepted adjuvant radiotherapy of 5600 cGy. Disease-free survival has been > 1 year, with no recurrence or metastasis detected to date. MSFT is rare and treatment for locally advanced or metastatic MSFT remains controversial. The efficacy of the present therapeutic strategy requires further research.

Survey of Paediatric Oncologists and Pathologists regarding Their Views and Experiences with Variant Translocations in Ewing and Ewing-Like Sarcoma: A Report of the Children's Oncology Group

Advances in molecular diagnostics have identified subsets of Ewing and Ewing-like sarcomas driven by variant translocations with unique biology. It is likely that patients with these tumours will have different clinical features and therapeutic outcomes. Nevertheless, the management of these patients both locally and within cooperative group trials depends on the local pathological diagnosis. It is not known what molecular diagnostic approaches are employed by local pathologists or if the exact translocation is commonly determined. In addition, it is not known what therapeutic approaches are employed for these patients or what cooperative trials are deemed appropriate for these patients by expert consensus. To answer these questions, we performed an international survey of oncologists and pathologists to better understand the diagnostic approaches used to identify variant translocations and the influence the findings have on therapy and clinical trial eligibility. An online survey was distributed to oncologists and pathologists primarily in North America. A total of 141 surveys were completed, representing a 28% response rate. The majority of respondents considered EWSR1-ETS gene family translocations (range 61–96%) to be Ewing sarcoma and would include them on the primary arm of a Ewing sarcoma clinical trial. There was a lack of consensus on how to classify and stratify BCOR-CCNB3, CIC-DUX4, and EWSR1+ with non-ETS partner fusions. Most respondents were either unsure how their institution tested, or their institution did not perform the test. In cases with atypical Ewing morphology, most respondents favoured additional fusion transcript testing. There is a lack of consensus regarding the classification and stratification of rare molecular subtypes in Ewing sarcoma. It is not clear how these alternative translocations have impacted outcomes for past clinical studies. This suggests a need for molecular confirmation of diagnoses and centralized or minimum standardization of testing for future trial enrolment.

Fine Needle Aspiration Cytology of Malignant Digestive System Gastrointestinal Neuroectodermal Tumor in a Lymph Node Metastasis from a Previously Diagnosed Liver Primary: A Case Report and Review of Literature

Malignant gastrointestinal neuroectodermal tumor (GNET) is an extremely rare neoplasm. Immunohistochemically, GNET typically demonstrates neural differentiation but lacks melanocytic differentiation, making it distinct from clear cell sarcoma of the soft tissues (CCS). Herein we report for the first time the cytomorphologic features of lymph node metastasis from presumably liver GNET. A 36-year-old female presented with fevers, night sweats, loss of appetite, and a 20-lbs weight loss. Radiographic imaging showed a 13 cm heterogeneously enhancing mass in the right lobe of the liver and a hypermetabolic 0.9 cm periportal lymph node on positron emission tomography-computed tomography (PET/CT). Initially, a CT-guided liver biopsy was performed followed by right hepatic lobectomy and portal lymphadenectomy. The liver biopsy and resection showed an S100-protein and SOX10 positive malignant neoplasm and genomic profiling of liver biopsy revealed EWSR1-CREB1gene rearrangement. These findings in conjunction with the morphologic and immunohistochemical profile were diagnostic of GNET. Two months later, she presented with recurrent lymphadenopathy in the upper abdomen. Fine needle aspiration of the periportal nodal mass revealed single and clusters of primitive, large to medium-sized neoplastic cells with round to oval nuclei, high nuclear-cytoplasmic ratio, vesicular chromatin, and prominent nucleoli. The tumor cells were S100 protein and SOX10 positive, consistent with metastasis of the patient's recently diagnosed malignant digestive system GNET. Palliative chemotherapy was administered but the patient died a few days later, 4 months from the initial diagnosis. Awareness of this entity and judicial use of ancillary studies including molecular testing are essential for achieving accurate diagnosis.

Primary pancreatic Ewing sarcoma: a cytomorphologic and histopathologic study of 13 cases

INTRODUCTION

Ewing sarcoma (ES) is a small, round cell sarcoma that rarely occurs in solid organs, including the pancreas. A diagnostic overlap exists with other primary pancreatic neoplasms, especially for specimens from small biopsies and fine needle aspiration (FNA). To improve the diagnosis of this rare pancreatic tumor, we have reported a series of 13 cases of primary pancreatic ES and reviewed the cytopathologic, surgical pathology, clinical, and radiologic features of these neoplasms.

MATERIALS AND METHODS

We performed a retrospective case review of 13 patients with a diagnosis of pancreatic ES from 2 tertiary academic medical centers. A combination of cytology and histopathologic slides were reviewed, and the patient demographics, clinical information, somatic genetics, and radiologic findings were obtained from the electronic medical records.

RESULTS

Five FNA specimens from 5 patients and 8 surgical biopsy or resection specimens were identified and reviewed. The patients included 9 males and 4 females, with a median age of 27 years (range, 15-78 years). The cytology smears were highly cellular and showed a combination of complex tissue fragments and singly dispersed small round blue cells. The final diagnosis was ES for all 5 FNA specimens in accordance with the characteristic cytomorphology, diffuse and/or strong membranous immunolabeling for CD99, membranous β-catenin, and molecular confirmation of EWSR1 using fluorescence in situ hybridization or reverse transcriptase polymerase chain reaction.

CONCLUSIONS

The cytologic diagnosis of ES is challenging, especially in unusual locations such as the pancreas. However, the correct cytologic diagnosis is important because these patients will require neoadjuvant therapy before surgery. Confirmatory molecular studies should be required to render the diagnosis of pancreatic ES.