Small Round Cell Sarcomas Research Articles

Osseous Myxochondroid Sarcoma

Extraskeletal myxoid chondrosarcoma (EMC) is a rare mesenchymal neoplasm with a characteristic translocation usually involving NR4A3 and EWSR1. EMC has rarely been reported in the bone and may be confused with conventional chondrosarcoma with myxoid features or various small round cell sarcomas. We present 5 cases of molecularly confirmed EMC arising primarily in the bone. Patients included 4 men and 1 woman, aged 38 to 77 years (median 54 y). Tumors arose in the ilium (2 cases), manubrium, rib, and humerus. Four tumors extensively infiltrated and destroyed preexisting bone with cortical breakthrough and associated soft tissue extension; 1 case demonstrated only focal cortical breakthrough. Microscopically, 2 cases had small round cell features; 1 of these was hypercellular, whereas the other was hypocellular with abundant myxochondroid matrix. Three cases were composed of eosinophilic spindled cells with variable fascicular to corded or wreath-like growth patterns. Fluorescence in situ hybridization was positive for both EWSR1 and NR4A3 translocation in 3 cases; rearrangement for EWSR1 or NR4A3, but not both, was seen in 2 tumors. After definitive therapy, 1 patient experienced multiple local recurrences at 36 months and died of disease at 61 months. Two patients developed lung metastases at 26 and 74 months and are alive with disease at 44 and 74 months, respectively. Two patients are disease free at 5 and 24 months. EMC of the bone is a diagnostic dilemma and requires molecular confirmation. We propose to classify tumors with the appropriate phenotype and molecularly confirmed NR4A3/EWSR1 rearrangements as myxochondroid sarcoma, either osseous or extraskeletal variants.

EWS and RE1-Silencing Transcription Factor Inhibit Neuronal Phenotype Development and Oncogenic Transformation in Ewing Sarcoma

The gene encoding EWS (EWSR1) is involved in various chromosomal translocations that cause the production of oncoproteins responsible for multiple cancers including Ewing sarcoma, myxoid liposarcoma, soft tissue clear cell sarcoma, and desmoplastic small round cell sarcoma. It is well known that EWS fuses to FLI to create EWS/FLI, which is the abnormal transcription factor that drives tumor development in Ewing sarcoma. However, the role of wild-type EWS in Ewing sarcoma pathogenesis remains unclear. In the current study, we identified EWS-regulated genes and cellular processes through RNA interference combined with RNA sequencing and functional annotation analyses. Interestingly, we found that EWS and EWS/FLI co-regulate a significant cluster of genes, indicating an interplay between the 2 proteins in regulating cellular functions. We found that among the EWS-down-regulated genes are a subset of neuronal genes that contain binding sites for the RE1-silencing transcription factor (REST or neuron-restrictive silencer factor [NRSF]), neuron-restrictive silencer element (NRSE), suggesting a cooperative interaction between REST and EWS in gene regulation. Co-immunoprecipitation analysis demonstrated that EWS interacts directly with REST. Genome-wide binding analysis showed that EWS binds chromatin at or near NRSE. Furthermore, functional studies revealed that both EWS and REST inhibit neuronal phenotype development and oncogenic transformation in Ewing sarcoma cells. Our data implicate an important role of EWS in the development of Ewing sarcoma phenotype and highlight a potential value in modulating EWS function in the treatment of Ewing sarcoma and other EWS translocation-based cancers.

A Case of Peritoneal Dissemination of High-grade Small Round Cell Sarcoma

A Case of Peritoneal Dissemination of High-grade Small Round Cell Sarcoma

Interval compressed vincristine, doxorubicin, cyclophosphamide alternating with ifosfamide, etoposide in patients with advanced Ewing’s and other Small Round Cell Sarcomas

BackgroundTo evaluate tolerability and maintenance of dose intensity of 2 weekly treatment with vincristine, doxorubicin, cyclophosphamide alternating with ifosfamide, etoposide (VDC/IE) in patients with advanced small round cell sarcomas including Ewing family tumours (EFT), desmoplastic small round cell tumours (DSRCT) and undifferentiated high grade round cell sarcomas (UHGRCS).MethodsRetrospective review of 16 patients treated at a single centre with VDC/IE. Dose received, treatment delay, toxicity and clinical outcome were recorded for each cycle up to a maximum of 14 cycles.ResultsA total 193 cycles of VDC/IE were administered to 10 patients with EFT, 4 with DSRCT and 2 with UHGRCS. Median age was 22 years with 75% over 18 years. Metastases were present in 14 patients. The mean duration of each cycle was 16.7 days. Febrile neutropenia occurred in 14 % of cycles, and grade 3/4 haematologic toxicity including anaemia and thrombocytopenia in 16 % and 11 % of cycles respectively. Seven patients had a dose reduction. Five patients discontinued VDC/IE early due to toxicity.ConclusionsThis schedule of VDC/IE is feasible in patients with EFT and DSRCT including adults and those with metastases. Its comparison with other standard regimens for these diseases is justified.

High-grade Sarcomatous Overgrowth in Solitary Fibrous Tumors

We describe 10 solitary fibrous tumors (SFT) with high-grade malignant overgrowth, all of which showed the presence of a synchronous or previous classic SFT/malignant SFT (MSFT) component. Seven were "dedifferentiated," with an abrupt transition from a classic SFT/MSFT to a high-grade component consisting of a nondistinctive high-grade sarcoma in 4 cases and divergent differentiation in 3. The nondistinctive high-grade component consisted of epithelioid and/or spindle cells often associated with overt pleomorphism or small round cell sarcomas. The divergent differentiation featured a rhabdomyosarcoma in 2 cases and an osteosarcoma in 1. Three cases (tentatively called "evolved") showed a gradual transition from classic SFT/MSFT to a nondistinctive high-grade sarcoma or presented features of high-grade sarcoma at the time of metastasis (assessed by fine-needle aspiration cytology) without any component suggesting a diagnosis of classic SFT/MSFT. The high-grade component showed loss of CD34 expression in half of the dedifferentiated SFTs and all of the dedifferentiated SFTs with divergent differentiation, whereas Ki-67 was markedly increased in all of the evaluable cases and paralleled the tumor grade. In 4 cases, the expression and phosphorylation status of key factors that control transcription and protein synthesis were also investigated. Both S6 and 4E-BP1 showed low activation in the low-grade MSFT and a high level of activation in the high-grade component. Seven of the 10 patients died of their disease during follow-up, with a median overall survival of 73 months (range, 5 to 288 mo). The median time to distant metastasis was 156 months after the initial diagnosis, and median overall survival from the first signs of metastasis was 8 months.

Primary Undifferentiated Penile Sarcoma in Adolescence

We report a case of primary penile undifferentiated sarcoma. A 16-year-old adolescent man visited Pusan National University Hospital complaining of a painless mass on his penis that was increasing in size. Magnetic resonance images revealed a 5×5-cm mass and pathological examinations revealed small round cell sarcomas with neuroendocrine differentiation. The tumor, which had metastatic pulmonary nodules, was treated by tumorectomy and systemic chemotherapy. Thirty-four months after the initial diagnosis, the patient was still alive without evidence of local recurrence or metastatic disease. This is our second case of an undifferentiated penile sarcoma.

High prevalence of CIC fusion with double‐homeobox (DUX4) transcription factors in EWSR1‐negative undifferentiated small blue round cell sarcomas

Primitive round cell sarcomas of childhood and young adults have been problematic to diagnose and classify. Our goal was to investigate the pathologic and molecular characteristics of small blue round cell tumors (SBRCT) that remained unclassified after exhaustive immunohistochemistry and molecular screening to exclude known sarcoma-related translocations. As rare examples of EWSR1-negative SBRCT have been shown to carry rearrangements for FUS and CIC genes, we undertook a systematic screening for these two genes. CIC rearrangements by FISH were detected in 15/22 (68%), while none showed FUS abnormalities. RACE, RT-PCR, and/or long-range DNA PCR performed in two cases with frozen material showed that CIC was fused to copies of the DUX4 gene on either 4q35 or 10q26.3. Subsequent FISH analysis confirmed fused signals of CIC with either 4q35 or 10q26.3 region in six cases each. Tumors positive for CIC-DUX4 fusion occurred mainly in male young adult patients (median age: 29 years), with the extremities being the most frequent location. Microscopically, tumors displayed a primitive, round to oval cell morphology with prominent nucleoli, high mitotic count, and areas of necrosis. O13 expression was variable, being either diffuse or patchy and tumors mostly lacked other markers of differentiation. Although CIC-DUX4 resulting in a t(4;19) translocation has been previously described in primitive sarcomas, this is the first report implicating the related DUX4 on 10q26 in oncogenesis. These results suggest the possibility of a newly defined subgroup of primitive round cell sarcomas characterized by CIC rearrangements, distinct from Ewing sarcoma family of tumors.

Recent advances in the molecular diagnosis of paediatric soft tissue sarcomas

Sarcomas comprise a significant portion of solid tumours diagnosed in children. As they commonly are composed of primitive round or spindled cells, morphologic diagnosis can be difficult, and ancillary studies are often necessary. In recent years, progress has been made in understanding the cytogenetic and molecular changes underlying many of these tumours, and molecular techniques have emerged from strictly being research tools to becoming standard diagnostic tests. Paediatric sarcomas fall into two categories: those with characteristic underlying translocations, and those without. Translocation associated paediatric sarcomas include, but are not limited to alveolar rhabdomyosarcoma, Ewing’s family of tumours, desmoplastic small round cell sarcoma, synovial sarcoma, infantile fibrosarcoma, clear cell sarcoma of soft tissue, and low-grade fibromyxoid sarcoma. Sarcomas without translocations tend to be more pleomorphic in appearance, and include embryonal rhabdomyosarcoma, malignant rhabdoid tumour and epithelioid sarcoma. This review will describe the molecular and immunohistochemical methods most applicable in diagnosing these soft tissue malignancies.

Rapid Verification of Unusual Tracer Uptake Patterns by Means of SPECT/CT

Abstract: A 45-year-old woman with gluteal mass and a histopathological diagnosis of malign small round cell sarcoma was investigated for metastatic spread. The patient was referred to nuclear medicine for further evaluation by means of somatostatin analogues. 111Indium- pentetreotide whole body imaging revealed an intense and inverted arrow-shaped uptake in the left upper quadrant resembling cardiac activity. Although the location and posterior appearance of the tracer uptake was indicating somehow splenic activity, a SPECT/CT scan was performed for anatomic verification. The reconstructed SPECT/CT fusion images depicted clearly that the totality of the atypical activity originated from the spleen, which was defined as an anatomic variant. In this case, SPECT/CT easily clarified the unusual appearance of the spleen, suggesting a pathologic finding on conventional whole body imaging.

9407 Ewing's family (EFT) tumours: biomolecular characterization on paraffine-embedded samples

Differentiation of Ewing sarcoma family of tumors (ESFT) and Ewing-like tumors remains problematic. Certain ESFT with morphological and immunohistochemical (IHC) profiles lack the EWSR1-ETS transcript. To improve diagnostic accuracy we investigated the presence of several specific transcripts in 200 small round cell tumors (SRCT) displaying ESFT morphology and immunophenotype in which EWSR1 FISH analysis was non-informative or negative.200 tumors (formalin-fixed, paraffin-embedded) were analyzed by RT-PCR. All tumors were tested for EWSR1-ETS, EWSR1/WT1, PAX3/7-FOX01 or SYT/SSX transcripts, and the negative tumors were subsequently analyzed for CIC/DUX4, BCOR/CCNB3 and CIC/FOX04 transcripts.133 (66.5%) ESFT displayed one of the above EWSR1-ETS translocations. Three cases (1.5%) revealed the SYT-SSX transcript for Synovial sarcoma, and one (0.5%) a EWSR1-WT1 transcript for Desmoplastic Small Round Cell tumor. The CIC-DUX4 translocation was found in six Ewing-like tumors (3%) with CD99 positivity. The BCOR-CCNB3 gene fusion was observed in 5 tumors (2.5%) displaying round or spindle cells with strong CCNB3 IHC expression in 3 tumors. Moreover, RT-PCR failed to detect any gene fusion transcripts in 19 tumors (9.5%) and were considered “undifferentiated small round cell sarcoma” (SRCS). Molecular biology results were non-informative in 33 SRCTs (16.5%) due to RNA degradation through inadequate fixation and/or decalcification.Our analysis of 200 SRCTs confirms the molecular heterogeneity of neoplasms with ESFT morphology and highlight that molecular studies with RT-PCR including new emerging gene fusion transcripts are mandatory for the diagnosis when EWSR1 FISH is negative or non-informative. The incidence of CIC-DUX4, BCOR-CCNB3 and CIC-FOX04 transcripts was relatively low. A small group of Ewing-like sarcomas or undifferentiated SRCS remains unclassified. Adopting appropriate tissue fixation and processing protocols is important to avoid degradation of fixed/embedded tissue when no frozen tumor is available.

Small Round Cell Sarcomas

Small round cell sarcomas are the most aggressive of the tumors morphologically and clinically encountered in children and adults, and in some ways the most leukemia- or lymphoma-like of sarcomas. Small round cell sarcomas often are associated with chromosomal translocations, like hematologic malignancies, and are usually more sensitive to chemotherapy than other sarcoma subtypes. They have a high risk of mortality, but chemotherapy (in addition to surgery and often radiation therapy) provides a good cure rate, although treatment is often long and intensive. The biology of these tumors is very telling in terms of some of the mechanisms of cancer cell survival and proliferation. Although there is some overlap of the discussion below with the section on translocation associated sarcomas, we have highlighted some of the key issues with these sarcomas below, with some ideas that may bear fruit both in terms of the management of these, other sarcomas, and other cancers alike.

Sarcomas With Spindle Cell Morphology

In the days before the term "high-grade undifferentiated pleomorphic sarcoma" came into use, one of the most common sarcoma diagnoses was "malignant fibrous histiocytoma," and before that, in an era before immunohistochemistry, "fibrosarcoma" was used to describe most sarcomas. "Spindle cell" is a descriptive phrase that denotes the cellular shape of many of the sarcomas encountered in the adult population. As a result, they are usually treated differently from small round cell sarcomas, and have different biological characteristics than those tumors and sarcomas with epithelioid morphology. As a very broad generalization, sarcomas with a spindle cell microscopic morphology occur in adults and are treated primarily with surgery and often adjuvant or neoadjuvant radiation as primary therapy. In comparison to small round cell sarcomas such as Ewing sarcoma, the use of adjuvant chemotherapy remains controversial, and the sensitivity of these tumors to chemotherapy in the metastatic setting is highly variable. In this article, we describe some of the clinical and biological characteristics of this group of sarcomas.

Tumeur neuro-ectodermique primitive (TNEP) de la voie excrétrice supérieure

Primitive neuroectodermal tumors (PNETs) are rare and aggressive malignant small round cell sarcomas. Primitive urogenital location of PNETs is rare and occurs most frequently in the kidney. PNETs of the upper-urinary tract are exceptional (only one case reported in the literature). Its diagnosis is almost postoperative within pathological study of the operatory specimen, supported by immunohistochemistry and cytogenetics. Treatment is similar in all to that of Ewing's sarcoma and involves surgery, chemotherapy and radiotherapy. We report a new case of upper-urinary tract PNET and discuss the diagnostic and therapeutic problems posed by this particular tumor.

Undifferentiated Small Round Cell Sarcomas with Rare EWS Gene Fusions : Identification of a Novel EWS-SP3 Fusion and of Additional Cases with the EWS-ETV1 and EWS-FEV Fusions

Ewing family tumors (EFTs) are prototypical primitive small round blue cell sarcomas arising in bone or extraskeletal soft tissues in children or adolescents. EFTs show fusions of EWS with a gene of the ETS family of transcription factors, either EWS-FLI1 (90 to 95%) or EWS-ERG (5 to 10%). Rare cases with fusions of EWS to other ETS family genes, such as ETV1, E1AF, and FEV, have been identified, but their clinicopathological similarity to classic EFTs remains unclear. We report four new cases of EFT-like tumors with rare EWS fusions, including two with EWS-ETV1, one with EWS-FEV, and a fourth case in which we cloned a novel EWS-SP3 fusion, the first known cancer gene fusion involving a gene of the Sp zinc finger family. Analysis of these three new cases along with data on nine previously reported cases with fusions of EWS to ETV1, E1AF, or FEV suggest a strong predilection for extraskeletal primary sites. EFT-like cases with fusions of EWS to non-ETS translocation partners are also uncommon but involve the same amino-terminal portion of EWS, which in our novel EWS-SP3 fusion is joined to the SP3 zinc-finger DNA-binding domain. As these data further support, these types of EWS fusions are associated with primitive extraskeletal small round cell sarcomas of uncertain lineage arising mainly in the pediatric population.

High-dose chemotherapy and autologous peripheral blood stem cell transfusion for adult and adolescent patients with small round cell sarcomas

The treatment of small-round-cell tumors (SRCT) in adult patients remains a challenge to clinicians. In the present study, we analyzed the feasibility and efficacy of high-dose chemotherapy (HDCT) followed by autologous peripheral blood stem-cell rescue as a consolidation therapy exclusively for patients with good disease control through a single regimen of induction chemotherapy and local therapy. Twenty-one patients (12 females, median age 22.0 years) were analyzed, including seven cases with rhabdomyosarcoma (RMS) and 14 cases with Ewing's family tumors (EFT). Overall, survival was 46% and failure-free survival (FFS) was 33% at 3 years. Patients with EFT had better FFS than those with RMS, with an estimated 3-year FFS of 50% (P<0.01). There was a single case of possible treatment-related death and two cases of secondary malignancies. This study cannot conclusively determine the beneficial effects of HDCT for improving treatment outcomes in adult SRCTs due to the small number of subjects. However, study findings suggest that a subgroup of patients with EFT may obtain prolonged survival benefits from this therapy.

Systemic treatment options for patients with refractory adult-type sarcoma beyond anthracyclines

For the subgroup of patients with inoperable gastrointestinal stromal tumors, progress has been made by the rapid development and approval of the targeted therapy imatinib mesylate. Small round cell sarcoma, such as Ewing/PNET, desmoplastic small round cell sarcoma and rhabdomyosarcoma, are chemotherapy-sensitive and potentially curable malignancies, which are treated with multimodality, dose-intensitive and neoadjuvant protocols regardless of size or overt metastatic disease. A limited number of effective agents available for the treatment of patients with metastatic adult soft-tissue sarcoma exists, which have failed anthracyline and ifosfamide-based chemotherapy. Most other high-grade (grading >I) so-called adult-type soft-tissue sarcomas such as fibro, lipo, pleomorphic and synovial sarcoma are treated with a anthracycline-based regimen with or without ifosfamide as front-line therapy. In this review, the therapeutic activities of drugs currently available as second-line treatment in patients with metastatic soft tissue sarcoma are summarized, providing an overview of contentious or emerging treatment issues. In relapsed 'adult-type' soft-tissue sarcomas trofosfamide, gemcitabine and ecteinascidin (ET-743) appear to be drugs associated with moderate activity and an acceptable toxicity profile. An interesting finding to be noted is that the different drugs have particular effects in distinct subtypes of soft-tissue sarcoma; however, it has to be taken into account that the number of patients included in those phase II trials are limited. The role of the newer agents (e.g. patupilone derivates, brostallicin) is currently not definable. The so-called selective therapy targeting vascular endothelial growth factor (receptor), epidermal growth factor receptor, c-kit, Raf kinase or platelet-derived growth factor receptor and bcl-2 antisensing, proteasome, protein kinase C/B, and mammalian target of rabamycin inhibition will continue to be tested in gastrointestinal stromal tumors patients refractory to imatinib mesylate as well as in selected sarcoma subtypes.

Adamantinoma-like Ewing’s sarcoma with EWS-FLI1 fusion gene: a case report

Recent studies have advocated the genotypic and phenotypic delineation of a novel Ewing's sarcoma histologic variant showing epithelial features defined as "adamantinoma-like Ewing's sarcoma". We described an 18-year-old girl with a primary small round-cell sarcoma of the right tibia showing polyphenotypic differentiation with epithelioid features. The neoplastic cells had mainly round or oval nuclei with fine chromatin with a portion of epithelial arrangements. The immunohistochemical analysis showed the epithelial markers of cytokeratin 5/6/18, AE1/AE3, and cytokeratin high molecular weight were stained especially in the foci with epithelioid features, as well as MIC2, S100, and NSE. The diagnosis of the lesion was confirmed as Ewing's sarcoma by the presence of the EWS-FLI1 fusion transcript, and could be defined as the so-called "adamantinoma-like Ewing's sarcoma". After wide excision and high-dose chemotherapy with peripheral blood stem cell transfusion, the patient has been well and continuously event-free for 3 years since the initial diagnosis.

Calretinin expression in tumors of adipose tissue

Although well established as a marker of mesothelial cells, calretinin is also expressed in several other tissue types, including adipose tissue. Accordingly, immunohistochemical staining for calretinin has been described in an increasing number of neoplasms other than mesothelioma. A detailed analysis of calretinin expression in lipogenic tumors has not yet been reported, however. Given the known expression patterns of calretinin in normal tissues, we predicted that calretinin immunoreactivity would be detected in lipoma and the various histologic subtypes of liposarcoma, and that this marker might be of use in the differential diagnosis of selected fatty tumors. A variety of pleomorphic and small round cell sarcomas were studied for comparison. Calretinin immunoreactivity was detected, at least focally, in all 10 samples of normal adipose tissue and in 22 of 23 lipomas or lipoma variants. Staining for calretinin was also positive within the lipogenic component of 28 of 29 liposarcoma variants. Of the 7 dedifferentiated liposarcomas, 3 were focally positive for calretinin. Pleomorphic variants of other sarcomas, including undifferentiated high-grade pleomorphic sarcoma, rhabdomyosarcoma, leiomyosarcoma, and malignant peripheral nerve sheath tumor also exhibited focal calretinin immunoreactivity in a minority of cases, as did some small round cell sarcomas. These results suggest that calretinin immunoreactivity in normal and neoplastic adipose tissue is more ubiquitous than previously reported and may be a useful, albeit nonspecific marker of lipogenic differentiation. However, its utility in the differential diagnosis of fatty tumors appears limited.

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Trabectedin

Establishment and Characterization of a Clonal Human Extraskeletal Ewing's Sarcoma Cell Line, EES1

Ewing's sarcoma, a small round cell sarcoma arising in soft tissue as well as the bone, is one of the most malignant tumors in children and young adults. Few established cell lines of extraskeletal Ewing's sarcoma (EES) have been reported, which made it difficult to examine the biological features of EES. Therefore, we have established a new clonal cell line of EES. We report its morphological characters, results of chromosomal and immunohistochemical analysis. A piece of tumor obtained from the 18-year-old female patient with EES was xenografted in a nude mouse. In vitro subcultured cells were then obtained from this xenograft. A clonal cell line was subsequently established by limiting dilution and designated EES1. EES1 cells had a doubling time of 24 hours. In the xenografted tumor, the cells expressed vimentin, CD99 (MIC2), neuron specific enolase (NSE) and cytokeratin. The original tumor cells also expressed vimentin, CD 99, and NSE, but was negative for cytokeratin. The morphological and immunohistochemical features of this cell line established, except for cytokeratin expression, were consistent with those of the primary tumor. Cytogenetic analysis of EES1 revealed chromosomal translocation of t(11; 12)(q24;ql2). The chimeric fusion of the Ewing's sarcoma gene in band 22q12 with the Friend leukemia virus integration-1 gene in band 11q24 was also demonstrated. Fluorescence in situ hybridization further confirmed the presence of translocation involving the Ewing's sarcoma gene in both the primary tumor and EES1 cells. In conclusion, we have established a human EES cell line EES1, which will provide a useful model for studying various aspects of human EES.