Clear cell sarcoma of soft tissue: a retrospective review and analysis of 31 cases treated at Istituto Ortopedico Rizzoli

Successful surgical resection of a metastatic clear cell sarcoma in the heart: a case report

Background

Clear cell sarcoma (CCS) is a very rare disease and one with a very poor prognosis. Furthermore, its occurrence in the heart is very rare and past reports are scarce.

Case summary

A 33-year-old man who had undergone left arm amputation due to CCS came to the hospital because a positron emission tomography computed tomography (PET-CT) four years post-amputation showed an accumulation in the heart. The PET-CT with glucose suppression treatment showed fluorodeoxyglucose accumulation in the myocardium between the middle of the anterolateral wall and the papillary muscle of the posterior lateral wall of the left ventricle (LV). Based on the course of the disease up to now, it was considered that the accumulation was most likely metastasis of CCS. Observation of the heart after a median sternotomy revealed a white tone, well-defined lesion in the middle of the anterolateral wall of LV. The tumour on the posterolateral side of LV was not exposed on the surface, but it was palpated and was still recognizable as a firm neoplastic lesion. Because the mass was identified as a sarcoma on intraoperative rapid pathology, we decide to perform a total resection. Both lesions were excised, and pathology revealed a diagnosis of CCS.

Discussion

Clear cell sarcoma is a very rare disease that accounts for <1% of all soft tissue sarcomas, and its occurrence in the heart is even rarer. It requires a combination of many imaging modalities. To our knowledge, this is the first case of CCS in the heart treated with surgical resection.

Metastatic clear cell sarcoma of the pancreas: A rare case report

BACKGROUND

Clear cell sarcoma (CCS) is a rare soft-tissue sarcoma. The most common metastatic sites for CCS are the lungs, bones and brain. CCS is highly invasive and mainly metastasizes to the lung, followed by the bone and brain; however, pancreatic metastasis is relatively rare.

CASE SUMMARY

We report on a rare case of CCS with pancreatic metastasis in a 47-year-old man. The patient had a relevant medical history 3 years ago, with abdominal pain as the main clinical manifestation. No abnormalities were observed on physical examination and the tumor was found on abdominal computed tomography. Based on the medical history and postoperative pathology, the patient was diagnosed with CCS with pancreatic metastasis. The patient was successfully treated with surgical interventions, including distal pancreatectomy and splenectomy.

CONCLUSION

This report summarizes the available treatment modalities for CCS and the importance of regular postoperative follow-up for patients with CCS.

Review on Lymph Node Metastases, Sentinel Lymph Node Biopsy, and Lymphadenectomy in Sarcoma

Soft tissue sarcomas (STS) originating from connective tissue rarely affect the lymph nodes. However, involvement of lymph nodes in STS is an important aspect of prognosis and treatment. Currently, there is no consensus on the diagnosis and management of lymph node metastases in STS. The key risk factor for nodal involvement is the histological subtype of sarcoma. Radiological and pathological evaluation seems to be the most effective method of assessing lymph nodes in these neoplasms. Thus, sentinel lymph node biopsy (SLNB), which has been shown to be valuable in the management of melanoma or breast cancer, may also be a beneficial diagnostic option in some high-risk STS subtypes. This review summarizes data on the risk factors and clinical characteristics of lymph node involvement in STS. Possible management and therapeutic options are also discussed.

Factors associated with survival in patients with clear cell sarcoma

Aims

Clear cell sarcoma (CCS) of soft-tissue is a rare melanocytic subtype of mesenchymal malignancy. The aim of this study was to investigate the clinical and therapeutic factors associated with increased survival, stratified by clinical stage, in order to determine the optimal treatment.

Methods

The study was a retrospective analysis involving 117 patients with histologically confirmed CCS, between July 2016 and November 2017, who were enrolled in the Bone and Soft Tissue Tumour Registry in Japan.

Results

The five- and ten-year survival rates were 41% (95% confidence interval (CI) 29 to 52) and 37% (95% CI 25 to 49), respectively. On multivariable analysis, the size of the tumour of > 10 cm (p = 0.006), lymph node metastasis at the time of diagnosis (p < 0.001), distant metastases at the time of diagnosis (p < 0.001), and no surgery for the primary tumour (p = 0.019) were independently associated with a poor survival. For N0M0 CCS (n = 68), the development of distant metastases was an independent prognostic factor for survival (early (< 12 months), hazard ratio (HR) 116.78 (95% CI 11.69 to 1,166.50); p < 0.001; late (> 12 months), HR 14.79 (95% CI 1.66 to 131.63); p = 0.016); neoadjuvant/adjuvant chemotherapy (p = 0.895) and/or radiotherapy (p = 0.216) were not significantly associated with survival. The five-year cumulative incidence of local recurrence was 19% (95% CI 8 to 35) and the size of the tumour was significantly associated with an increased rate of local recurrence (p = 0.012). For N1M0 CCS (n = 18), the risk of mortality was significantly lower in patients who underwent surgery for both the primary tumour and lymph node metastases (HR 0.03 (95% CI 0.00 to 0.56); p = 0.020). For M1 CCS (n = 31), excision of the primary tumour was independently associated with better survival (HR 0.26 (95% CI 0.09 to 0.76); p = 0.013). There was no significant difference in survival between the different types of systemic treatment (p = 0.523).

Conclusion

Complete excision of the primary tumour and lymph nodes is associated with a better survival in patients with CCS. Systemic treatment appears to provide limited benefits, demonstrating a pressing need for novel systemic agents.

The current management of clear cell sarcoma

Clear cell sarcoma (CCS) is a rare melanocytic soft tissue sarcoma with a high propensity for lymphatic metastasis and poor prognosis. It is characterized by the translocation of t (12;22), resulting in the rearrangement of the EWSR1 gene and overexpression of MET. Despite improvements in the diagnosis and treatment of soft tissue sarcomas, the management of CCSs remains challenging owing to their rarity, unique biological behaviour and limited understanding of their molecular pathogenesis. The standard treatment for localized CCSs is surgical excision with negative margins. However, there is an ongoing debate regarding the role of adjuvant chemotherapy, radiotherapy and lymphadenectomy in the management of this disease. CCSs are usually resistant to conventional chemotherapy. Targeted therapies, such as sunitinib and MET inhibitors, may provide promising results. Immunotherapy, particularly immune checkpoint inhibitors, is currently under investigation as a potential treatment option for CCSs. Further research is needed to better understand the biology of CCSs and develop effective therapeutic strategies. The purpose of this review is to provide a comprehensive overview of current knowledge and advances in the diagnosis and treatment of CCSs.

Targeting the Clear Cell Sarcoma Oncogenic Driver Fusion Gene EWSR1::ATF1 by HDAC Inhibition

Clear cell sarcoma (CCS), a rare but extremely aggressive malignancy with no effective therapy, is characterized by the expression of the oncogenic driver fusion gene EWSR1::ATF1. In this study, we performed a high-throughput drug screening, finding that the histone deacetylase inhibitor vorinostat exerted an antiproliferation effect with the reduced expression of EWSR1::ATF1. We expected the reduced expression of EWSR1::ATF1 to be due to the alteration of chromatin accessibility; however, assay for transposase-accessible chromatin using sequencing and a cleavage under targets and release using nuclease assay revealed that chromatin structure was only slightly altered, despite histone deacetylation at the EWSR1::ATF1 promoter region. Alternatively, we found that vorinostat treatment reduced the level of BRD4, a member of the bromodomain and extraterminal motif protein family, at the EWSR1::ATF1 promoter region. Furthermore, the BRD4 inhibitor JQ1 downregulated EWSR1::ATF1 according to Western blotting and qPCR analyses. In addition, motif analysis revealed that vorinostat treatment suppressed the transcriptional factor SOX10, which directly regulates EWSR1::ATF1 expression and is involved in CCS proliferation. Importantly, we demonstrate that a combination therapy of vorinostat and JQ1 synergistically enhances antiproliferation effect and EWSR1::ATF1 suppression. These results highlight a novel fusion gene suppression mechanism achieved using epigenetic modification agents and provide a potential therapeutic target for fusion gene-related tumors.

Significance

This study reveals the epigenetic and transcriptional suppression mechanism of the fusion oncogene EWSR1::ATF1 in clear cell sarcoma by histone deacetylase inhibitor treatment as well as identifying SOX10 as a transcription factor that regulates EWSR1::ATF1 expression.

Clear cell sarcoma: state-of-the art and perspectives

INTRODUCTION

Clear cell sarcoma (CCS) is an ultrarare soft tissue sarcoma (STS) with a poor prognosis due to its propensity to metastasize and its low chemosensitivity. The standard treatment of localized CCS consists of wide surgical excision with or without additive radiotherapy. However, unresectable CCS is generally treated with conventional systemic therapies available for treatment of STS despite the weak scientific evidence to support its use.

AREAS COVERED

In this review, we discuss the clinicopathologic characteristics of CSS, as well as the current treatment landscape and future therapeutic approaches.

EXPERT OPINION

The current treatment strategy of advanced CCSs, based on STSs regimens, shows a lack of effective options. Combination therapiesin particular, the association of immunotherapy and TKIs, represent a promising approach. Translational studies are needed in order to decipher the regulatory mechanisms involved in the oncogenesis of this ultrarare sarcoma and identify potential molecular targets.

Clear cell sarcoma of soft tissue with plasmacytoid morphology: A rare case report

RATIONALE

Clear cell sarcoma of soft tissue (CCSST) is a rare malignant tumor that occurs in the extremities of young adults. CCSST has been documented to have atypical histopathological features, such as epidermotropism or myxoid differentiation, which may set pitfalls in the differential diagnosis. We report a case of CCSST with plasmacytoid morphology which has never been described.

PATIENT CONCERNS

A 15-year-old male, presented with a 5-cm mass in his left inguinal area.

DIAGNOSIS

Positron emission tomography-computed tomography examination showed nodules in the left groin and the lung, the latter was considered metastasis. A core needle biopsy with the diagnosis of CCSST with plasmacytoid morphology was made according to histology, immunostaining, and molecular analysis.

INTERVENTIONS

The patient received chemotherapy of doxorubicin and ifosfamide.

OUTCOMES

The patient failed to respond to the standard chemotherapy and deceased twelve months after diagnosis.

LESSONS

This special case of CCSST with plasmacytoid features demonstrated a morphological variation never been documented and may easily lead to misdiagnosis. For such cases, molecular analysis is essential to provide solid evidence for accurate diagnosis.

Systemic treatment of advanced clear cell sarcoma: results from a retrospective international series from the World Sarcoma Network

Background

Clear cell sarcoma (CCS) is a translocated aggressive malignancy with a high incidence of metastases and poor prognosis. There are few studies describing the activity of systemic therapy in CCS. We report a multi-institutional retrospective study of the outcomes of patients with advanced CCS treated with systemic therapy within the World Sarcoma Network (WSN).

Materials and methods

Patients with molecularly confirmed locally advanced or metastatic CCS treated with systemic therapy from June 1985 to May 2021 were included. Baseline demographic and treatment information, including response by Response Evaluation Criteria in Solid Tumours (RECIST) 1.1, was retrospectively collected by local investigators. Descriptive statistics were carried out.

Results

Fifty-five patients from 10 institutions were included. At diagnosis, the median age was 30 (15-73) years and 24% (n = 13/55) had metastatic disease. The median age at diagnosis was 30 (15-73) years. Most primary tumours were at aponeurosis (n = 9/55, 16%) or non-aponeurosis limb sites (n = 17/55, 31%). The most common fusion was EWSR1–ATF1 (n = 24/55, 44%). The median number of systemic therapies was 1 (range 1-7). The best response rate was seen for patients treated with sunitinib (30%, n = 3/10), with a median progression-free survival of 4 [95% confidence interval (CI) 1-7] months. The median overall survival for patients with advanced/metastatic disease was 15 months (95% CI 3-27 months).

Conclusions

Soft tissue sarcoma-type systemic therapies have limited benefit in advanced CCS and response rate was poor. International, multicentre prospective translational studies are required to identify new treatments for this ultra-rare subtype, and access to early clinical trial enrolment remains key for patients with CCS.

•

This is the largest reported series of advanced CCS patients treated with systemic therapy.

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The activity of sarcoma-type systemic therapy is poor and modest responses were seen only with sunitinib.

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Effective therapies are needed to improve outcomes for patients with this ultra-rare sarcoma type.

18F-FDG PET/CT in Clear Cell Sarcoma With Multiple Bone Metastases

ABSTRACT

A 26-year-old man presented with right facial pain for more than 20 days. Admission diagnosis was considered as jaw osteomyelitis. CT of the chest before surgery showed multiple bone destructions, which were considered as bone metastases. Then the 18F-FDG PET/CT was recommended for finding the primary tumor and evaluation of disease extent. 18F-FDG PET/CT revealed multiple abnormal foci at the skeleton and the left arm. Pathological examination and molecular analysis revealed the diagnosis of clear cell sarcoma. We present a case of clear cell sarcoma with multiple bone metastases, which is an extremely rare tumor.

Histopathological and Molecular Profiling of Clear Cell Sarcoma and Correlation with Response to Crizotinib: An Exploratory Study Related to EORTC 90101 "CREATE" Trial

Simple Summary

Clear cell sarcoma (CCSA) is a rare subtype of soft tissue sarcoma characterized by EWSR1 rearrangement and subsequent MET upregulation. The European Organisation for Research and Treatment of Cancer 90101 phase II trial evaluated the MET inhibitor crizotinib in CCSA but resulted in only sporadic responses. The aim of this exploratory study was to identify the molecular alterations potentially relevant for the treatment outcome by using archival CCSA samples and trial-related clinical data. We characterized MET signaling and revealed an infrequent activation of MET, which may explain the lack of response to crizotinib in the disease cohort. Based on sequencing analyses, we discovered copy number alterations, mutations and dysregulated pathways with potentially predictive or prognostic values for patients’ outcomes. This work describes the molecular heterogeneity in CCSA and provides deep insight into the biology of this ultra-rare malignancy, which may potentially lead to better therapeutic approaches.

Abstract

Clear cell sarcoma (CCSA) is characterized by a chromosomal translocation leading to EWSR1 rearrangement, resulting in aberrant transcription of multiple genes, including MET. The EORTC 90101 phase II trial evaluated the MET inhibitor crizotinib in CCSA but resulted in only sporadic responses. We performed an in-depth histopathological and molecular analysis of archival CCSA samples to identify alterations potentially relevant for the treatment outcome. Immunohistochemical characterization of MET signaling was performed using a tissue microarray constructed from 32 CCSA cases. The DNA from 24 available tumor specimens was analyzed by low-coverage whole-genome sequencing and whole-exome sequencing for the detection of recurrent copy number alterations (CNAs) and mutations. A pathway enrichment analysis was performed to identify the pathways relevant for CCSA tumorigenesis. Kaplan–Meier estimates and Fisher’s exact test were used to correlate the molecular findings with the clinical features related to crizotinib treatment, aiming to assess a potential association with the outcomes. The histopathological analysis showed the absence of a MET ligand and MET activation, with the presence of MET itself in most of cases. However, the expression/activation of MET downstream molecules was frequently observed, suggesting the role of other receptors in CCSA signal transduction. Using sequencing, we detected a number of CNAs at the chromosomal arm and region levels. The most common alteration was a gain of 8q24.21, observed in 83% of the cases. The loss of chromosomes 9q and 12q24 was associated with shorter survival. Based on exome sequencing, 40 cancer-associated genes were found to be mutated in more than one sample, with SRGAP3 and KMT2D as the most common alterations (each in four cases). The mutated genes encoded proteins were mainly involved in receptor tyrosine kinase signaling, polymerase-II transcription, DNA damage repair, SUMOylation and chromatin organization. Disruption in chromatin organization was correlated with longer progression-free survival in patients receiving crizotinib. Conclusions: The infrequent activation of MET may explain the lack of response to crizotinib observed in the majority of cases in the clinical trial. Our work describes the molecular heterogeneity in CCSA and provides further insight into the biology of this ultra-rare malignancy, which may potentially lead to better therapeutic approaches for CCSA.

Molecular Characteristics of Genes and the Immune Microenvironment of a Rare Chest Malignant Tumor (Pulmonary Clear Cell Sarcoma): A Case Report

Pulmonary clear cell sarcoma is a rare malignant tumor that has rarely been reported and is challenging to diagnose, especially when differentiating from malignant melanoma. Currently, EWSR1-ATF1 is the key marker for distinguishing clear cell sarcoma from melanoma, but IHC has diagnostic limitations. We report a patient diagnosed with pulmonary clear cell sarcoma, in which an NGS was used to help with the pathological diagnosis. The exposure to the immune microenvironment in pulmonary clear cell sarcoma suggests that TIGIT-related drugs may be a new and effective treatment for this rare disease. Immune microenvironment-related markers, including PD-L1, CD8, TIM3, LAG3, and CD163, were negatively expressed in pulmonary clear cell sarcoma.

Soft-tissue Sarcoma of the Hand: Patient Characteristics, Treatment, and Oncologic Outcomes

INTRODUCTION

The aim of this study was to describe patient characteristics, treatment, and oncologic outcomes of soft-tissue sarcomas (STSs) of the hand.

METHODS

Sixty-nine STSs of the hand in adult patients treated at a tertiary referral center were retrospectively included. We describe patient and tumor characteristics along with oncologic outcomes.

RESULTS

Epithelioid sarcoma (23%) was the most common histologic subtype, followed by synovial sarcoma (15%). Of all tumors, 17 (25%) were grade I, 22 (32%) were grade II, and 30 (44%) were grade III. The 5-year disease-free survival for epithelioid sarcomas was 75% with a disease survival of 100%, along with a metastatic rate of 15%. Of the patients with a synovial sarcoma, 40% developed metastases, and the 5-year disease-free survival was 68% and the 5-year disease survival was 73%.

CONCLUSION

Hand STSs are aggressive tumors with a high metastatic potential. Even with adequate oncologic treatment, long-term clinical follow-up (10 years) in these tumors is advised. The treating surgical oncologist should not be deceived by their smaller size.

Clear cell sarcoma of soft tissue with eccrine differentiation: A case report and review of the literature

Clear cell sarcoma of soft tissue (CCSST) is a deep soft tissue tumor presenting in the extremities of young adults. Histopathologically, nests and sheets of polygonal cells with clear to eosinophilic cytoplasm separated by fibrous septa as well as occasional "wreath-like" giant cells are visualized. However, CCSST has been noted to have atypical histopathological features, such as epidermotropism or myxoid differentiation, or occurrence at unusual sites. Here, we present a case of eccrine ductal differentiation in CCSST. The patient, a 21-year-old woman, presented with a lump of 10-year duration sized 3 × 5 cm on the plantar surface of the fourth and fifth interdigital spaces. There had been an increase in size as well as pain and redness over 6 years. Besides the characteristic findings, there were ductal structures in continuity with the upper dermis indicative of ductal differentiation. The tumor stained positively for S100, HMB45, and succinic dehydrogenase; ducts stained positively for epithelial membrane antigen (EMA) and carcinoembryonic antigen (CEA). CCSST was confirmed with cytogenetic analysis showing the translocation associated with EWSR1-ATF1 fusion gene. Therefore, ductal differentiation is a unique finding that should be considered when evaluating for CCSST.

Clear Cell Sarcoma of the Foot in an 18-Year-Old Female

We report a case of an 18-year-old female without a relevant medical history who presented with an 8-month history of a left foot mass. It started as a small nodule that progressively increased in size over time. The mass then became ulcerative with foul-smelling discharge. There was no palpable left inguinal or other lymph nodes upon physical examination. Histological examination of the biopsy confirmed a diagnosis of clear cell sarcoma. Clear cell sarcoma is a rare soft tissue neoplasm. However, early diagnosis is crucial to prevent metastasis and worsened prognosis. Clear cell sarcoma has an extremely poor prognosis once metastasis occurs, and to the best of our knowledge, only fewer than 100 cases have been reported in the literature.

Eribulin Suppresses Clear Cell Sarcoma Growth by Inhibiting Cell Proliferation and Inducing Melanocytic Differentiation Both Directly and Via Vascular Remodeling

Clear cell sarcoma (CCS) is a rare but chemotherapy-resistant and often fatal high-grade soft-tissue sarcoma (STS) characterized by melanocytic differentiation under control of microphthalmia-associated transcription factor (MITF). Eribulin mesilate (eribulin) is a mechanistically unique microtubule inhibitor commonly used for STS treatment, particularly liposarcoma and leiomyosarcoma. In this study, we examined the antitumor efficacy of eribulin on four human CCS cell lines and two mouse xenograft models. Eribulin inhibited CCS cell proliferation by inducing cell-cycle arrest and apoptosis, shrunk CCS xenograft tumors, and increased tumor vessel density. Eribulin induced MITF protein upregulation and stimulated tumor cell melanocytic differentiation through ERK1/2 inactivation (a MITF negative regulator) in vitro and in vivo Moreover, tumor reoxygenation, probably caused by eribulin-induced vascular remodeling, attenuated cell growth and inhibited ERK1/2 activity, thereby upregulating MITF expression and promoting melanocytic differentiation. Finally, downregulation of MITF protein levels modestly debilitated the antiproliferative effect of eribulin on CCS cells. Taken together, eribulin suppresses CCS through inhibition of cell proliferation and promotion of tumor differentiation by acting both directly on tumor cells and indirectly through tumor reoxygenation.

Clear cell sarcoma of soft tissue in pleural cavity: A case report

BACKGROUND

Clear cell sarcoma (CCS) of soft tissue is a rare malignant soft tissue sarcoma usually reported to locate at distal end of extremities and rarely at trunk. Herein, we report a case of CCS in pleural cavity.

CASE SUMMARY

A 31-year-old male was admitted for an uncertain mass in left pleural cavity in routine physical examination without any symptoms. A VATS surgery was performed to remove the tumor. The pathological finding displayed a cystic mass with 6.5 cm at the longest diameter, dark red in section and cysts could be found locally. A strong expression of S-100, HMB45 and Vimentin was detected in immunohistochemical staining, which was inclined to the diagnosis of the CCS of soft tissue. The patient refused chemotherapy, radiotherapy and targeted therapy because of the personal financial situation. Follow-up computed tomography scans were done at the 90^th postoperative day and the 180^th postoperative day, and no obvious sign of recurrence was found till now.

CONCLUSION

CCS of soft tissue also can be found in pleural cavity although in an extremely rare incidence. Radical resection is useful to improve the prognosis.

Prognostic Factors for Survival in Patients with Clear Cell Sarcoma: An Analysis of the Surveillance, Epidemiology, and End Results (SEER) Database

Background

Clear cell sarcoma (CCS) of soft tissue, or malignant melanoma of soft parts, is a rare disease. We aimed to identify prognostic factors linked to patient survival in CCS by analyzing demographic and clinical features using the Surveillance, Epidemiology, and End Results (SEER) database. This study aimed to identify prognostic factors associated with CCS that would be of clinical value.

Material/Methods

We collected data from patients diagnosed with CCS between 1973 and 2009 from the SEER database. The Kaplan-Meier method and Cox regression analysis were performed to identify prognostic factors for patient survival.

Results

A total of 175 patients with CCS were identified from the SEER database. The 5-year survival rate was 62.9%, and the 10-year survival rate was 51.3%. Patients with CCS with local stage, and with tumor size ≤3 cm were more likely to have good survival rates.

Conclusions

The findings from this study showed that the identifiable prognostic factors in patients with CCS were stage and tumor size. Local stage and tumor size ≤3 cm were favorable prognostic factors for patient survival in CCS.

Prognostic analysis of surgically treated clear cell sarcoma: an analysis of a rare tumor from a single center

BACKGROUND

The objective of this retrospective study was to evaluate the prognostic value of various factors in clear cell sarcoma patients after radical surgery.

METHODS

Forty-two clear cell sarcoma patients from August 2006 to March 2018 were included in the study. Curves of disease-free survival and overall survival were calculated using the Kaplan-Meier method, and univariate and multivariate analyses of various prognostic factors were performed using a Cox proportional hazard regression model. Laboratory test of peripheral blood was recorded before surgery. The optimal cutoff value of systemic inflammatory markers was defined by receiver-operating curve analysis.

RESULTS

The 5-year DFS and 5-year OS rate were 22% and 46%, respectively. The median DFS and OS times were 12 and 41.5 months, respectively. In univariate analysis, there was a significant association between shorter DFS and tumor size larger than 5 cm (p = 0.0043), positive surgical margin (p = 0.0233), and the neutrophil-to-lymphocyte ratio (NLR) higher than 2.73 (p = 0.0009). Furthermore, we observed a significant association between shorter OS and tumor size larger than 5 cm (p = 0.0075), positive surgical margin (p = 0.0101), NLR higher than 2.73 (p = 0.0126), the platelet-to-lymphocyte ratio (PLR) higher than 103.89 (p = 0.0147) and the lymphocyte-to-monocyte ratio (LMR) lower than 4.2 (p = 0.0445). A multivariate analysis demonstrated that the surgical margin (p = 0.013) and NLR (p = 0.001) were significantly associated with DFS. Tumor size (p = 0.010) and NLR (p = 0.013) were independent prognostic factors for OS.

CONCLUSIONS

This study had the second largest sample around the world and preoperative NLR may be a useful prognostic factor in CCS patients after radical surgery.

Intra-Extracranial Primary Clear Cell Sarcoma: The First Report and Review of the Literature

BACKGROUND

Clear cell sarcoma (CCS) is a rare malignant soft tissue tumor with poor prognosis owing to metastasis and insensitive response to chemotherapy and radiotherapy.

METHODS

We first searched PubMed and Embase using the terms "clear cell sarcoma," "malignant melanoma of soft tissue," "head," and "neck." In the 15 articles selected for literature review, only 27% (4/15) of patients were diagnosed with primary CCS of the head. Pathologically, those tumors arose from either the scalp or the superficial temporal fascia, but none invaded the skull and brain. Next, the search was performed in the same database using the terms "clear cell sarcoma," "malignant melanoma of soft tissue," and "bone," and only 24 articles were selected.

RESULTS

In the case reported here, a 36-year-old woman was found to have a palpable mass located at the left temporal-occipital region, and surgical finding confirmed the invasion into the skull and the brain. The diagnosis of primary CCS was made because of the detection of t(12;22)(q13;q12) in >50% of tumor cells by fluorescence in situ hybridization, and metastasis to the lymph nodes and lungs was discovered by postoperative positron emission tomography-computed tomography.

CONCLUSIONS

To the best of our knowledge, this is the first case of primary central nervous system CCS. Primary CCS may involve the skull and should be one of the differential diagnoses for intra-extracranial communicating tumors. Further research on biological characteristics and molecular targeted therapy of CCS are needed to improve its poor prognosis.

The epidemiology and survivorship of clear cell sarcoma: a National Cancer Database (NCDB) review

PURPOSE

Clear cell sarcoma (CCS) is a rare soft tissue tumor thought to originate from tendons and aponeuroses. This is the largest and most comprehensive study of CCS to the best of our knowledge. In addition, this is the first study to determine the estimated 10-year overall survival, specific treatment modalities including neoadjuvant and adjuvant combinations, and sites of distant metastasis in CCS utilizing a national database.

METHODS

The National Cancer Database (NCDB) was used to study 489 patients diagnosed with CCS from 2004 to 2014. Kaplan-Meier methods were used to estimate 5- and 10-year overall survival, and log-rank tests were used to compare survival amongst stage.

RESULTS

Median age at diagnosis was 39 years. Males and females were equally affected. Race distribution was 78% Caucasian and 15% Black. Most common primary site was lower limb or hip (53%). Percentage of patients with distant organ metastases was 15%, with lung being the most common site (4%). Median overall survival was 57.2 months. Overall estimated 5- and 10-year survival was approximately 50 and 38%, respectively. Approximate 5-year survival for Stages I-IV was 75, 65, 35, and 15%, respectively. Stages at disease presentation were 34% at Stage I, 13% at Stage II, 16% at Stage III, and 38% at Stage IV. Surgery was the most common form of treatment (83%); 34% received radiation and 20% received chemotherapy.

CONCLUSION

The 5-year overall survival for CCS in Stages III and IV was much worse than Stages I and II. Overall estimated 5- and 10-year survival was approximately 50 and 38%, respectively. Men and women were equally affected and had a median age at diagnosis of 39 years. The most common tumor location was lower limb and hip and the most common site of metastases was the lung.

Clear cell sarcoma of the gastrointestinal tract and malignant gastrointestinal neuroectodermal tumour: distinct or related entities? A review

Clear cell sarcoma is an uncommon sarcoma which rarely occurs as a primary tumour in the gastrointestinal tract (CCS-GIT). It shares common molecular genetic abnormalities with the more recently described entity, malignant gastrointestinal neuroectodermal tumour (GNET) but is distinguished by its morphological and immunohistochemical findings. The exact nosological relationship between these tumours continues to be debated. In this review, we present two cases of these rare neoplasms from our files and perform a statistical comparison of all published cases to determine if significant differences exist in their clinicopathological features and biological behaviour. Thirteen cases of CCS-GIT and 58 of GNET were included. CCS-GIT occurred more commonly in males (84.6% vs 46.6%, p = 0.01) and in an older age group (median 57 vs 33 years, p < 0.01). There was no significant difference in their location in the gastrointestinal tract, median tumour size and proportion of cases with an EWSR1-ATF1 vs EWSR1-CREB1 fusion. Median survival for CCS-GIT was 13.5 months and for GNET, 9.5 months (p = 0.78). There was no significant difference in the Kaplan-Meier survival curves for either time to first metastasis (p = 0.88) or overall survival (p = 0.18), including after controlling for tumour size using regression models. Our analysis confirms that aside from morphological variations between these tumours, they also exhibit epidemiological and clinical differences. Despite the prevalent perception that GNET is associated with a more aggressive clinical course, our findings indicate that there is no significant difference in their biological behaviour, although both clearly share a bleak prognosis. Further experience is awaited to determine optimal treatment strategies and whether CCS-GIT and GNET would differ in their response to various therapies.

Local Ablative Therapies to Metastatic Soft Tissue Sarcoma

The approach to metastatic soft tissue sarcoma is complex and depends upon several factors, such as the extent of the disease, the histologic subtype of the primary tumor, the disease-free interval, patient status and comorbidities, and previous treatments. The effect of systemic chemotherapy is suboptimal, therefore local ablative therapies are often considered when the disease is limited, especially if confined to a single site/organ. Historically, surgery has been considered the treatment of choice for isolated lung metastases. This approach also has been extended to metastases in the liver, although a formal demonstration of its benefit has never been provided. Radiation therapy instead has been mainly used to obtain pain control and to reduce the risk of bone fracture and cord compression. Advances in techniques, such as the development of more precise conformational modalities and the employment of particles, may change the role of this modality in the strategic approach to metastatic soft tissue sarcoma. Recently, the use of interventional radiology in this scenario has expanded. Ablative approaches, such as radiofrequency ablation and cryoablation, have shown durable eradication of tumors. Catheter-directed therapies, such as hepatic artery embolization, are potential techniques for treating the patient who has multiple unresectable liver metastases. Understanding the timing and role of these three different modalities in the multidisciplinary approach to metastatic soft tissue sarcoma is critical to provide better care and to personalize the approach to the single patient.

Biology and management of clear cell sarcoma: state of the art and future perspectives

INTRODUCTION

Clear cell sarcoma (CCS) is an aggressive tumor, typically developing in tendons or aponeuroses. The outcome of this orphan disease is poor, with 5-year and 10-year survival rates of localized CCS around 60-70% and 40-50%. Once the disease has metastasized, it is usually fatal due to its chemotherapy-resistant nature. Systemic treatment options are poorly standardized and the use of chemotherapy is based on weak scientific evidence.

AREAS COVERED

In this review, we systematically discuss the current scientific evidence for the systemic treatment of CCS, including tyrosine kinase inhibitors, immunotherapy and MET inhibitors. Expert commentary: Recent insights in the biology of CCS have identified new potential therapeutic targets, which should be tested in prospective clinical trials. Whenever possible, patients with metastatic CCS should be included in clinical trials with good biological rationale. Innovative trial methodology and new regulatory mechanisms are required to provide patients with uncommon cancers with active drugs.

Diagnostically Challenging Epithelioid Soft Tissue Tumors

In this article, we focus on the histologic features, differential diagnosis, and potential pitfalls in the diagnosis of epithelioid sarcoma, alveolar soft part sarcoma, clear-cell sarcoma, ossifying fibromyxoid tumor, and malignant extrarenal rhabdoid tumor. Numerous other soft tissue tumors also may have epithelioid variants or epithelioid features. Examples include epithelioid angiosarcoma, epithelioid malignant peripheral nerve sheath tumor, epithelioid gastrointestinal stromal tumor, and perivascular epithelioid cell tumor, among others.

Whole-exome sequencing identifies a somatic missense mutation of NBN in clear cell sarcoma of the salivary gland

Clear cell sarcoma (CCS) is a rare, low-grade carcinoma commonly located in the distal extremities of young adults involving tendons and aponeuroses. CCS is characterized by its poor prognosis due to late diagnosis, multiple local recurrence, propensity to late metastases, and a high rate of tumor-related mortality. The genetic cause for CCS is thought to be EWSR1 gene translocation. However, CCS lacking a translocation may have other, as yet uncharacterized, genetic mutations that can cause the same pathological effect. A combination of whole‑exome sequencing and Sanger sequencing of cancer tissue and venous blood from a patient diagnosed with CCS of the salivary gland revealed a somatic missense mutation, c.1061C>T (p.P354L), in exon 9 of the Nibrin gene (NBN). This somatic missense mutation led to the conversion of proline to leucine (p.P354L), resulting in deleterious effects for the NBN protein. Multiple-sequence alignments showed that codon 354, where the mutation (c.1061C>T) occurs, is located within a phylogenetically conserved region. In conclusion, we here report a somatic missense mutation c.1061C>T (p.P354L) in the NBN gene in a patient with CCS lacking an EWSR1-ATF1 fusion. Our findings broaden the genotypic spectrum of CCS and provide new molecular insight that should prove useful in the future clinical genetic diagnosis of CCS.

Primary tumor size predicts pathologic findings in the retroperitoneal lymph nodes in patients with paratesticular rhabdomyosarcoma

To determine patient and tumor characteristics that could predict pathologic findings after retroperitoneal lymph node dissection (RPLND) in paratesticular rhabdomyosarcoma (PTRMS), a total of 266 cases of PTRMS diagnosed between 1973 and 2010 were identified from a national database. RPLND dissection was performed in 67 patients, with a mean age of 14.9 years and median survival of 80 months. PTRMS occurred more often on the right side, had embryonal histology, and had an average size of 6.7 cm. Retroperitoneal lymph node (RPLN) metastasis occurred in 40 % (n = 27) of patients. Tumor size and age were strong predictors of finding rhabdomyosarcoma in the retroperitoneal lymph nodes when examined by pathologists. Primary tumors larger than 7 cm in size developing in males 12 years or older had four times more odds of being associated with positive findings on pathologic examinations of the retroperitoneal lymph nodes. Patient race, histology, and tumor laterality were not significant predictors of PTRMS metastasis to the RPLN basin. Patients 12 years or older with PTRMS larger than 7 cm have a significant risk of retroperitoneal lymph nodes involvement with PTRMS. Detailed pathologic examination of the lymph nodes in these patients is recommended.