Diagnosis and management of synovial sarcoma

Synovial Sarcoma: Advances in Diagnosis and Treatment Identification of New Biologic Targets to Improve Multimodal Therapy

Synovial sarcoma is a translocation-associated soft-tissue malignancy that frequently affects adolescents and young adults. It is driven by one of the fusion oncoproteins SS18-SSX1, SS18-SSX2, or rarely, SS18-SSX4. Prognosis of patients with recurrent or metastatic disease is generally poor, and newer therapeutic strategies are needed. In this review, we present recent discoveries in the pathogenesis, diagnosis, and treatment of synovial sarcoma. We discuss potential therapeutic strategies to improve clinical outcomes in this disease.

Metastatic biomarkers in synovial sarcoma

Synovial sarcoma (SS) is an aggressive soft tissue sarcoma (STS) that typically occurs in the extremities near a joint. Metastatic disease is common and usually occurs in the lungs and lymph nodes. Surgical management is the mainstay of treatment with chemotherapy and radiation typically used as adjuvant treatment. Although chemotherapy has a positive impact on survival, the prognosis is poor if metastatic disease occurs. The biology of sarcoma invasion and metastasis remain poorly understood. Chromosomal translocation with fusion of the SYT and SSX genes has been described and is currently used as a diagnostic marker, although the full impact of the fusion is unknown. Multiple biomarkers have been found to be associated with SS and are currently under investigation regarding their pathways and mechanisms of action. Further research is needed in order to develop better diagnostic screening tools and understanding of tumor behavior. Development of targeted therapies that reduce metastatic events in SS, would dramatically improve patient prognosis.

Primary mediastinal synovial sarcoma: A rare case report

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Synovial sarcomas commonly occur in the extremities of young adults.

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A primary occurrence in the mediastinum is very rare with only a few reported cases in the world literature.

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This paper highlights the importance of recognizing an unusual presentation of this aggressive neoplasm to aid appropriate clinical management.

Introduction

Synovial sarcomas commonly occur in the extremities of young adults. A primary occurrence in the mediastinum is very rare with only a few reported cases in the world literature.

We report a case of mediastinal synovial sarcoma. This paper is about a 47-year-old male who presented with retrosternal chest pain and shortness of breath on exertion. Imaging showed an anterior mediastinal mass. Pathological examination of the resected mass showed a biphasic neoplasm with a spindle cell component admixed with gland-like elements. The tumor showed positive staining with cytokeratin, epithelial membrane antigen and vimentin confirming the diagnosis of a biphasic synovial sarcoma.

Discussion

A wide range of neoplasms, both primary and metastatic, occur in the mediastinum, which pose considerable diagnostic difficulties. A synovial sarcoma should always be considered in the differential diagnosis, and immunohistochemistry is an important adjuvant tool in this situation.

Conclusion

This paper highlights the importance of recognizing an unusual presentation of this aggressive neoplasm to aid appropriate clinical management.

Diagnosis of a rare primary pulmonary synovial sarcoma with endobronchial ultrasound-guided transbronchial needle aspiration

Primary pulmonary synovial sarcoma (PPSS) is a rare disease. Diagnosis is made postoperatively following resection of the tumor. We describe the case of a 39‐year‐old non‐smoking woman whose chest imaging revealed a heterogeneous mass (5.4 cm × 4.6 cm), with soft tissue density in the right upper lobe and pleural effusion in the right hemithorax. The tumor was enhanced on a computed tomography scan, in which enlargement of the mediastinal lymph nodes compressing the adjacent superior vena cava was observed. Endobronchial ultrasound‐guided transbronchial needle aspiration (EBUS‐TBNA) was then performed, which demonstrated PPSS, subsequently confirmed by immunohistochemistry and the detection of a SYT‐SSX fusion gene. We believe that a diagnostic approach of EBUS‐TBNA for lung sarcoma would provide helpful information to clinicians.

Synovial Sarcoma Mimicking Myositis Ossificans

A calcification mass was incidentally found in the soft tissue of a patient who had a history of trauma to the extremity during examination. The patient had no symptom. The pathological analysis of the mass revealed it was an early-phase synovial sarcoma (SS). The diagnosis was made before the onset of symptoms and proper surgical intervention was performed. Therefore, in case of a <1 cm lesion clinically suspicious of myositis ossificans, SS should be taken into consideration as a possible diagnosis.

Vascular resection en-bloc with tumor removal and graft reconstruction is safe and effective in soft tissue sarcoma (STS) of the extremities and retroperitoneum

BACKGROUND

To analyze the outcome of a series of patients who underwent vascular resection as part of an excision of a soft tissue sarcoma (STS).

STUDY DESIGN

All consecutive patients affected by localized STS of an extremity or retroperitoneum treated between January 2000 and December 2013 with surgery including vascular resection were considered. Overall survival (OS), crude cumulative incidence (CCI) of local recurrence (LR) and distant metastases (DM) were estimated by Kaplan-Meier. Long-term vascular graft patency rate was assessed.

RESULTS

2692 patients received an operation for localized disease with 105 (3.9%) cases undergoing vascular resection. Median FU was 32 months. 5-year OS, CCI of LR and DM were 62%, 12% and 58% respectively. Vascular reconstructions consisted of 52 arterial and 16 venous grafts in extremities; 12 arterial and 33 venous grafts in the retroperitoneum. Graft thrombosis occurred in 16 patients (7/64 arterial and 9/49 venous reconstructions). Arterial occlusions occurred at a median of 36 months after surgery and were treated by prosthesis replacement (3), Fogarty catheter embolectomy (2), percutaneous angioplasty (1) and observation (1). One patient eventually required amputation. Venous occlusions occurred at a median of 4 months post surgery and were all treated conservatively. Overall arterial and venous reconstruction patency rates were 89% and 82% respectively.

CONCLUSIONS

Vascular resection to facilitate resection of STS has an acceptable long term patency rate. However it was associated to a high risk of distant spread. Although the encasement of the vascular bundle does not represent a contraindication to surgery there is an association with a high metastatic risk by virtue of the locally advanced nature of the disease and this should be considered when planning treatment.

Targeting EZH2-mediated methylation of H3K27 inhibits proliferation and migration of Synovial Sarcoma in vitro

Synovial sarcoma is an aggressive soft tissue sarcoma genetically defined by the fusion oncogene SS18-SSX. It is hypothesized that either SS18-SSX disrupts SWI/SNF complex inhibition of the polycomb complex 2 (PRC2) methyltransferase Enhancer of Zeste Homologue 2 (EZH2), or that SS18-SSX is able to directly recruit PRC2 to aberrantly silence target genes. This is of potential therapeutic value as several EZH2 small molecule inhibitors are entering early phase clinical trials. In this study, we first confirmed EZH2 expression in the 76% of human synovial sarcoma samples. We subsequently investigated EZH2 as a therapeutic target in synovial sarcoma in vitro. Knockdown of EZH2 by shRNA or siRNA resulted in inhibition of cell growth and migration across a series of synovial sarcoma cell lines. The EZH2 selective small-molecule inhibitor EPZ005687 similarly suppressed cell proliferation and migration. These data support the hypothesis that targeting EZH2 may be a promising therapeutic strategy in the treatment of synovial sarcoma; clinical trials are initiating enrollment currently.

Synovial Sarcoma Microvesicles Harbor the SYT-SSX Fusion Gene Transcript: Comparison of Different Methods of Detection and Implications in Biomarker Research

Background. Synovial sarcoma is an aggressive soft-tissue malignancy. This study examines the presence of the SYT-SSX fusion transcript in synovial sarcoma microvesicles as well as its potential role as a biomarker for synovial sarcoma. Patients and Methods. Microvesicle release of synovial sarcoma cells was examined by transmission electron microscopy. RNA-content was analyzed by qPCR, nested PCR, nested qPCR, and droplet digital PCR to compare their sensitivity for detection of the SYT-SSX fusion gene transcript. Whole blood RNA, RNA of mononuclear cells, and microvesicle RNA of synovial sarcoma patients were analyzed for the presence of the fusion gene transcripts. Results. Electron microscopic analysis revealed synovial sarcoma cells releasing membrane-enclosed microvesicles. In vitro, the SYT-SSX fusion gene transcript was detected in both synovial sarcoma cells and microvesicles. Nested qPCR proved to be the most sensitive in detecting the SYT-SSX fusion gene mRNA. In contrast, the fusion gene transcript was not detected in peripheral blood cells and microvesicles of synovial sarcoma patients. Conclusion. Synovial sarcoma cells release microvesicles harboring the SYT-SSX fusion transcript. Nested qPCR proved to be the most sensitive in detecting the SYT-SSX fusion gene mRNA; however, more sensitive assays are needed to detect cancer-specific microvesicles in the peripheral blood of cancer patients.

Primary Tumors of the Foot and Ankle

Tumors of the foot and ankle are rarely encountered in the general patient population. Even among studies of tumor patients, foot and ankle neoplasms are uncommon. Given the weight-bearing demands of the foot and its relatively small area, even small masses are likely to be symptomatic and/or palpable to both patient and physician. Only 3% of osseous neoplasms are found in this region, while 8% of benign soft tissue tumors and 5% of malignant soft tissue tumors are localized to the foot and ankle. Despite the rarity of presentation, it is important for orthopaedic surgeons to be familiar with the diagnostic criteria and therapeutic options for these patients, as each tumor varies in its presentation, level of aggressiveness, and natural history of the disease. With appropriate diagnostic tests and treatment, patients can anticipate a reasonable chance of survival and preservation of function. In this review article, the authors survey the current literature regarding the presentation, diagnostic workup, and treatment for the most common benign and malignant tumors of the foot and ankle.

LEVELS OF EVIDENCE

Level IV: Literature Review.

Potential for immunotherapy in soft tissue sarcoma

Soft tissue sarcomas (STS) are rare, heterogeneous tumors of mesenchymal origin. Despite optimal treatment, a large proportion of patients will develop recurrent and metastatic disease. For these patients, current treatment options are quite limited. Significant progress has been made recently in the use of immunotherapy for the treatment of other solid tumors (e.g. prostate cancer, melanoma). There is a strong rationale for immunotherapy in STS, based on an understanding of disease biology. For example, STS frequently have chromosomal translocations which result in unique fusion proteins and specific subtypes have been shown to express cancer testis antigens. In this review, we discuss the current status of immunotherapy in STS, including data from human studies with cancer vaccines, adoptive cell therapy, and immune checkpoint blockade. Further research into STS immunology is needed to help design logical, subtype-specific immunotherapeutic strategies.

[Synovial tumors and tumor-like lesions]

Synovial tumors comprise a variety of lesions, including those with benign and aggressive neoplastic changes as well as inflammatory causes. In this article we focus on neoplastic tumors. Synovial tumors with other etiologies, such as sarcoidosis, granuloma, synovitis, or gouty arthritis, are not dealt with here. Through a precise differentiation between these disease entities can an optimization of treatment be achieved.

Identification of a blood-borne miRNA signature of synovial sarcoma

Background

Synovial sarcoma account for approximately 10 % of all soft-tissue tumors and occur most frequently in young adults. A specific translocation in this sarcoma induces fusion of the SYT gene on chromosome 18 to the SSX genes on chromosome X, leading to proliferation of the tumor cells. The need for non-invasive biomarkers indicating recurrence and activity of this disease has sparked research into short non-coding RNA known as microRNA (miRNA).

Methods

Blood samples of patients with active synovial sarcoma and of synovial sarcoma patients in complete remission as well as of healthy donors and patients with active leiomyosarcoma, MPNST, Ewing sarcoma and liposarcoma were collected. Whole blood RNA was extracted and samples of patients with active synovial sarcoma and of healthy donors were analyzed using an Affymetrix GeneChip miRNA Array v. 4.0. qRT-PCR was carried out to confirm a panel of miRNAs which where differentially expressed in the miRNA array. This miRNA-panel was further evaluated in patients with synovial sarcoma in complete remission and patients with active leiomyosarcoma, MPNST, Ewing sarcoma and liposarcoma as well as in an independent cohort of synovial sarcoma patients.

Results

Unsupervised hierarchical clustering of the miRNA arrays separated patients with active synovial sarcoma from healthy controls. A panel of seven miRNAs (miR-99a-5p, miR-146b-5p, miR-148b-3p, miR-195-5p, miR-223-3p, miR-500b-3p and miR-505-3p) was further validated by qRT-PCR to be significantly upregulated in synovial sarcoma patients. Moreover, most of the analyzed miRNAs were shown to be significantly upregulated in synovial sarcoma patients compared to leiomyosarcoma, MPNST, Ewing sarcoma and liposarcoma patients. Validation of the miRNA panel in an independent cohort of synovial sarcoma patients confirmed higher expression levels compared to healthy controls and patients in complete remission.

Conclusion

Our results have identified a specific whole blood miRNA signature that may serve as an independent biomarker for the diagnosis of local recurrence or distant metastasis of synovial sarcoma. It even distinguishes synovial sarcoma from other sarcoma subtypes, thus potentially serving as a specific biomarker for synovial sarcoma.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-015-0424-z) contains supplementary material, which is available to authorized users.

Primary Pulmonary Synovial Sarcoma in a Tertiary Referral Center: Clinical Characteristics, CT, and 18F-FDG PET Findings, With Pathologic Correlations

The purpose of this study was to describe the patient characteristics, computed tomography (CT) and F-fluorodeoxyglucose positron emission tomography (FDG PET) findings, and clinical outcomes of primary pulmonary synovial sarcoma (PPSS), together with their pathologic correlations. The medical records of 14 patients with pathologically proven PPSS in a tertiary hospital from January 1997 to December 2014 were retrospectively reviewed. The CT findings were evaluated. The maximum standardized uptake value (maxSUV) of the tumors was obtained, and clinical outcomes with respect to tumor recurrence and mortality were assessed by Kaplan-Meier analysis. The median tumor size was 10.2 cm and the most common anatomic location was the lung followed by the pleura/chest wall and mediastinum. Most of the tumors appeared as single lesions and had circumscribed margins. All the cases showed heterogeneous enhancement with necrotic or cystic portions, and intratumoral vessels were frequently seen. Half of the tumors had intratumoral calcifications, and tumor rupture, pleural/chest wall extension, and pleural effusion occurred frequently. However, lymph node enlargement was rare. The median maxSUV of the tumors was 4.35. Patient outcomes with respect to tumor recurrence (n = 8, 57.1%) and death (n = 3, 21.4%) were poor despite their young age, and the mean follow-up period was 28.5 months.In conclusion, PPSS usually occurs in young adults, generally in the lung, presents as a large, circumscribed mass, and tumor rupture or extension of the pleura/chest wall may occur. The tumors often contain calcifications and vessels; they may exhibit triple attenuation on enhanced CT images, and clinical outcomes are poor.

Synovial sarcoma of the abdominal wall: Imaging findings and review of the literature

Synovial sarcoma is the fourth most common type of soft-tissue sarcoma (following undifferentiated pleomorphic sarcoma, liposarcoma, and rhabdomyosarcoma), and should be considered a high-grade neoplasm with a high number of local recurrences and late metastases. Synovial sarcoma predominantly occurs in adolescents and young adults, and typically arises near the joints of the lower extremity. However, this tumor can also occur at uncommon sites such as the abdominal wall, which is illustrated in this article. Furthermore, we reviewed the available literatures on the clinical, pathological and radiological appearances, as well as the current knowledge concerning treatment options and prognosis.

Morphologic, molecular, and ultrastructural characterization of a feline synovial cell sarcoma and derived cell line

A 2.5-year-old, male, neutered cat presented with a 5-month history of progressive right hind limb lameness and an enlarged right popliteal lymph node. Radiographs revealed significant bony lysis of the tarsus and distal tibia, and fine-needle aspirate of the bone lesion and lymph node revealed a neoplastic population of cells with uncertain origin. Amputation was elected, and the mass was submitted for histology and cellular culture for better characterization. Histologic examination revealed a mixture of spindle-shaped cells and larger, round to polygonal cells. All cells were immunoreactive for vimentin, and only the larger polygonal cells were also positive for cytokeratin. All cells were negative for desmin, smooth muscle actin, cluster of differentiation (CD)3, CD18, CD79a, macrophage antibody (MAC)387, and glial fibrillary acidic protein. Cultured neoplastic cells failed to express CD18, and were not able to secrete the pro-inflammatory cytokines tumor necrosis factor-α, interleukin-1 (IL-1)β, and IL-6 when stimulated by lipopolysaccharide, disproving that the cells originated from the macrophage or monocyte line. Ultrastructurally, neoplastic cells were characterized by abundant rough endoplasmic reticulum, interdigitating cellular processes, and membrane condensations. Based on location and cytologic, histologic, ultrastructural, and functional studies, this neoplasm was considered a synovial cell sarcoma.

Poorly differentiated synovial sarcoma in the wrist--case report

Synovial sarcomas are rare malignant tumors affecting mainly young adults, presenting as a slow growth mass located in deep soft tissues of extremities, near the joints. In this report a 34-year-old male patient, presented an ulcerovegetative lesion on the right wrist which was completely excised. Histopathology and immunohistochemistry confirmed synovial sarcomas with poorly differentiated cells. This patient presented 11 months later with ipsilateral axillary lymph node metastasis, which emphasizes the unfavorable prognosis of this synovial sarcoma variant. The indolent growth pattern of this sarcoma justifies the well circumscribed initial stages, which progressively infiltrate adjacent structures with lung metastasis (80%) and lymph node involvement (20%) and thus corroborates the importance of early diagnosis and proper treatment.

Synovial sarcoma presenting as an avascular mass: radiologic-pathologic correlation

Synovial sarcoma is a well-recognized soft tissue malignancy that typically arises in young adults. It is now generally accepted that its origin is likely from undifferentiated mesenchymal tissue with variable epithelial differentiation and a highly specific chromosomal translocation in more than 95% of cases. The lesion typically presents as a slow-growing soft tissue mass, with MR imaging demonstrating a heterogeneous mass with variable amounts of low-, intermediate- and high-signal intensity on fluid-sensitive images and prominent heterogeneous enhancement, reflecting its vascularity. The relative hypervascularity of synovial sarcoma has been well established and is reflected in its enhancement on MR imaging studies. Contrast enhancement on MR imaging has been long used as a marker for tissue vascularization and perfusion, with malignant lesions generally being more vascular and enhancing more rapidly. We recently encountered a patient with a high-grade synovial sarcoma with no discernable necrosis and no vascularity on contrast-enhanced MR images with the subtraction technique, despite enhancement in adjacent regional metastatic lymph nodes. The pathologic basis for this unusual imaging appearance was a paucity of small-caliber vessels within the sarcoma due to extensive hyalinization of the mass.

Prognostic and predictive role of CXCR4, IGF-1R and Ezrin expression in localized synovial sarcoma: is chemotaxis important to tumor response?

BACKGROUND

Synovial sarcoma (SS) is a rare tumor, with dismal survival when metastatic. The role of adjuvant chemotherapy is debated. New prognostic and predictive factors are needed.

METHODS

We reviewed patients with localized SS; SS18-SSX fusion transcript presence was confirmed by FISH and RT-PCR. Expression of CXCR4, IGF-1R and Ezrin were evaluated by immunohistochemistry.

RESULTS

Tumor samples from 88 SS patients (45 female; 43 male) with median age 37 years (range 11-63) were selected. The size of the lesion was > 5 cm in 68% of patients and 34% of cases presented biphasic histotype. All patients underwent surgery, 56% adjuvant radiotherapy (RT), 65% adjuvant chemotherapy. A positive stain for IGF-1R was detected in 55 patients, with nucleus expression in 21 patients. CXCR4 was expressed in 74 patients, nuclear pattern in 31 patients. 80 SS were positive to Ezrin, 48 had cytoplasmatic location, 32 membrane location. With a median follow-up of 6 years (1-30 years), the 5-year overall survival (OS) was 70% (95% CI 60-81). 5-year OS was 63% (95% CI 41-85%) for patients with positive IGF-1R/nuclear expression, and 73% (95% CI 61-85%; P = 0.05) in negative patients. 5-year OS was 47% (95% CI 27-66%) in patients with positive CXCR4/nuclear staining, and 86% (95% CI 76-96%, P = 0.0003) in negative cases. No survival difference was found according to Ezrin expression. By multivariate analysis, nuclear expression of CXCR4 and IGF-1R was confirmed independent adverse prognostic factor for SS patient survival linked to the use of chemotherapy.

CONCLUSIONS

Our findings have important potential implications demonstrating that together with clinical prognostic factors such as radiotherapy and age, CXCR4 and IGF-1R negatively influences survival in patients with localized SS. We believe that further studies addressed to the effects of CXCR4 and IGF-1R inhibitors on cell viability and function are needed to plan new and more appropriate SS treatments.

Synovial sarcoma of the spine: a case involving paraspinal muscle with extensive calcification and the surgical consideration in treatment

INTRODUCTION

Synovial sarcoma is a rare malignant tumor of the spine. This tumor may present as a painless mass of the spine or slowly enlarge, causing pain or neurologic deficits. As it is difficult to differentiate this lesion from other soft tissue tumors, synovial sarcoma requires histologic confirmation for definite diagnosis. Thus, the treatment strategy is often planned in the final step depending on the pathologic results. Despite its rare incidence, a few cases of primary or metastatic synovial sarcoma involving the spinal cord, foramen, vertebral body, or paraspinal muscles have been reported in the literature.

MATERIALS AND METHODS

We present the case of a 29-year-old man with a synovial sarcoma in the paraspinal muscle of the cervical spine. The patient was evaluated radiologically and histologically. Plain radiography, computed tomography, and magnetic resonance imaging were performed as part of the preoperative workup, and immunohistochemical and cytogenetic studies were additionally performed to identify the histologic features of the tumor. The patient underwent marginal resection followed by adjuvant radiation therapy. The patient has been followed up for 2 years.

CONCLUSIONS

This article highlights the features of synovial sarcoma of the spine via a comprehensive review. Synovial sarcoma of the spine is uncommon, but it is a challenging issue in both diagnostic and therapeutic aspects. The currently available evidence suggests the use of a multidisciplinary approach in the treatment of synovial sarcoma, which includes complete resection and radiation therapy.

A rare synovial sarcoma of the spine in the thoracic vertebral body

INTRODUCTION

Synovial sarcomas of the spine are very rare, most rare of which was occurring in the thoracic vertebral body. The diagnosis of synovial sarcomas was very difficult. It depends on the radiological examination, immunohistochemical examination and gene examination. The best treatment to them was completely surgical resection with negative margins. Other treatments such as radiation therapy and chemotherapy were just adjuvant. The prognosis of synovial sarcomas was disappointing.

CASE PRESENTATION

A 26-year-old male patient had low back pain. The radiological examination showed bony erosion of the T7 vertebral body and no soft tissue mass around the spine. He underwent T7 resection en bloc and internal fixation with two levels above T7 and two levels below T7. Then histopathological and gene examination revealed high malignant synovial sarcoma. So he was treated by chemotherapy and external beam radiation therapy after surgery.

CONCLUSION

Primary vertebral body synovial sarcoma is very rare and difficult to diagnose and treat.

Imaging features of primary and metastatic extremity synovial sarcoma: a single institute experience of 78 patients

OBJECTIVE

To study the appearance of primary and metastatic extremity synovial sarcoma (SS) on cross-sectional imaging.

METHODS

In this institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study, the imaging features of 78 patients (42 males and 36 females; mean age, 40 years) with primary and metastatic extremity SS on MRI and multidetector CT were reviewed, with baseline MRI of the primary available in 31 patients.

RESULTS

Primary SSs were predominantly well-circumscribed (27/31) and heterogeneously enhancing solid (18/31) or solid-cystic (13/31) tumours. Imaging features visualized included the presence of perilesional oedema (14/31), interfascial (15/31) and intercompartmental extension (7/31), triple sign (11/31), intratumoral haemorrhage (10/31), calcification (6/31), bowl of grapes appearance (5/31) and bone involvement (3/31). Smaller T1 stage tumours (8/31) appeared as heterogeneously enhancing lesions, with some lesions demonstrating interfascial and intercompartmental extension and perilesional oedema. Recurrent/metastatic disease developed in 49/78 (63%) patients. Of these, 20/78 (26%) had metastasis at presentation, while the remaining developed metastatic disease at a median interval of 27 months (range, 3-161 months). Pleuropulmonary metastases (46/78) were the most common sites, with most of the metastases being pleural based. On univariate analysis, larger tumour size, the presence of perilesional oedema, intercompartmental extension, the presence of intralesional haemorrhage and bowl of grapes appearance on MRI were associated with a significantly higher incidence of metastatic disease.

CONCLUSION

Certain imaging features of primary SS predict the risk of development of metastatic disease. Imaging features of T1 stage tumours included heterogeneous enhancement, interfascial extension and perilesional oedema. Pleural-based metastases are commonly seen in SSs.

ADVANCES IN KNOWLEDGE

Imaging features of primary SS correlate with metastatic disease. Pleural-based metastases are often present in SSs.

Perioperative radiotherapy is associated with improved survival among patients with synovial sarcoma: A SEER analysis

BACKGROUND AND METHODS

We examined the outcomes of synovial sarcoma (SS) patients in a national database. We identified 1,189 patients from the Surveillance, Epidemiology, and End Results (SEER) database with data on site and extent of surgery. We excluded patients diagnosed before 1990, <18 years, or lacking pathologic confirmation. Using Kaplan-Meier and Cox proportional hazards analyses, we determined predictors of overall (OS) and disease-specific survival (DSS).

RESULTS

The mean age was 41, 49.3% were female, and 82.2% were white. Radiotherapy (RT) was administered to 57.5%. On multivariable analysis, age at diagnosis, sex, race, anatomic site, SEER summary stage, tumor size, surgery type, and RT predicted OS. Similar predictors of DSS were identified. The hazard ratio (HR) for OS was 0.65 (95% CI 0.48-0.88) in favor of RT and 0.62 (95% CI 0.45-0.86) for DSS. Five-year OS improved 8.4 ± 1.0% with RT (P=0.003), and five-year DSS improved 7.7 ± 1.0% with RT (P=0.015).

CONCLUSIONS

In the largest study to date examining the role of RT in synovial sarcoma, we observed that RT was associated with a statistically significant improvement in oncologic outcome among SS patients. These data support the use of RT in the multi-modality treatment of patients with SS.

Tumors that mimic asbestos-related mesothelioma: time to consider a genetics-based tumor registry?

The diagnosis of mesothelioma is not always straightforward, despite known immunohistochemical markers and other diagnostic techniques. One reason for the difficulty is that extrapleural tumors resembling mesothelioma may have several possible etiologies, especially in cases with no meaningful history of amphibole asbestos exposure. When the diagnosis of mesothelioma is based on histologic features alone, primary mesotheliomas may resemble various primary or metastatic cancers that have directly invaded the serosal membranes. Some of these metastatic malignancies, particularly carcinomas and sarcomas of the pleura, pericardium and peritoneum, may undergo desmoplastic reaction in the pleura, thereby mimicking mesothelioma, rather than the primary tumor. Encasement of the lung by direct spread or metastasis, termed pseudomesotheliomatous spread, occurs with several other primary cancer types, including certain late-stage tumors from genetic cancer syndromes exhibiting chromosomal instability. Although immunohistochemical staining patterns differentiate most carcinomas, lymphomas, and mestastatic sarcomas from mesotheliomas, specific genetic markers in tumor or somatic tissues have been recently identified that may also distinguish these tumor types from asbestos-related mesothelioma. A registry for genetic screening of mesothelioma cases would help lead to improvements in diagnostic criteria, prognostic accuracy and treatment efficacy, as well as improved estimates of primary mesothelioma incidence and of background rates of cancers unrelated to asbestos that might be otherwise mistaken for mesothelioma. This information would also help better define the dose-response relationships for mesothelioma and asbestos exposure, as well as other risk factors for mesothelioma and other mesenchymal or advanced metastatic tumors that may be indistinguishable by histology and staining characteristics.

Oncologic conditions that simulate common sports injuries

Primary bone and soft-tissue tumors that mimic common sports injuries are relatively rare and are not often encountered by most orthopaedists. Prompt and accurate diagnosis of these tumors is crucial to maximize the clinical outcome. Many bone and soft-tissue tumors present disproportionately in young and active patients who are often involved in athletic activities. Thus, the clinician may misdiagnose these rare tumors as more common sports injuries. Symptoms that should raise suspicion for a neoplastic process include pain unrelated to activity and a clinical course that does not follow the typically expected recovery for a common sports injury. An awareness of the salient features of several bone and soft-tissue tumors as well as nononcologic processes that may simulate sports injuries can aid clinicians in the prompt diagnosis and clinical decision making of these rare tumors.

Primary Pulmonary Synovial Sarcoma during Pregnancy: A Diagnostic and Therapeutic Dilemma

Synovial sarcoma is a rare soft tissue sarcoma that typically arises in the extremities of young adults. We report a case of a 26-year-old pregnant woman with biopsy-proven primary synovial sarcoma of the lung that was treated with chemotherapy with radiographic response. This is only the third documented case of primary pulmonary synovial sarcoma occurring during pregnancy and the first case where chemotherapy was given.

Primary synovial sarcomas of the mediastinum: a systematic review and pooled analysis of the published literature

Background. The aim of this systematic review is to attempt to provide a descriptive analysis for cases of synovial sarcoma (SS) arising in the mediastinum and to analyze prognostic factors. Methods. We performed PubMed database search in July 2013. Twenty-two studies, which included 40 patients, form the basis of this review. Demographic and disease-related factors were analyzed for possible influence on survival. Findings were compared with extremity SS studies reported in literature. Results. Sixteen cases (40%) presented with locally advanced unresectable disease, 2 (5%) with metastatic disease, and 22 (55%) with localized resectable disease. Median tumor size was 11 cm (range: 5–20 cm). Thirty patients were assessable for survival and had a 5-year OS of 36%. Completeness of resection was the only factor associated with significant improvement in OS (5-year survival of 63% and 0% in favor of complete resection, P = 0.003). Conclusion. Mediastinal SS is associated with poor prognosis as more cases are diagnosed at an advanced stage and with larger tumor size compared to extremity SS. Complete surgical resection is the only identified factor associated with better prognosis and may result in survival outcomes that are comparable with those for localized SS of the extremity.

Diagnostic utility of SOX10 to distinguish malignant peripheral nerve sheath tumor from synovial sarcoma, including intraneural synovial sarcoma

Synovial sarcoma and malignant peripheral nerve sheath tumor pose a significant diagnostic challenge given similar histomorphology. The distinction is further complicated by similar immunophenotype and especially by occasional synovial sarcomas that present as intraneural tumors. Although the presence of a t(X;18) rearrangement or expression of TLE1 can help confirm the diagnosis of synovial sarcoma, negative results for these tests are not diagnostic of malignant peripheral nerve sheath tumor. The SOX10 transcription factor, a putative marker of neural crest differentiation, may have diagnostic utility in this differential, but immunohistochemical data are limited. The goal of the present study was to determine the diagnostic utility of SOX10 to discriminate between synovial sarcoma and malignant peripheral nerve sheath tumor. Forty-eight cases of malignant peripheral nerve sheath tumor, all from patients with documented neurofibromatosis, and 97 cases of genetically confirmed synovial sarcoma, including 4 intraneural synovial sarcomas, were immunohistochemically stained for SOX10. The stain was scored for intensity and fraction of cells staining. Thirty-two of 48 malignant peripheral nerve sheath tumors (67%) were SOX10-positive. The majority of malignant peripheral nerve sheath tumors showed ≥2+ staining, but staining did not correlate with grade. By contrast, only 7/97 (7%) synovial sarcomas were SOX10-positive. Only three synovial sarcomas showed ≥2+ staining but, importantly, two of these were intraneural synovial sarcoma. Therefore, SOX10 is a specific (93%), albeit not very sensitive (67%), diagnostic marker to support a diagnosis of malignant peripheral nerve sheath tumor over synovial sarcoma. Furthermore, the stain needs to be interpreted with caution in intraneural tumors in order to avoid a potential diagnostic pitfall. It remains to be determined whether SOX10-positive cells in intraneural synovial sarcoma represent entrapped Schwann cells, synovial sarcoma cells or both.

The pathologic response of resected synovial sarcomas to hyperthermic isolated limb perfusion with melphalan and TNF-α: a comparison with the whole group of resected soft tissue sarcomas

Background

Hyperthermic isolated limb perfusion with tumor necrosis factor-α and melphalan (TM-HILP) has been successfully used to treat limb soft tissue sarcomas (STSs) with high response rates. The data on the effectiveness of HILP-TM for the treatment of STSs are mainly based on various STS types. The aim of this study was to investigate the responses of synovial sarcomas (SS) to TM-HILP.

Methods

A total of 125 TM-HILP-treated tumors (STS^all), including 14 SSs, were included in the study. The tumors were subdivided into proximal and distal limb localizations. Tumor typing (using the WHO classification), resection status (using the UICC classification), and response to therapy were assessed using light microscopy. The SSs were tested for the SYT-SSX translocation using RT-PCR. The following tests were applied: a chi-squared test, a t test, and the Mann-Whitney U test.

Results

The SSs were localized distally more often than were the STS cohort (STS^−SS) (85.7% vs. 32.4%) and were smaller (5.8 cm vs. 10.7 cm). There were no differences in the responder/nonresponder ratios or the mean percentages of pathological regression between the SS and STS^−SS cohorts (74.0% vs. 76.0%). A general localization-dependent difference in the tumor responses to TM-HILP could not be detected in the STS^all cohort (distal, 72.0% vs. proximal, 78.0%); however, a UICC R0 status was more often observed in proximal tumors (distal, 50.0% vs. proximal, 71.4%). There was no association between the SYT-SSX type and SS responses to TM-HILP.

Conclusions

Because of the high response rates, TM-HILP is recommended for the treatment of SSs. The distal limb localization of TM-HILP-treated STSs was generally (STS^all cohort) associated with fewer R0 resections.

Synovial sarcoma presenting with huge mediastinal mass: a case report and review of literature

Background

Synovial sarcoma presenting in the mediastinum is exceedingly rare. Furthermore, data addressing optimal therapy is limited. Herein we present a case where an attempt to downsize the tumor to a resectable state with chemotherapy was employed.

Case presentation

A 32 year female presented with massive pericardial effusion and unresectable huge mediastinal mass. Computed axial tomography scan - guided biopsy with adjunctive immunostains and molecular studies confirmed a diagnosis of synovial sarcoma. Following three cycles of combination Ifosfamide and doxorubicin chemotherapy, no response was demonstrated. The patient refused further therapy and had progression of her disease 4 months following the last cycle.

Conclusion

Synovial sarcoma presenting with unresectable mediastinal mass carry a poor prognosis. Up to the best of our knowledge there are only four previous reports where primary chemotherapy was employed, unfortunately; none of these cases had subsequent complete surgical resection. Identification of the best treatment strategy for patients with unresectable disease is warranted. Our case can be of benefit to medical oncologists and thoracic surgeons who might be faced with this unique and exceedingly rare clinical scenario.

Testicular synovial sarcoma: a case report

This paper reports a case of testicular synovial sarcoma with molecular genetic analysis. A 24-year-old male presented with painless scrotal mass. Ultrasonography showed a heterogeneous mass of 66 mm × 34 mm in size involving the inguinal region. Histological examination of a surgical biopsy showed a grade III monophasic growth pattern of spindle cell proliferation. Immunohistochemical analyses indicated positive staining for pancytokeratine and epithelial membrane antigen. Cytogenetic analysis showed the presence of CYT-SSX1 mutation, and CT scan showed non-specific pleural micro-nodules with a size of 7.5 mm. The patient had an extended left orchidectomy but was lost to follow-up for 1 year. A local recurrent scrotal mass of 32 mm × 25 mm, multiple inguinal lymph nodes, and increased pleural nodules, which were confirmed by histological examination, were treated with three cycles of adriamycine and ifosfamide chemotherapy, surgical resection, and radiotherapy with complete response. After 3 months, the patient developed local recurrence and pulmonary metastases that did not respond to second-line chemotherapy based on gemcitabine and paclitaxel. The patient had dyspnea at the time of this writing and chest pain, and is under third-line chemotherapy based on Deticene after 30 months of following up. This patient died on November 16, 2012 after a resperatory failure and malignant pelural effusion. Synovial sarcoma should be considered in the differential diagnosis of soft tissue tumor and it should be aggressively treated to improve prognosis. Although our patient has shown numerous factors of bad prognosis, he has had a relatively long survival time.

Expression of FGFR3 and FGFR4 and clinical risk factors associated with progression-free survival in synovial sarcoma

Although rare, synovial sarcoma (SS) is one of the most common soft tissue sarcomas affecting young adults. To investigate potential tumor markers related to synovial sarcoma prognosis, we carried out a single-institution retrospective analysis of 103 patients diagnosed with SS between 1980 and 2009. Clinical outcome data were obtained from medical records, and archived tissue samples were used to evaluate the relationship between progression-free survival (PFS) and several prognostic factors, including tumor expression of FGFR3 and FGFR4. No associations were found between PFS and gender, body mass index, tumor site, SS18-SSX translocation, or FGFR4 expression. As seen in previous studies, age at diagnosis (<35, 63% versus ≥35 years, 31% 10-year PFS; P = .033), histologic subtype (biphasic, 75% versus monophasic 34% 10-year PFS; P = .034), and tumor size (≤5 cm, 70% versus >5 cm, 22% 10-year PFS; P < .0001) were associated with PFS in SS patients. In addition, in a subset of patients with available archived tumor samples taken prior to chemotherapy or radiation (n = 34), higher FGFR3 expression was associated with improved PFS (P = .030). To the best of our knowledge, this is the largest study of SS to date to suggest a potential clinical role for FGFR3. While small numbers make this investigation somewhat exploratory, the findings merit future investigation on a larger scale.

Synovial sarcoma of the foot

We report the case of a 75-year-old male who underwent lung lobectomy for presumed lung cancer. Thereafter, he presented with a painful mass between the third and fourth metatarsal heads in the foot that was assumed to be Morton's neuroma. After extensive oncologic evaluation, the foot mass was diagnosed as a synovial sarcoma. In retrospect, his lung lesion was understood to be metastatic disease.

Primary synovial sarcoma of the parietal pleura: a case report

Synovial sarcoma is a malignant soft tissue tumor that most commonly occurs in the extremities of young and middle-aged adults, in the vicinity of large joints. Although synovial sarcoma is frequently associated with joints, it may arise in unexpected sites, such as the mediastinum, heart, lung, pleura, or chest wall. Primary synovial sarcoma of the pleura is rare. To date, nearly 36 cases of primary synovial sarcoma of the pleura have been reported since Gaertner et al. published the first case in 1996. The oncologic characteristics, treatment, and prognosis for pleural synovial sarcomas are not well defined because of a paucity of data. However, a multimodal approach, including surgical resection, chemotherapy, and radiotherapy, has generally been suggested. We report the outcome of one patient with primary pleural synovial sarcoma treated with radical resection and adjuvant treatment.

Synovial sarcoma of primary bone origin arising from the cervical spine

Synovial sarcoma of primary bone origin is very rare and has not been previously reported in the cervical vertebra. We report the first case of a synovial sarcoma of the cervical vertebra, presenting as an expansile osteolytic lesion in the posterior osseous elements of the C3 vertebra characteristically with prominent intratumoral vessels.

A 63-year-old woman presenting with a synovial sarcoma of the hand: a case report

Introduction

Synovial sarcoma is a high-grade, soft-tissue sarcoma that most frequently is located in the vicinity of joints, tendons or bursae, although it can also be found in extra-articular locations. Most patients with synovial sarcoma of the hand are young and have a poor prognosis, as these tumors are locally aggressive and are associated with a relatively high metastasis rate. According to the literature, local recurrence and/or metastatic disease is found in nearly 80% of patients. Current therapy comprises surgery, systemic and limb perfusion chemotherapy, and radiotherapy. However, the 5-year survival rate is estimated to be only around 27% to 55%. Moreover, most authors agree that synovial sarcoma is one of the most commonly misdiagnosed malignancies of soft tissues because of their slow growing pattern, benign radiographic appearance, ability to change size, and the fact that they may elicit pain similar to that caused by common trauma.

Case presentation

We describe an unusual case of a large synovial sarcoma of the hand in a 63-year-old Caucasian woman followed for 12 years by a multidisciplinary team. In addition, a literature review of the most pertinent aspects of the epidemiology, diagnosis, treatment and prognosis of these patients is presented.

Conclusion

Awareness of this rare tumor by anyone dealing with hand pathology can hasten diagnosis, and this, in turn, can potentially increase survival. Therefore, a high index of suspicion for this disease should be kept in mind, particularly when evaluating young people, as they are the most commonly affected group.

Synovial sarcoma: imaging features of common and uncommon primary sites, metastatic patterns, and treatment response

OBJECTIVE

The purpose of this review is to describe the imaging features, common and uncommon sites, metastatic pattern, and treatment response of synovial sarcoma.

CONCLUSION

Synovial sarcoma primarily occurs in young adults, most commonly in the lower extremities; presents as a large, noninfiltrative, well-circumscribed mass adjacent to joints, often with punctuate calcifications; and may exhibit a triple signal pattern on T2-weighted images. Small synovial sarcomas can mimic benign lesions. This tumor has a propensity for late local recurrence and metastasis, most commonly to lung.