Synovial sarcoma: imaging features of common and uncommon primary sites, metastatic patterns, and treatment response. AJR Am J Roentgenol. 2012;199:W208-W215. [PMID: 22826423 DOI: 10.2214/ajr.11.8039]

Transducin-like enhancer of split-1 (TLE-1)-positive primary pleuropulmonary synovial sarcoma in a 14-year-old female adolescent: A case report and literature review

Primary pleuropulmonary synovial sarcoma (PPSS) is a rare malignant soft tissue sarcoma primarily affecting adolescents and young adults. Diagnosis relies on clinical examination, radiological imaging, and confirmation through histopathological and immunohistochemical analyses. Due to nonspecific symptoms, diagnosis is often delayed. Treatment typically involves a multimodal approach, including systemic chemotherapy, surgical intervention, and radiotherapy. We present the case of a 14-year-old female with a 5-month history of cough, low-grade fever, and weight loss. A contrast-enhanced chest CT scan revealed a large left thoracic mass with lung infiltration, mediastinal invasion, and multiple enlarged lymph nodes. Histopathological and immunohistochemical analyses confirmed a primary pulmonary synovial sarcoma positive for transducer-like enhancer of split-1 (TLE-1). The patient underwent 2 cycles of neoadjuvant chemotherapy with ifosfamide and doxorubicin, but no significant improvement was observed. Local control options, including surgery and radiotherapy, were deemed infeasible, and palliative care was initiated.

Optimizing imaging modalities for sarcoma subtypes in radiation therapy: State of the art

The choice of imaging modalities is essential in sarcoma management, as different techniques provide complementary information depending on tumor subtype and anatomical location. This narrative review examines the role of imaging in sarcoma characterization and treatment planning, particularly in the context of radiation therapy (RT). Magnetic resonance imaging (MRI) provides superior soft tissue contrast, enabling detailed assessment of tumor extent and peritumoral involvement. Computed tomography (CT) is particularly valuable for detecting osseous involvement, periosteal reactions, and calcifications, complementing MRI in sarcomas involving bone or calcified lesions. The combination of MRI and CT enhances tumor delineation, particularly for complex sites such as retroperitoneal and uterine sarcomas, where spatial relationships with adjacent organs are critical. In vascularized sarcomas, such as alveolar soft-part sarcomas, the integration of MRI with CT or MR angiography facilitates accurate mapping of tumor margins. Positron emission tomography with [18 F]-fluorodeoxyglucose ([18 F]-FDG PET) provides functional insights, identifying metabolically active regions within tumors to guide dose escalation. Although its role in routine staging is limited, [18 F]-FDG PET and emerging PET tracers offer promise for refining RT planning. Advances in artificial intelligence further enhance imaging precision, enabling more accurate contouring and treatment optimization. This review highlights how the integration of imaging modalities, tailored to specific sarcoma subtypes, supports precise RT delivery while minimizing damage to surrounding tissues. These strategies underline the importance of multidisciplinary approaches in improving sarcoma management and outcomes through multi-image-based RT planning.

A Case of Metastatic Synovial Sarcoma of the Lung With Recurrent Spontaneous Pneumothorax

BACKGROUND

Synovial sarcoma, a highly aggressive soft tissue sarcoma, is mostly seen among young people and tends to occur in the extremities. It most commonly metastasizes to the lungs, and symptoms such as chest tightness, shortness of breath, and coughing are common after metastasis. However, multiple spontaneous pneumothorax is relatively rare. This article aims to further enhance the understanding of synovial sarcoma by introducing a case of pulmonary metastasis after surgery for synovial sarcoma originating from the sole of the foot and reviewing relevant literature.

CASE

The Cardiothoracic Surgery Department of the Northeast Yunnan Central Hospital Region admitted a 40-year-old male patient. He had previously undergone surgery for synovial sarcoma on the left foot dorsum. Seven years after the surgery, the patient experienced two spontaneous pneumothorax events. A chest CT scan revealed solid nodules in the upper lobe of the left lung. Our department performed surgical removal, and pathology confirmed metastatic pulmonary synovial sarcoma. After the surgery, the patient's symptoms improved significantly, and there were no further pneumothorax attacks. The patient was then transferred to the oncology department for further treatment to improve prognosis.

CONCLUSION

Pulmonary metastasis of synovial sarcoma is not uncommon, and a considerable number of patients are found to have no surgical opportunity when diagnosed. In this case, the patient presented with a single solid nodule, and we adopted surgery as the first-line treatment, combined with a comprehensive treatment plan of postoperative chemotherapy to further improve the patient's prognosis.

Whether unplanned excision on synovial sarcoma will influence the prognosis? An retrospective analysis of prognostic factors in 54 synovial sarcoma cases at a single center

OBJECTIVE

In this study, we examined the reason and prognosis of unplanned excision on synovial sarcoma.

METHODS

We retrospectively analyzed 54 patients diagnosed with synovial sarcoma between March 2013 and February 2021, including 26 cases of unplanned excision surgery. Patients were divided into two groups based on whether they underwent unplanned excision. Then, factors such as gender, age, tumor size, tumor location, American Joint Committee on Cancer (AJCC) staging, unplanned excision, time of onset, duration of disease, radiotherapy, chemotherapy, amputation, local recurrence factors, and death were statistically evaluated.

RESULTS

The results of a multivariate analysis revealed that the AJCC staging is an independent factor for patient prognosis. When patients were divided into two groups, those who had undergone unplanned excision and those who had not, statistical analysis revealed that there was no difference of survival between two groups, but tumor size and AJCC staging had statistical difference. To further explore the influences of unplanned excision, we performed propensity score analysis with 1:1 matching using the nearest neighbor matching method to balance the covariates between the two groups. There was no difference of survival between two groups after propensity score matching.

CONCLUSION

Unplanned excision is commonly performed in synovial sarcoma and do not impact the prognosis after extensive resection.

CT and MR imaging of a huge retroperitoneal synovial sarcoma: A case report

Retroperitoneal synovial sarcoma is extremely rare, with only a few cases reported in the literature. The diagnosis is often made late, due to anatomical considerations, with common symptoms including low back pain and weight loss. Imaging is critical for diagnosis, often revealing a heterogenous mass with the "triple sign" and calcifications. The main differential diagnoses include liposarcoma, undifferentiated pleomorphic sarcoma and leiomyosarcoma. Surgical resection remains the treatment of choice, though it is not always feasible, which contributes to the poor prognosis. The presented case is a retroperitoneal synovial sarcoma in a 29 years old man with findings from ultrasound, computed tomography and magnetic resonance imaging.

Advances of SS18-SSX fusion gene in synovial sarcoma: Emerging novel functions and therapeutic potentials

Synovial sarcoma is a rare type of soft tissue sarcoma that primarily affects adolescents and young adults, featured by aggressive behavior and a high potential for metastasis. Genetically, synovial sarcoma is defined by the fusion oncogene SS18-SSX arising from the translocation of t(X;18)(p11;q11). SS18-SSX fusion gene is the major driver of the oncogenic event in synovial sarcoma. SS18-SSX fusion protein, while not containing any DNA-binding motifs, binds to the SWI/SNF (BAF) complex, a major epigenetic regulator, leading to the disruption of gene expression which results in tumor initiation and progression. Emerging studies on the molecular mechanisms of SS18-SSX associated signaling pathway hold promise for developments in diagnosis and treatments. Advanced diagnostic methods facilitate early and precise detection of the tumor, enabling disease monitoring and prognostic improvements. Treatment of synovial sarcoma typically comprises local surgery, radiotherapy and chemotherapy, while novel managements such as immunotherapy, targeted therapies and epigenetic modifiers are explored. This review focuses on the recent studies of SS18-SSX fusion gene, epigenetic landscape, signaling pathways, diagnostic techniques, and relevant therapeutic advances, aiming to inhibit the oncogenic processes and improve outcomes for patients with synovial sarcoma.

Primary Renal Synovial Sarcoma: A Rare Case Presentation

Synovial sarcoma is a rare mesenchymal tumor, and its occurrence as a primary renal tumor is exceedingly rare. We are presenting a case of renal synovial sarcoma with lung involvement in a 47-year-old female patient who initially presented with typical renal symptoms, including blood in urine and left flank pain. Imaging revealed a large renal mass with extension into the renal vein and metastatic nodules in the lungs. Histopathological examination and genetic analysis confirmed monophasic synovial sarcoma with SYT-SSX2 translocation. Treatment included radical nephrectomy followed by systemic chemotherapy with doxorubicin and ifosfamide. Despite the initial response, the disease progressed, leading to fatal complications. This case highlights the diagnostic challenges, limited treatment options, and poor prognosis associated with primary renal synovial sarcoma.

Mediastinal monophasic synovial sarcoma with vertebral metastases: A case report

Mediastinal monophasic synovial sarcoma is a rare subtype that often lacks specific imaging characteristics, posing diagnostic challenges. This case report describes a mediastinal monophasic synovial sarcoma with vertebral metastasis, emphasizing imaging findings, differential diagnosis, and pathological features, thereby providing crucial support for accurate diagnosis and treatment planning.

An infrequent case of retroperitoneal synovial sarcoma

Synovial sarcoma (SS) is an uncommon malignant tumor, ranking third in prevalence within the soft tissue sarcomas group. The vast majority of synovial sarcomas are present in the extremities, with only 15% developing in the retroperitoneal space. Retroperitoneal synovial sarcoma (RSS) is an infrequent case of SS, with only about 20 cases reported in the literature. Diagnosing RSS before treatment remains challenging because of its nonspecific clinical symptoms. The disease is often detected at a later stage, leading to additional damage to other organs as well as complicated and ineffective treatment. Consequently, the 5-year survival rate is only 20%-29%. This report introduces a case of RSS in a 19-year-old male patient with imaging characteristics on computed tomography (CT) and magnetic resonance (MR).

Small gastric synovial sarcoma diagnosed and treatment by laparoscopic-endoscopic cooperative surgery: a case report

We report a case of small gastric synovial sarcoma (SS) finally diagnosed after laparoscopic-endoscopic cooperative surgery (LECS). A 50 year-old male underwent medical examination for a chief complaint of epigastric pain. Endoscopic examination showed a 20 mm submucosal tumor (SMT) located in the anterior wall which extended to the lesser curvature of the middle stomach. The biopsy tissue did not yield a definitive diagnosis. During 6 months of follow-up for this lesion suspected to be an inflammatory tumor, neither the shape nor the size of the tumor changed. We performed LECS for both diagnosis and treatment. Histologically, the tumor was composed of fascicles of spindle cells. Immunohistochemically, the tumor cells were focally positive for epithelial membrane antigen, cytokeratin (AE1/AE3) and S100 protein, while being negative for desmin, α-smooth muscle actin, CD34, c-kit and DOG1. The expression of INI1 was reduced. Fluorescence in situ hybridization (FISH) detected SS18 rearrangement. The SMT was diagnosed as primary SS. A SMT measuring < 20 mm might be malignant potential tumor such as SS even if there are no typical malignant findings by endoscopy. Surgical resection should be considered for SMT measuring < 20 mm with atypical findings even in the absence of definitive high-risk features.

Imaging diagnosis and differential diagnosis of extraskeletal osteosarcoma

OBJECTIVE

The aim of this study was to investigate the clinical, imaging and pathological features of extraskeletal osteosarcoma (EOS) and to improve the understanding of this disease and other similar lesions.

METHODS

The data for 11 patients with pathologically confirmed extraosseous osteosarcoma, including tumour site and size and imaging and clinical manifestations, were analysed retrospectively.

RESULTS

Six patients were male (60%), and 5 were female (40%); patient age ranged from 23 to 76 years (average age 47.1 years). Among the 11 patients, 7 had clear calcifications or ossification with different morphologies, and 2 patients showed a massive mature bone tumour. MRI showed a mixed-signal mass with slightly longer T1 and T2 signals in the tumour parenchyma. Enhanced CT and MRI scans showed enhancement in the parenchyma. Ten patients had different degrees of necrosis and cystic degeneration in the mass, 2 of whom were complicated with haemorrhage, and MRI showed "fluid‒fluid level" signs. Of the 11 patients, five patients survived after surgery, and no obvious recurrence or metastasis was found on imaging examination. One patient died of lung metastasis after surgery, and 2 patients with open biopsy died of disease progression. One patient died of respiratory failure 2 months after operation. 2 patients had positive surgical margins, and 1 had lung metastasis 6 months after operation and died 19 months after operation. Another patient had recurrence 2 months after surgery.

CONCLUSION

The diagnosis of EOS requires a combination of clinical, imaging and histological examinations. Cystic degeneration and necrosis; mineralization is common, especially thick and lumpy mineralization. Extended resection is still the first choice for localized lesions. For patients with positive surgical margins or metastases, adjuvant chemoradiotherapy is needed.

Primary pulmonary synovial sarcoma with delayed diagnosis in a 69-year-old man: A case report

RATIONALE

Primary pulmonary synovial sarcoma is a rare malignant pulmonary tumor accompanied by calcifications in approximately 15% of cases. These calcifications usually have a fine, stippled appearance; coarse shapes have seldom been reported. Moreover, the presence of coarse calcifications often suggests benign tumors, which vastly differ in treatment. We present a rare case of primary pulmonary sarcoma with coarse intratumoral calcifications, the diagnosis of which was delayed because of its radiologic appearance.

PATIENT CONCERNS

A computed tomography (CT) scan of a 69-year-old man with right upper quadrant (RUQ) pain revealed an incidental mass at the base of the right lower lobe, the margin of which was not well described with respect to the liver, and intratumoral coarse calcification was noted. Initially, the lesion was believed to be hepatic, and magnetic resonance imaging (MRI) was performed. Based on its imaging features, the mass was thought to be a pulmonary lesion, and a preliminary diagnosis of a benign lesion, such as a hamartoma or granuloma, was made. Four months after the initial CT scan, the patient's RUQ pain had aggravated; however, no change in the mass was observed on follow-up CT.

DIAGNOSIS

The final diagnosis was primary pulmonary sarcoma, proven by surgical biopsy.

INTERVENTIONS

Wedge resection of the right lower lobe was performed, and the patient received adjuvant chemotherapy.

OUTCOMES

The patient's RUQ pain improved, and no recurrence or metastasis has been reported to date.

LESSONS

This case describes a rare presentation of a primary pulmonary synovial sarcoma with coarse intratumoral calcifications and the MRI features of the lesion. Intratumoral coarse calcifications often suggest benign lesions, such as hamartomas or post-inflammatory granulomas; however, as malignant lesions cannot be completely excluded, other radiologic and clinical features should be considered carefully. Focal areas of enhancement and eccentric calcification distribution might suggest malignant lesions such as primary pulmonary synovial sarcoma. Furthermore, despite not being used routinely, MRI scans might be helpful because advanced MRI techniques, such as diffusion-weighted imaging, can help distinguish malignant lesions from benign lesions. If the clinical course of a patient suggests malignancy, a more aggressive biopsy strategy should be considered.

Incidental intra-abdominal synovial sarcoma

Intra-abdominal synovial sarcomas are a rare type of soft tissue sarcomas that arise in the soft tissues of the abdominal cavity. They account for less than 1% of all primary synovial sarcoma cases. We report a case of a male patient in his early 30s who presented to the hospital with abdominal pain of 2 weeks duration. On examination, a mass was felt in the left mid-abdomen. MRI revealed a 12.7 cm×8.2 cm×8.6 cm soft tissue mass on the mesentery of the jejunum. The patient underwent surgical resection of the tumour, and the final pathology was synovial sarcoma, pT2b, grade 3.

Safety and Efficacy of NY-ESO-1 Antigen-Specific T-Cell Receptor Gene-Transduced T Lymphocytes in Patients with Synovial Sarcoma: A Phase I/II Clinical Trial

PURPOSE

To determine, for patients with advanced or recurrent synovial sarcoma (SS) not suitable for surgical resection and resistant to anthracycline, the safety and efficacy of the infusion of autologous T lymphocytes expressing NY-ESO-1 antigen-specific T-cell receptor (TCR) gene and siRNA to inhibit the expression of endogenous TCR (product code: TBI-1301).

PATIENTS AND METHODS

Eligible Japanese patients (HLA-A*02:01 or *02:06, NY-ESO-1-positive tumor expression) received cyclophosphamide 750 mg/m2 on days -3 and -2 (induction period) followed by a single dose of 5×109 (±30%) TBI-1301 cells as a divided infusion on days 0 and 1 (treatment period). Primary endpoints were safety-related (phase I) and efficacy-related [objective response rate (ORR) by RECIST v1.1/immune-related RECIST (irRECIST); phase II]. Safety- and efficacy-related secondary endpoints were considered in both phase I/II parts.

RESULTS

For the full analysis set (N = 8; phase I, n = 3; phase II, n = 5), the ORR was 50.0% (95% confidence interval, 15.7-84.3) with best overall partial response in four of eight patients according to RECIST v1.1/irRECIST. All patients experienced adverse events and seven of eight patients (87.5%) had adverse drug reactions, but no deaths were attributed to adverse events. Cytokine release syndrome occurred in four of eight patients (50.0%), but all cases recovered with prespecified treatment. Immune effector cell-associated neurotoxicity syndrome, replication-competent retrovirus, and lymphocyte clonality were absent.

CONCLUSIONS

Adoptive immunotherapy with TBI-1301 to selectively target NY-ESO-1-positive tumor cells appears to be a promising strategy for the treatment of advanced or recurrent SS with acceptable toxicity.

Synovial sarcoma in the prevertebral space can mimic malignant neurogenic neoplasm: Case report and literature review

Synovial sarcoma, a rare malignant neoplasm with a poor prognosis, accounts for approximately 5%-10% of all primary soft-tissue malignancies worldwide. Typically affecting adolescents and young adults, it primarily manifests near the joints of the lower extremities. This study aimed to demonstrate that this tumor can also affect the prevertebral space. A 32-year-old male patient presented at our outpatient clinic with a 2-month history of upper limb numbness and a 1-month complaint of palpable neck mass. Imaging studies revealed a bulky, lobulated, and heterogeneous mass exhibiting heterogeneous enhancement. Furthermore, the mass caused expansion of the neuroforamen in the neck, initially suggesting a diagnosis of malignant schwannoma. However, a histopathologic examination suggested synovial sarcoma. The article provided a comprehensive review of the clinical, pathological, and radiological features of this condition. Additionally, it explored current treatment options and prognoses by referencing relevant literature.

Synovial Sarcoma in the Extremity: Diversity of Imaging Features for Diagnosis and Prognosis

Synovial sarcomas are rare and highly aggressive soft-tissue sarcomas, primarily affecting adolescents and young adults aged 15-40 years. These tumors typically arise in the deep soft tissues, often near the large joints of the extremities. While the radiological features of these tumors are not definitely indicative, the presence of calcification in a soft-tissue mass (occurring in 30% of cases), adjacent to a joint, strongly suggests the diagnosis. Cross-sectional imaging characteristics play a crucial role in diagnosing synovial sarcomas. They often reveal significant characteristics such as multilobulation and pronounced heterogeneity (forming the "triple sign"), in addition to features like hemorrhage and fluid-fluid levels with septa (resulting in the "bowl of grapes" appearance). Nevertheless, the existence of non-aggressive features, such as gradual growth (with an average time to diagnosis of 2-4 years) and small size (initially measuring < 5 cm) with well-defined margins, can lead to an initial misclassification as a benign lesion. Larger size, older age, and higher tumor grade have been established as adverse predictive indicators for both local disease recurrence and the occurrence of metastasis. Recently, the prognostic importance of CT and MRI characteristics for synovial sarcomas was elucidated. These include factors like the absence of calcification, the presence of cystic components, hemorrhage, the bowl of grape sign, the triple sign, and intercompartmental extension. Wide surgical excision remains the established approach for definitive treatment. Gaining insight into and identifying the diverse range of presentations of synovial sarcomas, which correlate with the prognosis, might be helpful in achieving the optimal patient management.

Extra-skeletal Ewing's sarcoma of the leg with multiple skeletal and pulmonary metastases: A rare pediatric case report

Being the second most common malignant bone tumor in children and young adults, Ewing's sarcoma can also occur as a primary soft-tissue tumor called extraosseous or extra-skeletal Ewing's sarcoma. It is a rare entity, especially in the pediatric population. We report the case of an adolescent who presented to our department for lower extremity magnetic resonance imaging to explore leg swelling. It revealed an extra-skeletal Ewing's sarcoma with multiple bone metastases. By reporting this case, we also review the literature on this rare abnormality.

Synovial sarcoma of the abdominal wall: A case report for a rare entity with a challenging treatment

INTRODUCTION AND IMPORTANCE

Synovial Sarcoma is an intriguing disease, it represents a distinctive subtype of soft tissue sarcoma that does not exceed 10 % of all STS. This tumor can arise from the abdominal wall in very rare cases. Due to its unique presentation (occurring at a young age, various anatomical locations, and slow evolutionary kinetics), diagnosis can be challenging. The mainstay of treatment remains wide surgical excision with negative margins.

CASE PRESENTATION

We herein report a challenging diagnosis of synovial sarcoma with exceptional location, presented as a slowly evolving abdominal mass of the right iliac fossa. Soft tissue MRI confirmed the presence of a sub cutaneous mass without signs of local invasion. Surgical management as indicated. Anatomopathological findings were in favor of a synovial sarcoma of the abdominal wall. The patient was discharged. No complication was observed after 3 months follow up.

CLINICAL DISCUSSION

Patients with synovial sarcoma of the abdominal wall is a very rare entity, therefor positive pre operative diagnosis is hard to achieve, because of the lack of specific clinical and radiological signs. No standard treatment is advised, beside surgical management wish is the main course of management.

CONCLUSION

Synovial sarcoma is an infrequent pathology, with no specific signs in both clinical and radiological findings. The main course of management is surgery with healthy resection margins. Long term follow up is advised because of the high risk of recurrence.

Axillary synovial sarcoma recurrence involving brachial plexus, a rare case report from Pakistan

INTRODUCTION

Synovial sarcomas are rare tumors, and the incidence of axillary synovial sarcoma involving the brachial plexus has been reported as 2.9 % among all axillary soft tissue tumors. However, the recurrence of axillary synovial sarcomas has not been reported in literature.

CASE PRESENTATION

A 36-years-old Afghan female presented in Karachi, Pakistan with a history of persistently increasing, recurrent, right axillary mass for 6 months. Initially diagnosed as a spindle-cell tumor on excision in Afghanistan, she had received ifosfamide and doxorubicin, but the lesion recurred. On examination, it was a 5 × 6 cm, hard mass palpable in right axilla. After radiological work-up and a multidisciplinary team discussion, she underwent complete excision of the tumor with successful preservation of brachial plexus. The final diagnosis was reported as monophasic synovial sarcoma FNCLCC Grade 3.

DISCUSSION

Our patient presented with a recurrent right axillary synovial sarcoma that was involving the axillary neurovascular bundle and brachial plexus, which was initially diagnosed as a spindle cell sarcoma. Pre-operative core-needle biopsy was unable to provide a definitive diagnosis. MRI scan was useful in delineating the proximity of the neurovascular structures. Re-excision of the tumor was performed which is the mainstay of treatment for axillary synovial sarcomas, combined with radiotherapy depending on the disease grading, staging and patient factors.

CONCLUSION

Axillary synovial sarcoma recurrence with involvement of the brachial plexus is an extremely rare presentation. Our patient was successfully managed through a multidisciplinary approach with complete surgical excision and preservation of the brachial plexus followed by adjuvant radiotherapy.

Cyberknife Radiosurgery for Synovial Sarcoma Metastasizing to the Spine: Illustrative Case Reports

Synovial sarcoma (SS) is a rare and aggressive type of soft tissue sarcoma that commonly affects young adults. Metastasis in the spine is a rare complication, and the management of these lesions is challenging. Radiosurgery is an increasingly popular treatment option for spinal metastasis due to its ability to deliver high doses of radiation to the target volume with minimal exposure to surrounding healthy tissues. In this paper, we present two cases of SS with spinal metastasis that were treated with CyberKnife radiosurgery (CKRS). The first case was a 52-year-old female with a history of multiple thoracotomies and lobectomies for lung metastases, who was diagnosed with T6-T8 and T4 spinal metastasis. The second case was a 53-year-old female with Down syndrome, who was diagnosed with T12-L1 spinal metastasis. Both patients experienced an improvement in their symptoms following CKRS treatment and showed stable or decreasing lesion sizes on follow-up imaging. The progression-free survival (PFS) in the first case was 37 months and overall survival (OS) was 79 months. In the second case, the PFS was 12 months and OS was 18 months. These cases highlight the potential benefits of CKRS as a treatment option for SS with spinal metastasis and support its use in the management of this challenging condition.

Early progression of a pancreatic metastasis of synovial sarcoma after pancreatectomy

BACKGROUND

Synovial sarcoma is a malignant tumor that constitutes up to 10% of all soft-tissue sarcomas. The most frequent metastatic sites of synovial sarcoma are the lungs, lymph nodes, and bone, whereas pancreatic metastasis is extremely rare. Here, we report a case of pancreatic metastasis of synovial sarcoma.

CASE PRESENTATION

Nine years before presentation, a 31-year-old woman underwent extensive resection of the primary tumor after chemotherapy for left upper extremity synovial sarcoma. Six months before presentation, interscapulothoracic amputation was performed for an enlarged mass in the left upper extremity; the patient was treated with pazopanib. Three months before presentation, chest computed tomography showed multiple lung metastases; during subsequent follow-up, abdominal computed tomography revealed a pancreatic metastasis of synovial sarcoma. The doubling time of the pancreatic tumor was 14 days, and it grew rapidly. Furthermore, treatment-resistant pancreatitis symptoms were detected; thus, we performed distal pancreatectomy and administered one course of a 70% dose of trabectedin. However, the patient died of rapid progression of lung metastasis and respiratory failure within 2 months after surgery.

CONCLUSIONS

Pancreatectomy may be carefully performed in cases of isolated pancreatic metastasis. However, the presence of other distant extrapancreatic metastases (e.g., uncontrolled lung metastases) may rule out pancreatectomy treatment.

A Case of Poorly Differentiated Synovial Sarcoma Arising in a Nasal Cavity Radiation Field: An Unusual Tumor in an Unusual Location

Synovial sarcomas are high-grade soft tissue sarcomas of primitive mesenchymal origin which are defined by a pathognomonic t(X;18)(p11,q11) translocation, and which occur in pediatric and adult populations. Herein we report a case of a 33-year-old female with a history of nasopharyngeal carcinoma status post radiotherapy, presenting with a poorly differentiated synovial sarcoma of the nasal cavity arising in the radiation field. While the development of radiation-associated sarcoma is a known complication of radiotherapy, to date only 10 cases of synovial sarcoma have been reported to occur in previously irradiated tissues. Moreover, only 1 case of poorly differentiated synovial sarcoma involving the nasopharynx has been described.

First Recurrence of Synovial Sarcoma Presenting With Solitary Pancreatic Mass

Synovial sarcoma usually presents in the lower extremities and metastasizes to the lungs; however, unusual patterns of recurrence can occur. For patients with recurrent synovial sarcoma to a proximal peripancreatic lymph node, a pancreaticoduodenectomy or Whipple procedure is the best option for a cure. Lymph node metastasis from synovial sarcoma is exceptionally rare, and data guiding the use of the Whipple procedure for curative resection of metastatic synovial sarcoma are even more sparse. In this report, we describe the management of a patient with metastatic synovial sarcoma to a proximal peripancreatic lymph node with a pancreaticoduodenectomy.

Sedimentation sign: a classical finding on tumorous calcinosis

The authors describe the case of a man in his 60s who presented with progressive pain and swelling of the right hip. Imaging features showed a densely calcified lesion associated with 'sedimentation sign'. Laboratory tests revealed slight hyperphosphataemia. Surgical excision of the lesion was performed. Histological examination revealed chalky material surrounded by fibrosis and giant multinucleated cells, compatible with tumorous calcinosis. Patient made a full recovery. We report a rare case of tumorous calcinosis and compare this condition with its common mimics.

Malignant primary intraosseus synovial sarcoma – a rare case report

Primary intraosseous synovial sarcoma is an extremely rare malignancy that occurs primarily in young adults. We present a case of a primary intraosseous synovial sarcoma of the right distal ulna in a 19-year-old female. It has a propensity to mimic other radiologic and pathologic diagnosis. Histopathology after a surgical excisional biopsy with a wide margin plus adjunct radio and chemotherapy are necessary to improve prognosis.

Nomogram to Predict Overall and Cancer-Specific Survival in Patients with Synovial Sarcoma in the Extremities: A Population-Based Study

Background

Synovial sarcoma is a rare disease, and synovial sarcoma that first appears in the extremities accounts for more than 80% of cases. We established two nomograms to predict the overall survival (OS) and cancer-specific survival (CSS) rates of patients with synovial sarcoma.

Methods

A total of 227 patients diagnosed with synovial sarcoma in the extremities between 2010 and 2015 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox analyses were performed to explore independent prognostic factors and to create two separate nomograms for OS and CSS. The C-index, the area under the curve (AUC), calibration curve, decision curve analysis (DCA), and Kaplan-Meier (KM) curve were used to evaluate the column line graphs and analyze prognostic factors.

Results

Age, Stage M, and surgery were identified as independent prognostic factors for OS and CSS. The ROC curve showed good discriminative power for the nomogram. Calibration curves and DCA curves showed that the nomogram had a satisfactory ability to predict OS and CSS. The KM curve showed that chemotherapy alone did not affect patient survival.

Conclusion

Age, Stage M, and surgery are variables that affect OS and CSS in patients with synovial sarcoma in the extremities. Two nomograms were established based on the above variables to provide patients with more accurate individual survival predictions and to help physicians make appropriate clinical decisions.

Chemosensitivity of Lung Metastatic High-Grade Synovial Sarcoma

Background: Synovial sarcoma is a relatively chemosensitive type of soft tissue sarcoma and it often metastasizes to the lung. We investigated the role of adjuvant chemotherapy in patients with high-grade synovial sarcoma at their first lung metastasectomy (LMTS). Methods: Forty-six HGSS patients had their first LMTS at our institute (Rizzoli Orthopedic Hospital, Bologna, Italy) between 2000 and 2020. We divided them into two groups: (1) those undergoing adjuvant chemotherapy (n = 24) and (2) those not receiving adjuvant chemotherapy (n = 22). The primary outcome was a median survival at 32.5 (IQR 18.0-82.7) median follow-up. The disease-free interval was calculated at time zero (DFI₀, interval between the diagnosis of the primary tumor and the first CT-diagnosed lung metastasis) and at any further lung relapse (DFI_1-3). T₀ was defined as the time at first LMTS and T₁-T₃ referred to the time of further metastasectomy. Results: Freedom from SS-specific mortality at 60 months was significantly higher in patients without chemotherapy (50.0% (33.0-76.0%) vs. 20.8% (9.55%-45.4%), p = 0.01). Chemotherapy was associated with a higher risk of SS-specific mortality at multivariable Cox regression (HR 2.8, p = 0.02). Furthermore, DFI₀ ≤ 6 months, female sex, age > 40 years, and primary tumor > 10 cm increased the risk of death by about four, six, >three, and >five times, respectively. Conclusions. Adjuvant chemotherapy did not show any advantage in terms of freedom from SS-specific mortality in HGSS patients. Further larger studies are necessary to confirm our findings.

Clinical Characteristics, Pathology and Outcome of 237 Patients With Synovial Sarcoma: Single Center Experience

BACKGROUND

Synovial sarcoma (SS) is a rare soft tissue sarcoma. Available data regarding survival outcomes of patients with SS still remains limited. In this study, a single center retrospective analysis was performed to investigate the clinical characteristics, pathology and survival outcomes in patients with SS in China.

METHODS

Patient data were systematically reviewed at the National Cancer Center from January 2015 to December 2020. The general information and treatment condition of patients were collected. Overall survival (OS) was evaluated using the Kaplan-Meier and Cox regression method.

RESULTS

A total of 237 consecutive patients were included in this study (follow-up cut-off date: December, 2020). The median age of patients involved was 35 years (ranging from 5 to 83 years) and the mean tumor diameter was 5.3 cm (ranging from .2 to 26.0 cm). The main findings of the immunohistochemical staining analyses were EMA (111/156) (71%), keratin (32/64) (50.0%), keratin (12/20) (60%), keratin (42/70) (60%), S-100 (18/160) (11%), BCL-2 (128/134) (96%), CD99 (137/148) (93%) and TLE1 (23/26) (88%). It was found that 109 patients (66%) were presented with monophasic subtype and 55 (34%) with biphasic subtype. A total of 137 patients were tested by FISH method and 119 patients (87%) demonstrated SS18 rearrangement, whereas 18 patients (13%) did not show SS18 rearrangement. Generally, it was found that the 3-year OS rate was 86% and the 3-year DFS was 55%. Results of univariate analysis revealed that age, tumor size, tumor site, radiotherapy and targeted therapy were significantly correlated with the overall survival (P < .05). Further, multivariate Cox regression analysis revealed that age, tumor size and radiotherapy were significantly associated with OS (P < .05).

CONCLUSIONS

In conclusion, this study shows that the outcomes of patients with SS significantly decrease with age and tumor size. It was evident that radiotherapy is an independent and positive prognostic factor for patients with SS. In addition, it was shown that the prognosis of SS varies with tumor location. For instance, primary tumors in lower extremities have a higher prognosis, whereas tumors located in thorax have a lower prognosis.

The Biology of Synovial Sarcoma: State-of-the-Art and Future Perspectives

New molecular insights are being achieved in synovial sarcoma (SS) that can provide new potential diagnostic and prognostic markers as well as therapeutic targets. In particular, the advancement of research on epigenomics and gene regulation is promising. The concrete hypothesis that the pathogenesis of SS might mainly depend on the disruption of the balance of the complex interaction between epigenomic regulatory complexes and the consequences on gene expression opens interesting new perspectives. The standard of care for primary SS is wide surgical resection combined with radiation in selected cases. The role of chemotherapy is still under refinement and can be considered in patients at high risk of metastasis or in those with advanced disease. Cytotoxic chemotherapy (anthracyclines, ifosfamide, trabectedin, and pazopanib) is the treatment of choice, despite several possible side effects. Many possible drug-able targets have been identified. However, the impact of these strategies in improving SS outcome is still limited, thus making current and future research strongly needed to improve the survival of patients with SS.

Case 290: Intravascular Cystic Synovial Sarcoma

History A 26-year-old man presented with a 1-month history of chest pain, a palpable and painful right inguinal mass, and edema in the right lower extremity. One month earlier, he started to experience left chest pain with no cough. Pulmonary CT angiography (CTA) revealed a left lower lobe segmental pulmonary embolus. The local hospital made a diagnosis of pulmonary embolism. He received anticoagulants, and his chest pain was gradually relieved. At the time of current presentation, the patient was experiencing right lower extremity swelling and pain. Physical examination revealed a 4 × 3 cm palpable right inguinal mass with no redness. His medical history and family history were negative. The results of laboratory work-up were normal, with a d-dimer level of 0.16 mg/L fibrinogen equivalent units (reference range, <0.46 mg/L) and an international normalized ratio of 2.45 (therapeutic range, 2.0-3.0 for a patient taking warfarin), except the prothrombin time was 28.2 seconds (reference range, 9.6-12.8 seconds) and the activated partial thromboplastin time was 52.2 seconds (reference range, 24.8-33.8 seconds). Echocardiography, chest radiography, chest CT, and contrast-enhanced (CE) CT revealed no abnormalities. The patient underwent right lower extremity vascular conventional US (Philips IU22; Philips) with an L9-3 probe (3-9 MHz, venous condition) and contrast-enhanced US (1.5-2.0 mL, SonoVue; Bracco) with an intravenous bolus injection at the initial evaluation. Two days later, noncontrast and contrast-enhanced CT images of the lower abdomen (1.5 mL per kilogram of body weight, 300 mg/mL iomeprol, Iomeron; Bracco) were acquired for further evaluation.

Soft tissue masses of the epitrochlear region

The epitrochlear lymph nodes (ELN) are rarely examined clinically and are difficult to identify radiologically in healthy patients. They are, therefore, generally under appreciated as a source of significant pathology. Despite this, enlargement of an ELN is almost always secondary to a pathological process, the differential for which is relatively narrow. The following pictorial review illustrates the spectrum of infectious, inflammatory and malignant conditions affecting the ELN, some of which are quite specific to this location. We also emphasise the importance of distinguishing enlarged ELNs from benign and malignant non-nodal soft tissue masses, which can have very similar clinical presentation and imaging appearances.

Long non-coding RNA HOTAIR promotes the progression of synovial sarcoma through microRNA-126/stromal cell-derived factor-1 regulation

The long non-coding RNA (lncRNA) HOTAIR is an oncogene, that has been reported to be aberrantly expressed in multiple types of malignant tumor tissues. However, its expression and association with synovial sarcoma (SS) remains unclear. The present study aimed to elucidate the expression level of HOTAIR in SS tissues and also identify its role. Reverse transcription-quantitative PCR was used to detect the expression level of HOTAIR and microRNA (miR)-126 in 54 tissue samples from patients with SS, in 10 tissue samples from synovium tissues of normal patients, and in SW982 cells. The protein expression level was measured using western blot analysis and cellular immunofluorescence. Cellular proliferation, invasion and migration were assessed using MTT, Transwell and wound healing assays, respectively. HOTAIR was expressed at high levels in SS tissues. In contrast, miR-126 was expressed at low levels in SS tissues, and was negatively correlated with HOTAIR expression. HOTAIR knockdown in SW982 cells inhibited cellular proliferation in vitro, but also significantly increased the ratio of cells in the G1/G0 phase of the cell cycle, and decreased the ratio of cells in the G2/S phase. In addition, HOTAIR knockdown inhibited the invasion and migration of the SW982 cells, as observed in the Transwell and wound healing assays. Furthermore, HOTAIR knockdown increased miR-126 expression level and decreased the expression level of stromal cell-derived factor-1 (SDF-1) at the protein level. On the other hand, while miR-126-mimic decreased the protein expression level of SDF-1, miR-126-inhibitor increased its expression level in SW982 cells. Notably, HOTAIR knockdown or SDF-1 knockout significantly decreased the protein expression levels of CDK1, CDK2, cyclin D1, MMP-9, vimentin and N-cadherin, and significantly increased the protein expression levels of p21, p53 and E-cadherin in SW982 cells. HOTAIR was highly expressed in SS tissues, wherein it could promote the proliferation, invasion and migration of SS cells by increasing the expression of SDF-1 via miR-126 inhibition.

Synovial Sarcoma: A Clinical Review

Synovial sarcomas (SS) represent a unique subset of soft tissue sarcomas (STS) and account for 5–10% of all STS. Synovial sarcoma differs from other STS by the relatively young age at diagnosis and clinical presentation. Synovial sarcomas have unique genomic characteristics and are driven by a pathognomonic t(X;18) chromosomal translocation and subsequent formation of the SS18:SSX fusion oncogenes. Similar to other STS, diagnosis can be obtained from a combination of history, physical examination, magnetic resonance imaging, biopsy and subsequent pathology, immunohistochemistry and molecular analysis. Increasing size, age and tumor grade have been demonstrated to be negative predictive factors for both local disease recurrence and metastasis. Wide surgical excision remains the standard of care for definitive treatment with adjuvant radiation utilized for larger and deeper lesions. There remains controversy surrounding the role of chemotherapy in the treatment of SS and there appears to be survival benefit in certain populations. As the understanding of the molecular and immunologic characteristics of SS evolve, several potential systematic therapies have been proposed.

Synovial Sarcoma: A Series of Small Tumors in Active Duty Service Members

Synovial Sarcoma is a soft tissue sarcoma with a propensity to imitate a benign neoplasm. It is most common in males 15-40 years old, typically presents as a slow growing painful mass, and often arises insidiously without alarm to the patient. Three patients with synovial sarcomas who had each undergone an index procedure to treat a small presumedly benign mass that was later identified as synovial sarcoma were reviewed. All three patients required re-excision of the tumor and tumor bed and are currently undergoing routine surveillance. All patients exhibited the classic translocation t(X;18) (p11.2; q11.2) and all were of the monophasic type. All lesions were less than 35 mm in greatest longitudinal dimension on MRI. None have experienced recurrences of synovial sarcoma to date. Healthcare providers should be aware of the synovial sarcoma's propensity to masquerade as a benign disease and the characteristic clinical and radiological findings. We advocate for a low threshold to obtain advanced imaging and consideration of a tissue diagnosis prior to excision. A referral to an orthopedic oncologist should be considered and biopsy should only be performed where the definitive treatment will take place if malignancy is identified.

Primary Renal Synovial Sarcoma and Clinical and Pathological Findings: a Systematic Review

PURPOSE OF REVIEW

To update epidemiological, diagnostic, and therapeutic information on primary synovial sarcoma of the kidney.

RECENT FINDINGS

A total of 96 studies were analyzed; age at presentation was 38.6±14.2 years, predominant location of tumor was right kidney; frequent reported symptoms at diagnosis were hematuria and pain. For definitive diagnosis, cytogenetic technique was used. Detected oncogene was available in 37.8% cases with fusion of SS18-SSX in most patients. Surgery is treatment of choice, with adjuvant chemotherapy; most frequently ifosfamide-based associated with doxorubicin or epirubicin. Overall median survival was 34 months. Mortality was 29% of the cases which reported death and the recurrence rate was 39.8%. Risk of death was increased in patients with metastases at diagnosis Primary RSS occurs more often in young men. RSS often presents with symptoms and in an advanced stage. Surgical treatment is the most commonly used and chemotherapy for advanced or recurrent treatment.

The management of pancreatic metastasis from synovial sarcoma of the soft tissue: A case report

Pancreatic metastases are rare, accounting for 2%–3% of pancreatic tumors. The pancreas represents an unusual metastatic site of synovial sarcoma (SS) outside the usual localizations (regional nodes, lung, bone, and liver). The diagnosis is evoked by the personnel medical history of SS and imaging then confirmed by histological examination of the guided pancreatic biopsy. Its therapeutic management is mainly surgical with extensive removal of the lesion. So far only four cases have been reported in the English literature. We reported the case of a male aged 30-year-old who was admitted to our Institute for a local recurrence of SS of the left thigh which was initially treated by surgical excision. The patient underwent a wide surgical excision followed by chemotherapy and radiotherapy. About 15 months later, he experienced a pancreatic metastasis of his SS. He had a caudal splenopancreatectomy with partial resection of the transverse colon followed by chemotherapy. This report highlights the diagnostic difficulties of this rare localization and therapeutic challenge.

Synovial sarcoma of the spine in the lumbar vertebral body: A rare case report

RATIONALE

Synovial sarcoma (SS) is a soft tissue neoplasm that rarely occurs in the vertebral body and should be considered in the differential diagnosis in patients with SS and vertebral lesions. SS often presents as a painless mass in the spine, which may undergo slow enlargement, resulting in sustained symptoms of neurologic deficit and pain. Due to the difficulty in differentiating between SS from other soft tissue tumors and metastatic tumors, careful histological confirmation is required for definite diagnosis. Furthermore, due to its malignancy, the appropriate treatment procedure for SS should be carefully considered.

PATIENT CONCERNS

A 56-year-old female patient had low back pain. Radiological examination revealed bony erosion of the L-2 vertebral body, and no soft tissue mass around the lumbar spine.

DIAGNOSIS

Histopathological and immunohistochemical examination revealed SS.

INTERVENTIONS

The initial treatment of posterior laminectomy decompression and percutaneous vertebro plasty (PVP) was performed, however, this initial treatment course was inappropriate, but she eventually underwent L-2 complete resection and internal fixation. After the second surgery, she was treated by external beam radiation therapy.

OUTCOMES

operation radiotherapy was finally performed. No local recurrence in L-2 vertebral body or distant metastasis was found at 1-year follow up postoperation; the neurologic symptom gradually relieved, and no other symptom was noted. And no local recurrence in L-2 vertebral body and distant metastasis was found in 1 year follow up postoperation.

LESSONS

Solitary spinal SS is extremely rare. Early surgery for total resection and adjuvant radiotherapy/chemotherapy should be emphasized.

A rare case of synovial sarcoma presenting as abdominal pain

Abdominal pain can arise from numerous sources, including those extra-abdominal. It is important to obtain additional imaging in the setting of clinical suspicion for malignancy.

Ultrasonography of Pediatric Superficial Soft Tissue Tumors and Tumor-Like Lesions

Ultrasonography (US) is usually the first imaging examination performed to evaluate palpable or visible superficial soft tissue lesions that are common in children. Although clinical assessments, such as age at presentation, clinical course, and overlying skin discoloration, are important for the differentiation of pediatric soft tissue lesions, US allows a specific diagnosis of some typical benign lesions and helps in guiding further investigation since it provides detailed information about the lesion location, characterization including solid versus cystic, vascularity, and compressibility. Therefore, sufficient knowledge of the normal anatomy, proper ultrasonographic techniques, and the imaging findings of common and uncommon soft tissue lesions in children are crucial for accurate assessment and management of patients. In this article, we review the techniques and imaging findings focusing on the ultrasonographic features of a variety of superficial soft tissue lesions detected in children.

Synovial Sarcoma of the Anterior Chest Wall: A Case Report

Synovial sarcoma is a malignant soft tissue tumor that usually involves the extremities, particularly near the knees; a synovial sarcoma originating in the chest wall is extremely rare. We describe a 26-year-old woman diagnosed with a synovial sarcoma originating in the chest wall, based on CT and MRI findings. Contrast-enhanced CT images revealed a small, well-defined enhancing mass with calcification, in the subpleural area. This lesion was initially diagnosed as a benign tumor; however, the patient developed sudden severe pain with spontaneous bleeding and hemothorax, suggesting the possibility of malignancy. MRI revealed a multilobulated mass with a fluid-fluid level, which characterizes a synovial sarcoma.

Synovial sarcoma mimicking a traumatic pseudoaneurysm in the upper extremity

Synovial sarcomas are a rare but aggressive malignancy that primarily affects young patients. Diagnosis is often difficult and delayed due to its insidious onset, heterogenous presentation and mimicry of other pathologies. We present the case of a patient with a history of a slow-growing left arm mass that arose after a traumatic fracture of the humerus. Multimodal imaging was undertaken and reported the mass as being consistent with a vascular malformation of the brachial artery. The patient underwent surgical repair of the artery and intraoperative biopsies confirmed a diagnosis of synovial sarcoma. This case highlights the importance of maintaining suspicion for soft-tissue sarcomas in young patients presenting with a mass, and demonstrates the way in which these tumours may mimic other pathologies both clinically and radiologically. Early referral to a specialist sarcoma centre is key for further investigative workup.

Epigenetic Targets in Synovial Sarcoma: A Mini-Review

Synovial Sarcomas (SS) are a type of Soft Tissue Sarcoma (STS) and represent 8-10% of all STS cases. Although SS can arise at any age, it typically affects younger individuals aged 15-35 and is therefore part of both pediatric and adult clinical practices. SS occurs primarily in the limbs, often near joints, but can present anywhere. It is characterized by the recurrent pathognomonic chromosomal translocation t(X;18)(p11.2;q11.2) that most frequently fuses SSX1 or SSX2 genes with SS18. This leads to the expression of the SS18-SSX fusion protein, which causes disturbances in several interacting multiprotein complexes such as the SWItch/Sucrose Non-Fermentable (SWI/SNF) complex, also known as the BAF complex and the Polycomb Repressive Complex 1 and 2 (PRC1 and PRC2). Furthermore, this promotes widespread epigenetic rewiring, leading to aberrant gene expression that drives the pathogenesis of SS. Good prognoses are characterized predominantly by small tumor size and young patient age. Whereas, high tumor grade and an increased genomic complexity of the tumor constitute poor prognostic factors. The current therapeutic strategy relies on chemotherapy and radiotherapy, the latter of which can lead to chronic side effects for pediatric patients. We will focus on the known roles of SWI/SNF, PRC1, and PRC2 as the main effectors of the SS18-SSX-mediated genome modifications and we present existing biological rationale for potential therapeutic targets and treatment strategies.

Synovial sarcoma in the plantar region: A case report and literature review

BACKGROUND

Synovial sarcoma (SS), a rare malignant soft tissue tumor whose histological origin is still unknown, often occurs in limbs in young people and is easily misdiagnosed.

CASE SUMMARY

We report a 24-year-old man who sought treatment for plantar pain thought to be caused by a foot injury that occurred 4 years prior. Currently, he had been seen at another hospital for a 1-wk history of unexplained pain in the left plantar region and was treated with acupuncture, a kind of therapy of Chinese medicine, which partly relieved the pain. Because of this, the final diagnosis of biphasic SS was made after two subsequent treatments by pathological evaluation after the last operation. SS is rarely seen in the plantar area, and his history of a left plantar injury confused the original diagnosis.

CONCLUSION

This study shows that pathological and imaging examinations may play a vital role in the early diagnosis and treatment of SS.