Diagnosis and management of synovial sarcoma

Primary synovial sarcoma in anal canal: Report of a very rare case

Extensive studies are required to understand the behavior as well as prognosis of SS in the colorectal region. IHC staining is essential for the accurate diagnosis when a lesion is encountered at an unusual site.

Management of Diaphragm Tumors

Diaphragm tumors are very rare, with secondary tumors being more common than primary tumors. The most common benign primary tumors include lipomas and cysts, and malignant primary tumors include rhabdomyosarcoma and leiomyosarcoma. Endometriosis is the most common benign secondary tumor, followed by malignant tumors with localized spread of disease. In addition, widely metastatic disease has been described. Benign lipomas and cysts can be managed conservatively, but more complex or concerning disease typically requires resection. The diaphragm can often be repaired primarily, though any large defect or tension would indicate the need for mesh or an autologous reconstruction.

Extensive surgical resections for rare pleural neoplasms: a single-center experience with a yolk sac tumor and synovial sarcoma

BACKGROUND

Pleural neoplasms are rare and can be subdivided into pleural metastasis and primary pleural neoplasms. Non-mesothelioma primary pleural neoplasms are a diverse group of extremely rare pathologies.

CASE PRESENTATION

In this case series, we describe the presentation and management of two rare primary pleural neoplasms. A first case describes a primary pleural yolk sac tumor treated with neoadjuvant chemotherapy, extended pleurectomy decortication, and hyperthermic intrathoracic chemotherapy. In a second case we describe the management of a primary pleural synovial sarcoma by neoadjuvant chemotherapy and extrapleural pneumonectomy. A complete resection was obtained in both cases and the post-operative course was uncomplicated. No signs of tumor recurrence were noted during follow-up in the first patient. In the second patient a local recurrence was diagnosed 6 months after surgery.

CONCLUSION

Neo-adjuvant chemotherapy followed by extensive thoracic surgery, including hyperthermic intrathoracic chemotherapy, is a feasible treatment strategy for non-mesothelioma primary pleural neoplasms, but careful follow-up is required.

Synovial sarcoma of the maxilla: A challenging diagnostic case report and literature review

Synovial sarcoma, a malignant mesenchymal tumor, is primarily associated with the extremities. Nevertheless, its appearance within the head and neck region, particularly in the maxillary area, is remarkably rare. This rarity underscores the significance of each case in unraveling the complexities of its behavior and management strategies. The core focus of this research is a detailed case report involving a 6-year-old female patient who presented with a conspicuous swelling in the left posterior maxilla. Subsequent incisional biopsy led to microscopic identification of malignant spindle cell proliferation, marked by dysplastic changes, and abundant mitoses. Immunohistochemical (IHC) analysis demonstrated negative reactivity for neural and muscular markers, while positive expression of Vimentin, Bcl-2, and TLE1. These morphological and IHC findings coalesced to definitively diagnose synovial sarcoma, substantiated by a notable 40% Ki67 proliferative index. The chosen treatment strategy encompassed surgery and radiotherapy, which yielded successful outcomes, with no recurrence observed during the one-year follow-up period. Beyond the specific case, this article undertakes a review of existing literature, meticulously analyzing nine similar cases reported in scholarly sources.

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.

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.

Cancer-Associated B Cells in Sarcoma

Despite being one of the first types of cancers studied that hinted at a major role of the immune system in pro- and anti-tumor biology, little is known about the immune microenvironment in sarcoma. Few types of sarcoma have shown major responses to immunotherapy, and its rarity and heterogeneity makes it challenging to study. With limited systemic treatment options, further understanding of the underlying mechanisms in sarcoma immunity may prove crucial in advancing sarcoma care. While great strides have been made in the field of immunotherapy over the last few decades, most of these efforts have focused on harnessing the T cell response, with little attention on the role B cells may play in the tumor microenvironment. A growing body of evidence suggests that B cells have both pro- and anti-tumoral effects in a large variety of cancers, and in the age of bioinformatics and multi-omic analysis, the complexity of the humoral response is just being appreciated. This review explores what is currently known about the role of B cells in sarcoma, including understanding the various B cell populations associated with sarcoma, the organization of intra-tumoral B cells in tertiary lymphoid structures, recent trials in immunotherapy in sarcoma, intra-tumoral immunoglobulin, the pro-tumor effects of B cells, and exciting future areas for research.

Metastatic pulmonary synovial sarcoma: A double coincidence: Case report

Synovial sarcomas are considered as one of the most aggressive neoplasms that account for approximately 8% of all soft tissue sarcomas; they are mainly localized in soft tissues of the extremities and joints and rarely occur in the thorax. In this case report, we describe a 34-year-old woman presenting a chest pain with a chest radiography showing a mass lesion occupying two-thirds of the right hemi-thorax. A malignant pulmonary tumor was suspected after CT imaging revealing a bilateral renal metastasis, and then a spindle-cell carcinoma was thought-about. The post-operative pathological analysis of the main mass confirmed the diagnosis of a pulmonary synovial sarcoma.

The early-stage of primary pulmonary synovial sarcoma: A case report

BACKGROUND

Primary pulmonary synovial sarcoma is a rare case of lung cancer. Surgical resection is standard therapy. Early-stage and complete resection offers a good prognosis.

CASE PRESENTATION

A 50-year-old woman complained of intermittent left chest pain. Chest X-ray showed a mass around the heart, MSCT also showed enhanced solid lesion in the lower left lung anterobasal segment adhered to the pericardium. The patient underwent surgery with wedge resection with both immunohistochemical (IHC) EMA and CD99 positive. After surgery, she received 3-cycle chemotherapy that consisted of a combination of doxorubicin and ifosfamide.

DISCUSSION

Surgical resection is the mainstay treatment for primary pulmonary synovial sarcoma. Chemotherapy can be considered for a patient with high-risk metastases. Early-stage and young age showed a good prognosis. Patient with stage IA still survives for 49 months after completing surgical resection and chemotherapy.

CONCLUSION

Resection of the tumor followed by chemotherapy may increase the survival tumor.

A rare case of synovial sarcoma of diaphragm

Background

Primary diaphragmatic synovial sarcoma is a rare clinical entity with only few cases reported in the literature. It is found mainly in young adults, in the limbs. However, the name is a misnomer as it probably arises from primitive mesenchyme rather than articular surfaces of the joints.

Case

We report a case of 21‐year‐old patient with synovial sarcoma of the diaphragm, treated by complete surgical excision of the tumor with diaphragmatic reconstruction and confirmed on immunohistopathology. The peculiarity of this case stems from the atypical location of the tumor with complete surgical resection and thereby providing a better quality of life for the patient.

Conclusion

Synovial sarcoma of the diaphragm is a rare malignancy and more data and research is needed for defining the best management for this tumor.

Genotyping of Circulating Free DNA Enables Monitoring of Tumor Dynamics in Synovial Sarcomas

Simple Summary

Synovial sarcomas (SS) are rare soft tissue tumors of mesenchymal origin. Following resection of the primary tumor, about one third to half of the patients suffer from recurrence. Detection of local and distant recurrence during follow-up is commonly accomplished by imaging. There are no biomarkers available for routine diagnostics. We employ a highly sensitive targeted next-generation sequencing approach to monitor tumor dynamics by genotyping of circulating free DNA (cfDNA) in SS patients. cfDNA which harbors tumor-specific mutations (circulating tumor-DNA; ctDNA) correlated with the presence of viable tumor tissue. This enables timely and non-invasive detection of tumor recurrence and monitoring of treatment response independent of the anatomic location.

Abstract

Background: Synovial sarcoma (SS) is a malignant soft tissue tumor of mesenchymal origin that frequently occurs in young adults. Translocation of the SYT gene on chromosome 18 to the SSX genes on chromosome X leads to the formation of oncogenic fusion genes, which lead to initiation and proliferation of tumor cells. The detection and quantification of circulating tumor DNA (ctDNA) can serve as a non-invasive method for diagnostics of local or distant tumor recurrence, which could improve survival rates due to early detection. Methods: We developed a subtype-specific targeted next-generation sequencing (NGS) approach specifically targeting SS t(X;18)(p11;q11), which fuses SS18 (SYT) in chromosome 18 to SSX1 or SSX2 in chromosome x, and recurrent point mutations. In addition, patient-specific panels were designed from tumor exome sequencing. Both approaches were used to quantify ctDNA in patients’ plasma. Results: The subtype-specific assay allowed detection of somatic mutations from 25/25 tumors with a mean of 1.68 targetable mutations. The minimal limit of detection was determined at a variant allele frequency of 0.05%. Analysis of 29 plasma samples from 15 tumor patients identified breakpoint ctDNA in 6 patients (sensitivity: 40%, specificity 100%). The addition of more mutations further increased assay sensitivity. Quantification of ctDNA in plasma samples (n = 11) from one patient collected over 3 years, with a patient-specific panel based on tumor exome sequencing, correlated with the clinical course, response to treatment and tumor volume. Conclusions: Targeted NGS allows for highly sensitive tumor profiling and non-invasive detection of ctDNA in SS patients, enabling non-invasive monitoring of tumor dynamics.

Mesenchymal Neoplasms of the Prostate and Seminal Vesicles: Spectrum of Disease with Radiologic-Pathologic Correlation

There is a wide spectrum of benign and malignant mesenchymal neoplasms of the prostate, which account for less than 1% of all prostatic tumors. These include distinctive tumors that arise from the specialized prostatic stroma and site-agnostic neoplasms such as smooth muscle tumors, fibrous or myofibroblastic neoplasms, neurogenic tumors, vascular tumors, and a plethora of sarcomas. Select tumors show classic sites of origin within the prostate. While stromal tumors of uncertain malignant potential (STUMPs) commonly involve the peripheral zone at the prostate base, leiomyomas typically originate from the central prostate toward the apex. Some "prostatic" neoplasms such as gastrointestinal stromal tumors, solitary fibrous tumor (SFT), paragangliomas, and neurogenic tumors arise primarily from periprostatic soft tissues. Most mesenchymal tumors of the prostate and seminal vesicles manifest as large tumors that cause nonspecific symptoms; prostate-specific antigen level is not typically elevated. Diverse mesenchymal neoplasms demonstrate characteristic histopathologic and immunocytochemical features and variable cross-sectional imaging findings. While leiomyoma and SFT typically display low signal intensity on T2-weighted images, synovial sarcomas commonly show hemorrhage. Diagnosis is difficult because of the rarity and lack of awareness of the tumors and the significant overlap in histopathologic features. Select tumors show characteristic genetic abnormalities that allow the diagnosis to be established. For example, more than 90% of SFTs are characterized by a unique NAB2-STAT6 gene fusion, and more than 95% of synovial sarcomas are associated with a distinctive SYT-SSX chimeric transcript. Accurate diagnosis is imperative for optimal management owing to markedly different tumor biology as well as attendant therapeutic and prognostic implications. While STUMPs commonly recur, sarcomas typically charter an aggressive course with poor prognosis. Online supplemental material is available for this article. ^©RSNA, 2022.

Primary thoracic synovial sarcomas: A case report

Primary pulmonary synovial sarcoma (SS) is a rare neoplasm. Its clinicoradiologic attributes are not yet well defined. We report the observation of a patient followed for primary pulmonary synovial sarcoma. We report the radio‐clinical features of this rare tumor.

A case of a 22-year-old man with primary synovial sarcoma of the parapharyngeal space with an AR somatic mutation: A case report and review of the literature

This case report describes a 22-year-old man with a pharyngeal foreign body sensation arising from the left side of the postpharyngeal wall. Histological examination showed a biphasic pattern of epithelioid and spindle cells including glandular differentiation. The tumour was positive for vimentin and SS18-SSX, and the spindle cells were positive for bcl-2; in contrast, the epithelioid tumour cells were positive for pan-cytokeratin, epithelial membrane antigen and CD99. There was no INI-loss in tumour cells. Then, the presence of the SYT-SSX gene fusion was demonstrated by fluorescence in situ hybridization. In addition, androgen receptor gene somatic mutations were detected by next-generation sequencing. However, 6 months postoperatively, the patient had neither developed a recurrence nor received adjuvant radiotherapy and chemotherapy. Accurate diagnosis depends on morphological and immunohistochemical examination and a proper molecular analysis, and novel technologies can detect a wide variety of genetic alterations. Although androgen receptor somatic mutations cannot provide addition treatment at present, surgical resection with a clean margin and follow-up is an appropriate approach.

Synovial sarcoma of the head and neck: A review of reported cases on the clinical characteristics and treatment methods

Synovial sarcoma (SS) is a high-grade soft-tissue sarcoma that occurs predominantly in older children and young adults in their thirties. It is usually very challenging to diagnose and treat synovial sarcoma in the head and neck region. The purpose of this review is to investigate the clinical manifestations and different treatment methods in the management of primary synovial sarcoma of the head and neck. HNSS has an aggressive nature and poor prognosis. Surgical resection, radiotherapy, and chemotherapy are the primary treatment methods. Typically, surgical resection with negative margins remains the foundation of therapy, which is not very easily achieved in the head and neck due to its complex anatomical structure and the presence of many blood vessels and nerves. However, synovial sarcoma has a high recurrence rate, so aggressive management and close follow-up are warranted for the optimal outcome.

Monophasic Synovial Sarcoma in the Elbow Misclassified but Successfully Treated as Ewing's Sarcoma with Chemotherapy

To the best of the authors’ knowledge, this is the first published case of monophasic synovial sarcoma (SS) initially diagnosed as Ewing’s sarcoma (ES), yet successfully treated with chemotherapy in a 24-year-old patient. The initial diagnosis showed a monotonous round cell tumor and positivity for CD99, characteristic of ES; however, the cytology was negative for the classic EWSR1 rearrangement of ES. The patient was treated with the standard chemotherapy protocol of ES – COG AEWS1031 Regimen A with vincristine, doxorubicin, cyclophosphamide, and mesna – as well as with wide resection. Post-resection tissue submission showed additional morphologic features which led to a re-evaluation of the classification of the tumor as well as additional molecular studies; these revealed positivity for translocations of SS18 (18q11.1) in 100% of the nuclei, which is most characteristic of SS, thus, reclassifying the neoplasm as a SS tumor. This case underscores the importance of considering several pathologic entities in the differential diagnosis of small, round blue cell tumors, including ES, SS, and lymphoma. It also demonstrates the importance of using chromosomal identification for a more definitive diagnosis, rather than relying on histological features and markers which are found in more than one tumor classification. There is conflicting evidence of the impact of chemotherapy on survival in SS, as it is primarily treated with radiation therapy. Since SS is rare, prospective studies on the effect of chemotherapy on survival are limited in number. However, our case study demonstrates that chemotherapy is another modality that can be used in the treatment of SS neoplasms.

Synovial sarcoma of the maxillary sinus - A rare condition managed with a rationalized surgery

Introduction

and importance: Synovial sarcoma is a type of spindle cell tumors with unknown cellular origin. It can present anywhere throughout the body; however, its onset in the maxillary sinus is an extremely rare condition, making it hard to diagnose. This tumor occurs equally, without predilection for males or females, and the incidence peaks in the age of 35. The diagnosis is confirmed by histopathological study, and the main treatment is complete surgical excision.

Case presentation

We are reporting a case of a 53-year-old male with a left sided hearing loss accompanied by a left sided nasal block and a vague facial and dental pain.

Clinical discussion

Magnetic Resonance Imaging (MRI) showed a heterogeneously enhancing tumor in the maxillary sinus that extended to the pterygopalatine fossa and other surrounding structures, and a biopsy showed the tumor to be a synovial sarcoma. The tumor was managed with a less aggressive curative surgery, and was put on an adjuvant radiotherapy, and is being followed regularly; with no recurrence 5 months after therapy.

Conclusion

In conclusion, we are writing this report to introduce a case of synovial sarcoma in a rare location that was managed by a “cosmetically oriented” curative surgery, satisfactory results and prognosis.

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Synovial sarcoma is a rare type of spindle cell tumors.

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Synovial sarcoma of the maxillary sinus is a quite rare condition.

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The term “synovial sarcoma” is an old misnomer.

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The cellular origin of Synovial sarcoma is still unknown.

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The main treatment for synovial sarcoma is surgical excision.

Efficacy of perioperative chemotherapy for synovial sarcoma: a retrospective analysis of a Nationwide database in Japan

BACKGROUND

Synovial sarcoma is an aggressive but chemosensitive soft-tissue tumor. We retrospectively analyzed the efficacy of perioperative chemotherapy for synovial sarcoma with data from the nationwide database, Bone and Soft Tissue Tumor Registry in Japan.

METHODS

This study included 316 patients diagnosed with synovial sarcoma between 2006 and 2012. Oncologic outcomes were analyzed using a Cox-hazard regression model. Moreover, the effects of perioperative chemotherapy on outcomes were evaluated using a matched-pair analysis. The oncologic outcomes of patients who did or did not receive chemotherapy were compared (cx + and cx-).

RESULTS

Multivariate analysis revealed significant correlations of age (over 40, hazard ratio [HR] = 0.61, p = 0.043), margin status (marginal resection, HR = 0.18, p < 0.001 and intralesional resection, HR = 0.30, p = 0.013 versus wide resection) with overall survival; surgical margin type (marginal resection, HR = 0.14, p = 0.001 and intralesional resection, HR = 0.09, p = 0.035 versus wide resection) with local recurrence; and postoperative local recurrence (HR = 0.30, p = 0.027) and surgical margin (marginal resection, HR = 0.31, p = 0.023 versus wide resection) with distant relapse-free survival. Before propensity score matching, perioperative chemotherapy was mainly administered for young patients and patients with deeper tumor locations, larger tumors, more advanced-stage disease, and trunk location. The 3-year overall survival, local control, and distant relapse-free survival rates were 79.8%/89.3% (HR = 0.64, p = 0.114), 89.6%/93.0% (HR = 0.37, p = 0.171) and 71.4%/84.5% (HR = 0.60, p = 0.089) in the cx+/cx- groups, respectively. After propensity score matching, 152 patients were selected such that the patient demographics were nearly identical in both groups. The 3-year overall survival, local control, and distant relapse-free survival rates were 71.5%/86.0% (HR = 0.48, p = 0.055), 92.5%/93.3% (HR = 0.51, p = 0.436) and 68.4%/83.9% (HR = 0.47, p = 0.046) in the cx+/cx- groups, respectively.

CONCLUSION

This large-sample study indicated that the margin status and postoperative disease control were associated directly or indirectly with improved oncologic outcomes. However, the efficacy of perioperative chemotherapy for survival outcomes in synovial sarcoma patients was not proven in this Japanese database analysis.

Imaging of Soft Tissue Tumors

Differentiation of malignant from benign soft tissue tumors is challenging with imaging alone, including that by magnetic resonance imaging and computed tomography. However, the accuracy of this differentiation has increased owing to the development of novel imaging technology. Detailed patient history and physical examination remain essential for differentiation between benign and malignant soft tissue tumors. Moreover, measurement only of tumor size based on Response Evaluation Criteria In Solid Tumors criteria is insufficient for the evaluation of response to chemotherapy or radiotherapy. Change in metabolic activity measured by ¹⁸F-fluorodeoxyglucose positron emission tomography or dynamic contrast enhanced-derived quantitative endpoints can more accurately evaluate treatment response compared to change in tumor size. Magnetic resonance imaging can accurately evaluate essential factors in surgical planning such as vascular or bone invasion and "tail sign". Thus, imaging plays a critical role in the diagnosis and treatment of soft tissue tumors.

Synovial sarcoma of the hand-wrist: a case report and review of the literature

Background

Synovial sarcomas are infrequent malignant tumors occurring mostly in adolescents and young adults. The occurrence of synovial sarcoma in the hand-wrist area is rare (4 to 8.5% of all synovial sarcomas in different studies).

Case presentation

This report documents an uncommon case of synovial sarcoma occurring in the hand-wrist of a 69-year-old Caucasian woman. She was subsequently treated with surgical excision and radiotherapy without recurrence after follow up.

Conclusions

This paper aims to characterize the demographic, pathologic, and clinical features with a literature review. The present literature review confirms that hand-wrist synovial sarcomas are more frequent among males and subjects 10 to 40 years old. Most cases in this location are usually not larger than 5 cm in size. The five-year survival rate is higher than that reported in a previous review on hand synovial sarcomas, and this suggests an improved survival in recent decades.

Multimodal Risk-Adapted Treatment in Surgical Patients With Synovial Sarcoma: A Preoperative Nomogram-Guided Adjuvant Treatment Strategy

Background: Synovial sarcoma is characterized by heterogeneous clinical manifestations, making it difficult to evaluate individual patients' prognoses and design personal treatment schemes. We established an effective preoperative nomogram to predict cancer-specific survival (CSS) and present a risk-adapted adjuvant treatment strategy in surgical patients with synovial sarcoma. Methods: This retrospective study included patients from the Surveillance, Epidemiology, and End Results (SEER) database who were diagnosed with synovial sarcoma between 1996 and 2015. The patients were randomly divided into training and validation groups. The predictors were selected using univariate and multivariate Cox hazards models. The nomogram performance was verified for its discriminatory ability and calibration. We further stratified the patients into different risk groups according to the nomogram scores and compared the efficacy of chemotherapy, radiotherapy, and combination of radiotherapy and chemotherapy. Results: There were 915 patients enrolled in our study, with 874 patients either alive or dead due to synovial sarcoma. We established a nomogram to predict 5-year CSS based on independent factors, including sex, age, grade, tumor size, location, and extent (all p < 0.05). Our model showed a consistently good discriminatory ability and calibration for predicting 5-year CSS in both the training (c-index = 0.78, 95% CI 0.75-0.81) and validation (c-index = 0.73, 95% CI 0.68-0.78). Based on their nomogram scores, we divided patients into 5 groups. Compared to patients without adjuvant treatment, nomogram I patients with adjuvant treatment had no improvements in 5-year CSS (100.0% vs. 100.0%), nomogram II patients had higher 5-year CSS with radiotherapy or chemotherapy (92.9% vs. 72.2%, p = 0.015), nomogram III patients had higher 5-year CSS with combination of chemotherapy and radiotherapy (70.1% vs. 47.2%, p = 0.004), nomogram IV patients had higher 5-year CSS with radiotherapy (41.3% vs. 15.6%, p = 0.015), and nomogram V patients had no improvements in 5-year CSS rates with adjuvant treatment (28.9% vs. 16.9%, p = 0.18). Conclusion: The nomogram showed a satisfactory discriminatory ability and calibration for predicting 5-year CSS in synovial sarcoma patients. Based on this nomogram, we stratified synovial sarcoma patients according to risk levels, which enabled us to provide a useful grouping scheme that can inform multimodal risk-adapted treatment in synovial sarcoma.

Intra-articular Partial Acetabular Resection and Allograft Reconstruction for Synovial Sarcoma

Introduction:

The aim of this case report is to present an option of reconstruction in tumors involving the posterior wall and column of the acetabulum with sparing of the anterior column and the weight-bearing dome.

Case Report:

We are reporting a case of a 25-year-old female with histopathologically proven synovial sarcoma involving the left inferior pubic ramus, ischium, and posterior wall of the acetabulum, along with a large soft-tissue extension in the posterior and medial thigh. Wide local excision involving partial acetabular resection and reconstruction using a femoral head allograft was carried out. The patient was allowed full weight-bearing mobilization after 6 weeks. At 3 months’ follow-up, the patient was able to walk without support and was able to do active straight leg raising. There were no radiological signs of joint degeneration at the 12-month follow-up.

Conclusion:

Reconstruction with non-articular femoral head allograft can be a viable alternative after resection of tumor involving acetabulum. This procedure is expected to support the hip joint and restore function in the short term and recreate bone stock for future arthroplasty if the need arises.

Evaluation of conditional treatment effects of adjuvant treatments on patients with synovial sarcoma using Bayesian subgroup analysis

BACKGROUND

The impact of adjuvant chemotherapy or radiation therapy on the survival of patients with synovial sarcoma (SS), which is a rare soft-tissue sarcoma, remains controversial. Bayesian statistical approaches and propensity score matching can be employed to infer treatment effects using observational data. Thus, this study aimed to identify the individual treatment effects of adjuvant therapies on the overall survival of SS patients and recognize subgroups of patients who can benefit from specific treatments using Bayesian subgroup analyses.

METHODS

We analyzed data from patients with SS obtained from the surveillance, epidemiology, and end results (SEER) public database. These data were collected between 1984 and 2014. The treatment effects of chemotherapy and radiation therapy on overall survival were evaluated using propensity score matching. Subgroups that could benefit from radiation therapy or chemotherapy were identified using Bayesian subgroup analyses.

RESULTS

Based on a stratified Kaplan-Meier curve, chemotherapy exhibited a positive average causal effect on survival in patients with SS, whereas radiation therapy did not. The optimal subgroup for chemotherapy includes the following covariates: older than 20 years, male, large tumor (longest diameter > 5 cm), advanced stage (SEER 3), extremity location, and spindle cell type. The optimal subgroup for radiation therapy includes the following covariates: older than 20 years, male, large tumor (longest diameter > 5 cm), early stage (SEER 1), extremity location, and biphasic type.

CONCLUSION

In this study, we identified high-risk patients whose variables include age (age > 20 years), gender, tumor size, tumor location, and poor prognosis without adjuvant treatment. Radiation therapy should be considered in the early stages for high-risk patients with biphasic types. Conversely, chemotherapy should be considered for late-stage high-risk SS patients with spindle cell types.

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.

An Unusual Case of Synovial Sarcoma with Breast Metastasis: Findings on Positron Emission Tomography-Computed Tomography

Synovial sarcomas are aggressive soft-tissue tumors with the propensity for metastases at presentation or later course of disease. The most common site of metastases is lung, followed by lymph node and bone. It rarely metastasizes to the liver and to the brain. Breast metastases from extramammary tissue are extremely rare, more so from synovial sarcoma. ¹⁸F-fluorodeoxyglucose positron emission tomography–computed tomography (FDG PET/CT) plays a very important role in diagnosing occult metastasis in sarcomas. Histopathological diagnosis and translocation studies are important to confirm the diagnosis. We present a case of synovial sarcoma who underwent ¹⁸FDG PET/CT which showed occult metastasis to the breast.

The Long-Term Outcomes of Intensive Combined Therapy of Adult Patients with Localised Synovial Sarcoma

Introduction: Synovial sarcoma (SaSy) is a high-grade, malignant soft tissue sarcoma (STS) accounting for 5–9% of STS. The aim of this study was to analyse outcomes of patients with localised SaSy treated in a single institution with a uniform neo- and adjuvant-combined therapy protocol. Methods: 171 patients with stage II/III SaSy were treated between 1997 and 2014. Chemotherapy consisted of 4 cycles of ifosfamide 12 g/m² and two cycles of a doxorubicin-based regimen 75 mg/m². With the exception of patients who underwent amputation, all patients received neoadjuvant radiotherapy. Results: Median age was 33 years (range 17–69). Tumours larger than 5 cm in size were found in 70% of patients. The 5-year overall survival (OS), local relapse-free survival (LRFS) and metastasis-free survival (MFS) rates were 75%, 80% and 60%, respectively. In multivariate Cox’s regression, age > 35 years, male sex, larger tumour size and histology other than monophasic were associated with worse OS. Conclusions: In adult patients with localised SaSy, long-term survival can be achieved in a significant proportion of cases with intensive combined therapy. The multivariate analysis identified age, sex, disease stage and histology subtype as independent prognostic factors of OS.

Radiation therapy strategies for skull-base malignancies

INTRODUCTION

The management of skull base malignancies continues to evolve with improvements in surgical technique, advances in radiation delivery and novel systemic agents.

METHODS

In this review, we aim to discuss in detail the management of common skull base pathologies which typically require multimodality therapy, focusing on the radiotherapeutic aspects of care.

RESULTS

Technological advances in the administration of radiation therapy have led to a wide variety of different treatment strategies for the treatment of skull base malignances, with outcomes summarized herein.

CONCLUSION

Radiation treatment plays a key and critical role in the management of patients with skull base tumors. Recent advancements continue to improve the risk/benefit ratio for radiotherapy in this setting.

[Pulmonary synovial sarcoma: case study and literature review]

Le synovialosarcome est une tumeur maligne rare, soit 10% des sarcomes des tissus mous. Il se développe habituellement au niveau des membres et sa localisation pulmonaire est exceptionnelle. Nous rapportons un cas clinique de synovialosarcome du poumon chez un homme de 54 ans découvert à un stade localisé. Cette tumeur, extrêmement rare, présente un phénotype immunohistochimique particulier, qui contribue fortement au diagnostic. L'étude cytogénétique confirme le diagnostic en montrant la présence de la translocation spécifique t (X; 18), qui caractérise le synovialosarcome quelle que soit sa localisation anatomique. À travers cette observation, nous insistons sur les caractéristiques anatomo-cliniques, thérapeutiques et pronostiques de cette tumeur rare souvent méconnue par les cliniciens.

Radiotherapy is Associated With Improved Survival in Patients With Synovial Sarcoma Undergoing Surgery: A National Cancer Database Analysis

BACKGROUND

Previous studies have demonstrated an association of perioperative radiotherapy (RT) with improved survival in patients with synovial sarcoma (SS) undergoing surgery, but the mechanism for this is unknown. In this study, we sought to further analyze this association using a hospital-based data set where data on chemotherapy administration and surgical margin status are available.

METHODS

Using the National Cancer Database, we identified 1216 patients with SS (aged ≥18 y) from 2004-2012 undergoing surgery. Cox proportional hazards analysis was used to study the effect of clinicopathologic variables on overall survival (OS).

RESULTS

Mean age at diagnosis was 41.5 y (range 18-90), and 71.3% of tumors were high grade; 22.9% underwent surgery alone, 59.6% received RT with surgery, 44.2% received chemotherapy with surgery, and 26.3% received trimodality therapy. Age, sex, grade, Charlson-Deyo score, and RT (hazard ratio, 0.676; 95% confidence interval, 0.519-0.880; P = 0.004) were associated with improved OS, whereas chemotherapy (hazard ratio, 1.20; 95% confidence interval, 0.899-1.60; P = 0.217) and surgical margin status were not. Trimodality therapy with surgery, RT, and chemotherapy was associated with improved OS when compared with therapy with surgery and chemotherapy alone.

CONCLUSIONS

In patients with SS undergoing surgery, we observed a significant improved association of OS with the addition of RT when adjusting for comorbidity score, margin status, and receipt of chemotherapy. These data further support routine implementation of RT in the treatment of patients with SS, including those receiving aggressive multimodality and trimodality care.

Antiproliferative effect of bupivacaine on patient-derived sarcoma cells

Sarcomas are rare tumors with limited treatment options. Although chemotherapy is standard for certain subtypes, overall survival has not improved in several decades. Bupivacaine has been shown to induce apoptosis and prevent cell growth in multiple different types of malignancies but has not been studied in sarcoma. The current study evaluated the effects of bupivacaine on multiple patient-derived sarcoma cells and a commercial sarcoma cell line. Multiple patient-derived sarcoma cell subtypes and a commercial synovial cell sarcoma cell line were exposed to bupivacaine for different durations and at different concentrations. The patient-derived cells included a high-grade conventional osteosarcoma, a high-grade undifferentiated pleomorphic sarcoma of bone, and a high-grade synovial sarcoma. Flow cytometry and an MTT assay were used to evaluate whether a treatment effect was observed. Treatment of all the subtypes of sarcomas in this study with bupivacaine demonstrated a time- and dose-dependent increase in apoptosis and decrease in cell viability. A cell viability assay demonstrated that the IC₅₀ was between 0.04 and 0.05% and that the treatment effect occurred at clinically relevant doses in vitro. Bupivacaine was toxic to both the patient-derived cells and the commercial cell line at doses commonly used in the clinical setting. These findings provide a foundation for further in vivo studies to evaluate whether these effects will translate to the clinical setting. Although further research is necessary, bupivacaine shows promise as not only an adjunct for pain management but as a treatment modality for sarcoma.

Metastatic Synovial Sarcoma: Experience from a Tertiary Care Center from India

Background: Synovial sarcoma represents 8% of all soft-tissue sarcoma (STS). It is a high-grade STS, and 50% of patients develop metastasis. The most common site of metastasis is the lungs, lymph nodes followed by bones. Ifosfamide-based chemotherapy is associated with improved outcome. In this study, we report our experience of metastatic synovial sarcoma according to primary sites, metastatic pattern, and their outcome. Materials and Methods: This was a retrospective observational study carried out at our institute from January 2013 to December 2016. The aim of our study was to evaluate the pattern of metastasis, response to chemotherapy, and survival in patients with metastatic synovial sarcoma. Results: Over a period of 4 years, 43 patients with metastatic synovial sarcoma were diagnosed with median age of 30 years. Nearly 70% of patients had lung metastasis, other site of metastasis were lymph node, bone, and liver. Thirty patients received chemotherapy with a combination of ifosfamide and doxorubicin. The overall response rate was 87% with median progression-free survival of 8 months. Patients with lung only metastasis had better survival compared with nonpulmonary metastatic site (18 months vs. 12 months). The median survival was 18 months. Conclusion: Metastatic synovial sarcoma is chemoresponsive tumor with lung being the most common metastatic site. Patients with lung only metastasis had a better outcome than nonpulmonary metastasis.

Diagnostic Imaging and Management of Common Intra-articular and Peri-articular Soft Tissue Tumors and Tumorlike Conditions of the Knee

Intra-articular (IA) and peri-articular (PA) tumors of the knee are frequently encountered by orthopaedic surgeons. Nonetheless, due to the possibility of great morbidity and potential mortality, it is important to recognize and differentiate between benign and malignant lesions in a timely manner. Therefore, the purpose of this article is to provide a concise, practical, and updated review of commonly encountered IA and PA tumors including intratendinous gout, synovial chondromatosis, schwannoma, pigmented villonodular synovitis, and synovial sarcoma, and a detailed description of differentiating features to include various imaging modalities.

Synovial sarcoma of the brachial plexus - a rare tumor in a rare area: a case report

Background

Synovial cell sarcomas are usually seen in a juxta-articular location. However, they occur rarely in the head and neck region.

Case presentation

We report a rare case of brachial plexus synovial sarcoma in a 24-year old South Asian man treated successfully with surgical excision followed by radiotherapy.

Conclusions

Synovial sarcoma arising from the brachial plexus is rare. The treatment is multimodal with complete excision (often challenging owing to the proximity of the neurovascular structures) and adjuvant therapy.

Release of circulating tumor cells and cell-free nucleic acids is an infrequent event in synovial sarcoma: liquid biopsy analysis of 15 patients diagnosed with synovial sarcoma

BACKGROUND

Synovial sarcoma is a rare soft tissue tumor which contains the unique SS18-SSX1, SS18-SSX2 - or, rarely, SS18-SSX4 - fusion transcripts. It is well known that some soft tissue tumors, like Ewing sarcomas and myxoid liposarcomas, can spread via the blood with free circulating tumor cells (CTC); this can be detected by several sensitive molecular biology methods. Here we report a study of fifteen synovial sarcoma patients with varied clinical backgrounds.

METHOD

After blood withdrawal and nucleic acid isolation, we attempted to detect the SS18-SSX fusion genes from circulating tumor cells or cell-free nucleic acids with nested PCR and droplet digital PCR.

RESULTS

SS18-SSX2 fusion transcript was identified in a small copy number with droplet digital PCR in one case. Nested PCR could not detect any of the fusion transcripts in the examined 15 synovial sarcoma cases.

CONCLUSIONS

Heretofore two case reports could detect CTCs in synovial sarcoma - in the first paper, the patient was diagnosed with poorly differentiated type while the other had a rare primary gastric synovial sarcoma. However, until now, no other studies have detected CTCs in the peripheral blood of synovial sarcoma patients. Based on our findings, we can conclude that detection of the chimeric SS18-SSX fusion gene after surgical excision and/or chemotherapy/radiotherapy is a rare circumstance and hence in itself is not sufficient for monitoring the tumor recurrence. Therefore, monitoring of other possible biomarkers - for example synovial sarcoma specific miRNAs - is recommended.

Synovial Sarcoma of the Digits: A Case Report of an Unplanned Excision

Synovial sarcoma is a rare occurrence in the lower extremity, although the presenting symptoms can mimic those of other more common and benign musculoskeletal pathologies. We present the case of a patient who was originally thought to have a Morton's neuroma or ganglionic cyst. The correct diagnosis, synovial sarcoma, was determined only after an unplanned excision. Despite the patient presenting with symptoms similar to those of a compressive neuropathy, a high index of suspicion should be present when a patient presents with any soft tissue mass, especially if it has an unusual clinical appearance to avoid an unplanned excision.

In silico and in vitro screening of small molecule Inhibitors against SYT-SSX1 fusion protein in synovial sarcoma

Synovial sarcoma (SS) is characterized by a tumour specific chromosomal translocation t(X;18) (p11;q11) which results in the formation of SYT-SSX1 fusion protein. This fusion protein represents a clear therapeutic target and molecules specifically targeting SYT-SSX1 fusion protein are currently not available. In this study, SYT-SSX1 fusion protein sequence was retrieved from Uniprot and 3D structure was generated using I-TASSER modeling program. A structure based computational screening approach has been employed using Glide docking software to identify potential SYT-SSX1 small molecule inhibitors that bind to the junction region of the fusion protein. The obtained inhibitors were further filtered based on the docking score and ADME/T properties. Ten best fit compounds were chosen for in vitro studies. The anti-proliferative activities of these 10 compounds were screened in Yamato, ASKA (carries SYT-SSX1 fusion protein) and other sarcoma cell lines such as A673, 143B to understand the specificity of inhibition of the chosen compounds. The in vitro activity was compared against HEK293 cell lines. The compound 5-fluoro-3-(1-phenyl-1H-tetraazol-5-yl)-1H-indole (FPTI) was found to be selectively cytotoxic in synovial sarcoma cell lines (Yamato and ASKA) and this compound also showed insignificant anti proliferative activity on other cell lines. Further, target gene expression study confirmed that FPTI treatment down-regulated SYT-SSX1 and modulated its downstream target genes. Cell cycle analysis revealed the involvement of an apoptotic mechanism of cell death. Further experimental validations may elucidate the therapeutic potentials of FPTI against SYT-SSX1 fusion protein.

Primary monophasic synovial sarcoma of the pleura: Neoadjuvant chemotherapy followed by complete resection

We describe a rare case of primary pleural synovial sarcoma in a 27-year-old man with a 4-month history of dry cough and left-sided chest pain. A CT scan showed a large cystic mass in the left pleural cavity. The patient underwent two video-assisted thoracoscopic biopsies and the diagnosis of synovial sarcoma of the pleura was established. After neoadjuvant chemotherapy, which resulted in a partial response, the tumor was completely resected with extrapleural pneumonectomy. Pathological findings showed less than 5% of viable cancer and free surgical margins. The patient is clinically well 24 months after surgery, with no evidence of recurrent disease.

Synovial sarcoma of the maxillary sinus: an extremely rare case with excellent response to chemotherapy

This paper presents an extremely rare case of synovial sarcoma arising from the maxillary sinus, which resulted in a clinically complete response to chemotherapy. Synovial sarcoma is a rare soft tissue malignant tumor, most commonly affecting the extremities. While ~10% occur in the head and neck region, synovial sarcoma of the sinonasal tract is extremely rare, with only 11 cases having been reported previously. As with other sarcomas, the standard treatment is complete resection while allowing for a safe margin, but this is often difficult in the head and neck area due to the complicated anatomy there. This makes the treatment of head and neck sarcoma challenging and leads to the need for a multimodal approach in advanced cases. However, the exact efficacy of chemotherapy is not well understood. In this report, we present a case of unresectable maxillary sinus synovial sarcoma that was successfully treated by chemotherapy followed by radiation therapy. A 53-year-old Japanese man was referred to our hospital with a history of left nose obstruction over the previous couple of years. Computed tomography/magnetic resonance imaging revealed a tumor arising from the maxillary sinus that extended to adjacent tissues. A biopsy was performed, and the tumor was diagnosed as synovial sarcoma. Since the tumor was unresectable, neoadjuvant chemotherapy was administered. The response was excellent, and the tumor became undetectable under endoscopy and radiological imaging. This provided us with a clinical evaluation of “complete response”. The treatment was concluded with definitive radiotherapy and two more cycles of adjuvant chemotherapy. The patient remains free of disease 12 months after treatment. Synovial sarcoma of the head and neck is a rare entity; complete resection is the treatment of choice but (neo)adjuvant chemotherapy can be considered in unresectable cases, as we show here in the present case.

A primary gastric synovial sarcoma: A case report and literature review

RATIONALE

When a gastric spindle cell tumor is observed, the possibility of synovial carcinoma, besides common mesenchymal tumor, should also be considered.

PRESENTING CONCERNS OF THE PATIENT

The patient is a 51-year-old American woman who underwent medical check-up at a general hospital. Upper endoscopy showed a 2-cm sized mass covered with intact mucosa, and a central depression located on the posterior wall of the mid body. Biopsy of the mass showed focal atypical cells proliferation in mucosa on hematoxylin & eosin (H&E) staining. Endoscopic ultrasound showed a 17-mm homogenously hypoechoic mass within the submucosal layer.

INTERVENTIONS

After diagnostic endoscopic submucosal dissection was performed, H&E and immunohistochemical staining showed synovial sarcoma (SS). To confirm the diagnosis, reverse transcriptase-polymerase chain reaction was performed, revealing a chimeric transcript of the SYT-SSX1 fusion gene. The diagnosis of primary gastric SS was confirmed because no evidence of possible primary lesions or metastatic lesions was observed. Therefore, the patient underwent distal gastrectomy.

OUTCOMES

After surgery, the surgical specimen demonstrated no residual tumor cells. The patient received no adjuvant therapy, and there has been no evidence of local recurrence or distant metastasis for 2 months after the operation.

LESSONS

When gastric subepithelial tumor is suspicious, we should also consider gastric SS.

MicroRNAs in Different Histologies of Soft Tissue Sarcoma: A Comprehensive Review

Soft tissue sarcomas (STS) constitute a rare tumour entity comprising over 50 histological subtypes. MicroRNAs (miRNAs) are short non-protein coding RNA molecules that regulate gene expression by targeting the 3'-untranslated region of messenger RNAs. They are involved in a variety of human diseases, including malignancies, such as endometrial cancer, osteosarcoma, bronchial carcinoma and breast cancer. In STS, various miRNAs are differentially expressed, thus contributing to development, progression and invasion. Therefore, the aim of the present review is to summarise current knowledge on the role of miRNAs in STS. Furthermore, the potential role of miRNAs as diagnostic, prognostic and predictive biomarkers is discussed.

Histone deacetylase inhibitors vorinostat and panobinostat induce G1 cell cycle arrest and apoptosis in multidrug resistant sarcoma cell lines

Synovial sarcoma and high grade chondrosarcoma are characterized by their lack of response to conventional cytotoxic chemotherapy, the tendency to develop lung metastases, and low survival rates.

Research within the field prioritizes the development and expansion of new treatment options for dealing with unresectable or metastatic diseases. Numerous clinical trials using histone deacetylases inhibitors (HDACi) have shown specific efficacy as an active antitumor agent for treating a variety of solid tumors. However, as of yet the effect of different HDACi on synovial- and chondrosarcoma cells has not been investigated. In this study, vorinostat (SAHA), panobinostat (LBH-589), and belinostat (PXD101) decreased cell viability of synovial sarcoma (SW-982) and chondrosarcoma (SW-1353) cells in a time- and dose dependent manner and arrested SW-982 cells in the G1/S phase. Western blot analysis determined the responsible cell cycle regulator proteins. In addition, we found apoptotic induction by caspase 3/7 activity, caspase 3 cleavage, and PARP cleavage. In SW-1353 cells only SAHA showed comparable effects. Noteworthy, all HDACi tested had synergistic effects with the topoisomerase II inhibitor doxorubicin in SW-1353 chondrosarcoma cells making the cells more sensitive to the chemotherapeutic drug.

Our results show for the first time that SAHA and LBH-589 reduced viability of sarcoma cells and arrested them at the G1/S checkpoint, while also inducing apoptosis and enhancing chemotherapeutic sensitivity, especially in chondrosarcoma cells. These data demonstrate the exciting potential of HDACi for use in sarcoma treatment.

Canine intrathoracic sarcoma with ultrastructural characteristics of human synovial sarcoma - case report

Background

Canine joint sarcomas, designated synovial sarcomas, are uncommon malignant mesenchymal neoplasms that occur in the large joints of the extremities of middle-aged, large-breed dogs. We report the diagnosis of an intrathoracic sarcoma with ultrastructural characteristics reminiscent of human synovial sarcoma in a dog.

Case presentation

A 7-year-old female spayed Tibetan terrier crossbred dog was presented for acute severe labored breathing and diagnosed with an intrathoracic neoplastic mass. The neoplasm resulted in the accumulation of substantial amounts of viscous pleural fluid that led to dyspnea. The neoplastic mass consisted of interweaving bundles of large pleomorphic mesenchymal cells, supported by an alcian blue positive myxomatous matrix. The neoplastic cells were immunohistochemically negative for cytokeratin and CD18. Transmission electron microscopy indicated that the neoplastic cells had desmosome junctions, short microvilli-like structures and ample amounts of rough endoplasmic reticulum resembling type B-like synoviocytes and synovial sarcoma as reported in people. Despite complete surgical excision of the neoplastic mass, clinical signs recurred after a month and led to the euthanasia of the dog.

Conclusion

Currently, there are no immunohistochemical markers specific for synovial sarcoma. Canine neoplasms with transmission electron microscopy characteristics resembling type B-like synoviocytes should be considered similar to the human sarcomas that carry the specific translocations between chromosomes X and 18.

Reasons why a second radiological opinion is advisable: a case report of a misreported crural synovial cell sarcoma

Synovial sarcoma (SS) is a rare condition that accounts for 5–10% of all soft-tissue sarcomas (STS). SS locates most frequently near the joints, in particular at the lower extremities, but it can also occur in other locations. We report a case of a 42-year-old male complaining of a slow-growth mass on his right thigh, reported as a femoral nerve shwannoma on the basis of the preoperative radiological investigations, which revealed to be a monophasic SS on the histological examination. During the surgical procedure, the assistance of vascular surgeons was required to reconstruct the wall of the femoral vein underlying the tumor, that was pathologically thickened, and communicated with the tumoral capsule. Although extremely rare, SS should be considered in the differential diagnosis of peripheral nerve sheath tumors, in particular if next to a large vein at the lower extremities.