Synovial Sarcoma of the Gastrointestinal Tract

We report the clinicopathologic and immunohistochemical features of 18 cases of confirmed primary synovial sarcoma of the gastrointestinal tract. The neoplasms arose in 10 women and 8 men ranging in age from 23 to 81 years (mean: 50; median: 57.5 years). The tumors for which size was known ranged from 1.8 to 15.0 cm (mean: 5.2; median: 5.1 cm). Microscopically, 14 synovial sarcomas were of the monophasic type, 2 were biphasic, and 2 were poorly differentiated. Immunohistochemical analysis of 4 cases showed strong, diffuse staining for SS18::SSX (4/4 cases). Pancytokeratin and EMA immunohistochemistry were performed on 13 and 9 tumors, respectively, and each showed patchy-to-diffuse staining. By reverse-transcription PCR, 3 cases were positive for the SS18::SSX1, and 2 cases were positive for the SS18::SSX2 gene fusion. Six cases contained an SS18 gene rearrangement by fluorescence in situ hybridization, and next-generation sequencing identified an SS18::SSX2 gene fusion in one case. Clinical follow-up information was available for 9 patients (4 months to 4.6 years; mean, 2.8 y; median: 29 months), and one patient had a recent diagnosis. Three patients died of disease within 41 to 72 months (mean, 56 months) of their diagnosis. Five patients were alive without evidence of disease 4 to 52 months (mean, 17.6 months) after surgery; of whom 1 of the patients received additional chemotherapy treatment after surgery because of recurrence of the disease. A single patient was alive with intraabdominal recurrence 13 months after surgery. We conclude that synovial sarcoma of the gastrointestinal tract is an aggressive tumor, similar to its soft tissue counterpart, with adverse patient outcomes. It is important to distinguish it from morphologically similar gastrointestinal tract lesions that may have different treatment regimens and prognoses.

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.

Sarcoma care in the era of precision medicine

Sarcoma subtype classification is currently mainly based upon histopathological morphology. Molecular analyses have emerged as an efficient addition to the diagnostic workup and sarcoma care. Knowledge about the sarcoma genome increases, and genetic events that can either support a histopathological diagnosis or suggest a differential diagnosis are identified, as well as novel therapeutic targets. In this review, we present diagnostic, therapeutic, and prognostic molecular markers that are, or might soon be, used clinically. For sarcoma diagnostics, there are specific fusions highly supportive or pathognomonic for a diagnostic entity-for instance, SYT::SSX in synovial sarcoma. Complex karyotypes also give diagnostic information-for example, supporting dedifferentiation rather than low-grade central osteosarcoma or well-differentiated liposarcoma when detected in combination with MDM2/CDK4 amplification. Molecular treatment predictive sarcoma markers are available for gastrointestinal stromal tumor (GIST) and locally aggressive benign mesenchymal tumors. The molecular prognostic markers for sarcomas in clinical practice are few. For solitary fibrous tumor, the type of NAB2::STAT6 fusion is associated with the outcome, and the KIT/PDGFRA pathogenic variant in GISTs can give prognostic information. With the exploding availability of sequencing technologies, it becomes increasingly important to understand the strengths and limitations of those methods and their context in sarcoma diagnostics. It is reasonable to believe that most sarcoma treatment centers will increase the use of massive-parallel sequencing soon. We conclude that the context in which the genetic findings are interpreted is of importance, and the interpretation of genomic findings requires considering tumor histomorphology.

Team Approach: Extremity Soft Tissue Sarcoma

» Synovial sarcoma is a soft tissue sarcoma that most commonly presents in the extremity in a periarticular location.» As the history and physical examination of patients with synovial sarcoma can overlap considerably with those of patients with non-oncologic orthopedic conditions, it is important that orthopedic surgeons maintain a high level of suspicion when caring for patients with extremity masses.» Soft tissue sarcomas are best treated using a team approach. Early recognition and referral to a multidisciplinary sarcoma team are crucial to ensure the best clinical outcome for the patient.

Primary synovial sarcoma and acinar adenocarcinoma of prostate rarely occur simultaneously: A case report

RATIONALE

Primary synovial sarcoma of the prostate is an extremely rare mesenchymal malignant soft tissue tumor with unique morphological features. Synovial sarcoma often occurs in the pararticular tissues of limbs in young people, but rarely occurs in prostate. Because it is very rare, it is easily misdiagnosed as benign prostatic hyperplasia or prostate cancer clinically. A case of synchronous acinar adenocarcinoma of the prostate has not been reported. In this article, we report a unique case of primary prostatic synovial sarcoma with acinar adenocarcinoma.

PATIENT CONCERNS

A 58-year-old male patient was found to have a prostate mass during physical examination. Prostate ultrasound examination showed an increase in prostate volume of 5.2 × 3.3 × 3.3 cm, mixed echo mass can be seen on the left side of the prostate, with a size of approximately 4.9 × 4.3 cm, left seminal vesicle compressed.

DIAGNOSES

Prostatic synovial sarcoma (biphasic type) combined with prostatic acinar adenocarcinoma (Gleason 3 + 3).

INTERVENTION

The patient received radical prostatectomy, followed by adjuvant chemotherapy and radiotherapy.

OUTCOME

After 2 months of follow-up, at the time of writing this article, the patient received a comprehensive treatment plan of adjuvant chemotherapy and radiotherapy for 2 months, and no recurrence or metastasis was found.

LESSONS

Primary prostatic synovial sarcoma (biphasic type) combined with prostatic acinar adenocarcinoma is a very unique and rare case, and effective treatment guidelines are not yet clear, posing new challenges to clinical treatment. Making full use of pathological and imaging examinations, early diagnosis and radical surgery combined with multidisciplinary treatment seem to be still a positive method.

Localized Synovial Sarcoma: A Population-Based Analysis of Treatment Patterns and Survival

Purpose: Synovial sarcoma (SS) is a rare, high-grade soft tissue tumor that requires multidisciplinary and multimodal care with surgery, radiotherapy, and chemotherapy. We examined the impact of sociodemographic and clinical factors on treatment patterns and survival in localized SS patients. Methods: Adolescents and young adults (AYAs, 15-39 years) and older adults ("adults," ≥40 years) diagnosed with localized SS from 2000 to 2018 were identified in the California Cancer Registry. Multivariable logistic regression identified clinical and sociodemographic factors associated with receipt of chemotherapy and/or radiotherapy. Cox proportional hazards regression identified factors associated with overall survival (OS). Results are reported as odds ratios (ORs) and hazard ratios (HRs), respectively, with 95% confidence intervals (CIs). Results: More AYAs (n = 346) than adults (n = 272) received chemotherapy (47.7% vs. 36.4%) and radiotherapy (62.1% vs. 58.1%). Age at diagnosis, tumor size, treatment at National Cancer Institute-Children's Oncology Group (NCI-COG)-designated facilities, insurance status, and neighborhood socioeconomic status (SES) influenced treatment patterns. Among AYAs, treatment at NCI-COG-designated facilities was associated with receiving chemotherapy (OR 2.74, CI 1.48-5.07) and low SES was associated with worse OS (HR 2.28, 1.09-4.77). In adults, high SES was associated with receiving chemoradiotherapy (OR 3.20, CI 1.40-7.31), whereas public insurance was associated with decreased odds of chemoradiotherapy (OR 0.44, CI 0.20-0.95). With regard to treatment, absence of radiotherapy (HR 1.94, CI 1.18-3.20) was associated with worse OS in adults. Conclusion: In localized SS, both clinical and sociodemographic factors influenced treatment patterns. Further research should investigate how SES-related factors produce treatment disparities and identify interventions to improve treatment equity and outcomes.

Relapsed Synovial Sarcoma: Treatment Options

OPINION STATEMENT

Synovial sarcoma (SS) is a fusion-driven subtype of sarcoma that is a more chemo-sensitive subtype of soft tissue sarcoma. While chemotherapy options are currently standard of care, our fundamental understanding of the biology of SS is driving new therapies. We will review the current standard of care, as well as the current therapies showing promise in a clinical trial. It is our hope that by encouraging participation in clinical trials, the fundamental therapies available for SS will change the current treatment paradigm.

New benchmarks to design clinical trials with advanced or metastatic liposarcoma or synovial sarcoma patients: An EORTC - Soft Tissue and Bone Sarcoma Group (STBSG) meta-analysis based on a literature review for soft-tissue sarcomas

BACKGROUND

Recently, we performed a meta-analysis based on a literature review for STS trials (published 2003-2018, ≥10 adult patients) to update long-standing reference values for leiomyosarcomas. This work is extended for liposarcomas (LPS) and synovial sarcomas (SS).

MATERIALS AND METHODS

Study endpoints were progression-free survival rates (PFSRs) at 3 and 6 months. Trial-specific estimates were pooled per treatment line (first-line or pre-treated) with random effects meta-analyses. The choice of the therapeutic benefit to target in future trials was guided by the European Society for Medical Oncology Magnitude of Clinical Benefit Scale (ESMO-MCBS).

RESULTS

Information was acquired for 1030 LPS patients (25 trials; 7 first-line, 17 pre-treated, 1 both) and 348 SS patients (13 trials; 3 first-line, 10 pre-treated). For LPS, the overall pooled first-line PFSRs were 69% (95%-CI 60-77%) and 56% (95%-CI 45-67%) at 3 and 6 months, respectively. These rates were 49% (95%-CI 40-57%)/28% (95%-CI 22-34%) for >1 lines. For SS, first-line PFSRs were 74% (95%-CI 58-86%)/56% (95%-CI 31-78%) at 3 and 6 months, and pre-treated rates were 45% (95%-CI 34-57%)/25% (95%-CI 16-36%). Following ESMO-MCBS guidelines, the minimum values to target are 79% and 69% for first-line LPS (82% and 69% for SS) at 3 and 6 months. For pre-treated LPS, recommended PFSRs at 3 and 6 months suggesting drug activity are 63% and 44% (60% and 41% for SS).

CONCLUSIONS

New benchmarks are proposed for advanced/metastatic LPS or SS to design future histology-specific phase II trials. More data are needed to provide definitive thresholds for the different LPS subtypes.

[Clinical analysis of 24 cases of synovial sarcoma of head and neck]

Objective: To investigate the pathological characteristics, treatment and prognosis of synovial sarcoma of head and neck. Methods: The clinical data of 24 patients with synovial sarcoma of the head and neck treated in the First Affiliated Hospital of Zhengzhou University from January 2012 to December 2020 were retrospectively analyzed. There were 16 males and eight females, aged 17 to 75 years. The pathological features, treatment and follow-up were summarized. Cumulative survival was estimated by Kaplan-Meier method. Results: All patients' diagnoses were confirmed by pathological examinations. Most cases showed the tumors were composed of spindle cells under microscope, with the characteristics of malignant tumor cells, and some tumors also showed epithelioid cell morphology, forming the typical pathological characteristics of biphasic differentiation. Except for one patient who could not tolerate surgery and the diagnosis was only confirmed by biopsy, the remaining 23 patients received surgical treatment, including three patients receiving surgical treatment alone, five patients receiving post-operative adjuvant radiotherapy, seven patients receiving post-operative adjuvant chemotherapy, and eight patients receiving post-operative adjuvant radiotherapy. Follow-up time was 3.0-114.1 months (median follow-up time: 25.2 months), including two cases of loss to follow-up, 10 cases of recurrence, five cases of lung metastases, one case of bone metastasis, and 12 cases of death. The 1-year, 3-year and 5-year survival rates for the 24 patients with synovial sarcoma of head and neck were 74.4%, 58.9% and 39.2%, respectively. Conclusion: Synovial sarcoma of the head and neck has a high recurrence rate, common distant metastasis and poor prognosis. Histopathology and immunohistochemical examinations are an important basis for diagnosis, if necessary, combined with molecular genetics. Surgical resection is the main treatment, preferring radical or expanded resection.

Synovial sarcoma of the spinal canal and paraspinal muscle and retroperitoneum: a case with extensive calcification

INTRODUCTION

Synovial sarcoma (SS) is a rare mesenchymal malignant tumor. SS of the spine or retroperitoneum is an extremely rare site. Approximately 30% cases show focal calcifications on radiographs and computed tomography (CT) images, while extensive calcification rarely occurs. We presented a case of SS involving the spinal canal and paraspinal muscle and retroperitoneum, which showed extensive calcification on CT.

CLINICAL PRESENTATION

The present report describes the case of a 13-year-old girl suffering from a tumor in the spinal canal and paraspinal muscle and retroperitoneum with extensive calcification on CT. The patient underwent lumbar and retroperitoneal giant tumor resection, lumbar decompression, and spinal tumor resection with a small tumor remnant remaining in the paravertebral region. Histological examination and genetic testing after surgery confirmed synovial sarcoma. After surgery, the patient refused local radiotherapy but agreed to receive chemotherapy. After 4 months of follow-up, her condition was basically stable, and the pain in her left lower limb disappeared. The residual tumor was not increased.

CONCLUSION

Extensive calcification of SS is rare. The possibility of synovial sarcoma should be considered in those who show extensive calcification in the spinal canal and paraspinal muscle and retroperitoneum on CT. For cases that cannot be completely resected, adjuvant chemotherapy can control the residual tumor in the short term. In addition, the long-term effects need to be observed.

Development and Validation of the Nomograms for Predicting Overall Survival and Cancer-Specific Survival in Patients With Synovial Sarcoma

BACKGROUND

The study aimed to build and validate practical nomograms to predict overall survival (OS) and cancer-specific survival (CSS) for patients with synovial sarcoma (SyS).

METHODS

A total of 893 eligible patients confirmed to have SyS between 2007 and 2015 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. Patients were randomly divided into the training cohort (n = 448) and validation cohort (n = 445). Clinically independent prognostic and important factors were determined according to the Akaike information criterion in multivariate Cox regression models when developing the nomograms with the training cohort. The predictive accuracy of nomograms was bootstrapped validated internally and externally with the concordance index (C-index) and calibration curve. Decision curve analysis (DCA) was performed to compare the clinical usefulness between nomograms and American Joint Commission on Cancer (AJCC) staging system.

RESULTS

Two nomograms shared common indicators including age, insurance status, tumor site, tumor size, SEER stage, surgery, and radiation, while marital status and tumor site were only included into the OS nomogram. The C-index of nomograms for predicting OS and CSS was 0.819 (0.873-0.764) and 0.821 (0.876-0.766), respectively, suggesting satisfactory predictive performance. Internal and external calibration curves exhibited optimal agreement between the nomogram prediction and the actual survival. Additionally, DCA demonstrated that our nomograms had obvious superiority over the AJCC staging system with more clinical net benefits.

CONCLUSIONS

Two nomograms predicting 3- and 5-year OS and CSS of SyS patients were successfully constructed and validated for the first time, with higher predictive accuracy and clinical values than the AJCC staging system regarding OS and CSS.

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.

Primary renal synovial sarcoma: A case report

RATIONALE

Synovial sarcoma (SS) is a malignant neoplasm that arises from soft tissues proximal to the joints. It occurs primarily at the major joints of the extremities, but may also occur in the deep soft tissues around the joints. While primary renal synovial sarcoma (PRSS) is extremely rare, it is important to have a better understanding of their imaging and clinical features to establish an effective treatment plan. Correct identification of PRSS is also useful for treating renal neoplasms.

PATIENT'S CONCERNS

A 56-year-old Chinese man was admitted to our hospital due to moderate, paroxysmal left-sided loin pain.

DIAGNOSIS

Renal enhanced computed tomography (CT) scanning showed a relatively hypovascular lesion with calcification in the left kidney. A radical nephrectomy was performed in the left kidney. Postoperative pathology indicated SS with necrosis. The immunohistochemical findings were as follows: 34βE12 (Epithelium+), Bcl-2(+), CD99(+), CK-pan((Epithelium+), EMA(Epithelium+), Ki-67(+60%), and Vimentin(+), CD34(-).

INTERVENTIONS

The patient underwent radical left nephrectomy with no complications.

OUTCOMES

After discharge, a close review for 3 months showed no evidence of recurrence.

LESSONS

PRSS should be considered for the differential diagnosis of renal hypovascular tumors. When problems arise in distinguishing renal hypovascular tumors, surgical pathology is helpful in the final diagnosis and further treatment of the disease.

Treatment of limb synovial sarcoma with metastasis at presentation

Limb synovial sarcoma (LSS) patients with metastasis at presentation usually have a very poor prognosis. Little is known about survival prediction and risk factors in these patients owing to the condition's rarity. Thus, this study examined the survival and prognostic variables of metastatic LSS.Clinical data for LSS patients with metastasis at presentation from 1975 to 2016 were obtained from the surveillance, epidemiology, and end results database. The Kaplan-Meier method was used to determine the survival curves. Univariate and multivariate Cox regression analysis were conducted to identify the prognostic predictors.The study enrolled 217 patients. Male predominance was observed in the metastatic LSS group. The median age at diagnosis of this population was 40 years. The subtypes were "not otherwise specified" (49.8%), spindle cell (32.7%), biphasic (17.1%), and epithelioid cell (0.5%). The 3-year overall and cancer-specific survival rates of the entire group were 27.2% and 28.3%, respectively. Tumor size <10 cm, surgery, radiotherapy, and chemotherapy were independent predictors of improved overall and cancer-specific survival in the multivariate analyses.Comprehensive treatment for LSS patients with metastasis at diagnosis is necessary and effective and can prolong survival.

Primary Synovial Sarcoma of the Thyroid: Challenges in Cytologic Diagnosis and Review of the Literature

BACKGROUND

Primary synovial sarcoma (SS) of the thyroid (PSST) is extremely rare. Its differential diagnosis from other neoplasms is essential since it has different management protocols and prognosis.

CASE

A 26-year-old man with a 4.5-cm solid lobulated mass was seen at an outside hospital. Fine needle aspiration (FNA) was interpreted as a papillary carcinoma, and a total thyroidectomy was performed. The final histologic diagnosis was spindle epithelial tumor with thymus-like differentiation (SETTLE). No metastases were detected at that time, and the patient received radioactive iodine treatment. Two years post-surgery, he was seen at our hospital with a local recurrence, and FNA was considered as consistent with SETTLE. The mass was resected, and a left modified radical neck dissection was performed. The tumor revealed necrosis and a high mitotic index. Following histologic, immunohistochemical, and molecular studies, the tumor was classified as a PSST. The patient received chemotherapy and targeted immunotherapy, but he died 41 months after the initial presentation.

CONCLUSION

The main diagnostic pitfall of PSST is SETTLE. The presence of mitotic figures and basal lamina material, negative staining for smooth muscle actin, and positive staining for transducer-like enhancer of split 1 antibody favor SS over SETTLE. SYT gene rearrangement is essential to establish the definitive diagnosis of PSST.

Pediatric Tonsillar Synovial Sarcoma- Very Rare Localization: A Case Report and Review of the Literature

Tonsillar synovial sarcoma is an extremely rare entity and only 9 adult patients have been reported up to now. Here, we describe the first pediatric tonsillar synovial sarcoma of the literature in a patient who presented with a 2-month history of dysphagia and snoring. Clinical and radiological examinations showed that the tumor arose from the right palatine tonsil and narrowed the parapharyngeal space. An incisional biopsy from the palatine tonsil revealed the diagnosis of synovial sarcoma. The patient has underwent total tonsillectomy and received radiotherapy and chemotherapy because of the positive surgical margins. The patient is clinically in good condition and free of tumor 30 months after the initial diagnosis. We achieved a long-term complete remission with a combination of surgery, radiotherapy and chemotherapy in our case. Tonsillar synovial sarcoma should be kept in mind while dealing with tonsillar masses. We can conclude that a multidisciplinary approach is warranted while treating synovial sarcoma with this localization.

The use of apatinib in treating primary pleural synovial sarcoma: A case report

RATIONALE

Apatinib is an oral tyrosine kinase inhibitor targeting vascular endothelial growth factor receptor-2. It has been shown that apatinib is effective and safe for treatment of multiple solid tumors, including gastric cancer, liver cancer, non-small-cell lung cancer, and breast cancer. However, there is currently no consensus as to using Apatinib for the treatment of pleural synovial sarcoma, due to the rarity of primary pleural synovial sarcoma and lack of clinical studies as a consequence.

PATIENT CONCERNS AND DIAGNOSES

We reported here in the case of a 26-year-old Chinese woman diagnosed with pleural synovial sarcoma. She has undergone 2 surgeries, multiple regimens of chemotherapy and traditional Chinese medicine in other hospitals. Then the patient was admitted to our hospital with the compliant of chest pain and dyspnea. The medical history and available data supported the diagnosis of recurrence of pleural synovial sarcoma.

INTERVENTIONS AND OUTCOMES

Due to the lack of efficacy of previous standard treatment, the patient was given apatinib and radiotherapy to relieve the symptoms. This patient achieved stable disease with apatinib at a dose of 500 mg/day. Her progression-free survival time was more than 7 months, and her overall survival was 8.5 months. Except for hand-foot syndrome, no grade 3 or 4 side effects were observed.

CONCLUSIONS

Apatinib may thus be an option for treatment of advanced synovial sarcoma after failure of other treatments. However, further study is needed to determine the efficacy of apatinib in pleural synovial sarcoma.

Pericardial Synovial Sarcoma: Case Report, Literature Review and Pooled Analysis

BACKGROUND

Pericardial synovial sarcomas (PSS) are very rare tumors, with dismal prognosis and limited data. We describe the clinical features and identify prognostic factors of primary PSS.

CASE REPORT

We describe the case of a 56-year-old male patient with PSS managed by the multidisciplinary team of thoracic oncology. The therapeutic plan comprised surgery, chemotherapy, stereotactic radiosurgery and targeted therapy, with excellent results.

MATERIALS AND METHODS

Data from 37 cases reported in English during the past 20 years were gathered and analyzed. PSS was found to occur at a mean age of 36±17.082 (range=13-67) years. Survival analysis was performed on 20 cases with follow-up of at least 6 months.

CONCLUSION

Only complete resection of the tumor seems to be an independent prognostic factor. To our knowledge, this is the first report on the safety and effectivity of pazopanib in PSS and may provide guidance for similar cases in the future.

Systemic Interferon-γ Increases MHC Class I Expression and T-cell Infiltration in Cold Tumors: Results of a Phase 0 Clinical Trial

Interferon-γ (IFNγ) has been studied as a cancer treatment with limited evidence of clinical benefit. However, it could play a role in cancer immunotherapy combination treatments. Despite high expression of immunogenic cancer-testis antigens, synovial sarcoma (SS) and myxoid/round cell liposarcoma (MRCL) have a cold tumor microenvironment (TME), with few infiltrating T cells and low expression of major histocompatibility complex class I (MHC-I). We hypothesized that IFNγ treatment could drive inflammation in a cold TME, facilitating further immunotherapy. We conducted a phase 0 clinical trial treating 8 SS or MRCL patients with weekly systemic IFNγ. We performed pre- and posttreatment biopsies. IFNγ changed the SS and MRCL TME, inducing tumor-surface MHC-I expression and significant T-cell infiltration (P < 0.05). Gene-expression analysis suggested increased tumor antigen presentation and less exhausted phenotypes of the tumor-infiltrating T cells. Newly emergent antigen-specific humoral and/or T-cell responses were found in 3 of 7 evaluable patients. However, increased expression of PD-L1 was observed on tumor-infiltrating myeloid cells and in some cases tumor cells. These findings suggest that systemic IFNγ used to convert SS and MRCL into "hot" tumors will work in concert with anti-PD-1 therapy to provide patient benefit.

Synovial sarcoma of cervicodorsal spine: A case report

Synovial sarcoma is a soft-tissue sarcoma. Its involvement of the spine is extremely rare. We report a 40 year old male who presented with shoulder pain and progressive weakness in all four limbs for six months with a visible, slowly growing bulge in his upper back. On examination he had quadriparesis and diffuse sensory deficit. MRI of the cervical spine showed a large soft tissue mass, iso to hypointense, extending into the neural canal, compressing the cord. The mass had a few internal areas of contrast enhancement with extension into the right paraspinal regions involving the vertebral bodies. Sub-periosteal spine dissection was done. Tumour was primarily extradural, involving and extending from paraspinal soft tissues to the posterior arches, laminae and spinous processes of the verteberae, with their destruction. Gross radical removal of the visible mass was done, followed by three cycles of radiation therapy. Excisional biopsy showed synovial sarcoma TYPE II. In conclusion, synovial sarcomas should be kept in the differentials of a mass arising in spinal axis.

The role of immunohistochemistry in the diagnosis and management of synovial sarcoma

Synovial sarcoma (SS) is a malignant soft tissue tumor representing 5-10% of all soft tissue sarcomas. Most synovial sarcomas are found at the extremities, especially in the lower limbs. A 28-year-old female presented at the Department of Plastic and Reconstructive Surgery, "Dr. Pius Brînzeu" Clinical Hospital, Timişoara, Romania, for evaluation of a mass located in the anterior region of the elbow. Imagistic, histological and immunohistochemically evaluations established the diagnosis of monophasic spindle cell SS G2. Block excision of the tumor with oncological safety margins was performed followed by total elbow arthroplasty. The patient then received radio- and chemotherapy. The case was followed-up at regular intervals for local recurrence and metastases and was free of symptoms at two years. Early diagnosis of SS, multimodal therapies and performing an arthroplasty of the elbow allowed the patient to resume daily activities. The unpredictable evolution requires regular follow-up for a long period of time.

Diagnosis, Classification, and Management of Soft Tissue Sarcomas

BACKGROUND

Soft tissue sarcomas are challenging to oncologists due to their unique character, the infrequency of their occurrence, and the difficulties in predicting outcomes. Advances in imaging, as well as improvements in surgical techniques and adjunctive treatment methods, have improved care for patients with these unusual disorders.

METHODS

The various types of soft tissue tumors are defined, and the statistics for the Orthopaedic Oncology Group in relation to them are reviewed and compared with literature references.

RESULTS

The overall survival rate for 1,220 tumors treated at our institute from June 1972 to June of 2001 was 72%, with a wide range. Patients with leiomyosarcomas, clear cell sarcomas, and malignant fibrous histiocytomas had a poorer survival rate, while those with fibrosarcomas, liposarcomas, and neurofibrosarcomas fared better. Outcome was affected by patient age, tumor anatomic site, tumor stage, and a history of recurrence.

CONCLUSIONS

Competent imaging, predictive immunological and genetic studies, improved surgery, and newer methods of adjunctive and neoadjunctive treatment should result in improvements in outcomes for patients with these tumors.

Phase 1/2 study of immunotherapy with dendritic cells pulsed with autologous tumor lysate in patients with refractory bone and soft tissue sarcoma

BACKGROUND

There are limited options for the curative treatment of refractory bone and soft tissue sarcomas. The purpose of this phase 1/2 study was to assess the immunological and clinical effects of dendritic cells (DCs) pulsed with autologous tumor lysate (TL) in patients with advanced bone and soft tissue sarcomas.

METHODS

Thirty-seven patients with metastatic or recurrent sarcomas were enrolled in this study. Peripheral blood mononuclear cells obtained from the patients were suspended in media containing interleukin 4 (IL-4) and granulocyte-macrophage colony-stimulating factor. Subsequently, these cells were treated with TL, tumor necrosis factor α, and OK-432. The DCs were injected into the inguinal or axillary region. One treatment course comprised 6 weekly DC injections. The toxicity, clinical response (tumor volume, serum interferon-γ [IFN-γ], and serum IL-12), and oncological outcomes were observed.

RESULTS

In total, 47 courses of DC therapy were performed in 37 patients. No severe adverse events or deaths associated with the DC injections were observed in the study patients. Increased serum IFN-γ and IL-12 levels were observed 1 month after the DC injection. Among the 37 patients, 35 patients were assessed for clinical responses: 28 patients showed tumor progression, 6 patients had stable disease, and 1 patient showed a partial response 8 weeks after the DC injection. The 3-year overall and progression-free survival rates of the patients were 42.3% and 2.9%, respectively.

CONCLUSIONS

Although DC therapy appears safe and resulted in an immunological response in patients with refractory sarcoma, it resulted in an improvement of the clinical outcome in only a small number of patients. Cancer 2017;123:1576-1584. © 2017 American Cancer Society.

A clinicopathologic study on SS18 fusion positive head and neck synovial sarcomas

OBJECTIVE

To determine clinicopathologic factors on survival in patients with head and neck synovial sarcoma.

PATIENTS AND METHODS

We retrospectively identified patients with molecularly confirmed synovial sarcomas of the head and neck (SS-HN), either by the presence of SS18-SSX fusion transcript by RT-PCR or SS18 gene rearrangement by FISH, who were managed at our institution over a 20-year period (1996-2015). Kaplan-Meier survival analysis and log-rank test were performed to evaluate variables related to disease specific survival (DSS). Fisher exact test was performed to evaluate variables related to local recurrence.

RESULTS

Thirty-four patients (20 males and 14 females, mean of 31years) with SS18-SSX fusion-positive SS-HN were identified. The parapharyngeal region of the neck was the most common site. The mean tumor size was 4.8cm (0.8-10cm). Two-thirds (n=23) of cases had a monophasic histology. The 2, 5 and 10-year DSS rates were 97%, 79% and 68%. The 5-year DSS rates for the adult/pediatric cohort were 74%/88%. Recurrence showed significant effect on DSS (p=0.021). There was no significant effect on DSS with age, therapy modality, tumor site, surgical margin, tumor size (⩽5cm vs. >5cm) and histopathologic subtype. Tumor site (i.e. skull base/paranasal sinus region) was associated with local recurrence (p=0.003).

CONCLUSION

In our cohort DSS rate was associated with recurrence. Tumors located in the skull base/paranasal sinus region were associated with a higher rate of local recurrence. Thus appropriate selection of high risk patients who can benefit from multimodality therapies might improve survival.

First-in-human Phase 1 CRISPR Gene Editing Cancer Trials: Are We Ready?

A prospective first-in-human Phase 1 CRISPR gene editing trial in the United States for patients with melanoma, synovial sarcoma, and multiple myeloma offers hope that gene editing tools may usefully treat human disease. An overarching ethical challenge with first-in-human Phase 1 clinical trials, however, is knowing when it is ethically acceptable to initiate such trials on the basis of safety and efficacy data obtained from pre-clinical studies. If the pre-clinical studies that inform trial design are themselves poorly designed - as a result of which the quality of pre-clinical evidence is deficient - then the ethical requirement of scientific validity for clinical research may not be satisfied. In turn, this could mean that the Phase 1 clinical trial will be unsafe and that trial participants will be exposed to risk for no potential benefit. To assist sponsors, researchers, clinical investigators and reviewers in deciding when it is ethically acceptable to initiate first-in-human Phase 1 CRISPR gene editing clinical trials, structured processes have been developed to assess and minimize translational distance between pre-clinical and clinical research. These processes draw attention to various features of internal validity, construct validity, and external validity. As well, the credibility of supporting evidence is to be critically assessed with particular attention to optimism bias, financial conflicts of interest and publication bias. We critically examine the pre-clinical evidence used to justify the first-inhuman Phase 1 CRISPR gene editing cancer trial in the United States using these tools. We conclude that the proposed trial cannot satisfy the ethical requirement of scientific validity because the supporting pre-clinical evidence used to inform trial design is deficient.

Primary Pulmonary Synovial Sarcoma Showing a Prolonged Survival with Multimodality Therapy

A 54-year-old man was referred to our hospital due to a mass shadow noted on a chest X-ray. Thoracoscopic lobectomy yielded a diagnosis of primary pulmonary synovial sarcoma according to the histology and SYT-SSX1 gene analyses. Five months after the thoracic surgery, he developed brain metastasis; therefore, we performed resection of the brain metastatic focus followed by radiotherapy. As a local recurrence in the thoracic cavity concurrently emerged, systemic chemotherapy was also administered. These observations indicated that a multidisciplinary approach may be useful against primary pulmonary synovial sarcoma, although there is presently no established therapeutic strategy due to its rarity and highly aggressive nature.

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

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

Biphasic synovial sarcoma in a 19-year-old pregnant woman: a case report

Synovial sarcoma is a rare malignant tumor of mesenchymal multipotent cells. We hereby present a case of synovial sarcoma of the upper left thigh. A 19-year-old patient was referred to our clinic by another hospital in Bucharest, Romania, for a soft tissue mass in the left upper thigh. Local examination of the left thigh revealed a 15÷13 cm, ovoid, painful upon touch, soft tissue mass occupying the proximal-medial aspect of the thigh. Bilateral inguinal nodes' enlargement was noticed. Upon suspecting regional node involvement, the surgical team decided to perform left limb amputation due to tumor size and the proximity to major arterial and nervous trunks as well as the femoral shaft, making curative surgery and 'free of disease' resection margins improbable. The patient refused the operation. The surgical team (plastic surgeon, orthopedic surgeon) decided to attempt limb-sparing surgery. After tumor resection, free-of-disease surgical margins were achieved. The pathological examination as well as the immunohistochemistry (IHC) diagnosed a large biphasic synovial sarcoma warranting oncologic treatment. The association between tumor growth and pregnancy poses important therapeutic problems, such as the use of preoperative chemotherapy, potential pregnancy termination, limb amputation versus limb salvage intervention and types of protocols of chemotherapy or radiotherapy indicated.

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

INTRODUCTION

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

CASE PRESENTATION

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

CONCLUSION

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

L-carnitine treatment in a seriously ill cancer patient with severe hyperthyroidism

OBJECTIVE

To report a case of vaccine-induced Graves' disease successfully managed with L-carnitine and propranolol and without antithyroid drugs (ATDs). ATDs sometimes need to be used at low doses or can be contraindicated/refused. One of the ancillary compounds available is L-carnitine. L-carnitine is a naturally occurring quaternary amine, which acts by impairing thyroid hormone access to the cell nucleus.

REPORT

A 32-year-old Chinese woman with a synovial sarcoma received radiotherapy, chemotherapy and experimental immunotherapy. Two months after the start of immunotherapy, she developed autoimmune hyperthyroidism [thyroid-stimulating immunoglobulins (TSI)=152%, normal values <140]. Left untreated, hyperthyroidism worsened (TSI=248%), so that for 3 months she took L-carnitine (1-4 g/d) and propranolol (20-80 mg/d). Though the hyperthyroidism worsened biochemically (FT4>50 pg/ml, FT3>20 pg/ml, TSI=501%), it was tolerated very well clinically. Fearing a life-threatening thyroid storm, she agreed to have, while still hyperthyroid, total thyroidectomy. The operation was uneventful.

CONCLUSIONS

This case expands previous observations involving two more patients who survived thyroid storms while being treated with L-carnitine (combined with low doses of ATD). Taking also into account that tissue concentrations of L-carnitine decrease in hyperthyroidism, there is room for wide therapeutic use of L-carnitine in several hyperthyroidism settings.

Autoimmune thyroid disease elicited by NY-ESO-1 vaccination

BACKGROUND

Immunotherapies and targeted therapies are frequently associated with thyroid dysfunction, which is in contrast with the rare thyroid abnormalities induced by cytotoxic agents. Immunotherapy with NY-ESO-1, a tumor-associated antigen expressed by a number of malignancies, was reported to trigger hyperthyroidism or hypothyroidism in two HLA-A2 patients with ovarian cancer. We describe now a case of Graves' disease triggered by NY-ESO-1 in a HLA-A2-negative woman.

PATIENT FINDINGS

A 32-year-old woman with a synovial sarcoma received radiotherapy, chemotherapy, and finally NY-ESO-1 vaccine. The patient was found to have HLA A11/A33(19), B13/B56(22), Cw3/-. One month after the beginning of immunotherapy, thyroid dysfunction was clinically suspected and Graves' disease was biochemically confirmed. Fearful of the antithyroid drugs' side effects, the patient was treated with a beta-blocker (propranolol, 80-20 mg/day). As hyperthyroidism progressively worsened, the patient underwent total thyroidectomy. We hypothesized that NY-ESO-1 shared partial homology with thyroid autoantigens (the so-called molecular mimicry mechanism) and that at least one pair of homologous sequences contained amino acid sequence binding motifs to a restricted number of HLA molecules. We used BLAST software to search amino acid sequence homologies between NY-ESO-1 and thyroid autoantigens (thyrotropin receptor [TSH-R], thyroperoxidase, and thyroglobulin), and the HLA ligand/motif database to look for HLA/T-cell receptor binding motifs in the regions of NY-ESO-1 and thyroid autoantigens that were homologous. We found 15 epitopic regions of NY-ESO-1 homologous to 15 regions of thyroid autoantigens, some of which epitopic: 5 of TSH-R, 8 of thyroglobulin, and 2 of thyroperoxidase. These homologous sequences contain binding motifs belonging to several HLA class I antigens, including HLA A2 and the patient's A11 and A33.

SUMMARY

Genetically predisposed patients who receive NY-ESO-1 vaccination are at risk to develop thyroid dysfunction.

CONCLUSIONS

Considering the increasing use of NY-ESO-1, thyroid dysfunctions induced by NY-ESO-1 are expected to increase in cancer patients over the next years.

A patient with primary pericardial synovial sarcoma who presented with cardiac tamponade: a case report and review of the literature

A 36-year-old man presented with near-syncope. He was found to have massive pericardial effusion with a giant pericardial tumorous lesion. The pericardial effusion exhibited a bloody nature; however, neither malignant cells nor infectious organisms were detected. (18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET) showed an increased uptake of FDG in the pericardial tumor only. Although the tumor was not resectable, thoracotomy and tissue sampling were performed. A histological analysis showed CD99 positivity and SYT gene rearrangement, leading to a diagnosis of synovial sarcoma arising from the left lateral pericardial surface. The patient is now receiving chemotherapy.

[Synovial sarcoma of the head and neck--a retrospective study of 39 cases]

OBJECTIVE

Synovial sarcoma (SS) of the head and neck is rare in comparison with those took place in the extremities. This study was planned to investigate the relationship between pathological diagnosis, tumor location and clinical outcome of SS of the head and neck.

METHOD

Thirty-nine cases of SS in head and neck hospitalized in West China Hospital from 1966 to 2011 was retrospectively studied by reviewing the medical record data, the pathological slices of the operative specimen and followed-up from 1 to 192 months with the mean time of 43.2 months postoperatively. The parameters of clinical outcome were focused on the time to first recurrence after primary surgery and follow-up time. The reviewed results were statistically processed.

RESULT

The age of the patients ranged from 8 to 66 years old with the median age of 35, among them 27 are males. Pathologically, 18 cases are biphasic, 17 cases are monophasic and 3 cases are low-differentiated SS. 4 cases were proved by cytogenetic methods of either fluorescence in situ hybridization(FISH) or RT-PCR. 23 cases experienced repeated recurrence with the most up to 4 times operations after sole surgical approach. Only one lymphatic metastasis was suspected in all. 16 patients got adjuvant radiotherapy or chemotherapy. 4 patients died but only one death was associated directly with SS recurrence. There was no significant relationship between pathological subtype and recurrence (Fisher's Exact Test P-value > 0.05), no significant relationship between tumor location and recurrence (Fisher's Exact Test P-value > 0.05).

CONCLUSION

SS of head and neck is a special entity that has potential of easy recurrence but good prognosis. Surgery should still be the primary treatment approach. Cytogenetic methods are recommended to as certain the diagnosis in order to choose reasonable treatment protocols.

Pelvic synovial sarcoma of unknown primary origin: case report and literature review

A case report of a 26-year-old woman with pelvic pain for one-month duration is presented. The physical exam was unremarkable, but a right pelvic mass was found on ultrasound. Computed tomography (CT) of the abdomen/pelvis confirmed a heterogeneous 6 x 4.4 cm mass within the right pelvis adjacent to the superior-lateral aspect of the uterus. Laparoscopy was performed, and the mass was found to be friable and necrotic. The origin of the mass was not able to be determined due to the collapse of the mass upon instrumentation. Histology revealed spindle cells. Further studies, including immunochemical staining, revealed a synovial sarcoma. Patient underwent laparotomy for staging and in hopes of obtaining clear tumor margins. Surgery revealed subsequent tumors involving the mesentery of the small intestine and the peritoneal wall. Biopsies taken at surgery did not reveal the primary origin of the original pelvic tumor.

Primary synovial sarcoma of the kidney with unusual follow up findings

We present a case report of a 17-year-old patient with a large renal mass that was detected on a computed tomography scan during investigation for secondary hypertension. Radical nephrectomy was performed and the morphologic and immunocytochemical findings were compatible with a diagnosis of monophasic synovial sarcoma of the kidney. A cytogenetic search for t(X;18) translocation was performed, which was negative. The patient underwent an ifosfamide-based chemotherapy regimen. During follow up, a positron emission tomography scan showed increased 18F-fluorodeoxyglucose metabolism at the right femur. Although cancer cells were expected in the biopsy specimen, only fibrous dysplasia of the bone was found. The patient was disease free at his 29 month follow up check up.

Pathological fracture of femur secondary to infected synovial sarcoma

Pathological fracture is not uncommon in musculoskeletal oncological surgical practice. When complicated by infection, it is both limb- threatening and life-threatening problem. Pathological fractures require urgent investigation, not urgent treatment. We present the case of a 75-year-old man who presented with an infected sarcoma causing a pathological fracture of his right femur.

Parapharyngeal space synovial sarcoma

Synovial sarcoma is a rare soft tissue sarcoma that commonly involves the lower extremities and occurs predominantly in young adults. It very rarely occurs in the head and neck region and carries a poor prognosis. The tumor demonstrates both a loco-regional and a systemic pattern of spread that makes management challenging. Combined modality therapy of this aggressive tumor yields better results. Herein, we described a 58 years old lady presented with left parapharyngeal synovial sarcoma. This is to demonstrate the aggressiveness of the disease despite complete surgical excision followed by post operative radiotherapy. Local regional control was difficult and recurrence of disease was seen in this particular patient.

Total allograft transplantation of the elbow joint after wide resection of synovial cell sarcoma: a case series

Total elbow allograft transplantation is an option for patients who have extensive joint defects secondary to tumor surgery, trauma, or failed total elbow arthroplasty. This salvage procedure provides patients with a useful, painless range of motion of the elbow. We report our experience with two complete elbow allograft reconstructions after tumor resection surgery with 5 and 6 years of follow-up.

Laryngeal synovial sarcoma: case report and literature review

Synovial sarcoma is a rare malignant mesenchymal neoplasm of youth with no benign counterpart. This cancer typically occurs about the knee and ankle joints. The involvement of the head and neck region is rare, and the laryngeal location is exceptional, which make the correct diagnosis challenging for the surgical pathologist and unanticipated for the clinician. Up to our knowledge, only 14 cases have been reported so far within this site. Here we add a new case in a 26-year-old Saudi man who presented with voice change and dysphagia, which are common symptoms of a more common benign condition in this site. The patient was operated and the histopathological diagnosis of synovial sarcoma was made, after which he received radiotherapy with no recurrence after 20 months. The correct diagnosis is crucial in such a case for proper management.

Monophasic synovial sarcoma presenting as mitral valve obstruction

We report the case of a 26-year-old man who experienced progressive left-sided chest pain and 2 episodes of near-syncope. Studies revealed a 15-cm mass in the upper left lung, a 10-cm mass in the medial base of the left lung, and a 5-cm left atrial mass that involved the left lung, infiltrated the left pulmonary vein, and prolapsed into the mitral valve, causing intermittent obstruction. The patient underwent surgical excision of the left atrial tumor. Pathologic evaluation confirmed the diagnosis of monophasic synovial sarcoma.To our knowledge, this is only the 3rd report of left atrial invasion and resultant mitral valve obstruction from a synovial sarcoma that infiltrated the pulmonary vein. We believe that this is the 1st documented case of a metastatic left atrial synovial sarcoma in monophasic form.