[Primary Pulmonary Synovial Sarcoma;Report of a Case].

A 66-year-old man was referred to our hospital for an abnormal shadow. Chest computed tomography (CT)showed a heterogeneous mass with well-defined border in the right S10and ipsilateral pleural effusion. Fluorodeoxyglucose-positron emission tomography(FDG-PET)showed the accumulation in the mass and pleural effusion. Right lower lobectomy with lymphnode dissection was performed for diagnosis and treatment. Histologically,the tumor was mainly composed of complicated spindle-shaped cells with extensive necrosis, showing a large number of nuclear fission images. Immunohistochemistry showed the tumor cells to be positive for cytokeratin AE1/AE3, Bcl-2, EMA, vimentin and negative for TTF-1, S-100, calretinin, CD34, being compatible with monophasic fibrous synovial sarcoma.

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

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

Clinical suspicion of bilateral carotid body paraganglioma and an unexpected histologic diagnosis.

Carotid body tumor (CBT) is the most common of the head and neck paragangliomas (PGLs). Conversely, synovial sarcomas are usually located around knee and ankle joint and rare variants occur in the oral cavity. A 68-year-old man presented with a left voluminous painless cervical mass. The diagnosis of CBT of type III Shamblin was suspected. The cervical mass was removed en bloc. Unexpectedly, pathologic examination showed monophasic synovial sarcoma. Excision of PGLs remains the therapy of choice, especially to make a correct histologic diagnosis.

Primary pulmonary synovial sarcoma: a rare primary pulmonary tumor.

INTRODUCTION: Pulmonary sarcomas overall are very uncommon and comprise only 0.5 % of all primary lung malignancies. The diagnosis is established only after sarcoma-like primary lung malignancies and a metastatic extrathoracic sarcoma have been excluded. Synovial sarcoma accounts for ~8 % of soft-tissue sarcomas. Synovial sarcoma arising from the pleura has rarely been reported. METHODS: We report a case of a 58-year-old woman who complained of right-sided chest pain and shortness of breath. Chest CT scan revealed a large heterogeneous mass, occupying most of the right hemithorax. Histologic diagnosis was supplemented by interphase cytogenetic (FISH) analysis. RESULTS: Computed tomography guided Tru-cut biopsy was suspicious for a sarcomatous or fibrous malignancy. However, intraoperative frozen-section diagnostics confirmed the diagnosis of a sarcoma. Immunohistochemistry showed that tumor cells expressed epithelial membrane antigen, CD99 and BCL2. Based on immunohistochemistry, the diagnosis of synovial sarcoma was suspected and was confirmed by FISH analysis. The patient was treated with right upper bilobectomy. Due to R1-resection status, postsurgical systemic chemotherapy was administered. CONCLUSIONS: Primary pulmonary synovial sarcoma is a rare primary lung tumor. Due to extensive size of the tumor with pleural and mediastinal invasion only a R1-resection status could be achieved by thoracic surgery.

Primary synovial sarcoma of the kidney.

Synovial Sarcoma (SS) is a soft tissue neoplasm that occurs generally in the proximity of large joints. Here, we report a case of a 45-year-old man who was diagnosed with Primary SS of the kidney which is an extremely rare tumor that accounts for less than 2% of malignant renal tumors. We also review the literature on primary synovial sarcomas of the kidney and focus especially on the renal tumors' differential diagnosis.

Tonsillar synovial sarcoma, unusual anatomical location: case report and literature review.

BACKGROUND: Synovial sarcoma is a rare soft tissue malignancy, occasionally found in the head and neck region. The diagnosis necessitates a multidisciplinary approach involving the clinical presentation, proper imaging studies and histological confirmation, with molecular testing for definitive identification. Treatment entails surgical resection with adjuvant therapies as needed. CASE PRESENTATION: A 33-year-old male patient presented with globus sensation concomitant with right-sided neck swelling. He was clinically found to have right tonsil enlargement with posterior extension. Therefore, he underwent right tonsillectomy with pharyngoplasty. Histopathological examination revealed a biphasic tumor consistent with synovial sarcoma, confirmed by immunohistochemistry and fluorescence in situ hybridization. CONCLUSIONS: Tonsillar synovial sarcoma represents a diagnostic challenge, requiring a high index of suspicion and comprehensive evaluation. With only twenty previously published cases documented in the literature, awareness of this rare presentation is crucial for prompt diagnosis and appropriate management. Collaboration among multidisciplinary healthcare teams and ongoing research efforts are essential for optimizing diagnostic accuracy, treatment efficacy, and patient outcomes in this rare malignancy.

Clinical and pathological features of primary renal synovial sarcoma: analysis of 64 cases from 11 years of medical literature.

OBJECTIVE: To describe, for the first time, the clinical characteristics of primary renal synovial sarcoma (SS) and to examine the association of histological features with the expression of immunohistochemical markers. PATIENTS AND METHODS: We collated published data on all cases of primary renal SS, from its first description in 2000 to September 2011. Data on clinical and pathological characteristics were extracted and used to create a database. Disease-free survival (DFS) and overall survival (OS) rates were estimated using the Kaplan-Meier method with Rothman's 95% confidence intervals (CIs) and compared across the groups using the log-rank test. The associations between tumour extension and histological features were evaluated using the non-parametric Spearman rank test. A chi-squared test was used to assess the differences between groups. RESULTS: In the overall cohort, the median OS was 48 months (95% CI, 14.1-81.9). Cox analysis showed that the risk of death at diagnosis was greatly increased in patients with metastatic disease compared with those with non-metastatic disease (hazard ratio [HR]: 343.9, 95% CI, 2.8-42,000; P= 0.017). The median DFS was 33.0 months (95% CI, 16.8-49.2), and patients who develop metastatic disease have a very poor prognosis with a median survival of 6 months (95% CI, 5.1-6.9). Microscopic features were monophasic, biphasic and poorly differentiated synovial sarcoma in 76, 16 and 8% of patients, respectively. Significant differences in expression of immunohistochemical markers or genetic mutation were found between different subtypes. CONCLUSIONS: Despite its retrospective nature, this study shows that renal SS comprises different histological subtypes, which are characterized by specific immunohistochemical stains and by specific translocations. When diagnosed at metastatic stage, the prognosis was very poor compared with that for non-metastatic disease, even though one out of three patients with non-metastatic disease had disease relapse. Cooperative efforts and publication of cases with adequate follow-up are necessary to better define prognosis and therapeutic strategies for this rare disease.

Heart failure resulting from giant left atrial synovial sarcoma metastasis.

Synovial sarcoma metastasis affecting the heart and infiltrating the mitral valve is a very rare pathology. We report the case of a 44-year-old male treated with chemotherapy for atypical synovial sarcoma of the oral mucosa who presented to our clinic after cardiac decompensation with a presumptive diagnosis of myxoma of the left atrium. A large necrotic tumour positive for CK 22, EMA, CD 99 and BCL-2 but negative for translocation in COBRA-FISH analysis by break-apart probe could be excised and revealed a very rare subtype of synovial sarcoma metastasis arising from the endocard of the left atrium. The tumour was resected and the mitral valve reconstructed through ring annuloplasty.

Usefulness of SS18-SSX antibody as a diagnostic marker for pulmonary metastatic synovial sarcoma.

BACKGROUND: The novel SS18-SSX fusion-specific antibody is reported to have high sensitivity and specificity for the diagnosis of primary synovial sarcoma (SS), which often metastasizes to the lung. Thus far, no study has validated the diagnostic efficacy of SS18-SSX antibody for pulmonary metastatic SS. Therefore, we aimed to investigate the usefulness of the SS18-SSX antibody in the diagnosis of pulmonary metastatic SS. METHODS: We evaluated the immunohistochemistry of SS18-SSX fusion-specific antibody (E9X9V) in 10 pulmonary metastatic SS cases and the corresponding five primary sites (four limbs and one mediastinum) in five patients, for whom SS was already diagnosed and confirmed by fluorescence in-situ hybridization in the metastatic and primary sites, and in 93 clinical and histologic mimics including 49 non-SS, pulmonary metastatic sarcomas, 39 primary lung cancers, and five intrathoracic solitary fibrotic tumors. All specimens were surgically resected at Shinshu University Hospital during 2001-2019. For primary and metastatic SS, we also evaluated SS18-SSX immunohistochemistry using needle biopsy and touch imprint cytology specimens from the primary site. RESULTS: SS18-SSX staining was diffusely-strongly positive in all 10 pulmonary metastatic SS cases and the corresponding five primary sites; whereas, it was negative in all 93 clinical and histologic mimics (100% sensitivity and 100% specificity). Further, SS18-SSX staining was also sufficiently positive in the biopsy and cytology specimens. CONCLUSIONS: Immunohistochemistry of the SS18-SSX fusion-specific antibody is useful for the differential diagnosis of pulmonary metastatic SS in clinical practice. This simple and reliable method has the potential to replace traditional genomic tests. However, further studies are warranted in this regard.

A minute primary gastric synovial sarcoma with ulcer: a case report.

BACKGROUND: Synovial sarcomas are a rare type of high-grade sarcomas with unknown cell origin. They arise predominantly in the soft tissues but rarely in the stomach. We recently encountered a rare case of minute gastric synovial sarcoma. CASE PRESENTATION: A 61-year-old Japanese woman was pointed out edematous erosion at the body of the stomach. Biopsy specimen showed dense proliferation of spindle-shaped tumor cells mixed with smooth muscle fibers of the muscularis mucosae. Although the definite histological diagnosis was undetermined, the patient underwent laparoscopic wedge resection of the stomach. Histological examination of the resected sample revealed that the maximum diameter of the tumor was only 6 mm and that dense proliferation of rather uniform spindle tumor cells were observed mainly in the submucosa. Immunohistochemistry showed that they were positive for pan-keratin, CD99 and TLE1. SS18-SSX fusion-specific antibody gave diffuse positive staining to the tumor cells, and analysis using mRNA extracted from paraffin sections revealed that the tumor had SS18-SSX1 fusion gene. Thus, it was diagnosed as gastric synovial sarcoma, monophasic fibrous type. CONCLUSIONS: Primary synovial sarcoma of the stomach is rare and only 47 cases have been reported in the English literature to date. The maximum diameter of the lesion of our case was 6 mm which is the smallest among them.

Primary cardiac synovial sarcoma: a clinicopathological, immunohistochemical, and molecular genetics study of five clinical cases.

BACKGROUND: Primary cardiac synovial sarcoma was an exceedingly rare tumor that less reported. The study investigated the clinicopathologic, immunohistochemical, and molecular features of primary cardiac synovial sarcoma. METHODS: A total of five cardiac synovial sarcoma cases were assessed and reviewed using H&E, immunohistochemical and fluorescence in situ hybridization staining methods. Clinicopathological data were retrospectively analyzed and followed up. RESULTS: The cases occurred in four males and one female ranging in age from 23 to 48 years (mean, 32 years). The tumors were grossly large and solid (7.4-13.7 cm; mean 8.6 cm). Microscopically, clinical cases were biphasic (n = 2) and monophasic (n = 3) types and were diffusely immunoreactive for EMA, vimentin, and BCL-2. All cases demonstrated SS18 rearrangement by fluorescence in situ hybridization staining. Clinically, three patients died within 1 year after surgery, while one patient had bone metastasis and still carried the disease. One last patient underwent a heart transplant and survived without evidence of the disease. CONCLUSION: Cardiac synovial sarcoma was an aggressive tumor whose differentiation may be a continuous and complex morphologic spectrum. SS18 rearrangement demonstration by fluorescence in situ hybridization was decisive in our study for differential diagnosis of cardiac synovial sarcoma and other tumors. Cardiac synovial sarcoma usually endured poor survival rates. Patients in advanced stages may undergo heart transplantation as a means of improving their survival rates.

Exploring Two Protocols of FISH Using Cytocell SYT-SSX Probe on Formalin Fixed Paraffin Embedded Tissue Sections.

BACKGROUND: Chromosomal translocation t(X;18)(p11.2;q11.2) is the cytogenetic hallmark of synovial sarcoma and have been identified as an alternative diagnostic strategy in differentiating synovial sarcoma from other histologic mimics. This study was carried out to test the efficacy of two FISH protocols using the SYT-SSX break apart probe from Cytocell. METHODOLOGY: Representative paraffin blocks of synovial sarcoma were utilized in this study. FISH study was performed on formalin-fixed paraffin embedded tissue sections using the SYT-SSX break apart probe from Cytocell, to detect two form of SYT-SSX transcript, SYT-SSX1 and SYT-SSX2. FISH protocol, including the hybridization was done following two different protocols, Cytocell FISH protocol and Optimized Dako FISH protocol. RESULTS: Tissue samples subjected to FISH using Cytocell FISH protocol showed the absence of signal corresponding to the probe used. Utilizing Optimized Dako FISH protocol, the two signals (red and green) corresponding to the break-apart probes was detected. These findings suggested that Optimised Dako FISH protocol is more suited for use with the tested probe on paraffin embedded tissues in comparison to Cytocell FISH protocol. CONCLUSION: Optimised Dako FISH protocol was noted to be more suited for detecting SYT-SSX FISH signals on paraffin embedded tissues in comparison to Cytocell FISH protocol.

Primary synovial sarcoma of the prostate: report of 2 cases and literature review.

Two cases of primary prostatic synovial sarcoma presenting as a prostatic mass are presented in patients aged 44 and 46 years. Histologically, both tumors were mainly composed of uniform spindle cells forming interlacing fascicles. Clusters of immature epithelioid cells were also observed among the spindle cells in case 1. Immunohistochemically, the tumor cells of both cases were strongly positive for vimentin, bcl-2, CD99, and E-cadherin, as well as focally positive for cytokeratin. However, they were negative for prostate-specific antigen, S-100 protein, CD34, CD117, muscle-specific actin, desmin, and calretinin. The presence of an SYT-SSX gene fusion resulting from t(X;18) was demonstrated from paraffin blocks by reverse transcriptase polymerase chain reaction in both cases. To the authors' knowledge, these represent the fifth and sixth reported cases of prostatic synovial sarcoma. Accurate diagnosis depends on morphologic and immunohistochemical examination and proper molecular analysis.

Synovial sarcoma of the kidney.

The renal parenchyma is a rare site of origin for primary synovial sarcoma (SS). The present study describes the clinicopathologic, immunohistochemical, and molecular analysis of 7 cases of SS occurring in the kidney. There were 5 female and 2 male patients, with an age range of 15 to 46 years. They presented with solitary renal masses ranging in size from 10.0 cm to 17.0 cm in greatest dimension. Radical nephrectomy was performed in all cases. On gross examination, tumors were large, partially necrotic, and were seen to contain smooth-walled cysts in 4 cases. Histologically, the tumors were characterized by monomorphic spindle cells with indistinct cell borders arranged in intersecting nodular foci with hypocellular myxoid areas, together with a prominent hemangiopericytomatous pattern. The cysts were lined by hobnailed cells with eosinophilic cytoplasm. Immunohistochemically, BCL-2 was positive in all 6 cases in which it was performed, followed by vimentin (4/5 cases), MIC2 (CD99; 2/5 cases), calponin (2/2 cases), and epithelial membrane antigen (1/4 cases). Stains for cytokeratin and CD34 were consistently negative. Reverse transcription-polymerase chain reaction (RT-PCR) using RNA extracted from formalin-fixed paraffin-embedded tissues was carried out in 4 cases and SYT-SSX fusion gene transcript, which is the diagnostic hallmark of SS, was detected. Two patients developed pulmonary metastasis and died 6 and 12 months after diagnosis, respectively. This series of cases is distinct in terms of its morphological spectrum and confirmation by molecular technique.

[Primary synovial sarcoma of the kidney]. / Primární synoviální sarkom ledviny--popis dvou prípadu.

The authors present two cases of primary synovial sarcoma of the kidney. Both patients had a tumor mass in the kidney with vascular invasion of the inferior vena cava and right atrium of the heart in case no. 1. In case no. 2 retroperitoneal lymph node metastasis and multiple metastases to both lungs were observed. Radical nephrectomies were performed in both patients. Histologically, the tumor in case no. 1 was monophasic and in case no. 2 poorly differentiated. Immunohistochemically, vimentin was diffusely positive and a few tumor cells were positive for epithelial membrane antigen. The tumor cells were negative for keratins, S- 100 protein, CD 34, smooth muscle actin, and desmin. In both cases, reverse transcription-polymerase chain reaction using ribonucleic acid extracted from formalin-fixed, paraffin-embedded tissues detected SYT-SSX 1 fusion gene transcripts, which are characteristic molecular findings of synovial sarcoma.

Primary Synovial Sarcoma of the Kidney: A Rare Presentation.

Primary renal synovial sarcoma (PRSS) is a rare entity. It should be considered as one of the differential diagnoses of spindle cell tumors of the kidney. Immunohistochemistry and genetic translocation studies should be used to confirm the diagnosis. Because of a lack of consistent literature data regarding the treatment options, management of PRSS remains a therapeutic challenge. In view of the chemosensitive nature of the tumor, we propose a multimodality treatment in form of surgery and chemotherapy in patients with PRSS. Here we report a rare case of PRSS in a 17-year-old adolescent.

Primary thyroid biphasic synovial sarcoma and synchronous papillary carcinoma: report of a remarkable case.

Synovial Sarcoma (SS) is the fourth most common soft tissue sarcoma, characterized by translocation t(X;18) (p11.2;q11.2). Although its histological features have been extensively described, this entity is characterized by a wide morphological spectrum so that the recognition can be very challenging at atypical anatomical localization, like the thyroid. We describe a case of a 42-ys-old female patient complaining a cervical swelling due to left intrathyroid nodule, measuring 35 mm in its greatest dimension. A Fine Needle Aspiration Cytology (FNAC) was performed and diagnosis of indeterminate neoplastic lesion, indefinite whether primary or metastatic, was formulated. After complete thyroidectomy, the histological picture of the nodule was characterized by a dual cellular population: several glandular structures composed by columnar cells with clear cytoplasm were embedded in a highly cellular stroma composed of spindle-shaped elements. Immunohistochemistry and molecular biology confirmed the morphological suspicion of SS identifying the fusion transcript SYT-SSX1 and thus ruling out several differential diagnoses which include more common thyroid malignancies. Moreover a synchronous papillary microcarcinoma was detected in the controlateral lobe.This case is noteworthy since it describes the synchronous presence in the thyroid of two completely different malignancies, the first one belonging to the soft tissue neoplasm category and the other one originating from the thyroid follicular epithelium.

Molecular detection of SS18-SSX fusion gene transcripts by cRNA in situ hybridization in synovial sarcoma using formalin-fixed, paraffin-embedded tumor tissue specimens.

SS18-SSX fusion genes resulting from a chromosomal translocation t(X;18)(p11.2;q11.2) are a genetic hallmark of synovial sarcoma. Although such cytogenetic or molecular aberrations have mostly been detected by fluorescence in situ hybridization or reverse transcription-polymerase chain reaction, the expression of SS18-SSX has been poorly investigated at a cellular or tissue level. In this study, biotinylated tyramide (BT)-based in situ hybridization (ISH) was performed to detect SS18-SSX transcripts using formalin-fixed, paraffin-embedded tissues from 15 synovial sarcomas. Digoxigenin-labeled cRNA probes flanking the fusion points of SS18-SSX1 and SS18-SSX2 were generated by in vitro transcription, and hybridized signals were detected by a streptavidin-biotin complex method after chemical enhancement with BT. The localizations of signals were compared with the immunohistochemical expressions of epithelial or neuroectodermal markers and those of cell adhesion including cytokeratins (CAM5.2, AE1/AE3, CK7), epithelial membrane antigen, E-cadherin, beta-catenin, c-erbB-2 (HER2/neu), CD56, and claudin-1. The ISH signals of the SS18-SSX transcripts were identified in 13 synovial sarcomas, and their fusion types correlated with those determined by reverse transcription-polymerase chain reaction. In biphasic tumors, the ISH signals tended to localize to epithelial areas, whereas spindle-cell areas or monophasic fibrous tumors showed a less intense or focal expression pattern. Notably, the expression patterns of AE1/AE3, CK7, and c-erbB-2 often colocalized with the ISH signals (7 of 11 cases positive for each marker). Our results suggest that BT-based ISH can be used as a molecular technique for the detection of SS18-SSX using formalin-fixed, paraffin-embedded tissues.

Primary synovial sarcoma of the kidney with rhabdoid features.

Synovial sarcoma is a soft tissue sarcoma with clearly defined histologic, immunophenotypic, and molecular features. It occurs predominantly in the extremities of young adults but has been reported in many other anatomic sites. Histologically, it is classified as biphasic, monophasic, and poorly differentiated. The latter category, which includes tumors with a rhabdoid morphology, has been associated with a more aggressive behavior. Generally, the biphasic variant does not pose any diagnostic problem because of its typical histologic appearance; in contrast, the monophasic and poorly differentiated variants may represent a diagnostic challenge because their microscopic features can be confused with those of other spindle cell tumors with rhabdoid features. The application of molecular techniques, such as reverse transcriptase polymerase chain reaction to detect the fusion transcript associated with the characteristic t(X;18) translocation of synovial sarcoma, has enabled the confirmation of this diagnosis, even in cases of unusual localization, such as the one we present here.