Synovial sarcoma

Recurrent Metastatic Pulmonary Synovial Sarcoma during Pregnancy: A Case Report and Literature Review

Primary pulmonary synovial sarcoma is a rare type of soft tissue tumor. Exceptionally it can occur during pregnancy, representing a challenge in management and treatment given its notable aggressiveness and the not infrequent incidence of maternal death. We report our case of metastatic recurrence of pulmonary synovial sarcoma during pregnancy, with the aim to emphasize the decision-making, diagnostic, and therapeutic multidisciplinary processes and the evolution of the pathology. Besides, we focused on the analysis of the limited literature data available on the topic.

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.

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.

Tumor size and surgical margins are important prognostic factors of synovial sarcoma - A retrospective study

Background

Synovial Sarcoma (SS) is a rare soft tissue sarcoma. Mean time to get a SS diagnosis from the onset of symptoms is 10 years, furthermore, SS is associated with late metastasis. Surgery is the main treatment option, whose quality deeply affects SS outcomes, and it can be associated to preoperative or post-operative radiotherapy. Chemotherapy is considered very effective in Children, while in adults its efficacy is still under debate. The aim of this study was to investigate the oncologic results in SS treatment and to identify the risk factors for local and systemic control of the disease.

Methods

From 1994 to 2018, 211 patients affected by SS were treated in 3 Referral Centres of Orthopaedic Oncology. One hundred seventy-seven patients were included in the study, the median follow-up length was 96 months (5-374).

Results

Overall Survival on the Kaplan Meier Analyses was 80%, 70% and 56% at 5, 10 and 20 years. In multivariate analyses, OS correlated with tumour size and negative surgical margins. Chemotherapy use wasn't associated with better survival although patients who underwent CT had bigger and more aggressive tumours.

Conclusions

Our findings suggests that surgery with negative margins is the most important factor in Synovial Sarcoma. Adjuvant treatments as chemotherapy and radiation therapy didn't change the disease's course.

Olfactory groove monophasic sinovial sarcoma and von Recklinghausen's disease: A case report and literature review

BACKGROUND

Soft-tissue sarcomas are a rare and diverse group of neoplastic lesions. They represent only 1% of malignant tumors in adults and 15% in children. Synovial sarcoma (SS) is a type of soft-tissue sarcoma, accounting for 5-10% of cases, and commonly affecting extremities. Diagnosis, treatment, and prognosis remain challenging especially when localized in uncommon areas, such as intracranial lesions.

CASE DESCRIPTION

A 13-year-old male patient with a clinical history of neurofibromatosis Type I (NF1) presenting holocranial headache with jet vomiting and apathy 2 days before admission, without neurological deficits and/or focal findings. On magnetic resonance imaging: an extra-axial infiltrative lesion with contrast uptake at the base of the skull in the olfactory groove topography. After total tumor resection, the anatomopathological examination showed monophasic SS. The patient returned after 6 months with similar symptoms, and the lesion recurred and was reoperated. Unfortunately, 7 months after the second surgery, the patient died.

CONCLUSION

SS can occur extraarticulously and with a variable clinical presentation and poor prognosis despite adjuvant therapies with radiotherapy and chemotherapy. In individuals with clinical history of NF1, there is still no direct correlation between the two manifestations, although current descriptions are suggestive of a possible interaction.

Synovial sarcoma: cytopathology of 51 cases highlighting the application of ancillary molecular testing

INTRODUCTION

Among sarcomas, synovial sarcoma (SS) is defined by its unique SS18 cytogenetic translocation. Fine needle aspiration (FNA) biopsy is in a key position to exploit this uniqueness for diagnostic purposes.

MATERIALS AND METHODS

Our cytopathology files were searched for examples of SS with histopathologic verification. FNA biopsy, imprint smears, and core needle biopsy (CNB) were performed using standard techniques.

RESULTS

Fifty-one cases from 49 patients (male/female ratio, 1:1; age range, 12-79 years; mean age, 40 years) met the inclusion criteria. Of the 51 cases, 44 (86%) were FNAs, 6 were cytology imprints, and 1 was pleural fluid. Eleven aspirates had concurrent CNB. All cases had tissue confirmation. The biopsy sites included extremities (n = 24; 47%), trunk (n = 12; 24%), lung (n = 8; 16%), head or neck (n = 6; 12%), and pleural fluid (n = 1; 2%). The aspirates were from primary (n = 36; 71%), metastatic (n = 12; 24%), and recurrent (n = 3; 5%) neoplasms. The cytologic diagnoses were SS (69%), suspicious for SS (12%), malignancy (10%), spindle cell neoplasm (4%), and malignancy other than SS (6%). In general, smears and imprints contained dense cell aggregates and single cells composed of a monotonous population having fusiform, rounded, or ovoid banal nuclei and scant cytoplasm. Poorly differentiated SS showed both large epithelioid cell and small cell cytomorphology. When performed, SS18 immunohistochemical and genetic testing was positive in all 19 FNA and 3 CNB cases.

CONCLUSIONS

When coupled with appropriate ancillary testing, FNA biopsy allows for a specific, accurate diagnosis of SS in most cases.

Monophasic synovial sarcoma in the temporomandibular joint region: A case report and review of the literature

INTRODUCTION AND IMPORTANCE

Synovial sarcoma is a malignant neoplasm that arises from soft tissue and makes up 5 % to 10 % of all types of sarcoma. It is most common between the ages of 15 and 40; it typically develops in the lower extremities; just 3 % to 10 % of cases arise in the head and neck. The usual main areas in the head and neck are the parapharyngeal, hypopharyngeal, and paraspinal.

CASE PRESENTATION

An 18-year-old woman presented with a painful mass in the left pre-auricular area.

CLINICAL DISCUSSION

Magnetic resonance imaging showed a well-defined lobular mass localized superior and anterior to the left ear. Incisional biopsy showed spindle cell sarcoma. A preauricular incision was done to remove the tumor with the superficial lobe of the parotid gland during the procedure, and histological examination revealed a high-grade spindle cell sarcoma the differential diagnosis included a monophasic synovial sarcoma. Immunohistochemistry was done for a full evaluation and the panel supported diagnosing a monophasic synovial sarcoma.

CONCLUSION

Synovial sarcoma is a malignant tumor that is rare to develop in the temporomandibular region, which makes it a significant challenge to diagnose and differentiate it from other lesions, it should be considered in all patients with a mass in this region. The cornerstone to identify synovial sarcoma is Immunohistochemistry (IHC), and molecular genetic analyses. Total surgical excision, with or without radiation and chemotherapy, is currently the best option for treatment. We present a review of the literature after the case presentation.

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

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

Chemosensitivity of Lung Metastatic High-Grade Synovial Sarcoma

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

Diagnostic Utility of TLE1 (Transducer-Like Enhancer of Split 1) in Distinguishing Synovial Sarcoma from Mimicking Tumors

Background

Synovial sarcoma (SS) is a high-grade spindle cell tumor that accounts for 5% to 10% of soft tissue sarcomas. The majority originate from the deep intramuscular soft tissues of extremities with common sites including knee, ankle and feet. Immunohistochemical (IHC) stain TLE1 (transducer-like enhancer of split 1) is a potent diagnostic marker for distinguishing SS from mimicking tumors.

Methodology

The study was performed on 177 tumor cases, including 89 SS and 88 non-synovial sarcoma (N-SS) cases which were diagnosed at Department of Pathology and Laboratory Medicine, Aga Khan University Hospital, from July 2019 to June 2020. Hematoxylin and eosin (H&E) and IHC stained glass slides of these cases were reviewed. TLE1 expression was assessed based on the Remmele scoring system.

Results

Eighty-nine cases of SS and 88 cases of N-SS were included in the study. SS cases included 42 (47.2%) monophasic subtype, 6 (6.7%) biphasic subtype and 41 (46.1%) poorly differentiated subtype. Major tumor types in N-SS cases were 27 (30.7%) Ewing sarcoma (ES), 13 (14.8%) leiomyosarcoma, 10 (11.4%) undifferentiated sarcoma (US), 8 (9.1%) fibrosarcomatous dermatofibrosarcoma protuberans and 7 (8%) malignant peripheral nerve sheath tumor cases. Mean patients’ age for SS cases was 26.14 years and for N-SS cases was 32.64 years. All 89 SS cases showed positive TLE1 expression. Out of 88 N-SS cases, 71 (80.7%) were TLE1 negative and 17 (19.3%) showed positive expression.

Conclusion

This study shows that TLE1 is a very sensitive and relatively specific IHC marker for SS. TLE1 expression can be observed in other soft tissue sarcomas but diffuse strong TLE1 expression is highly specific for SS. The diagnosis should not solely rely on TLE1 expression and morphologic features but should include soft tissue specific lineage markers to avoid misdiagnosis.

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.

Primary Intraosseous Synovial Sarcoma in the Mandible

Synovial sarcoma (SS) is a rare malignant mesenchymal tumor that mainly occurs in body extremities, being uncommon in the head and neck region. In the present study, we described a case of primary intraosseous SS arising in the mandible of a 22-year-old young male. The patient reported a painful swelling on the left side of the mandible for the last 7 months. Imaging exams showed the presence of an expansive and multilocular radiolucent lesion, extending from the left condyle to the mandibular body. The clinic diagnostic hypotheses were ameloblastoma or malignant neoplasm. Histologically, the lesion was characterized by a proliferation of spindle cells exhibiting vesicular nuclei and evident nucleolus. Neoplastic cells were positive for AE1/AE3, cytokeratin 7, vimentin, CD-99, and TLE-1 and negative for CD-34, S-100, SMA, and HHF-35. A combination of clinical, histologic, and immunohistochemical characteristics supported the diagnosis of SS. The patient was referred for treatment, and preoperative exams did not reveal any other tumor foci in the body of the patient. The final diagnosis was of a primary intraosseous SS of the mandible.

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

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

Innovative Surgical Planning in Resecting Soft Tissue Sarcoma of the Foot Using Augmented Reality With a Smartphone

Augmented or hybrid reality is a display technology that combines the real world with the virtual world; it permits digital images of preoperative planning information to be combined with the surgeon's view of the real world. Augmented reality (AR) can increase the surgeon's intraoperative vision by providing virtual transparency of the real patient and has been applied to a wide spectrum of orthopedic procedures, such as tumor resection, fracture fixation, arthroscopy, and component's alignment in total joint arthroplasty. We present a case of a male patient who presented with pain in the medial aspect of his left foot after he underwent an incomplete mass excision elsewhere where it turned out to be synovial sarcoma. Because the mass was small, impalpable, and deeply positioned beneath both the plantar and the medial plantar aponeuroses, it was impossible to preoperatively decide a plan for resection. We opted to use the aid of AR in the form of an application using the camera of a smartphone. We were able to excise the tumor with negative surgical margins. On 12-month follow-up, the patient is in complete remission and has optimal mobility and functionality of his foot. In conclusion, AR holds great potential for use in the future of orthopedic surgical oncology. We emphasize using it via a handheld device that we found to be optimal for planning resection of the small and relatively fixed tumor. Based on our literature review, this is the first case describing the surgical planning in resecting an impalpable synovial sarcoma of the foot using AR technology.

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.

Challenges in the Diagnosis of Pediatric Spindle Cell/Sclerosing Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common pediatric soft tissue sarcoma, representing approximately 40% of all pediatric soft tissue sarcomas. The spindle cell/sclerosing subtype of RMS (SSRMS) accounts for roughly 5% to 10% of all cases of adult and pediatric RMS. Historically, SSRMS were described as paratesticular tumors with an excellent outcome. However, more recent studies have identified unique molecular subgroups of SSRMS, including those with MYOD1 mutations or VGLL2/NCOA2 fusions, which have widely disparate outcomes. The goal of this article is to better describe the biological heterogeneity of SSRMS, which may allow the pathologist to provide important prognostic information.

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.

Monophasic synovial sarcoma of the pyriform fossa

Head and neck synovial sarcoma is rare. We report the case of a 71-year-old man who presented with progressive dysphagia, odynophagia, shortness of breath on exertion and hoarseness of voice. Nasendoscopy revealed a smooth, non-fungating, non-ulcerative mass arising from the left lateral pharyngeal wall. CT showed a well-defined, heterogenous enhancing lesion arising from the left pyriform fossa. Initial biopsy taken was inconclusive and patient underwent a transcervical complete excision of the tumour, where histopathological analysis confirmed the diagnosis of monophasic synovial sarcoma of the left pyriform fossa. This patient also received adjuvant radiotherapy postoperatively and remained disease free 1 year after completion of treatment.

GBAF, a small BAF sub-complex with big implications: a systematic review

ATP-dependent chromatin remodeling by histone-modifying enzymes and chromatin remodeling complexes is crucial for maintaining chromatin organization and facilitating gene transcription. In the SWI/SNF family of ATP-dependent chromatin remodelers, distinct complexes such as BAF, PBAF, GBAF, esBAF and npBAF/nBAF are of particular interest regarding their implications in cellular differentiation and development, as well as in various diseases. The recently identified BAF subcomplex GBAF is no exception to this, and information is emerging linking this complex and its components to crucial events in mammalian development. Furthermore, given the essential nature of many of its subunits in maintaining effective chromatin remodeling function, it comes as no surprise that aberrant expression of GBAF complex components is associated with disease development, including neurodevelopmental disorders and numerous malignancies. It becomes clear that building upon our knowledge of GBAF and BAF complex function will be essential for advancements in both mammalian reproductive applications and the development of more effective therapeutic interventions and strategies. Here, we review the roles of the SWI/SNF chromatin remodeling subcomplex GBAF and its subunits in mammalian development and disease.

TRPA1 Expression in Synovial Sarcoma May Support Neural Origin

Synovial sarcoma (SS) is a malignant mesenchymal soft tissue neoplasm. Despite its name, the cells of origin are not synovial cells, but rather neural, myogenic, or multipotent mesenchymal stem cells have been proposed as possible cells originators. Unlike other sarcomas, an unusual presentation of long-term pain at the tumor site has been documented, but the exact mechanisms have not been fully clarified yet. The transient receptor potential ankyrin 1 (TRPA1) is a nonselective cation channel mainly expressed in primary sensory neurons, where it functions as a pain sensor. TRPA1 have also been described in multiple non-excitable cells, including those derived from neural crest stem cells such as glial cells and, in particular, Schwann cell oligodendrocytes and astrocytes. We evaluated TRPA1 expression in SS. We selected a cohort of 41 SSs, and by immunohistochemistry, we studied TRPA1 expression. TRPA1 was found in 92.6% of cases. Triple TRPA1/pS100/SOX10 and TRPA1/SLUG/SNAIL staining strongly supports a neural origin of SS. TRPA1 positivity was also observed in a subset of cases negative with pS100, SOX10 and/or SLUG/SNAIL, and these divergent phenotypes may reflect a process of tumor plasticity and dedifferentiation of neural-derived SSs. Given the functional diversity of TRPA1 and its expression in neuronal and non-neuronal multipotent neural crest stem cells, it remains to be determined whether TRPA1 expression in SSs neoplastic cells plays a role in the molecular mechanism associated with premonitory pain symptoms and tumor progression.

A Rare Case of Synovial Sarcoma Involving the Brachial Plexus, Treated with Wide Local Excision and Reconstructed with Sural Nerve Grafts

This is a case report of monophasic synovial sarcoma involving right brachial plexus. Clinical and radiological examination is not very useful in diagnosis. Histopathology showed spindle cells with occasional mitotic figures. Immunohistochemistry showed positivity for EMA, S-100, Mic-2, Bcl-2, Calponin, TLE-1 and CD-56. Chromosomal translocation t (X;18) (p11.2;q11.2) and chimeric fusion proteins SYT/SSX1 or SYT/SSX2 are formed. Wide local excision of the tumour with involved brachial plexus and later reconstruction of the brachial plexus using sural nerve grafts was done. Patient showed full recovery. Wide excision and radiotherapy is the accepted mode of treatment.

Synovial Myxoma: Found in Canines, Rabbits, and Now Humans Too?: A Case Report

CASE

A 63 year-old woman presented with a multiple-year history of right knee pain and effusions and pain refractory to numerous knee aspirations and an arthroscopic synovectomy. The patient underwent a 2-incision synovectomy and intralesional resection. A pathologic review of the specimens revealed an infiltrative tumor of basophilic, cluster of differentiation 68-positive synovial cells embedded within a myxoid stroma with low proliferative activity, most consistent with a synovial myxoma.

CONCLUSIONS

This case report of a synovial myxoma-a benign, slow growing but locally aggressive mass that is most commonly found in canines-indicates that the lesion may occasionally occur in humans.

Frequency of Transducer-like Enhancer of Split 1 Immunohistochemical Expression in Synovial Sarcoma: An Institution-based Cross-sectional Study

Background Soft-tissue sarcomas comprise a diverse group of sarcomas with characteristic histologic features. However, histology alone is not adequate for a definitive diagnosis for many tumors. In such cases, immunohistochemistry (IHC) plays a key role in determining the line of differentiation and exact characterization. Transducer-like enhancer of split 1 (TLE1) has been recently described as a novel marker for synovial sarcoma (SS). Its high sensitivity and specificity make it a potential marker that distinguishes SS from histologic mimics such as malignant peripheral nerve sheath tumor (MPNST), Ewing's sarcoma (ES), and fibrosarcomatous dermatofibrosarcoma protuberans (FS-DFSP). The objective of our study was to assess the frequency of TLE1 immunohistochemical expression on SS cases of various subtypes. Methods This cross-sectional study was conducted at the Department of Histopathology, Aga Khan University, Karachi, Pakistan from February 3, 2018 to February 10, 2019. Tissue samples of 89 SS cases were selected for this study. Tumor sections were stained with hematoxylin and eosin (H&E), cytokeratin AEI/AE3 (CKAE1/AE3), epithelial membrane antigen (EMA), and TLE1 immunohistochemical stain. TLE1 expression was assessed based on the Remmele scoring system. Results Tissue samples of 89 SS cases were processed for the study. Mean (±) standard deviation (SD) of age was 25 (±7.36) years. Male:female ratio was 1.1:1. Of the 89 SS cases, 42 (47.2%) were monophasic, six (6.7%) were biphasic, and 41 (46.1%) were poorly differentiated. All the 89 cases showed positivity for TLE1 immunostain: 86 (96.6%) cases showed strong positivity, one (1.1%) case showed moderate expression, and two (2.2%) showed weak positivity. Conclusion This study shows that TLE1 is a highly sensitive immunostain for SS irrespective of the histologic type. However, it may show weak-to-moderate staining in poorly differentiated types. No statistically significant association was seen with respect to age group, gender, or type of SS.

Pretreatment Inflammatory Indexes as Prognostic Predictors of Survival in Patients Suffering From Synovial Sarcoma

Background: Inflammatory indexes have been considered as important prognostic factors in various types of cancers. This study aimed to evaluate prognostic values of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR) in patients with synovial sarcoma (SS). Methods: One hundred and three patients diagnosed with SS were collected during 2006-2017 and divided into high or low NLR, PLR, and LMR groups based on receiver operating characteristic curve analysis. Data of clinical variables were collected for univariate and multivariate analyses. The Kaplan-Meier method was used to analyze OS and PFS of SS patients and significance was evaluated by the log-rank test. Results: The optimal cut-off values of NLR, PLR, and LMR were 2.70, 154.99, and 4.16, respectively. Univariate analyses identified resection surgery, distant metastasis, NLR, PLR, and LMR as the potential predictors of progression-free survival (PFS) and overall survival (OS). In the multivariate analyses, NLR was independent predictors for OS (HR 5.074, 95% CI 1.200-21.463, p = 0.027). Resection surgery, metastasis and LMR was independent predictors for PFS (HR 5.328, p = 0.017; HR 3.114, p = 0.04 and HR 0.202, p = 0.025, respectively). Conclusion: Resection surgery, distant metastasis, NLR, and LMR were independent prognostic factors of PFS and OS in patients with synovial sarcoma. Surgery as an effective treatment strategy, other than radiotherapy and chemotherapy, can significantly prolong survival of synovial patients. Clinical utility of these inflammatory biomarkers should be validated in a larger sample size study.

Laryngeal Synovial Sarcoma: A Systematic Review of the Last 40 Years of Reported Cases

Primary laryngeal synovial sarcoma is an extremely rare tumor predominantly affecting young adults. There are currently no well-defined guidelines to direct investigation and management, and treatment is largely based on what is known for synovial sarcoma of the upper and lower limbs. This PROSPERO-registered study aims to review the diagnostic methods, treatment regimens, and survival outcomes for patients with synovial sarcoma of the larynx. A systematic search of databases Medline, Embase, SCOPUS, and Web of Science was undertaken in December 2017. The literature search identified 1031 potentially relevant studies, and after the deletion of duplicates and excluded papers, 98 full-text articles were screened. A total of 39 cases were reviewed from 32 studies in the data extraction. The average age at the time of laryngeal synovial sarcoma diagnosis was 32 years (range, 11-79 years). In all cases (n = 39), patients underwent wide surgical excision, with 20 patients requiring a partial or total laryngectomy. A total of 18 patients received adjuvant and 3 received neoadjuvant radiotherapy. Chemotherapy was used in 10 cases, with ifosfamide the most frequently used agent. There was considerable variability in the order and combinations of the abovementioned treatments. No clinicopathologic factors or treatment regimens were associated with improved overall survival or lower rate of recurrence. There is a paucity of literature and heterogeneity in clinical approaches to this highly aggressive sarcoma. Reporting of cases must be standardized and formal guidelines must be established to guide clinical management.

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.

An unusual local invasion of synovial sarcoma

Synovial sarcoma is a malignant tumor, it accounts for approximately 5-10% of the soft tissue sarcoma, and mainly develops in the para-articular regions in adolescents and young adults. We reported a case of synovial sarcoma extending into the vastus intermedius muscle beyond the intermuscular septum which is considered to be the greatest barrier to ensuring a safety margin in musculoskeletal surgery. Preoperative sequential MRI showed the intermuscular-septum line and direct tumoral invasion beyond the intermuscular septum. A histopathological examination showed the direct invasion to the intermuscular septum. Synovial sarcoma seldom shows such direct invasive pattern to barriers, much less the robust barrier like an intermuscular septum. To our knowledge, no previous study has reported such unique extension of a synovial sarcoma beyond the intermuscular septum. Surgeons should be aware of the potential vulnerability of the intermuscular septum.

Well-differentiated liposarcoma and dedifferentiated liposarcoma: An updated review

Well-differentiated liposarcoma (WDL)/atypical lipomatous tumor and dedifferentiated liposarcoma (DDL) together comprise the largest subgroup of liposarcomas, and constitute a histologic and behavioral spectrum of one disease. WDL and DDL typically occur in middle-aged to older adults, particularly within the retroperitoneum or extremities. WDL closely resembles mature adipose tissue, but typically shows fibrous septation with variable nuclear atypia and enlargement. WDL does not metastasize, but can dedifferentiate to DDL, which is associated with more aggressive clinical behavior, with a greater propensity for local recurrence and the capacity for metastasis. Although distant metastasis is rarer in DDL compared with other pleomorphic sarcomas, behavior is related to location, with a significantly worse outcome in retroperitoneal tumors. DDL typically has the appearance of undifferentiated pleomorphic or spindle cell sarcoma, and is usually a non-lipogenic sarcoma that is adjacent to WDL, occurs as a recurrence of WDL or which can arise de novo. WDL and DDL share similar background genetic aberrations; both are associated with high-level amplifications in the chromosomal 12q13-15 region, which includes the CDK4 and MDM2 cell cycle oncogenes. In addition, DDL harbor further genetic changes, particularly 6q23 and 1p32 coamplifications. While surgical excision remains the treatment mainstay with limited medical options for patients with aggressive recurrent disease or metastases, novel targeted therapies towards the gene products of chromosome 12 are being evaluated. This review summarizes the pathology of WDL and DDL, discussing morphology, immunohistochemistry, genetics and the differential diagnosis.

Management of primary retroperitoneal synovial sarcoma: A case report and review of literature

BACKGROUND

Synovial sarcoma (SS) is a rare type of soft tissue sarcoma that is usually developed from areas where synovial tissue exists, especially at the extremities. Nevertheless, several cases of retroperitoneal SS (RSS) have been described. We herein report a case of RSS presented in our institution.

CASE SUMMARY

A 69-year-old female patient was admitted with a large, palpable, firm mass in the right abdominal space SS. Computerized tomography scan depicted a concentric, sharply marinated retro-peritoneal lesion which was displacing the right kidney and the lower edge of the liver. Subsequently, the patient underwent surgical excision of the mass with additional right nephrectomy and resection of the right adrenal gland and a part of the diaphragm. The final histological diagnosis of the tumour was grade II monophasic RSS.

CONCLUSION

RSS is encountered in the biphasic type, the monophasic fibrous, and the monophasic epithelial category as well. Relevant clinical manifestations are not always documented at early stages. Therefore, the final diagnosis is posed after complete histological examination taking into consideration the results of immunochemistry and genetic analysis. Therapeutic approach happens often late when metastases at the lungs and the liver are apparent. Thus, 5-year survival rates remain low.

Production and characterization of monoclonal antibodies against recombinant extracellular domain of CD99

BACKGROUND AND OBJECTIVE

CD99/MIC2 gene product is a heavily glycosylated transmembrane protein which plays a major role in homotypic cell adhesion, apoptosis of double positive T cells and vesicular protein trafficking. It is over expressed in various cancers and has been considered as an ideal therapeutic target. The present study focused at developing monoclonal antibodies against the extracellular domain (ECD) of CD99 using hybridoma technology.

MATERIALS AND METHODS

In order to generate monoclonal antibodies, the recombinant ECD of CD99 was used for immunizing the mice. Resulting hybridomas were screened through indirect ELISA. Clones which gave high absorbance values were sub cloned by limiting dilution followed by isotype determination, IP, WB and FACS. The monoclonal antibody 547F2 4F12 was purified from culture supernatant using FPLC and further screened using IF. Finally, the antibodies were validated for specificity using siRNA knock-down.

RESULTS

We were able to establish stable hybridoma clones secreting CD99 antibodies. The antibodies reacted with both the recombinant ECD as well as the wild type CD99 and their isotype's were determined as IgM.

CONCLUSION

Based on these results, we propose that the purified monoclonal antibody 547F2 4F12 could be possibly used for targeting tumors which over express CD99.

Monophasic synovial sarcoma as a cause of obstructive ileus: A case report

Synovial sarcoma is a high-grade soft tissue sarcoma, divided histologically into 3 types: Monophasic, biphasic and poorly differentiated. An extremely rare case of obstructive ileus due to monophasic synovial sarcoma in a 54-year-old male patient is reported in the present study. The patient presented to the emergency department with signs and symptoms of obstructive ileus. Computer Tomography (CT)scan showed a pelvic mass (20×17×12 cm) causing obstruction at the sigmoid colon. An exploratory laparotomy through a midline incision was performed. The described mass was unresectable as it was infiltrating major vessels. Therefore, a diverting loop descending colostomy and biopsy of the solid mass were performed. Pathological examination revealed a monophasic synovial sarcoma. The patient was referred to the Department of Oncology and started treatment with doxorubicin and ifosfamide.

Pleural malignant mesothelioma versus pleuropulmonary synovial sarcoma: a clinicopathological study of 22 cases with molecular analysis and survival data

The aim of this study was to carry out a comparative analysis by transducin-like enhancer of split 1 (TLE1) immunohistochemistry and molecular analysis of SYT-SSX, for 16 pleural predominantly sarcomatoid mesotheliomas and six cases of pleuropulmonary synovial sarcoma (five pleural in distribution only, with one case of a predominantly subpleural upper lobe synovial sarcoma), all of which were solely or predominantly monophasic. Our comparison included survival and some clinical data. We consider that the following points emerged from this study.

Synovial sarcoma: Do children do better?

OBJECTIVES

Synovial sarcoma, a distinct subtype of soft tissue sarcomas (STS), is typically found in young patients. Long history of symptoms and heterogeneous clinical presentation sometimes delays diagnosis. Children have been reported to have a better prognosis than adults in some series. The main emphasis of this study was to determine differences between children and adults and to investigate prognostic factors regarding cancer specific survival (CSS).

METHODS

248 patients treated between 1982 and 2014 at one department were included. Mean age was 37.0 years, including 43 patients <16 years. Demographic, pathology- and treatment-related information was ascertained. Median follow-up was 5.2 years.

RESULTS

Median duration of symptoms was 11.5 months in children and 12 months in adults (p = 0.238). Patients with a prior unplanned excision had a significantly longer duration of symptoms (p = 0.001). No difference was present between children and adults regarding tumour size, site, grade and superficial/deep location. Treatment was with surgical excision and (usually) adjuvant radiotherapy but five patients received preoperative radiotherapy and 43 patients chemotherapy. In patients treated with curative intent, five-year CSS rates were 75.5% for adults and 89.0% for children, with 10-year CSS rates of 56.1% and 82.2% (p = 0.026). In multivariate analysis, large tumour size (p < 0.005) and patient age (p = 0.024) were associated with worse CSS, irrespective of tumour location and site.

CONCLUSION

Clinical presentation of synovial sarcoma is similar in children and adults, with no significant difference in tumour size, site, grade or location. Small tumour size and young patient age are independent positive prognostic factors influencing CSS.

Intraneural synovial sarcoma of the tibial nerve

Synovial sarcomas are malignant soft tissue tumors that carry a metastatic potential and portend poor prognoses. We report a very rare synovial sarcoma arising from the tibial nerve and describe its successful treatment including limb preservation. To the best of our knowledge, this is the 40th reported incident of intraneural synovial sarcoma, and only the fourth arising from the tibial nerve. Extensive resection of synovial sarcoma arising in the popliteal region is difficult, particularly when limb preservation is desired. Ours is the first reported patient treated for tibial nerve-derived synovial sarcoma whose limbs were preserved.

A review of soft-tissue sarcomas: translation of biological advances into treatment measures

Soft-tissue sarcomas are rare malignant tumors arising from connective tissues and have an overall incidence of about five per 100,000 per year. While this diverse family of malignancies comprises over 100 histological subtypes and many molecular aberrations are prevalent within specific sarcomas, very few are therapeutically targeted. Instead of utilizing molecular signatures, first-line sarcoma treatment options are still limited to traditional surgery and chemotherapy, and many of the latter remain largely ineffective and are plagued by disease resistance. Currently, the mechanism of sarcoma oncogenesis remains largely unknown, thus necessitating a better understanding of pathogenesis. Although substantial progress has not occurred with molecularly targeted therapies over the past 30 years, increased knowledge about sarcoma biology could lead to new and more effective treatment strategies to move the field forward. Here, we discuss biological advances in the core molecular determinants in some of the most common soft-tissue sarcomas - liposarcoma, angiosarcoma, leiomyosarcoma, rhabdomyosarcoma, Ewing's sarcoma, and synovial sarcoma - with an emphasis on emerging genomic and molecular pathway targets and immunotherapeutic treatment strategies to combat this confounding disease.

CD99: A Cell Surface Protein with an Oncojanus Role in Tumors

The cell surface molecule CD99 has gained interest because of its involvement in regulating cell differentiation and adhesion/migration of immune and tumor cells. However, the molecule plays an intriguing and dual role in different cell types. In particular, it acts as a requirement for cell malignancy or as an oncosuppressor in tumors. In addition, the gene encodes for two different isoforms, which also act in opposition inside the same cell. This review highlights key studies focusing on the dual role of CD99 and its isoforms and discusses major critical issues, challenges, and strategies for overcoming those challenges. The review specifically underscores the properties that make the molecule an attractive therapeutic target and identifies new relationships and areas of study that may be exploited. The elucidation of the spatial and temporal control of the expression of CD99 in normal and tumor cells is required to obtain a full appreciation of this molecule and its signaling.

Risk Factors Including Age, Stage and Anatomic Location that Impact the Outcomes of Patients with Synovial Sarcoma

Synovial sarcoma is a high-grade soft tissue sarcoma that inflicts mostly children and young adults with high mortality rate; however, the risk factors that impact the outcomes remain incompletely understood. We have identified the synovial sarcoma cases from the Kaiser Permanente Northern California cancer registry between 1981 and 2014. Kaplan–Meier plots were used to display disease-free survival (DFS) and overall survival (OS); log-rank tests and Cox proportional hazard models were used to determine the impact of clinical factors on DFS, OS, and disease-specific survival. Tumor size > 5.0 cm and age > 50 years were associated with higher risk of presenting with stage IV disease. Median OS for patients with stage IV was 1.3 years and 7.8 years for early-stage disease. For patients with early-stage disease, tumor size > 5.0 cm was significantly associated with worse DFS, sarcoma-specific morality, and OS. Compared to extremity primary, patients with head and neck and trunk primary had approximately three-fold higher sarcoma-specific mortality and lower OS. There was no significant difference in DFS or OS among three histologic subtypes. Pre-operative and/or post-operative chemotherapy was not associated with improvement in DFS or OS. Twenty-six patients relapsed with predominantly lung metastasis, thirteen of whom received metastatectomy with a median OS of 7.8 years, compared to 2.3 years for patients who did not receive metastatectomy. In conclusion, age older than 50 years and tumor size > 5.0 cm are risk factors for presenting with stage IV disease. For early-stage patients, trunk and head and neck primary as well as tumor size > 5.0 cm are risk factors for decreased OS.

CD99 at the crossroads of physiology and pathology

CD99 is a cell surface protein with unique features and only partly defined mechanisms of action. This molecule is involved in crucial biological processes, including cell adhesion, migration, death, differentiation and diapedesis, and it influences processes associated with inflammation, immune responses and cancer. CD99 is frequently overexpressed in many types of tumors, particularly pediatric tumors including Ewing sarcoma and specific subtypes of leukemia. Engagement of CD99 induces the death of malignant cells through non-conventional mechanisms. In Ewing sarcoma, triggering of CD99 by specific monoclonal antibodies activates hyperstimulation of micropinocytosis and leads to cancer cells killing through a caspase-independent, non-apoptotic pathway resembling methuosis. This process is characterized by extreme accumulation of vacuoles in the cytoplasmic space, which compromises cell viability, requires the activation of RAS-Rac1 downstream signaling and appears to be rather specific for tumor cells. In addition, anti-CD99 monoclonal antibodies exhibit antitumor activities in xenografts in the absence of immune effector cells or complement proteins. Overall, these data establish CD99 as a new opportunity to treat patients with high expression of CD99, particularly those that are resistant to canonical apoptosis-inducing agents.