Synovial Sarcoma Involving the Head: Analysis of 36 Cases With Predilection to the Parotid and Temporal Regions

Global frequency and distribution of head and neck sarcomas in adulthood: a systematic review

PURPOSE

Head and neck sarcomas (HNS) constitute a rare and heterogeneous cancer entity. Management remains a challenge due their rarity and different biological behaviour among tens of subtypes. This systematic review aimed to describe HNS global frequency and distribution in adulthood.

METHODS

A systematic review was performed using PICOTS search strategies for qualitative question and it was written in accordance with PRISMA 2020 Statement. 70,653 publications were identified, and 15 variables were evaluated for a total of 2428 patients.

RESULTS

We identified 47 studies from 21 different countries from 5 different continents. Most of studies (83.3%) were performed in single institutions and America and Asia overruled for number of papers included (21 and 10, respectivelly). Osteosarcoma was more frequent, followed by chondrosarcoma, angiosarcoma and malignant fibrous histiocytoma. Early stage accounted for almost 80% of cases; advanced stage prevailed in developing countries. 1783 patients (90.1%) underwent surgery and 780 (39.4%) had adjuvant therapy. 50.8% of patients experienced tumour recurrence and the lowest mortality rate was reported in Europe (29.9%).

CONCLUSIONS

HNS holds a relative poor prognosis possibly explained by the heterogeneity of the disease. Treatment of HNS has shown to be highly diverse among different countries, underlining the importance of uniformed treatment guidelines to achieve better patient management and to improve survival outcomes.

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

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

Small biopsies in the head and neck: Bone and soft tissue

Bone and soft tissue lesions in the head and neck encompass not only a broad morphologic spectrum but also significant inherent clinicopathologic overlap. Epidemiology, radiology, and location - similar to the diagnostic assessment in other sites - are especially important considerations in the context of an established mesenchymal proliferation. Herein, the approach towards diagnosis is stratified by morphology (spindle, sarcomatoid, epithelioid, round cell), cellular lineage (fibroblastic, nerve sheath, rhabdomyogenic), and tumor grade (benign, low- to high-grade malignant) as the basis of further immunohistochemical or molecular investigation.

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.

Early progression of a pancreatic metastasis of synovial sarcoma after pancreatectomy

BACKGROUND

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

CASE PRESENTATION

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

CONCLUSIONS

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

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

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

Tumors Involving the Infratemporal Fossa: A Systematic Review of Clinical Characteristics and Treatment Outcomes

BACKGROUND

Infratemporal fossa (ITF) tumors represent various pathologies and are seldom described in the literature, reflecting their rarity. Here we review the literature on tumors invading ITF and describe patient characteristics, treatment strategies, and clinical outcomes.

METHODS

Relevant articles were retrieved from PubMed, Scopus, and Cochrane. A systematic review and meta-analysis were conducted on the clinical presentation, treatment protocols, and clinical outcomes.

RESULT

A total of 27 articles containing 106 patients with ITF tumors (median tumor size: 24.3 cm³ [interquartile range, 15.2-42 cm³]) were included (median age: 46 years [interquartile range, 32-55 years]; 59.4% were males]). Of the confirmed tumor pathology data, schwannomas (n = 24; 26.1%) and meningiomas (n = 13; 14.1%) were the most common tumors. Facial hypoesthesia (n = 22; 18.5%), auricular/preauricular pain (n = 20; 16.8%), and headaches (n = 11; 9.2%) were the most common presenting symptoms. Of patients who had surgical resection (n = 97; 95.1%), 70 (73.7%) had transcranial surgery (TCS) and 25 (26.3%) had endoscopic endonasal surgery (EES). Among available details on the extent of resection (n = 84), gross-total resection (GTR) was achieved in 62 (73.8%), and 5 (6.0%) had biopsy only. Thirty-five (33.0%) patients had postoperative complications. Among cases with available data on reconstruction techniques (n = 8), four (50%) had adipofascial antero-lateral thigh flap, three (37.5%) had latissimus dorsi free flap, and one (12.5%) had antero-lateral thigh flap. Fourteen (13.2%) patients had adjuvant chemotherapy, and sixteen (15.1%) had adjuvant radiotherapy. During a median follow-up time of 28 months (IQR, 12.25-45.75 months), 15 (14.2%) patients had recurrences, and 18 (17.0%) patients died. The median overall survival (OS) time was 36 months (95% confidence interval: 29-41 months), and the 5-year progression-free survival (PFS) rate was 61%.

CONCLUSION

Various tumor types with different biological characteristics invade the ITF. The present study describes patient demographics, clinical presentation, management, and outcomes. Depending on the tumor type and patient condition, patient-tailored management is recommended to optimize treatment outcomes.

A rare incidence of primary Synovial Spindle Cell Sarcoma in a 46-year-old male, successfully managed by surgical intervention-A Case Report

INTRODUCTION AND IMPORTANCE

Synovial sarcoma (SS) is a rare form of Soft Tissue Sarcoma (STS) which results from the malignant proliferation of mesenchymal cells. Specific etiologies are not yet known, and its incidence rate ranges between 0.81 and 1.42 per 1 million individuals. Its gender-specific prevalence is almost the same between males and females and it is unique from other subtypes of STS in that it's slow growing and in almost half the cases, patients present with distant metastasis at the time of diagnosis.

CASE PRESENTATION

We present the case of a 46-year-old previously healthy male patient, who complained from a right lower extremity painless bulge, which began to be visibly noticeable by the patient 2 months prior to admission. There were no signs of allocated inflammation nor lower limb ischemia. Radiology revealed an irregular mass formation conformant with neoplasia.

CLINICAL DISCUSSION

Surgical resection of the mass along with synthetic graft replacement of the concomitant vascular bundle. Histopathological analysis of the resected mass revealed a monophasic synovial spindle cell sarcoma.

CONCLUSION

SS is a rare neoplasm poses a grave risk for patients due to its malignant pathophysiology and the wide margin of misdiagnoses. It is pivotal to set-up proper preoperative diagnostic guidelines for it and maintain high clinical suspicion so that we can bring down the high rates of the morbidity and mortality which ensue from this malignancy.

Biphasic synovial sarcoma of the hypopharynx: Case report and literature review

Introduction

Synovial Sarcoma is a rare malignancy that accounts between 8 and 10% of soft tissue neoplasms, with the highest presentation rate in extremities, an extremely uncommon condition in head and neck.

Clinical findings

We present a case of an 18-year-old male with synovial sarcoma situated at hypopharynx who underwent surgical resection and postoperative radiotherapy.

Conclusion

Synovial Sarcoma represents a rare head and neck malignancy with challenging diagnostic approach due to its frequency and nonspecific clinical manifestations. Surgical treatment must assure good free margins. Adjuvant radiotherapy has a positive impact in local recurrence and survival.

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Sinovial Sarcoma it's a rare and challenging entity, early diagnosis is related with better outcomes.

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On time adjuvant therapy needs to be done in order to improve oncologic outcomes.

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Multidisciplinary approach it's related to good postoperative outcomes and extended overall survival.

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Synovial sarcoma of the maxillary sinus and chest wall: An exceptional association of two synchronous rare locations, Case report

INTRODUCTION

Synovial sarcoma is a malignant tumour of mesenchymal origin with an aggressive character and a rare cervicofacial location. Its management is multidisciplinary in order to improve prognosis and survival.

CASE REPORT

We report the case of two rare and synchronous localizations of monophasic synovial sarcoma of the maxilla and chest wall in a 58-year-old woman, whose management was based on exclusive chemotherapy.

DISCUSSION

The cervicofacial location of synovial sarcoma represents 3% of all locations in the body. Its clinical and radiological manifestations are aspecific. Its diagnosis is based on a combination of histological and genetic arguments. Its therapeutic management depends on the tumour stage and prognostic factors.

CONCLUSION

Early diagnosis of cervicofacial synovial sarcoma allows to avoid a mutilating procedure for the patient and to improve the long-term prognosis by a good control of the tumour.

Epidemiology, incidence, and survival of synovial sarcoma subtypes: SEER database analysis

BACKGROUND

Synovial sarcoma (SyS) is a rare malignancy that is typically located on the limbs and occurs predominantly in adolescents. A study in a large population for SyS comparing subtypes has not yet been reported.

METHODS

National Cancer Institute's Surveillance, Epidemiology, and End Results database was queried for patients diagnosed with SyS between January 1975 and December 2016. Patients were classified demographically according to gender, age, race/ethnicity, and marital status, and they were also classified by tumors, subtypes, localization, grade, year of diagnosis, laterality, type of treatment, and follow-up results.

RESULTS

A total of 3228 patients were included, with a mean age of 39.3 ± 18.8 (range: 1-94), of which 1521 (47.1%) were females and 1707 (52.9%) were males. According to its subtypes, 47.2% were SyS not otherwise specified, 32.3% were spindle cell, 19.9% were biphasic, and 0.6% were epithelioid type. The overall survival period is 138.0 (95% confidence interval: 113.2-162.8) months. Survival duration was found to be significantly different between groups according to gender (log-rank test; p < 0.001), age groups (log-rank test; p < 0.001), race (log-rank test; p = 0.001), marital status (log-rank test; p < 0.001), tumor subtypes (log-rank test; p < 0.001), tumor location (log-rank test; p < 0.001), tumor laterality (log-rank test; p < 0.001), date of diagnosis (log-rank test; p = 0.025), tumor grade (log-rank test; p < 0.001), historic stage (log-rank test; p < 0.001), state of chemotherapy (log-rank test; p < 0.001), state of radiotherapy (log-rank test; p < 0.001), presence of metastasis (log-rank test; p < 0.001), and total number of malignant tumors (log-rank test; p < 0.001).

CONCLUSION

Male gender, being colored individual, being over 35 years at the time of diagnosis, epithelioid type, non-head and neck region localization is associated with poor prognosis. While radiotherapy improves survival, benefit of chemotherapy is unclear.

LEVEL OF EVIDENCE

III retrospective analysis.

Synovial sarcoma of the head & neck: A review of reported cases in the literature

Synovial sarcoma is a high-grade malignancy that seldom manifests in the head and neck. The purpose of this paper is to provide a comprehensive review of the existing literature on primary HNSS. This review study includes case reports, case series and retrospective cohort studies on primary HNSS published in the English language. All cases identified via PubMed were analyzed individually. Articles were included according to specified eligibility criteria. The total number of cases analyzed was 243 (91 case reports, 53 cases from 16 case series, and 99 cases from 8 retrospective cohort studies). The average age at the time of HNSS diagnosis was 33.5 years. The ratio of male-to-female was 1.64:1. The most frequently occurring histologic subtype was biphasic (59.2%). The most common location was the neck. Hoarseness was the most common presenting symptom. Almost all patients (98.3%) underwent surgical excision. 55.6% of patients received adjuvant radiotherapy. A smaller number of patients (30.7%) received adjuvant chemotherapy. 60.3% of patients were alive with no evidence of disease at follow-up while 28.0% of patients died of HNSS at follow-up. The average follow-up period was 52.0 months. Synovial sarcoma is a rare head and neck malignancy. Surgical excision with adjuvant radiation is the most frequently employed treatment modality. Regardless of treatment modality, the prognosis of the tumor is guarded.

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.

Radiation therapy strategies for skull-base malignancies

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Primary synovial sarcoma of parotid gland with intravenous extension into the heart

We are reporting a case of a 47-year-old male with primary synovial sarcoma of the right parotid gland with tumor thrombus extension in the right internal jugular vein and right atrium. The rarity of this occurrence as documented in the review of the literature provides for uncertainty about proper management. Our case represents a rare occurrence with the unique radiological finding that has implications for management.

The Imaging Spectrum of Synovial Sarcomas: A Pictorial Review From a Single-Centre Tertiary Referral Institution

Synovial sarcomas are malignant soft-tissue tumors that typically affect young patients. They can arise from nearly anywhere in the body, most commonly the extremities, head and neck, and thorax. The imaging features are highly variable and depend on the anatomic origin. Most lesions present as large aggressive heterogeneous masses containing hemorrhagic and cystic foci, often with calcification. However, up to one-third of lesions have commonly benign features and can appear homogeneously solid or cystic. Especially in these cases, their innocuous imaging and clinical presentation can lead to delayed diagnosis. Therefore, knowledge of the imaging spectrum is crucial to ensuring adequate follow-up or timely pathologic sampling. We reviewed 30 pathologically proven cases in various anatomic sites from our institution to illustrate these characteristics.

Uncommon tumors of temporomandibular joint: An institutional experience and review

BACKGROUND

The temporomandibular joint (TMJ) harbors a myriad of pathologic alterations including arthritides and benign and malignant neoplasms.

METHODS

Herein, we describe our institutional experience of some uncommon and unusual synovial pathologies of the TMJ along with a review of literature. We searched through the archives of department of pathology and institutional electronic medical record for specimens of TMJ between 1999 and 2019. Hematoxylin and eosin slides were reviewed and data (final diagnosis, age, gender, clinical presentation, tumor size, treatment modality, recurrence, and vital status) were collected.

RESULTS

A total of seven cases were identified including four cases of synovial chrondromatosis; and one case each of tenosynovial giant cell tumor, localized type, tenosynovial giant cell tumor, diffuse type, and synovial sarcoma.

CONCLUSIONS

The article emphasizes on the clinical, radiologic, pathologic, and molecular features of these uncommon entities. The differential diagnosis of each entity is also discussed. Current updates in the management are also reviewed.

From fine-needle aspiration cytology to fluorescent in-situ hybridization in an unusual case of pharyngeal synovial sarcoma

Synovial sarcoma arising in the pharynx is a rare entity, with very few cases described in literature, mainly as surgical-oriented case reports. We report the case of a healthy 20-year old man who presented with a painless right neck mass, clinically suspicious for a thyroid nodule. Ultrasound scan and fine-needle aspiration cytology failed to provide a definitive result, although suggesting a mesenchymal proliferation, in accordance with magnetic resonance imaging findings. Therefore, the lesion was removed with a minimally invasive surgical intervention. Definitive histologic and immunohistochemical examination of the surgical specimen revealed a biphasic synovial sarcoma, further validated by the detection of SS18 gene rearrangement on fluorescent in-situ hybridization examination. Although rarely, synovial sarcoma may arise in the pharynx. Radiological, cytological, histological and molecular findings are needed along each step of the diagnostic process.

Primitive synovial sarcoma of suboccipital region in child

Synovial sarcoma (SS) most commonly affects the lower limbs of males in the third to fifth decades of life, with masses of the head and neck accounting for 3–10% of all cases, mainly as a metastatic lesion. The lack of specific symptoms and radiological features in addition to the diversity of their microscopic aspects may cause confusion in the diagnosis; hence, knowledge of the unusual locations of SSs is very important. The immunohistochemistry, and more recently the cytogenetic studies, contribute to the differential diagnosis. We report the case of a 12-year-old girl with a rare primary SS in the suboccipital region, which underwent complete surgical resection.

Synovial sarcoma of the tongue: report of a case and review of the literature

This report outlines the work-up and management of a 35-year-old man with a synovial sarcoma of the lateral border of the tongue. Synovial sarcoma of the tongue is an extremely rare tumour with variable morphological microscopic types and characters of immunohistochemical profile. There have only been 15 cases previously reported. This report aims to update the literature on this subject and explore the best treatment options.

The "TROJAN HORSE" of a Dental Visit - Synovial Sarcoma

The term "synovial sarcoma (SS)" is a histological error, a misnomer as it neither arises from nor differentiates toward synovium. Head and neck region is the most commonly affected region after extremities, representing 5% of all cases. This case report focuses to discuss a case of a SS that was diagnosed after an inadvertent root canal therapy. A 46-year-old male came to the outpatient department with a chief complaint of pain and swelling in his upper right back tooth region since 15 days. An ulceroproliferative mass of was observed protruding from the gingivobuccal sulcus from 11 to 15 tooth region obliterating the vestibule.

Factors Associated With Survival in Patients With Synovial Cell Sarcoma of the Head and Neck: An Analysis of 167 Cases Using the SEER (Surveillance, Epidemiology, and End Results) Database

IMPORTANCE

Synovial cell sarcoma of the head and neck (SCSHN) is a rare tumor associated with significant morbidity and mortality. The literature regarding these tumors is limited to case series and case reports. We used data from the population-based US Surveillance, Epidemiology, and End Results (SEER) cancer registry to determine factors affecting both overall survival and disease-specific survival of patients with SCSHN.

OBJECTIVE

To determine the clinicopathologic and therapeutic factors determining survival in patients with SCSHN.

DESIGN, SETTING, AND PARTICIPANTS

The SEER registry was reviewed for patients with primary SCSHN from January 1, 1973, to January 1, 2011.

MAIN OUTCOMES AND MEASURES

Overall survival (OS) and disease-specific survival.

RESULTS

A total of 167 cases of SCSHN were identified. The mean (SD) age at diagnosis was 37.9 (17.3) years, and 100 (59.9%) of the patients were males. The monophasic spindle cell and biphasic variants were the most common histologic subtypes. Surgical resection and radiotherapy were performed in 150 (89.8%) and 108 (64.7%) of the cases, respectively. The median OS at 2, 5, and 10 years was 77%, 66%, and 53%, respectively. Univariate Kaplan-Meier survival analysis revealed that age, race, and tumor stage and size were associated with improved survival. Histologic subtype was not associated with significant differences in survival. Radiotherapy was associated with improved disease-specific survival (hazard ratio [HR], 0.29 [95% CI, 0.12-0.68]; P = .003), but surgical management was not associated with improved survival (HR, 0.52 [95% CI, 0.19-1.46]; P = .21). Multivariate Cox regression analysis revealed that size greater than 5 cm (adjusted HR, 3.60 [95% CI, 1.43-9.08]; P = .007) and stage at presentation (adjusted HR, 3.86 [95% CI, 2.01-7.44]; P < .001) were independent determinants of OS. In separate analysis of cohorts with tumors 5 cm or less and larger than 5 cm, stage at presentation was found to be a significant indicator of the probability of survival in both cohorts (adjusted HR, 3.10 [95% CI, 1.46-6.60]; P = .003 and 5.32 [95% CI, 1.49-18.98]; P = .01, respectively); surgical resection and radiotherapy were not associated with differential survival outcomes using this model.

CONCLUSIONS AND RELEVANCE

Synovial cell sarcoma of the head and neck is rare. Independent significant determinants of survival include size (>5 cm) and stage at presentation. Histologic subtype of the tumor is not a significant indicator of the probability of survival. Surgical resection and radiotherapy were not independent determinants of survival.

Survival changes in Patients with Synovial Sarcoma, 1983-2012

Background: Synovial sarcoma (SyS) is a rare malignancy that typically invades the extremities and occurs predominantly in adolescents. Studies on incidence and survival in SyS that were based on a large population had not been reported yet.

Methods: To evaluate changes in incidence and survival in SyS over three decades, we accessed data on SyS cases in each decade between 1983 and 2012 (1983-1992, 1993-2002, and 2003-2012) from the Surveillance, Epidemiology, and End Results (SEER) database. The survival difference between decades, age groups, sexes, race, pathologic types, sites, stages and socioeconomic status (SES) over three decades were accessed by comparing Kaplan-Meier curves.

Results: We located 2,070 SyS cases in 18 SEER registry regions between 1983 and 2012. Our study demonstrated that the incidence of SyS per 1,000,000 continued to increase from 0.906 to 1.348 to 1.548 in the total population and in most age groups and that the age of incidence peak was 15-29 years in three decades. But, the survival of patients with SyS did not significantly improve throughout the three decades, with 5-year survival rates of 69.4%, 61.1% and 60.5% respectively (p > 0.05). Interestingly, the widening survival gaps among races, sexes, pathological types and various SES over time were observed, with narrowing p values.

Conclusions: This study demonstrated the increasing incidence and unimproved survival rates across three decades in a large sample, indicating the urgency for further development of diagnosis, improving health care providers' awareness of SyS and lead to the development of novel treatments.

Synovial Sarcoma of the Head and Neck: A Single Institution Review

Background

The prognosis and clinical characteristics of head and neck synovial sarcomas (HNSS) are unclear. Herein, we present an update using a cohort of patients treated at our institution.

Methods

We performed a retrospective chart review of 44 patients diagnosed with primary HNSS between March 1990 and June 2012. Overall survival (OS) and progression-free survival (PFS) curves were estimated and hazard ratios (HRs) were calculated.

Results

The entire cohort's median PFS was 4.6 years, and 20 of the 44 (45%) patients developed either local or distant recurrence. Tumor size ≥ 5 cm (p = 0.008, HR = 4.69; 95% CI = 1.34–16.38) and a primary presentation in the soft tissues of the neck (p = 0.04, HR = 2.41; 95% CI = 1.003–5.82) were associated with significantly worse PFS. The OS and PFS of patients who received definitive local therapy versus those who received additional adjuvant systemic therapy did not differ significantly.

Conclusion

Despite the treatment challenges associated with HNSS, our cohort of patients had a better prognosis than one might expect in this unfavorable anatomical location. Our findings suggest that tumor size and site are predictive of PFS and that wide surgical excision is of vital importance, since traditional cytotoxic chemotherapy has limited efficacy at this site.

The First Ever Reported Case of Primary Synovial Sarcoma of Scalp

Synovial sarcomas are a rare entity with predilection for extremities and joints. The literature suggests that these tumours are rare in the head and neck region. Very few authors have reported their origin in head. Among the ones occurring in the head region, most of them are found to originate from the parotid area. According to our extensive review of available literature, there has been no reported case of the primary case of synovial sarcoma originating from the scalp convexity. We hereby report one such case in a young female which, by far to the best of our knowledge, is the first ever reported case of a synovial sarcoma occurring on the scalp. The tumour is also the largest ever reported in the literature and posed a great surgical and diagnostic challenge to our team. Through this paper, we recommend that synovial sarcoma should be included as a very rare yet possible differential diagnosis for the scalp tumours.

Primary synovial sarcoma of the scalp: Report of case with a clinicopathological and molecular cytogenetic study

Synovial sarcoma (SS) arising primarily in the scalp was scarcely reported. Here we described a subcutaneous mass in the right parietal region of the scalp of a 39year-old male patient. It has been present for 10years and enlarged recently. It was initially suspected as hemangioma by magnetic resonance imaging (MRI), but the histological examination revealed a sarcoma rich of spindle cells reminiscent of SS. Therefore, immunohistochemistry, florescence in site hybridization (FISH), reverse transcription-polymerase chain reaction (RT-PCR) and DNA sequencing were performed to determine the final diagnosis as biphasic SS. The detailed description of primary scalp SS might help differential diagnosis of scalp soft tumors.

Primary synovial sarcoma of the thyroid with locally repeated relapses in short periods: A case report

The primary occurrence of synovial sarcoma (SS) in the thyroid is quite rare. As other SS arise from the head and neck structure, it tends to present poor biological behaviors and is generally treated as a high-grade sarcoma. The present study reports the case of a 31-year-old male who presented a neck mass, involving the thyroid, as shown by ultrasonography. The tumor was resected by total thyroidectomy and diagnosed as SS by histopathology. However, the initial surgery was considered as incomplete (R2) and no adjuvant protocol was followed. At the follow-up, neck recurrences within local lymph nodes were found repeatedly. The tumor grade increased for the metastatic lesions, indicating poorer differentiations with repeated relapses. The accurate evaluations of the primary tumor facilitated it to tailor the initial treatments, otherwise, the prognosis may be deteriorated by inappropriate management.

Diagnostic Approach to Synovial Sarcoma of the Head and Neck Illustrated by Two Cases Arising in the Face and Oral Cavity

In the head and neck region, synovial sarcomas (SS) are rare tumours. We describe the diagnostic approach to SS based on two cases which developed in a 26-year-old male in the face and in a 53-year-old female on the alveolar mucosa of the upper jaw. The demographic profile of the patients was compatible with the literature. Histopathologically, both tumours presented as unencapsulated spindle cell tumours arranged into short fascicles. Although the chromosomal translocation of t(X;18)(p11.2;q11.2), transducin-like enhancer of split 1 (TLE-1) and SMARCB1 antibodies derived from gene expression studies are considered as the most sensitive makers to diagnose SS, these facilities were not available. Therefore, our cases were diagnosed as monophasic fibrous SS, utilizing a panel of immunohistochemical markers, including cytokeratins, EMA, Bcl-2, and CD99 as positive indicators and CD34, SMA, MYO-D, and S-100 as negative indicators. PAS staining was used to identify glycogen and to exclude spindle cell carcinomas and leiomyosarcoma, while Alcian blue was used to identify myxoid ground substance and to exclude nodular fasciitis. In conclusion, SS, although rare, should be included in the differential diagnosis of spindle cell tumours of the face and oral mucosa.

Detection of Rare Variant of SS18-SSX1 Fusion Gene and Mutations of Important Cancer-Related Genes in Synovial Sarcoma of the Lip: Gene Analyses of a Case and Literature Review

Synovial sarcoma (SS) accounts for 5 to 10% of soft tissue sarcomas; however, intraoral SS is rare. Histopathologically, SS shows a biphasic pattern with epithelial and spindle cell components or a monophasic pattern with only spindle cells. The precise diagnosis of SS, especially at an unusual site, is often a challenge to pathologists and clinical oncologists, because the differential diagnosis of SS includes a broad range of tumors, such as soft tissue sarcomas and carcinomas. In the present case, the patient was a 50-year-old woman who presented with the chief complaint of swelling and a slowly enlarging mass of the lower lip in the mucolabial fold region. The mass was covered with intact mucosa and intraoral examination showed no malignant findings. The clinical diagnosis was a benign tumor and a probable salivary gland tumor. Macroscopically, the excised mass also indicated a benign tumor; however, histopathologic findings suggested the diagnosis of SS. For definitive diagnosis, genetic analyses were performed with conventional polymerase chain reaction and next-generation sequencing. As a result, a rare variant of the SS18-SSX1 fusion transcript, which could not be identified by routine procedures for genetic diagnosis, was detected. In addition, 8 missense mutations of cancer-related genes were confirmed. Detection of the fusion transcript is widely used in the diagnosis of SS; however, reported cases of transcript variants of each fusion gene type are limited. Reports of mutational analysis of cancer-related genes on SS also are rare. The accumulation of rare transcript variants and the cytogenetic characters of SS are suggested to be necessary for assuming a genetic diagnosis of SS.

Needle biopsy of mesenchymal lesions of the head and neck: Evolving concepts and new strategies for diagnosis

Sarcomas are a rare and heterogeneous group of neoplasms that can be a significant diagnostic challenge in routine practice. Recent advances in the understanding of molecular mechanisms underlying oncogenesis have led to an array of novel diagnostic tools. Here we review several sarcomas of the head and neck region, focusing on neoplasms with new molecular findings and highlighting novel diagnostic tools.

Pediatric synovial sarcoma in the retropharyngeal space: a rare and unusual presentation

Synovial sarcomas in the head and neck are extremely rare tumors, especially in the pediatric population. 3–5% of synovial sarcomas occur in the head and neck region displaying varied imaging and histopathological features resulting in frequent misdiagnosis. These tumors have a poor prognosis; hence early diagnosis and accurate classification based on imaging, histopathology, and immunohistochemistry are critical for prompt treatment. To the best of our knowledge, imaging findings of pediatric retropharyngeal lipomatous synovial sarcoma have not been reported to date in English medical literature. We report, for the first time, a rare case of retropharyngeal lipomatous synovial sarcoma in a ten-year-old child and discuss the case-specific imaging findings in our patient using magnetic resonance imaging and computed tomography.

Tumor size predicts prognosis of head and neck synovial cell sarcoma

Head and neck synoviosarcoma (HNSS) is uncommon. To the best of our knowledge, the specific clinicopathological characteristics, treatment outcome and prognostic factors of HNSS were uninvestigated at the time of writing, so a meta-analysis was performed. An online data collection was carried out using PubMed and Google Scholar. Studies that reported primary HNSS and the treatment, follow-up time and outcome were chosen for the present study. In total, 93 cases from 26 studies were included for analysis. The study sample consisted of 55 males and 38 females and the median age was 32.1 years (range, 4-76 years). The median follow-up period was 62.1 months (range, 1-373 months). The tumor size was correlated with local recurrence and metastasis of HNSS, as well as with mortality (P=0.001, P<0.0001 and P<0.0001, respectively). The three-year, five-year and 10-year survival rates were 82.1, 80.4 and 78.2% for treatment with surgery alone, and 88.5, 85.5 and 82% for treatment with surgery plus radiotherapy, respectively. A significant tumor size-dependent difference was found between the overall survival (OS) rates (P<0.0001), as tumors that were >5.0 cm in diameter were associated with a worse OS rate (hazard ratio, 6.460; 95% confidence interval, 206-18.917; P=0.001). The tumor size was found to be an independent adverse prognostic factor for the OS of HNSS patients. In conclusion, surgical excision is a mainstream treatment of HNSS and post-operative adjuvant radiotherapy improves the OS rate of HNSS patients.

Synovial sarcoma: defining features and diagnostic evolution

Synovial sarcoma (SS) is a malignant mesenchymal neoplasm with variable epithelial differentiation, with a propensity to occur in young adults and which can arise at almost any site. It is generally viewed and treated as a high-grade sarcoma. As one of the first sarcomas to be defined by the presence of a specific chromosomal translocation leading to the production of the SS18-SSX fusion oncogene, it is perhaps the archetypal "translocation-associated sarcoma," and its translocation remains unique to this tumor type. Synovial sarcoma has a variety of morphologic patterns, but its chief forms are the classic biphasic pattern, of glandular or solid epithelial structures with monomorphic spindle cells and the monophasic pattern, of fascicles of spindle cells with only immunohistochemical or ultrastructural evidence of epithelial differentiation. However, there is significant morphologic heterogeneity and overlap with a variety of other neoplasms, which can cause diagnostic challenge, particularly as the immunoprofile is varied, SS18-SSX is not detected in 100% of SSs, and they may occur at unusual sites. Correct diagnosis is clinically important, due to the relative chemosensitivity of SS in relation to other sarcomas, for prognostication and because of the potential for treatment with specific targeted therapies in the near future. We review SS, with emphasis on the diagnostic spectrum, recent immunohistochemical and genetic findings, and the differential diagnosis.

Pericardial synovial sarcoma, a potential for misdiagnosis: clinicopathologic and molecular cytogenetic analysis of three cases with literature review

Synovial sarcomas arising in unexpected locations may lead to diagnostic challenges. In this report, we describe 3 cases of synovial sarcoma that manifested clinically as primary pericardial lesions. All 3 cases occurred in men in their fourth decade. Fever, cough, chest pain, and chest distress were the most common symptoms. Histologically, 2 of the tumors were spindle cell monophasic, and 1 tumor was biphasic. By immunohistochemical studies, the tumor cells were positive for cytokeratins and epithelial membrane antigen. In addition, the tumor cells displayed focal immunoreactivity for calretinin, cytokeratin 5/6, and HBME-1, resulting in the initial interpretations of malignant mesotheliomas. None of the 3 cases were diagnosed correctly until subsequent molecular cytogenetic assays demonstrated the presence of SYT gene rearrangements. As there are overlapping morphologic features between pericardial synovial sarcoma and mesothelioma, molecular analysis is essential for differential diagnoses.

Synovial sarcoma involving skull base--a retrospective analysis of diagnosis and treatment of 21 cases in one institution

To retrospectively review the diagnosis and treatment outcomes of 21 diagnosed with synovial sarcoma (SS) extending to skull base region and identify prognostic factors for local recurrence and distant metastasis. The clinical and pathological records of 21 synovial sarcoma cases involving skull base treated at Department of Oral and Maxillofacial Surgery, Affiliated to Ninth People's Hospital, Shanghai Jiao Tong University, from 2003 to 2008 were reviewed. Parameters including clinical, radiographic, histological findings, and treatment modalities were analyzed. Prognostic factors influencing overall survival, local recurrence, and metastasis were identified. Categorical variables were compared between groups for local recurrence and distant metastasis by using 2-tailed Fisher exact test. The sample consisted of 8 males and 13 females with a median age of 23. 42.9% of cases showed skull base bone erosion with 9.5% of cases presenting intracranial tumor extension. 52.4% of cases died from recurrence or metastasis with a median survival time of 11 months. Orbital involvement, perineural and cranial invasion along with other factors were statistically significant for their impact on overall survival. Local recurrence was associated with tumors located in the infratemporal space (p=0.01), perineural invasion (p=0.001), pathological grade 3 (p=0.005), and tumor size >5 cm (p=0.008). The aggressive behavior of skull base SS and its close proximity to vital structures make the diagnosis and management a challenge. The study reported high local recurrence rates despite surgical and postoperative radiotherapy. Adjuvant chemotherapy did not seem to affect distant metastasis rates.