Synovial sarcomas of the head and neck: comparative analysis with synovial sarcoma of the extremities

Synovial sarcoma of the larynx, a rare and unusual entity. Case report

INTRODUCTION AND IMPORTANCE

Synovial sarcoma (SS) is a high-grade malignancy, accounting for 2.5-3.5 % of all primary H&N sarcomas and 0.1 % of all H&N cancers.

CASE PRESENTATION

A 26-year-old woman presents with dyspnea and dysphonia. Flexible nasofibrolaryngoscopy and CT were performed with evidence of a laryngeal tumor. Total laryngectomy was performed due to a histopathological report of laryngeal synovial sarcoma.

CLINICAL DISCUSSION

Primary SS of the H&N is rare and accounts for <5 % of all synovial sarcomas and laryngeal-origin SS represents a rare subset within H&N sarcomas. There are 3 different histologic subtypes: biphasic, monophasic and poorly differentiated. Immunohistochemistry plays a crucial role in histologic diagnosis. The optimal treatment of synovial sarcoma is multimodal, depending on its size, location and grade. Radical surgical excision with negative margins is generally accepted as the mainstay of treatment. Disease recurrence is a significant problem, with up to 45 % of patients developing local disease and 33 % developing metastatic disease.

CONCLUSIONS

Laryngeal SS is exceptionally rare, requiring complex, multidisciplinary management.

Oncologic Outcomes in Patients with Localized, Primary Head and Neck Synovial Sarcoma

Background: this study aims to evaluate the survival outcomes of patients suffering from head and neck synovial sarcoma (HNSS), especially in relation to patients with a localized disease at diagnosis. Methods: this retrospective chart review includes 57 patients diagnosed with primary HNSS between 1981 and 2020 who presented with a localized disease at diagnosis. Overall survival (OS) from diagnosis, local recurrence-free survival (LRFS), and metastasis-free survival (MFS) from the end of the primary tumor treatment are estimated. The Kaplan-Meier method, the log-rank test, and the Cox proportional hazards regression are used. Results: the 5-year OS, LRFS, and MFS are estimated at 80.4% (95% CI: 66.6%, 88.9%), 67.7% (95% CI: 50.0%, 80.4%), and 50.6% (95% CI: 34.4%, 64.8), respectively. Compared to patients undergoing surgical resection alone, those receiving radiation therapy (RT) with surgery have better LRFS (HR: 0.03, 95% CI: 0.001, 0.57), and those undergoing neo/adjuvant chemotherapy with surgery and RT have better MFS (HR: 0.10, 95% CI: 0.01, 0.95). Moreover, among the patients with tumors ≥ 4 cm, those subject to neo/adjuvant chemotherapy have significantly better MFS (5-year MFS: 53.2%, 95% CI: 29.0%, 72.5%) than those treated with surgery and RT alone (5-year MFS: 20.0%, 95% CI: 0.8%, 58.2%) (LR-p = 0.003). Conclusions: overall, the prognosis of HNSS patients looks favorable. Perioperative RT significantly improves local control, and perioperative chemotherapy plays a vital role in delaying metastasis formation in patients with primary HNSS when diagnosed with a localized disease. Importantly, we recommend that systemic therapy should be considered for HNSS patients with tumors ≥ 4 cm.

Synovial Sarcoma of the Temporomandibular Joint and Infratemporal Fossa: A Case Report

Temporomandibular joint (TMJ) and infratemporal fossa (ITF) tumors, even though rare, present diagnostic complexities due to their nonspecific symptoms. Synovial sarcoma comprises 5-10% of adult soft-tissue sarcomas and is uncommon in the head and neck and exceptionally rare in the TMJ/ITF region. We presented a case of monophasic synovial sarcoma affecting the left TMJ/ITF in a 24-year-old man with severe preauricular pain who was misdiagnosed with temporomandibular disorder for 3 years. When in-depth evaluations uncovered a 40 mm tumor adjacent to the TMJ, extensive resection and immediate reconstruction were conducted, followed by postoperative radiotherapy and adjuvant chemotherapy. Magnetic resonance imaging photos of the early stage and after 3 years of tumor progression, initial signs and symptoms, and intraoperative images allowed tumor evolution assessment.

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.

Intraosseous synovial sarcoma of the mandible: A case report and review of the literature

Synovial sarcoma (SS) is a malignant soft tissue tumor that usually arises in the para-articular regions of the extremities. Only nine cases of SS in the mandible have been reported to date. The present study described a case of SS arising from the left mandible. A 54-year-old woman was referred to Kyushu University Hospital (Fukuoka, Japan) with a complaint of numbness in the left mental nerve area. Computed tomography revealed replacement of the left mandibular bone marrow with soft tissue and destruction of the mandibular canal. Magnetic resonance imaging revealed an isointense mass on T1-weighted images and hyperintensity on T2-weighted images. The tumor showed homogeneous enhancement. A biopsy was performed, and monophasic SS was diagnosed based on immunohistochemical staining features and genetic analysis. Hemimandible dissection and supraomophyoid neck resection were performed with fibular osteocutaneous flap reconstruction, followed by adjuvant chemotherapy. There was no evidence of recurrence or distant metastases. The present study also reviewed the clinical, imaging, histological, and immunohistochemical features of the SS in the mandible.

Primary synovial sarcoma of the thyroid gland: a CARE compliant case report and literature review

Rationale

Synovial sarcoma is a subtype of soft tissue sarcoma. Synovial sarcoma in the head and neck region is relatively unusual. Primary synovial sarcoma of the thyroid gland (PSST) is first reported in 2003 by Inako Kikuchi. PSST is extremely rare with only 15 cases documented globally. PSST shows rapid disease progression and a relatively poor prognosis. However, diagnosis and therapy are challenging for clinical surgeons. In this article, we reported the 16th PSST case and reviewed the PSST cases globally for further clinical application.

Patient concerns

The patient was referred to us because of gradually worsened dyspnea and dysphagia for 20 days. Physical examination showed a 5 × 4 cm mass with a clear boundary and good mobility. Contrast-enhanced ultrasonography (CEUS) and computed tomography (CT) showed a mass in the isthmus of the thyroid gland. The imageology diagnosis tends to be a benign thyroid nodule.

Diagnosis

After surgery, histopathology, immunohistochemistry, and fluorescence, in situ hybridization indicated the mass to be primary synovial sarcoma of the thyroid gland with no local and distant metastasis.

Interventions

The patient underwent total thyroidectomy and dissected the lymph nodes in the central compartment. This patient received postoperative chemotherapy (a combination of ifosfamide and epirubicin for five cycles). Patients tolerated chemotherapy well. No recurrence was found during the 9-month follow-up.

Lessons

Although PSST is an extremely rare disease, we should raise our awareness when we encounter a rapidly growing, cystic-solid mixed thyroid mass with neck compression symptoms to avoid misdiagnosis. Intraoperatively, surgeons should refine surgical procedures to avoid capsular rupture and tumor local implantation metastasis. Intraoperative frozen section pathology is necessary sometimes, especially when the diagnosis could not be established before surgery.

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

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

The effect of adjuvant therapies on long-term outcome for primary resected synovial sarcoma in a series of mainly children and adolescents

Background

The benefit of adjuvant therapy in synovial sarcoma (SS) treatment is under debate. Long-term follow-up data are missing.

Methods

SS patients treated in the consecutive trials CWS-81, CWS-86, CWS-91, CWS-96, CWS-2002-P, and the SoTiSaR-registry till 2013 were analyzed.

Results

Median age of 185 patients was 13.9 years (0.1–56)—with median follow-up of 7.4 years for 163 survivors. Most tumors (76%) were located in extremities. Size was < 3 cm in 58 (31%), 3–5 cm in 59 (32%), 5–10 cm in 42 (23%), and > 10 cm in 13 (7%) (13 missing). In 84 (45%) tumors, first excision was complete (R0 corresponding to IRS-I-group) and in 101 (55%) marginal (R1 corresponding to IRS-II-group). In a subsequent surgical intervention during chemotherapy, R0-status was accomplished in 23 additional IRS-II-group patients with secondary surgery. Radiotherapy was administered to 135 (73%), thereof 62 with R0-status and 67 R1-status (6 missing information). Adjuvant chemotherapy was administered to all but six patients. 5-year event-free (EFS) and overall survival (OS) was 82.9% ± 5.7 (95%CI) and 92.5% ± 3.9. Local and metastatic relapse-free survival was 91.3% ± 4.3 and 92.3% ± 4.1 at 5 years, respectively. In the multivariate analysis, tumor size and no chemotherapy were independently associated with EFS. Size and site were associated with OS. In a detailed analysis of local and metastatic events, tumor size was associated with an independent risk for developing metastases. No independent factor for suffering local recurrence could be identified.

Discussion

Omission of chemotherapy in a non-stratified way seems not justified. Size governs survival due to high linear association with risk of suffering metastatic recurrence in a granular classification.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-021-03614-6.

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.

Sinonasal synovial sarcoma: evaluation of the role of radiological and clinicopathological features in diagnosis

AIM

To explore the value of radiological and clinicopathological features in the diagnosis of sinonasal synovial sarcomas (SS).

MATERIALS AND METHODS

Six patients with sinonasal SS were studied retrospectively using computed tomography (CT; n=6) and magnetic resonance imaging (MRI; n=4). The radiological and clinicopathological findings in this series were reviewed.

RESULTS

Three lesions were located, in both the nasal cavity, and the paranasal sinuses; one was located in the nasal cavity and nasopharynx, and the remaining two were located restrictively within the nasal cavity. An aggressive nature (invasion of adjacent structure) was found in four cases. At CT, lesions were found with isodensity with calcification mainly in the peripheral areas. Bony changes were visible in all cases. Five cases showed marked heterogeneous enhancement, and three cases contained necrotic or cystic areas. At MRI, haemorrhage was observed in three cases. All cases demonstrated the "triple sign", and two high-grade SS showed a "cobblestone-like" appearance on T2-weighted imaging (WI). All time-signal intensity curves (TICs) were of the washout type. The mean apparent diffusion coefficient (ADC) values of the two high-grade cases were lower than those of the low-grade or intermediate-grade cases. Histopathologically, all but one was of the monophasic type. During the 8-40 month period of follow-up, recurrence occurred in four cases.

CONCLUSIONS

A sinonasal tumour exhibiting characteristic calcification and bony change, together with haemorrhage, "triple sign" or "cobblestone-like" appearance, should engender a diagnosis of SS.

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.

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

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

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.

Laryngeal Dysplasia, Squamous Cell Carcinoma, and Variants

Squamous cell carcinoma (SCC) is a malignant epithelial tumor showing evidence of squamous differentiation. It is the most common malignancy of the larynx, with several variants (verrucous, exophytic or papillary, spindle-cell, basaloid, acantholytic, adenosquamous) recognized, with well-established precursor lesions. Dysplasia is now separated into only low-grade and high-grade categories. Each SCC variant has unique cytomorphologic features and histologic differential diagnoses that are important to consider, as management and outcomes are different.

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.

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.

Primary renal synovial sarcoma: computed tomography imaging findings

BACKGROUND

A synovial sarcoma arising from the kidney is extremely rare. To date, few data are available on their radiological features.

PURPOSE

To identify the computer tomography (CT) imaging findings of primary renal synovial sarcomas (PRSSs).

MATERIAL AND METHODS

Five cases of PRSS confirmed by histopathological and cytogenetic studies were retrospectively analyzed. All patients had undergone unenhanced and multiphase enhanced CT examinations (one patient underwent CT twice). The CT characteristics, including shape, size, margin, attenuation, and enhancement pattern after intravenous contrast medium injection, were analyzed.

RESULTS

The study involved two female and three male patients (mean age, 27.4 years; range, 15-43 years). Unenhanced CT showed completely or partly well-defined masses, with heterogeneous (n = 5) or homogeneous (n = 1) patchy low density. On multiphase contrast-enhanced CT, in five of the six CT examinations, the tumors appeared as solid-cystic masses with cyst walls or pseudo-capsules, and demonstrated moderately heterogeneous (n = 5) and/or septate enhancement (n = 2), with a "rapid wash-in and slow wash-out" pattern of enhancement in the solid component. Only one tumor showed a simple cyst appearance and developed an irregular, intratumoral, septate soft density 8 months later. A renal vein and inferior vena cava thrombus was noticed in one patient, while lymphadenopathy was not observed in any patient.

CONCLUSION

PRSS should be included in the differential diagnosis when an adolescent or young adult presents with a renal neoplasm appearing as a solid-cystic mass with well-defined borders, a cystic wall or pseudo-capsule, heterogeneous or septate enhancement, a "rapid wash-in and slow wash-out" pattern of enhancement in the solid component, and no sign of lymphadenopathy.