Synovial sarcoma of the mandible

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.

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.

Primary synovial sarcoma of bone: A retrospective analysis of 25 patients

AIMS

To evaluate diagnostic accuracy of SSX and SSX-SS18 antibodies in decalcified surgical specimens and outcome of synovial sarcomas (SS) of bone.

METHODS AND RESULTS

Twenty-five cases were classified as bone SS (prevalence 0.32% among malignant primary bone sarcoma). Median age was 34 years (range 9 -79) . 24/25 patients presented with non-metastatic tumors, one with lung metastases. The majority of tumors involved the long bones of extremities with metaphyseal origin. Mean size of the tumor was 7.1 cm. 20 cases (80%) were monophasic and 5 (20%) biphasic. SS18-SSX fusion-specific antibody had 92% sensitivity and 99% specificity for primary bone SS, whereas SSX C-terminus antibody had 100% sensitivity and 94% specificity. FISH analysis was feasible in 9 (36%) cases and detected SS18 rearrangement in all 9 cases. All patients underwent surgical removal of their primary tumor, with adequate margins in 18 (72%) patients. Chemotherapy with metothrexate, cisplatin, doxorubicin, ifosfamide was used in the 7 patients. Two patients with inadequate surgical margins received radiotherapy. With a median follow-up of 80 months (range 6-428), 5-year and 10-year overall survival (OS) were 66.6% and 47.9% respectively and 5-and 10-years disease-free survival (DFS) were 36.8% (95% C.I.: 18.0-55.7%), and 32.2% (95% C.I.: 14.6-51.2%) respectively A significant improvement in 10-years DFS in patients undergoing chemotherapy as compared with patients who did not was observed (p 0.039).

CONCLUSIONS

Our series highlights the utility of SS18-SSX fusion-specific and SSX C-terminus antibodies to support the diagnosis of SS, Adjustment chemotherapy was associated with improved prognosis in this series.

Primary Intraosseous Synovial Sarcoma with Molecular Confirmation: Expanding and Clarifying the Spectrum of This Rare Neoplasm

Synovial sarcoma is a well-known malignant tumor usually originating within deep soft tissues of the lower extremities of adolescents and young adults. Rare radiologically confirmed examples of primary bone synovial sarcoma have been documented, generally in isolated case reports. Herein, we report two cases of primary intraosseous synovial sarcoma, with molecular confirmation, involving the left humerus of a 45-year-old female and the right fourth metatarsal bone in a 36-year-old male. Additionally, we clarify the spectrum of primary intraosseous synovial sarcoma by separately analyzing reported cases with radiographic confirmation of bone origin and molecular support for the diagnosis. There are clinicopathologic differences between those tumors with documented molecular confirmation and those lacking such confirmation, specifically regarding their anatomic distribution (p < 0.0001). Regarding the radiology of our two cases, the humeral lesion appeared almost entirely intramedullary without soft tissue extension; the midfoot lesion demonstrated a destructive, metatarsal-centered bone lesion, initially thought clinically to represent primary bone osteosarcoma. The diagnoses of monophasic synovial sarcoma were rendered via core needle biopsies, with molecular FISH confirmation of SYT gene rearrangement. Clinical follow-up data was only available for the female patient with the primary humeral lesion, who underwent surgical resection, with no local recurrence or distant metastasis at 7 months postsurgery. To our knowledge, these are the first reported examples of molecularly confirmed, primary intraosseous synovial sarcomas of the humerus and metatarsal bones. Primary intraosseous synovial sarcomas with molecular confirmation differ clinically from those lacking it; however, the demographic features and metastatic potential appear similar to primary soft tissue synovial sarcoma.

Primary intraosseous hybrid epithelioid schwannoma/perineurioma in the proximal tibia: a case report of benign hybrid neoplasm with local hypercellularity

Background

As a new entity included in the 4th edition of the WHO classification of tumours of soft tissue and bone in 2013, hybrid peripheral nerve sheath tumours are benign composite neoplasms that demonstrate features of more than one type of nerve sheath tumour, with a wide age distribution and a predilection for superficial location. Those involving deep sites are relatively rare. To the best of our knowledge, only one case of primary intraosseous hybrid peripheral nerve sheath tumours has been documented. In this article, we report another case of hybrid peripheral nerve sheath tumours occurring in bone with different clinical, radiological and pathological features from those in the previously reported cases.

Case presentation

A 28-year-old female presented with a painful nodule in the right tibia. Radiological examination revealed an oval eccentric osteolytic lesion in the proximal tibia. Histologically, the circumscribed but unencapsulated lesion demonstrated biphasic cellular differentiation. Bland, small epithelioid cells arranged in clusters in the myxoid or collagenous stroma and inconspicuous spindle cells scattered in the hypercellular areas were suggested to originate from Schwann cells according to the detection of S100. Both the elongated spindle cells with thin, wavy nuclei and the spindle cells in fascicular or storiform pattern in hypercellular areas showed a positive immunoreaction for epithelial membrane antigen, indicating perineurial differentiation. Based on histological and immunochemical examinations, the patient was diagnosed with hybrid epithelioid schwannoma/perineurioma. The lesion was resected and has not recurred for 8 months since resection.

Conclusion

The present case is the second primary intraosseous hybrid peripheral nerve sheath tumour to be reported. This is also the first reported intraosseous tumour composed of epithelioid schwannoma and perineurioma with hypercellularity, indicating diverse involvement sites and a wide range of histological features among hybrid peripheral nerve sheath tumours. Awareness of such diversity is critical for accurate diagnoses. The morphological overlap with other spindle and epithelioid cell neoplasms, especially pure peripheral nerve sheath tumours, requires that immunochemical and molecular examinations be used as objective tools to provide the necessary information for a differential diagnosis.

Electronic supplementary material

The online version of this article (10.1186/s13000-019-0829-x) contains supplementary material, which is available to authorized users.

Genetic and molecular reappraisal of spindle cell adamantinoma of bone reveals a small subset of misclassified intraosseous synovial sarcoma

Adamantinoma represents a distinct group of bone tumors showing both mesenchymal and epithelial differentiation most commonly involving the tibial diaphysis. Most adamantinomas contain a fibro-osseous component and an epithelial component consisting of squamous or basaloid cells. Adamantinomas are considered malignant neoplasms requiring en bloc excision that frequently recur locally and can rarely metastasize. Rare adamantinomas show an epithelial component consisting predominantly of monomorphic spindle cells, which, combined with an epithelial immunophenotype, can mimic monophasic synovial sarcoma. Synovial sarcoma is very rare in bone. It is considered a high-grade sarcoma that typically necessitates chemotherapy. However, the relationship between spindle cell adamantinoma and intraosseous synovial sarcoma has not been investigated. The current study was prompted by identification of a presumed spindle cell adamantinoma of the tibia with diffuse keratin expression that harbored a SS18 gene region rearrangement. FISH of eight additional bone tumors initially classified as spindle cell adamantinoma based on clinicoradiopathologic findings revealed one additional case with SS18 rearrangement. Histologically, both intraosseous synovial sarcoma and spindle cell adamantinoma demonstrated uniform fusiform nuclei with scant cytoplasm, short fascicles and low mitotic activity. The adamantinomas, but not the synovial sarcomas, were more likely to show overt epithelial differentiation in the form of pseudoglands or squamous nests. Immunohistochemistry of all cases, irrespective of SS18 status, showed diffuse keratin positivity in the spindle cell component, and less consistent EMA positivity. Clinical follow-up was available in both intraosseous synovial sarcomas, one of which recurred and the other metastasized. Two of the six spindle cell adamantinomas with follow-up metastasized. The above findings highlight the morphologic and immunophenotypic overlap between spindle cell adamantinoma and intraosseous synovial sarcoma of the tibia. Investigation of SS18 status to exclude synovial sarcoma is suggested prior to rendering a diagnosis of spindle cell adamantinoma.

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.

Primary biphasic synovial sarcoma of gingiva: Report of a rare case

Synovial sarcoma is a mesenchymal spindle cell tumor with variable epithelial differentiation. It is unrelated to the synovium as the name might suggest but arises in the soft tissues of the extremities around the knee joints and tendon sheaths. The tumor cells are thought to resemble normal synovial tissue histopathologically, hence named “synovial sarcoma” (SS). Head and neck lesions are less common and oral cavity involvement is extremely rare. Few cases in tongue, soft palate, mandible, buccal mucosa and floor of mouth have been described in the literature. Here, we probably report the first case of primary biphasic SS (BSS) involving gingiva in the retromolar area of the mandible in a 21-year-old male patient.

Biphasic synovial sarcoma in mandibular region

The term synovioma was coined by Smith in 1927, and later in 1936 Knox suggested the name synovial sarcoma. It occurs primarily in the paraarticular regions, usually in close association with tendon sheaths, bursae, and joint capsules. On rare occasions it may be seen in areas without any apparent relationship to synovial structures as in parapharyngeal region or the abdominal cavity. The first description of synovial sarcoma in the head and neck region was by Pack and Ariel in 1950. The majority of these tumors seem to take origin from paravertebral connective tissue spaces and manifest as solitary retropharyngeal or parapharyngeal masses near the carotid bifurcation. Synovial sarcoma has been reported in soft palate, tongue, maxillofacial region, angle of mandible, sternoclavicular region, scapular region, and the esophagus. We report a case of 28-year-old male patient with synovial sarcoma in mandibular region with biphasic pattern.

Primary synovial sarcoma involving the submandibular gland

Synovial sarcoma represents 5.6%-10% of all soft-tissue sarcomas. Adolescents and young adults are most frequently affected, mainly in the deep soft tissue of the extremities. Only 10% of synovial sarcomas affect the head and neck region; most of these are biphasic. We describe a case of an 18-year-old man who complained of a mass in the right submandibular region that had been present for approximately 12 months. On surgical removal, microscopic analysis showed a tumor formed by sheets of malignant spindle cells involving the submandibular gland. Immunohistochemistry displayed positivity for AE1/AE3, CK18/8, epithelial membrane antigen, CD99, CD56, and TLE-1. Based on these immunohistochemical and histopathologic features, a diagnosis of monophasic synovial sarcoma was rendered. The patient was treated with adjuvant radiotherapy and after 1 year was free of disease. To the best of our knowledge, this is the first reported case of synovial sarcoma involving the submandibular gland.

Intraosseous synovial sarcoma of the proximal tibia. Int J Surg Oncol. 2011;2011:184891. [PMID: 22312495 PMCID: PMC3265277 DOI: 10.1155/2011/184891]

Synovial Sarcoma is a malignant mesenchymal tumor that comprises 5–10% of all soft tissue sarcomas. The mean age of onset is thirty years old. Intraosseous presentation is very rare and has only been documented a few times. We report herein a case of a 53-year-old man with synovial sarcoma arising in the left proximal tibia. The patient underwent a wide surgical resection and reconstruction, followed by adjuvant chemotherapy. Three years later, the patient developed a local recurrence that resulted in an above-the-knee amputation. Eight months later, the patient has completed chemotherapy and is without signs of recurrence. The current recommended treatment for synovial sarcoma is wide surgical resection followed by chemotherapy as well as long-term followup. Despite improved surgical techniques, long-term survival rates remain low.

Diagnosis and treatment of primary synovial cell sarcoma that occurred in the left mandible body: a case report and literature review

OBJECTIVE

The authors describe a case of synovial sarcoma in the left mandible body.

STUDY DESIGN

The primary tumor was investigated morphologically and immunohistochemically. The patient was treated with madibulectomy and lymph node dissection, which was followed by an immediate reconstruction of the left mandible with a revascularized osteomyocutaneous fibula free flap.

RESULTS

The primary tumor was described as gingival sarcoma. The initial preoperative biopsy showed positive staining for cytokeratin, vimentin, smooth muscle actin, and desmin by immunohistochemistry. The definitive diagnosis of monophasic synovial sarcoma was established following postoperative excision biopsy. Antigens of S-100 and CD99 displayed positive staining but epithelial membrane antigen, Bcl-2, and CD34 were negative. Also, no metastasis or other bone swelling was observed by radionuclide survey suggesting the left mandible was the primary lesion of occurrence.

CONCLUSIONS

Synovial sarcoma is an uncommon soft tissue malignant neoplasm. This is the sixth case of primary synovial sarcoma occurring in the jaw.

Malignant inguinal monophasic synovial sarcoma: report of a case and review of the literature

Background

A synovial sarcoma (SS) is an aggressive soft tissue tumor that classically occurs in the extremities near, but rarely within large joints, in young adults. Variable symptoms and clinical manifestations may be encountered and a definite diagnosis should depend on pathological results. This poses certain difficulties in arriving at a prompt diagnosis and appropriate treatment.

Case presentation

We report the case of a 68-year-old woman patient who presented an inguinal mass with swelling and pain in the right lower limb. She underwent surgery, and later received systematic intravenous chemotherapy. The pathological studies, especially the specific chromosomal translocation of a t(X;18) (p11.2;q11.2), confirmed the diagnosis as a synovial sarcoma. To the best of our knowledge, this is the first report of a monophasic synovial sarcoma in the inguinal region.

Conclusion

Besides making the readership aware of the rarity of location and age of this present case, this report distinctly highlights the great value of a molecular analysis of an SYT associated genetic alteration in the diagnosis of synovial sarcoma occurring at rare sites especially when immunochemical results are equivocal.

Synovial sarcoma of primary bone origin: a rare case in a rare site with atypical features

Synovial sarcoma of bone origin is extremely rare and difficult to diagnose. We present a case in which the lesion arose in the cortex of the distal tibia. It showed heterogeneous intermediate signal intensity on T1-weighted images and heterogeneous intermediate to low signal intensity on T2-weighted images with heterogeneous contrast enhancement on MRI. The lesion was confirmed as synovial sarcoma using a combination of histological and molecular genetic studies.