Poorly differentiated synovial sarcoma of the sphenoid sinus: report of the first case and review of synovial sarcomas of the sinonasal tract

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.

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.

High-grade myoepithelial carcinoma can show histologically undifferentiated/anaplastic features

High grade malignant tumors with a poorly-/un-differentiated morphology pose significant diagnostic challenges. Increasingly, the use of adjunct immunohistochemical and molecular tests to characterize and delineate the histopathologic phenotype of these tumors has become necessary, particularly in head and neck tumors. Recently, several entities with a poorly-/un-differentiated light microscopic morphology have been defined based on specific immunohistochemical and genetic characteristics. We herein describe two cases of high-grade myoepithelial carcinoma, one occurring in the submandibular gland and the other occurring in the left nasal cavity, both showing undifferentiated histological and anaplastic cytomorphological features. This led to very broad differential diagnostic considerations and the diagnosis was only established after extensive immunohistochemical studies. Molecular testing for HPV was negative in both cases. Gene fusion analysis using a targeted sequencing assay (Archer® FusionPlex® system) did not identify fusions involving PLAG1, HMGA2, EWSR1 or ALK genes in either case. The submandibular tumor showed an aggressive clinical course, with diffuse pulmonary metastases at presentation, whilst the nasal cavity tumor showed only localized disease. Awareness of a subcategory of high-grade myoepithelial carcinomas with undifferentiated light microscopical features is of significant importance in antibody selection for immunohistochemical investigation of poorly-/undifferentiated malignant tumors in the head and neck region. This histological variant of myoepithelial carcinoma adds to the growing list of differential diagnoses in this diagnostically complex and multifaceted field.

Treatment, outcomes, and demographics in sinonasal sarcoma: a systematic review of the literature

Background

Sarcomas comprise a diverse group of soft tissue mesenchymal malignancies. The sinuses and nasal region are a relatively rare site of sarcomas.

Methods

Retrospective review of the literature on sinonasal sarcomas from 1987-2017. Data were analyzed for demographics, treatment type, stage, and histopathologic type. Kaplan-Meier analysis was used to assess and compare survival.

Results

A total of 198 cases of sinonasal sarcoma were identified and analyzed. The median age at diagnosis was 39 years. Overall 5-, 10-, and 20-year survival was 61.3%, 58.9%, and 49.1%, respectively, and disease-free 5-, 10-, and 20-year survival was 53.2%, 49.1%, and 38.3%, respectively. Lymph node metastasis was present at diagnosis in 3.0% of cases, and distant metastasis was present in 3.5% of cases. On univariate analysis T stage, overall stage, treatment type, histopathologic subtype, and presence of distant metastasis significantly affected survival. On multivariate analysis overall stage alone significantly predicted overall survival. Open vs. endoscopic surgery, total radiation dose, and presence of neck metastasis did not significantly affect survival. Combined modality treatment was associated with higher survival rates than single modality therapy.

Conclusions

Sinonasal sarcoma is a relatively rare malignancy. Lower T and overall stage, lack of distant metastasis, and multimodality therapy were associated with improved survival. Certain histopathologic subtypes were associated with poorer survival.

Electronic supplementary material

The online version of this article (10.1186/s12901-018-0052-5) contains supplementary material, which is available to authorized users.

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.

Sinonasal Tract Solitary Fibrous Tumor: A Clinicopathologic Study of Six Cases with a Comprehensive Review of the Literature

Solitary fibrous tumors (SFTs) are well recognized in the head and neck region, but rarely arise in the sinonasal tract (SNT). Six primary SNT SFTs were identified in the files of Southern California Permanente Medical Group between 2006 and 2017. The patients included five males and one female ranging in age from 33 to 72 years (mean 52 years), most of whom presented clinically with nasal obstruction. Three tumors involved the nasal cavity alone, one involved the paranasal sinuses, and two involved both the nasal cavity and paranasal sinuses. Histologically, the tumors were characterized by a variably cellular proliferation of cytologically bland spindle cells within a collagenous stroma with prominent interspersed branching vessels. Mitotic activity was low (range 0-2 per 10 high power fields) and there was no evidence of pleomorphism or tumor necrosis. Surface ulceration was noted. By immunohistochemistry, the lesional cells were positive for CD34, STAT6 and bcl-2. Clinical follow up information was available for all patients (range 32-102 months; mean 72 months). There were no recurrences or metastases and all were alive with no evidence of disease at last follow-up. SFTs rarely affect the SNT, but should be considered in the differential diagnosis of SNT mesenchymal lesions. Immunohistochemical expression of STAT6 can aid in diagnosis and separation of SFT from other spindle cell lesions occurring at this anatomic site. In combination with cases reported in the literature, primary SNT SFT behave in an indolent manner with conservative treatment.

Undifferentiated sarcoma of the sphenoid sinus

Paranasal sinuses sarcomas are rare and no treatments have been established. We report a young-adult case of sphenoid sinus sarcoma treated by carbon-ion radiotherapy. The patient presented with progressive left-sided visual impairment. A tumor was then identified and partial resection by transnasal approach was performed. The resected mass showed typical morphology of mesenchymal tumor, and morphological and molecular analyses ruled out a predominant-differentiation phenotype. The pathological diagnosis was undifferentiated sarcoma. The residual lesion was treated with carbon-ion radiotherapy, and tumor progression was absent for one year. The patient died of the tumor regrowth 20 months after initial diagnosis. Although this case had a poorer outcome compared with cases of the more-common sarcoma types, our experience suggested that carbon-ion radiotherapy is potentially beneficial in unresectable undifferentiated sarcomas cases of sphenoid sinus.

Biphenotypic sinonasal sarcoma: an expanded immunoprofile including consistent nuclear β-catenin positivity and absence of SOX10 expression

Biphenotypic sinonasal sarcoma (BSNS) is a recently recognized low-grade sarcoma that exhibits both neural and myogenic differentiation. This unique dual phenotype stems from recurrent rearrangements in PAX3, a transcription factor that promotes commitment along both lineages. While identification of PAX3 rearrangements by fluorescence in situ hybridization (FISH) can confirm a BSNS diagnosis, this assay is not widely available. This study evaluates whether an expanded immunohistochemical panel can facilitate recognition of BSNS without molecular analysis. Eleven cases of BSNS were identified from the surgical pathology archives of two academic medical centers. In 8 cases, the diagnosis was confirmed by FISH using custom probes for PAX3. In 3 cases, FISH failed but histologic and immunophenotypic findings were diagnostic for BSNS. All 11 BSNS (100%) were at least focally positive for S100 as well as calponin and/or smooth muscle actin. In addition, 10 (91%) of 11 expressed nuclear β-catenin, 8 (80%) of 10 expressed factor XIIIa, 4 (36%) of 11 expressed desmin, and 3 (30%) of 10 expressed myogenin. All 11 tumors were negative for SOX10. While no single marker resolves immunohistochemical overlap between BSNS and its histologic mimickers such as nerve sheath tumors, an extended immunohistochemical panel that includes β-catenin and SOX10 helps to support the diagnosis of BSNS without the need for gene rearrangement studies.

Sinonasal small round blue cell tumors: An approach to diagnosis

The differential diagnosis for small round cell tumors in the sinonasal tract is diverse and as the body of literature documenting not only uncommon presentations but also availability of ancillary studies grows, so does the need for a reminder to take a conservative and thorough approach before rendering a diagnosis. Small tissue samples are particularly problematic, with limitations that include volume of tumor cells available for studies, lack of architectural context and a non-specific gross description. Incorporation of patient history and presentation, radiologic findings, clinical impression and concurrent studies often guide the course of studies performed by the pathologist. If these are non-specific, the pathologist may need to perform ancillary studies, including a broad panel of immunohistochemical stains and molecular studies. If tissue is limited, a precise classification may not be achievable. Although the expectation to render a definitive diagnosis is high, the pathologist should never feel compelled to go further with a diagnosis than the tissue itself supports.