Huge primary mediastinal synovial sarcoma fully occupying the right hemithorax

Abstract

Primary mediastinal synovial sarcomas are exceedingly uncommon tumors. Herein, we present the case of primary mediastinal synovial sarcoma (monophasic spindle cell-shaped variant) fully occupying the right hemithorax in a 37-year-old woman who presented to clinic with a 2-month history of right-sided chest pain and shortness of breath. Although extremely rare, however, synovial sarcoma should be considered in the differential diagnosis of all monophasic and biphasic spindle cell neoplasms of the mediastinum. Despite molecular testing for (t[x; 18] [p11.2; q11.2]) is characteristically positive in 90% of synovial sarcoma cases, it is not routinely done. Histopathological and immunohistochemical analyses can greatly confirm the diagnosis. Optimal surgical resection is the standard of care. Adjuvant therapy (radiotherapy and/or chemotherapy) is indicated in inoperable advanced disease or unachieved surgical tumor-free surgical margins. Prognosis is poor with a 5-year overall survival (OS) rate of 35.7%. Early diagnosis and prompt appropriate management yield better disease-free and OS rates.

Rare Case of Mediastinal Synovial Sarcoma in an Indonesian Woman

“…Immunohistochemical examination of synovial sarcoma was found to be positive for epithelial membrane antigen BCL-2, CD99, S-100, and Vimentin (2) . S100 and EMA antibodies were found negative, thus further examination of cytogenetic analysis examination is needed to confirm the presence of chromosome t (x; 18) (p11; q11) translocation that is found in 90% of synovial sarcoma cases (7) .…”

“…The prognosis of this tumor is estimated at 35.7% for the 5-year survival rate. Factors causing poor clinical and microscopic prognosis include age more than 20 years, male patient, incomplete resection, tumor size more than 5 cm, neurovascular infiltration, extensive tumor necrosis, high rates of mitotic features (>10/10 HPF), tumor histology of undifferentiated high grade, biphasic variant, reciprocal SYT-SSXI chromosome translocation, and the presence of distant metastases (7,11) . The difference between mediastinal synovial sarcoma and tumor of thymic origin is radiological results.…”