Large Monophasic Synovial Sarcoma: A Case Report and Review of the Literature

Synovial sarcomas account for approximately 8% of all soft tissue tumors. The hallmark tumor marker is the t(X;18) translocation, which results in fusion of the SYT gene of chromosome 18 to the SSX gene of the X chromosome, creating most frequently either an SYT-SSX1 or SYT-SSX2 transfusion transcript. Clinically, synovial sarcomas most often present on the extremities and average roughly 7 cm in diameter. Metastatic spread to regional lymph nodes and/or the lungs is common. Because the incidence of this tumor is low, most studies have been retrospective; therefore, management and prognostic interpretation has remained controversial. We report a case of a patient who presented with a slowly growing, unusually large mass on the left forearm of 10 years’ duration. A diagnosis of monophasic synovial sarcoma was confirmed by biopsy. We also review the literature regarding management strategies for synovial sarcomas.