Synovial sarcoma (SS) is the fourth most common soft tissue sarcoma that predominantly occurs in the lower limbs of children and young adults. This tumor accounts for approximately 5% to 10% of soft tissue tumors, has a poor prognosis, and may occur in other areas of the body such as the head and neck, heart, abdominal wall, mediastinum, and lung, in addition to the extremities. SS18 rearrangements are found exclusively in this tumor and have been widely used to establish an accurate diagnosis. The major translocation in synovial sarcoma is  t(X;18)(p11.2;q11.2) which results in fusion of SS18 with one of the SSX (synovial sarcoma, X breakpoint) genes on the X chromosome (SSX1 or the SSX2 gene (or, rarely, SSX4)). SS18 gene (synovial sarcoma translocation, chromosome 18) codes the subunit of BAF chromatin remodeling complex.