Translocations involving the region 18q11.2 are found in over 90% of synovial sarcoma. Among soft tissue sarcomas, synovial sarcoma is one of the most common and classically occurs in the extremities of young adults with greater prevalence in males even though, the occurrence of synovial sarcoma has also been described in a wide variety of anatomical locations and in all ages. The most frequent translocation involving the SS18 gene region is t(X;18) (p11.23;q11.2) juxtaposing the SS18 gene in 18q11.2 either next to the SSX1 (synovial sarcoma, translocated to X chromosome) or the SSX2 gene, or very rarely to the SSX4 locus located in Xp11.23. Complex translocations involving other chromo-somes are observed in less than 10% of synovial sarcomas. In combination with histopathological diagnosis, detection of SS18 rearrangements via FISH analysis is a valuable tool to confirm the diagnosis of synovial sarcoma.