The current study used the FISH technique as an ancillary tool to detect MDM2 amplification and CHOP rearrangement in liposarcomas and SYT rearrangement in synovial sarcomas, aiming at differentiating liposarcoma and synovial sarcoma subtypes from other morphologically similar sarcomas and benign conditions. The gene discussed is MDM2; the disease is synovial sarcoma.