INTRAARTICULAR INVOLVEMENT BY SYNOVIAL SARCOMA: FIRST DIAGNOSED ON SYNOVIAL FLUID ASPIRATION

Synovial Sarcoma is a soft tissue neoplasm having incidence 6%- 10%.Malignant cells in synovial fluid aspiration is extremely rare. Only 5%cases have been reported to have joint cavity involvement. We report a case of synovial fluid malignant effusion of knee joint in a 35 year old male who presented with a left popliteal fossa swelling. Synovial fluid aspiration revealed tumor cell clusters with anaplastic morphology .Subsequent biopsy showed spindle cell tumor consistent with synovial sarcoma. This is a rare presentation of synovial sarcoma with the presence of malignant cells in synovial fluid.