Synovial sarcoma.

Joints and adjacent tissue are probably the site of origin of synovial sarcomas. From the literature review, however, it appears that in some instances synovial sarcoma may be of extra-articular soft tissue origin. This type of tumor should be considered highly malignant. It appears that the incidence is low among black Americans. The etiology is not known definitely, but trauma is incidental rather than a predisposing factor.