Villonodular synovitis with synovial chondromatosis.

Pigmented villonodular synovitis and synovial chondromatosis are uncommon benign lesions involving the articular surfaces of diarthrodial joints. Reported is a case of a benign synovial lesion of the temporomandibular joint, which was clinically thought to be a malignant parotid compartment tumor, showing histologic features of both pigmented villonodular synovitis and synovial chondromatosis. A review of the literature reveals a single case in which cartilaginous bodies were found in the joint; however, the synovial tissue showed features of only villonodular synovitis, with no mention of cartilaginous foci.