Synovial chondromatosis of the temporomandibular joint: radiologic and histopathologic findings.

Synovial chondromatosis is a formation of multiple intrasynovial nodules resembling osteochondromas, resulting from proliferative changes in the synovial linings of joints; as the disorder progresses, nodules increasingly withdraw from the intrasynovial areas for the joint cavities. This is a relatively unusual case that can arise at unilateral large joints, such as knee, hip, and elbow, with the temporomandibular joint being the rarest one of them. Early recognition of the signs and symptoms with resultant accurate diagnosis, as well as proper surgical treatment, offers patients the best hope of recovery and improved quality of life. We report a conventional radiologic film, computed tomography, magnetic resonance imaging, and histopathologic findings of the synovial chondromatosis presenting as a large right preauricular mass arising from the temporomandibular joint without bone destruction.