Extra-articular synovial chondromatosis of the temporomandibular joint - Pitfalls in diagnosis

Synovial chondromatosis is a benign disease that only rarely affects the te mporomandibular joint. When it does, disease is usually confined to the joi nt space itself hut can occasionally extend beyond the joint capsule into t he parotid gland, temporal bone, or cranium. The local clinical behavior, r adiographic appearance, and histopathologic features can combine to create the appearance of a malignant lesion. We report a case of synovial chondrom atosis that affected the temporomandibular joint and presented as an extern al auditory canal mass. The lesion was thought to be a chondrosarcoma prior to the definitive resection. Pitfalls in the diagnosis and management of s ynovial chondromatosis are discussed.