Chondroid Tenosynovial Giant Cell Tumor of Temporomandibular Joint.

Tenosynovial giant cell tumor (TGCT), a benign proliferative lesion arising from the synovial membrane of the joints, is rarely seen in the temporomandibular joint. It frequently presents as a painful, preauricular swelling and affects the jaw functions. Two types of TGCT seen are diffuse TGCT (TGCT-D) and localized TGCT. A case of TGCT-D is described here, the highlight of the case being extensive areas of chondroid metaplasia which mimicked chondroid lesions, but was ruled out based on negative immunohistochemical findings within the tumor cells.