Otolaryngology– Head and Neck Surgery Volume 120 Number 6 BATRA et al 951 Chondrosarcoma of the temporomandibular joint PETE S. BATRA, BA, MS4, SCOTT A. ESTREM, MD, ROBERT P. ZITSCH, MD, ROBERT MCDONALD, MD, and JOHN DITTO, MD, Columbia, Missouri C hondrosarcomas arise most commonly in the pelvis, femur, and humerus. 1 The occurrence of this malignant osseous tumor in the head and neck region, especially the mandible, is rare. In 1986 Weiss and Bennett 2 reviewed the lit- erature of chondrosarcoma involving the head and neck region and documented 161 cases, of which 56 involved the mandible. Even more rare is the occurrence of chondrosarcoma arising from the temporomandibular joint (TMJ). A current review of American and European literature revealed only 6 cases origi- nating at the TMJ, the most recent of which was reported by Nitzan et al 3 in 1993. In this article an additional case of chon- drosarcoma of the TMJ is presented. Pertinent clinical aspects, including presenting features, radiographic findings, histopathology, and treatment of chondrosarcoma of the mandible are discussed. Chondrosarcoma arising in the TMJ is emphasized because tumors at this site present a special management challenge because of the involvement of the cra- nial base and the temporal bone. CASE REPORT A 65-year-old man was referred to the University of Missouri–Columbia Division of Otolaryngology because of left preauricular swelling of 18 months’ duration. During this time this mass had gradually increased in size. The patient had also noticed left-sided hearing loss during the preceding 2 months. He denied symptoms of pain or trismus. A 2-cm firm, nontender mass was present in the left preau- ricular region. The left external auditory canal was nearly occluded by the preauricular mass, preventing adequate visualization of the tympanic membrane. Rinne test results were negative at 256 Hz, and the Weber test lateralized to the left ear. Intraoral examination was unremarkable with no evi- dence of limitation of mandibular movement or malocclusion. Facial nerve function was intact, and there was no evidence of palpable lymphadenopathy. The remainder of the head and neck examination was normal. An audiogram showed a left mild-to-moderate conductive hearing loss. MRI demonstrated a 4.0- × 1.8-cm mass just anterior to the left external ear canal encasing the mandibular condyle (Fig 1). CT with contrast showed erosion of bone along the lateral portion of the middle cranial base, with bony destruction of, and extension into, the external auditory canal (Fig 2). Although the mass was intimately associated with the mandibular condyle, there was no clear evidence of mandibu- lar destruction. An inability to obtain the diagnosis using fine-needle aspi- ration prompted an open preauricular biopsy, yielding the diagnosis of well-differentiated chondrosarcoma. A superfi- cial parotidectomy was required for facial nerve identification and tumor extirpation. Significant retraction of the frontal branch of the facial nerve was necessary. Wide local resection of the chondrosarcoma included removal of the glenoid fossa, the condyle, and the coronoid process of the mandible. The tumor appeared well encapsulated without any obvious infil- tration into the surrounding tissues. The dura was grossly uninvolved and was therefore not resected. The residual surgi- cal defect was ablated with a temporalis muscle flap. From the University of Missouri School of Medicine. Reprint requests: Scott A. Estrem, MD, Associate Professor of Surgery, University of Missouri School of Medicine, 1 Hospital Dr, MA314, Columbia, MO 65212. Otolaryngol Head Neck Surg 1999;120:951-4. Copyright © 1999 by the American Academy of Otolaryngology– Head and Neck Surgery Foundation, Inc. 0194-5998/99/$8.00 + 0 23/4/87885