We describe a rare case of spontaneous temporomandibular joint herniation into the external auditory canal, and we also review the presentation, aetiology and management of such cases.
An 87-year-old woman presented with a four-month history of left-sided otorrhoea and otalgia. Examination revealed a soft, polypoid mass in the left ear canal. When the patient opened her mouth the lesion disappeared. Subsequent computed tomographic imaging of the patient's temporal bones confirmed an 8.6 mm defect in the antero-inferior portion of the left ear canal, with herniation of retrodiscal soft tissues.
The external auditory canal is intimately related to the temporomandibular joint, separated only by its bony anterior wall. Neoplasm, trauma or inflammation in this area can result in displacement of the temporomandibular joint into the ear canal; however, spontaneous herniation is rare. Persistence of the primitive foramen of Huschke can result in dehiscence of the anterior canal wall, allowing articular tissue to prolapse into the ear canal. Surgical closure of these defects is known to be effective in ameliorating symptomatic cases.