Abstract
This report describes a case of adult temporal bone Langerhans cell histiocytosis（LCH） that presented as posterior canal dehiscence syndrome（PCDS）. The patient initially presented with vertigo, tinnitus, and hearing loss. Computed tomography（CT） revealed erosive changes in the mastoid and posterior semicircular canal. After the operation, the patient's hearing and vestibular symptoms disappeared and postoperative recovery was favorable. Adult LCH is relatively rare, and this case serves as an example to discuss the clinical features and treatment options of this disease, followed by a literature review.