A Case of Bilateral Amyloidosis of the External Auditory Canal

Amyloidosis is a disease characterized by dysfunction of various organs caused by the deposition of amyloid fibrils, and is classified as systemic or localized amyloidosis. We present a rare case of localized amyloidosis of the external auditory canals. An 83-year-old man complaining of an abnormal sensation in both ears was referred to our hospital. He had the habit of rubbing his ears with cotton swabs. Examination revealed several small nodules in the external auditory canals bilaterally, and biopsy of the nodules suggested the diagnosis of amyloidosis. Surgical resection of the nodules was performed under general anesthesia. Immunohistochemical studies revealed positive immunoreactivity of the amyloid deposits for immunoglobulin light chains. As whole-body examination showed no evidence of systemic amyloidosis, the patient was diagnosed as having localized amyloidosis of the external auditory canals. No recurrence was observed for a year after the resection and the patient is under long-term follow-up.