Schwannoma of the external auditory canal as a part of schwannomatosis

Abstract

Abstract We experienced a very rare case, which we believe to be sporadic schwannomatosis, in which a 49-year-old female patient presented with conductive hearing loss due to a subcutaneous tumor in the right external auditory canal and the symptoms were completely ameliorated by surgery. The patient had surgical histories of multiple cervical spinal cord schwannoma removal. At the age of 47, she was referred to our department due to a growing tumor in the right external auditory canal. At the initial visit, a smooth surface tumor was found in the right external auditory canal, and pure tone audiometry confirmed the conductive hearing loss of the right ear. Also, several tender masses with severe pain were observed around the right auricle. Contrast-enhanced MRI images revealed multiple well-defined masses in the right external ear canal, and above, behind, and below the right auricle. Furthermore, a small vestibular schwannoma localized in the left internal ear canal was found. We performed a surgical resection of the tumor in the right external auditory canal and the subcutaneous tumors around the right ear. Histopathological examination showed that all tumors were schwannomas with no malignant findings. After the surgery, the right air-bone gap completely disappeared, and so did the severe pain around the auricle. Her clinical course suggests that the schwannomas were a part of systematic schwannomatosis. This is the first case report of schwannomatosis of which the schwannoma was located in the external auditory canal.