A rare case of middle ear adenoma.

Middle ear adenoma is a rare disease that is thought to originate in the middle ear mucosa. It occurs over a wide age range, has no gender predilection, and is not characterized by specific symptoms or findings. The most frequent complaints are unilateral hearing loss and ear fullness. We report a 48-year-old woman with middle ear adenoma who had a history of unilateral ear fullness and hearing loss on the left side. Middle ear adenoma was suspected following a biopsy performed under local anesthesia. To remove the tumor, the patient underwent a left postauricular canal wall-up tympanoplasty type IIIc. Microscopic examination and immunohistochemistry confirmed a middle ear adenoma. In this case, we diagnosed the lesion as middle ear adenoma with neuroendocrine differentiation on the basis of the pathological findings. The patient has shown no recurrence for almost 5 years, but since this adenoma showed neuroendocrine differentiation, long-term observation is required.