Middle ear adenoma - Long-term follow-up of a rare neoplasm

Adenomas of the middle ear are rare benign glandular neoplasms arising from the middle ear mucosa. After previous operations 25 and 15 years before, a 67-year-old female comp lained about dizziness, tinnitus, and unilateral hearing loss on the left s ide. A tumor in the tympanum that was revealed by otoscopy could be removed completely. Histological examinations showed an adenoma of the middle ear with cholesteatoma. This was inconsistent with the histological result of t he operation in 1983,which had described a hidradenoma. An exact analysis o f the preparations confirmed that a middle ear adenoma had already been pre sent in 1983. Hidradenoma is one of the most important differential diagnoses. The charac teristic histological sign of middle ear adenomas in contrast to hidradenom as is the lack of myoepithelial cells. In addition, it is very difficult to differentiate middle ear adenoma and adenocarcinoma using histopathologica l and clinical methods. Therefore, thorough followup is mandatory for patie nts after surgical treatment of middle ear adenomas.