Background: A cholesteatoma is a non-neoplastic epithelial lesion that contains layers of keratin in a cavity lined by keratinizing squamous epithelium and subepithelial connective tissue. Although benign, it can cause serious complications by eroding nearby structures or precipitating infection. Surgical removal of the lesion is considered the only effective medical therapy. There are several theories on the etiopathogenesis of acquired cholesteatoma, including one based on the premise that a squamous pouch is drawn inward by traction exerted by the interaction of opposing ciliated epithelial surfaces of middle ear mucosa on the medial surface of the tympanic membrane and the lateral surface of the ossicles.
Study design: Comparative study of 73 human temporal bones.
Setting: Otopathology Laboratory in the Department of Otolaryngology, University of Minnesota, Minneapolis.