Cholesteatoma.

Caponetti G, Thompson LD, Pantanowitz L.
Ear Nose Throat J. 2009 Nov;88(11):1196-8.
FIRST PARAGRAPH: Cholesteatoma is a lesion formed from keratinizing stratified squamous epithelium. It may present intradurally (an epidermoid) or extradurally. Extradural lesions most commonly involve the middle ear cleft; involvement of the mastoid or external auditory canal is less common. The term cholesteatoma is actually a misnomer as these masses rarely contain cholesterol. Although they are not true neoplasms either, clinically they can mimic malignant neoplasms because of their propensity to destroy surrounding tissue and recur after excision.
PubMed ID: 19924660
Article Size: <1 MB