Definition of Cholesteatoma:

Cholesteatoma is a type of skin cyst located in the middle ear. Also it is called skin in wrong place.

Causes, incidence, and risk factors:

Cholesteatoma can be a birth defect (congenital), but it more commonly occurs as a complication of chronic ear infection.

Poor function in the eustachian tube leads to negative pressure in the middle ear. This pulls a part of the eardrum (tympanic membrane) the wrong way, creating a sac or cyst that fills with old skin cells and other waste material. The cyst becomes infected. The cyst may get bigger and break down some of the middle ear bones, affecting hearing.