A cyst like mass of squamous epithelial debris in the middle ear.
Congenital, primary acquired or secondary acquired types.
Tympanic membrane abnormality consisting of a keratin matrix surrounded by squamous epithelium.
Slow growing masses.
Congenital type thought to arise from embryonic rests.
Primary acquired disease secondary to eustachian tube dysfunction and negative middle ear pressures.
Squamous cell debris collects in pars flaccida of the tympanic membrane as a pocket develops secondary to eustachian tube dysfunction.
Typically develops from a retraction of the tympanic membrane due to chronic infection.
Tympanic membrane retraction typically occurs in the posterior superior quadrant of the tympanic membrane, in the pars flaccida, and may be associated with perforation of the membrane or purlent material.
A congenital cholesteatoma is thought to arise from an epidermoid rest in the developing middle ear, And it occurs behind an intact eardrum.
Congenital cholesteatomas are typically unilateral and in the anterior superior part of the middle ear..