cholesteatoma

…by a condition known as cholesteatoma of the middle ear. This is an ingrowth of skin from the outer-ear canal that forms a cyst within the middle ear. An infected cholesteatoma cyst enlarges slowly but progressively, gradually eroding the bone until the cyst reaches the brain cavity, the nerve that…

…susceptibility to otitis media and cholesteatoma (the formation of a cyst in the middle ear).