EXPANSION OF CHOLESTEATOMA AND DESTRUCTION OF BONE Once cholesteatoma enters the middle ear cleft, it invades the surrounding structures, first by following the path of least resistance, and then by enzymatic bone destruction. An attic cholesteatoma may extend backwards into the aditus, antrum and mastoid; downwards into the meso- tympanum; medially, it may surround the incus and/or head of malleus. Cholesteatoma has the property to destroy bone. It may cause destruction of ear ossicles,...