Mastoid Cavity

 

During the surgical excision of cholesteatoma, it is sometimes necessary to produce a mastoid cavity to excise all of the cholesteatoma extending into the mastoid bone.  A mastoid cavity is found posteriorly in the ear canal and resembles a widening of the posterosuperior part of the canal.  The cavity may become filled with wax or become infected.

 

 

The same cavity after the wax has been removed. A higher facial ridge is evident and the tympanic membrane appears to be perforated.