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.

 

 

This mastoid cavity is self-cleaning.  The lateral semicircular canal can be seen clearly in the centre of the image.  The residual tympanic membrane is significantly retracted and the head of the stapes can be seen.