Classification of middle ear cholesteatomas based on location in relation to the TM
| Initial Location | Pathogenesis | |
|---|---|---|
| Pars flaccida (attic) | Epitympanum, | Congenital |
| lateral to ossicles | Primary acquired | |
| Secondary acquired | ||
| Pars tensa (sinus) | Mesotympanum, | Congenital |
| medial to ossicles | Secondary acquired |