A cholesteatoma usually occurs as a result of recurrent ear infections and/or a tear or retraction of the eardrum.
It often develops as a cyst or pouch that sheds layers of old skin, which build up inside the middle ear. Over time, the cholesteatoma can increase in size and destroy the bony structures of the ear.
Proper treatment is important to avoid serious complications. Surgery may be needed to remove the cholesteatoma completely.