Cholesteatoma occurs as a result of recurrent inflammatory conditions in the middle ear or when there is insufficiency in the Eustachian tube functioning. The Eustachian tube is a tube that allows air passage through the nasal cavity to equalize the middle ear pressure, and has the task of opening and closing in certain situations between the middle ear and our nasal cavity. When the Eustachian tube works insufficiently due to reasons such as allergies, colds or sinusitis, the air in the middle ear is absorbed by the body, and a partial vacuum (negative pressure) occurs in the ear. Negative pressure pulls the eardrum inward and creates a pocket or pouch in the eardrum (especially the areas where the eardrum has weakened due to past ear infections are more vulnerable to this negative pressure). Earwax gradually begins to accumulate in this formed pouch or pocket.

 

Source:  http://www.kbb.org.tr