Cholesteatoma – A Potential Consequence of Chronic Middle Ear Inflammation

While the middle ear is the most typical localization, ectopic cholesteatoma has been described for many sites, including the mastoid process [5], the petrous bone [6-8], the external auditory canal [9-14], the paranasal sinuses [15-17] with special emphasis on the frontal sinus [18-19], the genitourinary tract [20] including the ureter [21-23], the renal pelvis [21], the pyelocaliceal region [21], and the kidney [2426], as well as the endocranium, predominantly the cerebellopontine angle [27], and the posterior cerebellar fossa [28]. Cases of bi-lateral congenital middle ear cholesteatoma have been described [29-31], some of them in association with ossicular chain abnormalities [29,31], e.g. as an aspect of branchio-oto-renal syndrome [31].