Cholesteatoma Invasion into the Internal Auditory Canal

Abstract

Introduction: Temporal bone cholesteatoma usually originates in the mastoid and middle ear cavity. The process of enzymatic bone lysis may result in erosion of the tympanic cavity and mastoid borders and finally extend into the bony labyrinth and internal auditory canal (IAC). The involvement of the membranous labyrinth and IAC poses a serious threat to the facial nerve and vestibulocochlear functions. The origin of cholesteatomas that invade the IAC continues to be a matter of controversy. Such invasion is rare and originates from either acquired giant cholesteatomas, which aggressively erode the labyrinth, or from congenital cholesteatomas that develop in the vicinity of the IAC. Cholesteatoma invasion into the IAC usually results in irreversible, complete hearing loss and facial paralysis on the affected side. The current study, which aims to investigate the clinical characteristics of patients with cholesteatoma invading the IAC, analyzes possible routes of cholesteatoma extension and describes the surgical approaches used and patient outcomes.