Lateral Displacement of Cochlea and Erosion of Internal Auditory Canal by a Congenital Cholesteatoma in a Young Child.

The main objective of this report is to describe a unique clinical case of a congenital cholesteatoma with complete lateral displacement of the cochlea and aggressive erosion of the internal auditory canal and lateral semicircular canals in a very young child. This report involves a 10-month-old female who initially presented with left intermittently bloody otorrhea at 2.5 months of age and audiology testing in the clinic demonstrated sensorineural hearing loss in the left ear. Initial computerized tomography (CT) revealed a destructive left temporal bone lesion displacing the left otic capsule and vestibular aqueduct with erosion and involvement of the inner ear structures including erosion into the cochlea and semicircular canals, and posterior fossa dura. A left transtemporal approach for cholesteatoma removal and ear canal closure was done. 4 months postoperatively, the patient required revision of the left transtemporal approach to the posterior fossa for recurrent cholesteatoma in the hypotympanum adjacent to the carotid artery and eustachian tube. This case is unique in the complete lateral displacement of the cochlea and aggressive erosion of the internal auditory canal and lateral semicircular canals in a very young child. It serves to remind otolaryngologists of the silent yet infiltrative nature of congenital cholesteatoma. The very young age of the patient and the presence of otorrhea at 1 month of age raise the question of whether this lesion could have been developing in utero. It lends support to the theory of developmental epithelial rests in congenital cholesteatoma.