Congenital Cholesteatoma Isolated to Mastoid Process : a Case Report

Congenital cholesteatoma(CC) accounts for 25% of all cholesteatomas[1] most common site being middle ear. We report an extremely rare case of congenital cholesteatoma isolated to the mastoid process, with no middle ear involvement. An 18 year old male presented with ear ache and minimal discharge for 4 months. On examination, external auditory canal was found narrowed with granulations and bony defect present in the posteroinferior part of canal. Computed tomography showed soft tissue contents in the mastoid bone causing full thickness erosion of the same along with attenuation of ear canal. At surgery, a large cholesteatoma sac was found within the mastoid process completely eroding it and extending to posterior part of external auditory canal. The mastoid antrum and aditus were found normal. Tympanic membrane was intact. CC isolated to the mastoid was diagnosed. Diagnosis of CC isolated to the mastoid should be based on clinical examination and radiological evaluation.