Evaluation and management of primary petrous apex cholesteatoma.

Primary cholesteatoma of the petrous apex is an uncommon congenital lesion that is suspected clinically by such indirect methods of examination as conventional and tomographic radiology, computerized axial tomographic scan, and angiography. If these indirect methods indicate a petrous apex lesion, the area should be investigated by biopsy through the sphenoid, middle fossa, or translabyrinthine routes. Tumor extension, sphenoid pneumatization, and normal labyrinthine function are factors that determine the surgical approach. Once a diagnostic surgical procedure confirms the presence of an epidermoid cyst at the petrous apex, permanent fistulization through the sphenoid or the middle ear is recommended as definitive management.