Cholesterol cysts of the petrous apex: radiological evaluation and surgical management.

The clinical presentation, diagnostic features and surgical management of three cases of giant cholesterol cysts involving the petrous apex of the temporal bone are presented. The ability to reach a confident pre-operative diagnosis using magnetic resonance imaging (MRI) due to its greater soft tissue contrast resolution, multiplanar imaging capabilities and sensitivity to blood products is illustrated. The operation of transmastoid infralabyrinthine draining of the petrous apex is described and other possible approaches discussed.