Large cholesterol granuloma of the petrous apex treated via subcochlear drainage.

This is a case report of a patient with bilateral cholesterol granuloma of the petrous apex, who presented with unilateral symptoms. Initially suspected as having a dermoid cyst, he underwent posterior fossa exploration, drainage and biopsy. Symptoms recurred one year later and subcochlear drainage of the petrous apex cyst was successfully performed. Follow-up for over 18 months shows no clinical nor imaging signs of recurrence. A MEDLINE literature search was carried out and relevant paper publications reviewed. Case presentation including initial, pre- and post-operative imaging is presented. This is followed by discussion of current concepts on the presentation and management of large cholesterol cysts of the petrous apex.