Petrous apex lesions

Objective: The accurate diagnosis of different petrous apex lesions is incr easingly common as a result of modern imaging techniques, combining compute d tomography and magnetic resonance imaging. The clinical features, diagnos tic evaluation, imaging, and treatment outcomes of patients with petrous ap ex lesions are reviewed. Study design: Retrospective case review. Setting: Private practice tertiary otologic referral center. Patients: Sixty-six patients treated at the House Ear Clinic in the last 2 decades for a lesion of the petrous apex. Lesions included cholesterol gran uloma, cholesteatoma, and chondrosarcoma, among others. Mean follow-up time was 27 months and ranged from 1 month to 10 years. Intervention(s): Cholesterol granulomas were treated with drainage procedur es, solid tumors were surgically removed using primarily the middle fossa o r infratemporal fossa approaches. Results: The most common presenting symptoms were hearing loss, dizziness, headaches, and tinnitus. Decreased cranial nerve V function was present in 22%. The most common cystic :Lesion was cholesterol granuloma, which consti tuted 60% of all lesions in the study, followed by cholesteatoma (9%). Chon drosarcomas were the most common solid lesion (6% of all lesions). Asymmetr ic pneumatization and retained secretions give radiographic findings common ly overdiagnosed as lesions of the petrous apex. Conclusions: Lesions of the petrous apex can be diagnosed accurately by CT and MRI and can be divided into cystic and solid lesions. Cholesterol granu lomas are by far the most common lesion found in this site and can be drain ed with minimal morbidity via the intracochlear approach. Solid tumors may require extensive exposure and a combined skull base approach for complete removal.