Cholesterol granuloma in the petrous apex: Case report and review

Cholesterol granuloma in the petrous apex presents with various symptoms of cranial nerve dysfunction, so the selection for surgical treatment remains controversial. We report a 41-year-old woman with a cholesterol granuloma at the left petrous apex, which was totally resected via a combined middle fossa and posterior trans-petrosal approach. In a review of 92 cases, including our case, treated for petrous apex cholesterol granuloma between 1990 and 2001, 38 were men (41.3%) and 54 were women (58.7%). The mean age of these patients was 37.4 years (males were 35.2 years, females were 39.4 years). The most common presenting clinical symptom was hearing loss due to dysfunction of cranial nerve VIII. Seventy-nine patients, including our case, underwent operation, and 13 patients were managed without surgery. The most frequently selected surgical approach was middle cranial fossa approach. Revision surgery (including the 2 cases who underwent revision twice and three times) was performed in 12 patients (15.2%). In 92 cases, all of these who underwent total removal have not shown re-accumulation of cyst contents. On the other hand, 11.4% of the patients with or without permanent drainage route proceeded by subtotal removal of the cyst wall needed revision surgery because of stenosis of the drainage route. Therefore we conclude that the most important treatment for the prevention of re-accumulation of cyst contents may be the extent of the cyst wall resection rather than the establishment of permanent drainage route.