Case of Cholesterol Granuloma of the Petrous Apex That Was Treated by Endoscopic Transnasal Surgery

We report a case of cholesterol granuloma ( CG ) that occurred at the petrous apex. A 51 -year-old female was referred to our hospital with the symptoms of diplopia and left-side hearing loss. She was diagnosed as having left CG of the petrous apex by imaging examination. She underwent endoscopic transnasal surgery for drainage of the sphenoid sinus. While her preoperative symptom of diplopia disappeared early on, the hearing loss did not improve after the surgery. Good ventilation has been maintained and a good postoperative course has been achieved. While there are some traditional approaches to the petrous apex, including the transtemporal/middle fossa, tympanic approach, and the infracochlear approach, they suffered from some problems, including the lack of a permanent drainage pathway and the incidence of some functional loss. The trans-sphenoidal approach is minimally invasive and can avoid these complications that accompany surgery. Although this surgical approach should be selected in consideration of the location and the relationship of the lesion with adjacent tissues, especially the internal carotid artery, it is considered the most safe and effective approach for CG of the petrous apex.