A Case of Cholesterol Granuloma at the Petrous Apex Drained Via the Transsphenoidal Approach

Abstract

　　We performed an endoscopic transnasal surgery for a cholesterol granuloma at the petrous apex. We report the surgical findings and intraoperative considerations. A 26-year-old female patient with a history of right-sided otorrhea was referred to us. CT scans revealed a cystic lesion exceeding 30 mm in diameter at the petrous apex, and the MRI findings suggested a cholesterol granuloma. We treated the lesion by endoscopic transnasal surgery. Intraoperative use of a navigation system and Doppler flowmetry allowed us to continuously monitor the internal carotid artery, and it enabling safe surgical manipulation. We created a drainage pathway by opening the sphenoid sinus, and covered the opening edges with a mucosal flap to prevent reclosure. The postoperative course was favorable. Indications of endoscopic transnasal surgery for lesions at the petrous apex are expanding, especially those in close proximity to the sphenoid sinus, as demonstrated in the case repoted herein. While we used a mucosal flap to prevent recurrence, further evaluation through accumulated cases would be needed to confirm its efficacy.