A case of petrous apex cholesterol granuloma successfully treated with endoscopic endonasal surgery.

A transcranial approach in combination with a transpetrosal setting has been the mainstream of surgical treatment of cholesterol granulomas in the petrous apex. However, endoscopic endonasal surgery has become a choice of treatment for these lesions with recent advancements in surgical techniques and instruments. We report a successful case of cholesterol granuloma managed with endoscopic endonasal surgery. A 45-year-old woman, who had a long-standing history of otitis media, presented with left abducens nerve palsy and discomfort around the left eye. Magnetic resonance (MR) imaging showed a large cystic lesion, suggesting cholesterol granuloma, in the left middle fossa abutting the cavernous sinus and lateral wall of the sphenoid sinus. We chose an endoscopic endonasal approach to drain the contents of the cyst because the lesion protruded into the left sphenoid sinus. The sphenoid sinus was widely opened and the cyst wall was fenestrated with the assistance of an image guidance navigation system. Postoperative MR images confirmed the complete collapse of the cyst. She has been free from symptoms since the operation.