Endoscopic transsphenoidal drainage of a cholesterol granuloma of the petrous apex

Abstract

Cholesterol granulomas commonly occur in the middle ear cavity, affecting such structures as the tympanum and mastoid air cells, while occurrence at the apex of the petrous bone is considered to be relatively rare. However, such granulomas are considered to be the most frequent of petrous apex diseases. In recent years, these cholesterol granulomas have been more easily detected due to advances and widespread availability of imaging tests, such as computed tomography and magnetic resonance imaging. Surgical drainage and restoration of ventilation are considered to be adequate treatments for this disease. However, the apex of the petrous bone is anatomically difficult to approach. Surgical approaches are selected in consideration of location, size, direction of progression, and the relationship of the lesion with adjacent tissue, as well as symptoms. Among the currently available approaches, the transsphenoidal approach, which is indicated only for lesions abutting the sphenoid sinus, is minimally invasive and rarely reported. We herein describe our experience with a case harboring a petrous apex cholesterol granuloma which was detected with abducens nerve palsy, followed by treatment with drainage via the transsphenoidal sinus approach, and showed a favorable course.