Aggressiveness in Cholesterol Granuloma of the Temporal Bone May Be Determined by the Vigor of Its Blood Source

Objective: Recently, it has been proposed that the aggressive behavior of cholesterol granuloma (CG) of the petrous apex is explained by its proximity to the richly vascular marrow of the petroclival junction. Most CGs of the lateral temporal bone are indolent. The purpose of the present study is to examine the factors responsible for atypical aggressive behavior in mastoid CG. Study Design: Retrospective case series. Setting: Tertiary academic practice. Patient Population: Four patients with atypically aggressive CG of the mastoid. Results: In each case, the CG abutted a rich blood source: the sigmoid sinus, carotid artery, a large dural vein, or a rich deposit of vascular marrow in the mastoid tip. Conclusion: These observations lend further support to the theory that aggressiveness of CG is sustained by a robust source of ongoing hemorrhage.