Petrous Apex Cholesterol Granuloma

A petrous apex cholesterol granuloma is a tumor that occurs when serum from leaky capillaries within the petrous apex begins to accumulate and forms a cystic structure.

Etiology for Petrous Apex Cholesterol Granuloma

A petrous apex cholesterol granuloma usually develops after trauma to the skull.  The trauma causes the capillaries found within the petrous apex to rupture.  This rupture causes an accumulation of serum within the petrous apex, which eventually forms into a cystic structure or a tumor.