[Cholesterol granuloma of the petrous apex].

Cholesterol granuloma of the petrous apex is an inflammatory granulation tissue response to the presence of cholesterol crystals. It is not generally associated with middle-ear pathology. CT and MRI are fundamental for diagnosis. MRI is more specific and shows a well-circunscribed mass with high signal intensity on both T1 and T2 weighted images. We present a case of cholesterol granuloma of the petrous apex that was previously diagnosed as cholesteatoma. We emphasize the importance of preoperatory differentiation of the lesion from cholesteatoma. Cholesterol granuloma does not require full excision of the lesion. Drainage and permanent aeration is usually sufficient.