[Cholesterol granuloma].

OBJECTIVE

We report 2 cases (52 and 29-year-old men) of CG in the petrous apex we treated in 2004-2006. We also review the literature and discus the mechanism of development of CG and the treatment of this lesion.

METHODS

Cholesterol granuloma (CG) is a chronic inflammatory process with associated foreign body reaction to hemorrhage-related cholesterol crystals. Although CG is found in various organs the temporal bone is the most common site of detection. Numerous ethiopathological hypotheses have been proposed but most authorities support the concept of air cell tract blockage in well pneumatized petrous apex. Obstruction of the air cells leads to rupture of blood vessels and hemorrhage. Red blood cell degradation into cholesterol crystals produces a foreign body giant-cell reaction with progressive accumulation of typical brownish glistening fluid. Clinically, this lesion can produce sensorineural hearing loss, tinnitus, hemifacial spasm, facial numbness and trigeminal neuralgia. Cholesteatoma is the main lesion to distinguish from CG. On MRI studies, CG appears with a high signal on both T1- and T2-weighted sequences, cholesteatoma appear bright only on T2-weighted ones. Goal of the surgery is to create a drainage and ventilation of the affected area to prevent recurrence. Several alternative approaches to the petrous apex have been described.

RESULTS

12-18 months follow up shows no clinical signs of recurrence.