Cholesterol Granuloma of the Petrous Apex: A 5-Year Review of Radiology Reports with Follow-Up of Progression and Treatment.

Objectives To assess the stability and outcomes of patients with cholesterol granulomas at Brigham and Women's Hospital. Design A retrospective review of neuroradiology magnetic resonance imaging (MRI) studies was performed. The number of newly diagnosed cases of cholesterol granuloma per year was determined. Additional data included age and gender, clinical presentation if applicable, growth on imaging follow-up, and recurrence on postoperative follow-up if applicable. Participants Inclusion criteria included patients who underwent MRI studies between January 1, 2009 and July 1, 2013. Upon review of imaging of these patients, 18 patients had findings compatible with cholesterol granuloma. Results During the study period, an average of three cases of cholesterol granuloma were diagnosed on MRI per year. Three of 18 patients underwent treatment. Two underwent surgery, both of whom demonstrated recurrence on postoperative follow-up imaging. One patient who underwent computed tomography-guided percutaneous aspiration and Gelfoam (Pfizer, New York, United States) embolization had no recurrence on imaging follow-up of up to 23 months. Among the patients who were observed without intervention, growth was identified in only one patient. Conclusions Cholesterol granulomas are a rare entity; however, their appearance on imaging may be greater than previously reported. Most of the lesions demonstrate stability and can be observed.