Atypical magnetic resonance findings in an orbitofrontal cholesterol granuloma

Abstract

Cholesterol granuloma of the orbit is an uncommon entity, although it frequently occurs in the middle ear and petrous apex. It is isodense with brain on computed tomographic scanning and cannot always be differentiated from more serious conditions. Magnetic resonance imaging (MRI) has facilitated the preoperative diagnosis of cholesterol granuloma outside of the orbit because of high signal characteristics on T1- and T2-weighted images. These findings have been considered nearly pathognomonic, but they have previously been described in only one patient with orbitofrontal involvement. We present a case of orbitofrontal cholesterol granuloma with uncharacteristic signal intensities on magnetic resonance imaging.