Fig. 1.

A 73-year-old woman who presented with diplopia and was clinically discovered to have a right abducens nerve palsy (see arrow). (A) T1-weighted axial noncontrast imaging demonstrates an expansile lesion in the right petrous apex with high T1 signal, compatible with a cholesterol granuloma. The patient elected to undergo surgical intervention. (B) First postoperative magnetic resonance imaging (MRI) 3 days status postresection via a retrosigmoid approach demonstrates T1 hyperintense and intermediate intense signal within the right petrous apex (see arrow) that is not as expansile as the preoperative study. These findings likely reflect a combination of postoperative blood products and/or residual cholesterol granuloma. (C) Follow-up MRI at 2 months status postsurgery demonstrates a reaccumulation of T1 hyperintense material within the right petrous apex lesion (see arrow) that has again become expansile and is compatible with interval growth of cholesterol granuloma. Clinically, the patient's diplopia improved with mild residual symptoms. However, she only had neurosurgical follow-up for 16 months status postsurgery.