Opercular Perivascular Cyst: Old Entity, New Location

Dilated perivascular spaces in the brain have typical neuroimaging appearances. The classification of dilated perivascular spaces is based on their relationship to blood vessels and is divided into 3 subtypes. A fourth type has been described and termed “opercular perivascular space.” We report on an incidental finding of an opercular perivascular space on MR imaging. Dilated perivascular spaces are benign; it is important to be familiar with their characteristic appearance to prevent reporting them as a neoplasm.