A Giant Tumefactive Virchow-Robin Space: A Rare Cause of a Homonymous Quadrantanopia.

A 53-year-old woman was found to have a left inferior homonymous quadrantanopia. Brain MRI disclosed a giant Virchow-Robin space compressing the right optic tract. After fenestration of this cystic lesion, most of the visual field loss resolved. Giant Virchow-Robin spaces may cause homonymous field defects which, with appropriate management, may improve.