Giant Tumefactive Perivascular Spaces Mimicking a Brain Mass Lesion: Report of Three Cases

Virchow–Robin spaces or perivascular spaces are pial-lined fluid-filled interstitial spaces recognized throughout brain parenchyma along the path of penetrating vessels. Occasionally, they may become enlarged, cause mass effect, and be mistaken for cystic neoplasms or infections. We report three cases of giant tumefactive perivascular spaces (GTPVS) incidentally found at brain magnetic resonance imaging (MRI). The lesions were multilocular cystic-appearing, isointense to cerebrospinal fluid on all pulse sequences, and did not enhance. They were located both in typical and atypical locations and in one case associated with hydrocephalus. We describe the key features of GTPVS on MRI and illustrate the need to acknowledge and promptly recognize these entities in daily practice in order to avoid unnecessary treatment.