Cysts that Deceive: Tumefactive Virchow–Robin Spaces

Tumefactive Virchow–Robin spaces (TVRS) are rare, enlarged perivascular spaces that can mimic neoplastic, vascular, or infectious brain lesions on imaging. These spaces are commonly found along the paths of penetrating arteries and typically measure less than 5 mm. However, when enlarged, they may produce a mass effect, cause hydrocephalus, or mimic cystic tumors. We report a case of a 48-year-old female presenting with mild, recurrent headaches whose magnetic resonance imaging (MRI) revealed multiple cystic lesions in the right frontoparietal lobe and anterior parafalcine region. The lesions followed cerebrospinal fluid (CSF) intensity on all sequences, without enhancement or diffusion restriction. No surrounding edema was noted. Thin-section susceptibility-weighted imaging (SWI) images were reviewed and showed no venous compression or vascular paucity. The imaging appearance and location were characteristic of TVRS. Recognizing this entity is crucial to prevent unnecessary biopsies. Differentiation from other cystic lesions—such as cystic neoplasms, cryptococcal infections, neurocysticercosis, or mucopolysaccharidosis—is essential and relies on specific imaging features. To our knowledge, this is the first reported case of tumefactive Virchow–Robin spaces causing mass effect on the ventricle along with overlying regional parenchymal atrophy, a combination not previously documented. This case highlights the importance of familiarity with the imaging spectrum of TVRS and its integration with radiology to make an accurate diagnosis.