We describe the imaging characteristics of giant tumefactive perivascular spaces in a 37-year-old man who initially presented at the age of twenty years with vision change and headache and was found to have probable low grade neoplasm. The patient was followed subsequently at 8 years and 17 years later at our institution with stable imaging and neurologic exam. Magnetic resonance imaging demonstrated multiple cystic mass in the right frontal lobe which was stable in size and appearance. The mass followed signal intensity identical to cerebrospinal fluid on all sequences and was consistent with a giant tumefactive perivascular space. This report illustrates the need to keep this entity in mind when imaging evaluation demonstrates a lesion isointense to cerebrospinal fluid on all sequences. These lesions can actually be quite large and ominous appearing and many proceed to biopsy unnecessarily.