Mesencephalic enlarged Virchow-Robin spaces in a 6-year-old boy: a case-based update

Background Perivascular spaces or Virchow-Robin spaces are normal anatomical structures within the brain, typically less than 5 mm in diameter. Rarely, they can reach much larger sizes and adopt bizarre single or multi-cystic configurations, as was the case in the patient that we report on. When there is such markedly gross dilatation, the phenomenon is known as Giant or tumefactive perivascular space enlargement. Case report We report a 6-year-old boy with a multi-cystic mesencephalic lesions presenting with obstructive hydrocephalus secondary to obstruction of the aqueduct of Sylvius due to tumefactive dilatation of Virchow-Robin spaces. The patient underwent an endoscopic fenestration and biopsy of the cystic portion abutting into the ventricular system. Conclusion In this paper, we discuss the phenomenon of perivascular (Virchow-Robin) spaces and their treatment options and review the relevant literature. To our knowledge, this is the first pediatric case of tumefactive dilatation of the Virchow-Robin spaces causing obstructive hydrocephalus that were directly fenestrated using neuroendoscopy.