Large anterior temporal Virchow-Robin spaces: unique MR imaging features

Area of Science:

• Neuroradiology
• Neuroimaging
• Neuropathology

Background:

• Large Virchow-Robin (VR) spaces, particularly in the anterior temporal subcortical white matter, can be misdiagnosed as cystic tumors.
• This location is rare, with only 18 previously reported cases, highlighting the need for improved diagnostic criteria.

Purpose of the Study:

• To identify unique Magnetic Resonance (MR) imaging features that can increase diagnostic confidence for large anterior temporal lobe VR spaces.
• To differentiate these lesions from cystic tumors prospectively.

Main Methods:

• Retrospective review of 39 cases of large anterior temporal lobe VR spaces identified between 2003 and 2014.
• Analysis included demographic and clinical data, initial radiological reports, and detailed review of MR imaging by two neuroradiologists.
• Histopathological data from surgically treated patients were reviewed by a neuropathologist.

Main Results:

• The majority of patients were female, with a median age of 58 years. No specific clinical symptoms were directly attributable to the lesions.
• Perilesional T2 or fluid-attenuated inversion recovery (FLAIR) hyperintensity was observed in 79% of cases. Mean maximal size was 9 mm.
• Unique MR features identified included focal cortical distortion (92%), smaller adjacent VR spaces (26%), and a contiguous cerebrospinal fluid (CSF) intensity tract (21%).

Conclusions:

• Large anterior temporal lobe VR spaces often exhibit perilesional T2/FLAIR signal abnormalities, increasing the risk of misdiagnosis as cystic tumors.
• Specific MR features such as focal cortical distortion by an adjacent middle cerebral artery branch, smaller adjacent VR spaces, and a contiguous CSF tract can significantly enhance diagnostic confidence.