A retrospective review of cases preoperatively diagnosed by radiologic imaging as cavernous venous malformations

The purpose of this study is to examine orbital lesions identified on preoperative radiologic imaging as cavernous venous malformations (CVMs), identify their imaging characteristics, and determine if these may help differentiate CVMs from other intraorbital masses. An IRB-approved retrospective chart review over 30 years was undertaken identifying lesions "consistent with cavernous hemangioma" on radiologic studies, which were subsequently surgically resected with a tissue diagnosis. All radiologic images (CT and MRI) obtained preoperatively were re-reviewed by a single masked neuroradiologist. The pattern of contrast enhancement on sequential MRI views was used to determine whether the enhancing characteristics helped identify CVMs compared to other intraorbital masses. Fifty-seven orbital lesions consistent with a CVM were identified on imaging. Fourteen (25%) of them were resected, of which nine (64%) were found to be CVMs on pathologic examination. Five (36%) were found to be a different lesion, most commonly schwannoma (21%). On imaging, CVMs tended to display heterogeneous progressive enhancement, whereas other tumors, in particular schwannomas, enhanced at their maximum level immediately. Based on these characteristics, on re-review, the masked neuroradiologist was able to differentiate a CVM versus other tumors for all 14 imaging cases. This study suggests that examining the pattern of contrast enhancement may help to correctly differentiate a CVM from other isolated, encapsulated orbital lesions on CT/MR imaging.