Radiological and surgical aspects of pure spinal epidural cavernous angiomas. Report on 5 cases and review of the literature

BACKGROUND: Cavernous angiomas (CAs) that are localized completely in the spinal epidural space are uncommon vascular malformations. Although they have increasingly been reported in the literature in recent years, diagnostic and surgical features are not clearly defined. METHODS: We report five patients with pure spinal epidural cavernous angiomas (PSECAs) and review the literature, focusing on their radiologic and surgical characteristics. We also compare these tumors with other extra-axial CAs as well as with their intra-axial counterparts. RESULTS: PSECAs, like all other extra-axial CAs, differ from intra-axial ones on MRI: the hemorrhagic variant is less frequent, hemosiderin rim is rare, the signal is different, and contrast enhancement is the rule. They are very similar to spinal meningiomas but they differ in their growth pattern and morphology, since they infiltrate intervertebral foramina and have an oval shape. In PSECA, intraoperative bleeding is rarely profuse, in contrast to other extra-axial CAs, especially those of the cavernous sinus. CONCLUSIONS: On MRI, PSECAs and other extra-axial CAs constitute a homogeneous group since they enhance significantly. At operation, since there is rarely enough bleeding to limit removal, radical excision of PSECAs can be achieved with good results.