Cavernous angiomas and arteriovenous malformations of the spinal epidural space: report of 11 cases.

We have retrospectively studied 11 cases of solitary cavernous and arteriovenous malformations of the spinal epidural space. The acute or subacute onset of symptoms was found in all cases, with a neurological deficit in five cases. A plain x-ray study revealed abnormal calcification in one case. Hyperdensity with no iodine enhancement was found on computed tomographic scans in all cases. Magnetic resonance imaging studies showed ovoid or round lesions with isosignal and gadolinium enhancement on T1-weighted images and hypersignal on T2-weighted images, except in one case with hypersignal on T1 and T2 before the administration of a contrast medium. Four lumbar cases were localized in the posterior vertebral ligament; all the thoracic cases were posterior with foraminal extension. The other cases were anterolateral. The surgical findings revealed a dark vascularized epidural lesion associated in two cases with a localized epidural hematoma. A pathological examination revealed seven cavernous angiomas and four arteriovenous malformations. These arteriovenous malformations were all lumbar, and two of four localized within the posterior ligament. The pathophysiology of these vascular malformations is discussed. In light of the good postoperative prognosis of these lesions, surgical removal is recommended for all the symptomatic cases.