PMC5482162_01
Lumbar spine MRI demonstrating intradural-extramedullary spinal cavernous malformation. Sagittal T2-weighted (a), fat-suppressed gadolinium-enhanced T1-weighted (b), and T2 inversion recovery turbo-spin echo images show an intradural extramedullary lesion at L2. Hemosiderin deposition is seen along the conus (arrows), and fluid-subarachnoid blood level is layered in the lumbar cistern (arrowheads). Axial T2-weighted images (d-g) corresponding to scout levels on image (c) show the nerve root proximal to the lesion (d), followed by sections in the midst (e) and immediately below (f) the lesion. Layering of subarachnoid blood is well-appreciated on axial images (arrowheads in g)
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Magnetic resonance imaging (MRI) of the spine revealed a 1.8 x 1.3 x 1.1 cm intradural-extramedullary hemorrhagic lesion below the conus medullaris (at the L2 level) along with moderate subarachnoid hemorrhage (SAH) in the lumbar cistern and superficial siderosis along the conus [Figure 1].
Brain and cervicothoracic MRI demonstrating extensive superficial siderosis. Cervical (a) and thoracic (b) T2-weighted sagittal MRI images show superficial siderosis (arrows) across the cervical and thoracic spinal cord. Intracranial involvement (arrows) is seen in the cerebellum and along the brain stem on axial gradient-echo sequences (c-f)
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MRI of the brain, cervical, and thoracic spine also identified diffuse superficial siderosis, a finding likely consistent with repeat hemorrhages [Figure 2].
Intraoperative images during resection of spinal cavernous malformation. Stimulation of the proximal (a) and distal (b) ends of the involved nerve root (arrows) did not reveal any detectable motor function, and therefore the lesion was resected en bloc, along with the adjacent nerve root segments entering/exiting the lesion (c)
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The lesion was readily separable from the surrounding nerve roots and was dissected out of the thecal sac [Figure 3]. As a clear margin could not be distinguished between the lesion and nerve roots and because direct stimulation of the proximal and distal nerve roots [Figure 3a and b] did not elicit any motor response on neuromonitoring, the lesion was removed en bloc [Figure 3c].
Sections showing a vascular lesion composed of tightly packed vascular channels with varying wall diameters and hyalinization. Vessel walls lacked any significant amount of smooth muscle or elastic tissue. Some vessel walls contained hemosiderin laden macrophages suggesting remote microhemorrhages. Scattered vessels showed thrombi at different stages of organization. These histologic features were consistent with a diagnosis of cavernous angioma. Intermediate power image (a) showing tightly packed vascular channels with vessels walls of varying diameters and some with hyalinization. Vessels walls lack elastic tissue and a significant amount of smooth muscle. High-power H and E image (b) of the cavernous angioma with entrapped nerve fibers. High-power image (c) of neurofilament staining the entrapped nerve fibers
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