Cavernous Malformation (CM) of the Spine

Diagnosis Definition

• Cavernous malformations (CMs, aka “cavernomas”) are slow flow vascular malformations with no intervening neuronal tissue; most are congenital
• Typically intramedullary and thoracic in location, spinal CMs represent ~5% of intramedullary lesions in adults
• Their propensity for internal hemorrhage can lead to progressive myelopathy related to mass effect

Imaging Findings

• Although the imaging appearance of CMs is variable, MRI typically shows a rounded mass that is heterogeneous in signal on T1-weighted images and predominantly hyperintense with a hypointense rim on T2 (described as having a “popcorn” or “mulberry” appearance)
• Almost all CMs have hypointense areas on GRE images and typically show minimal or no enhancement
• Extra- and intracellular methemoglobin and thrombosis account for the high-intensity signal on T1 and T2, while calcification, fibrosis, and acute and chronic blood products (e.g., hemosiderin) result in low-signal areas
• Cord expansion or edema is minimal unless there has been recent hemorrhage

KEY IMAGES

Pearls

• Cavernous malformations can occur de novo after radiation therapy in the spinal cord as well as within the brain
• The risk of significant acute hemorrhage is low due to low venous pressure; however, recurrent hemorrhage within the confined intramedullary space can lead to severe neurological deterioration

References

1. Rivera PP, Willinsky RA, Porter PJ. Intracranial cavernous malformations. Neuroimaging Clin N Am 2003; 13:27-40
2. Jabbour P, Gault J, Murk SE, Awad IA.  Multiple spinal cavernous malformations with atypical phenotype after prior irradiation: case report.  Neurosurgery 2004; 55(6):1431