Metastatic epidural spinal cord compression is the third most common cause of adult compressive myelopathy, after acute trauma and degenerative etiologies. In individuals with systemic cancer it is one of the most common neurologic complications, following the brain parenchymal metastases. Epidural spinal cord compression can be caused by metastases from most primary malignancies. Solid tumors of the lung, breast, prostate and kidney, lymphoma and sarcoma, however, have a higher predisposition for spinal metastases.
Metastases most commonly reach the epidural space from the vertebral body (85% of cases) or the intervertebral foramen (15% of cases). Hematogenous spread to the epidural space is extremely rare. Injury to the spinal cord results from mechanical injury to axons and myelin as well as from secondary vascular compromise of the spinal arteries and epidural venous plexus with resulting cord infarction and venous congestion.