Fig. 1.

Locations of metastases to the spine. Most tumor emboli seed the vertebral column surrounding the spinal cord, with the posterior half of the vertebral body being the most common initial focus (A). Tumor can also originate in a paravertebral location and track along the spinal nerves to enter the spinal column by way of the neural foramina (C). Both of these mechanisms can lead to epidural spinal cord compression. Intramedullary, subdural/leptomeningeal, and isolated epidural metastatic deposits are rarely encountered (B).