The spinal cord is the downward continuation of the brain and lies within the vertebral column. The part of the spinal cord lying in the region of the chest is called the dorsal cord.
Normally the spinal cord contains a very slender cavity. This is called the central canal of the spinal cord. It is lined by ependymal cells. The same water-like fluid that surrounds the brain and spinal cord flows through this cavity.
A syrinx is an abnormal fluid-containing cavity within the spinal cord. It expands and compresses the spinal cord and damages it.
At times such a cavity is formed by a tumour within the spinal cord. When this tumour arises from the lining of the normal central canal of the spinal cord, it is called an ependymoma.
The tumour can be removed at surgery and the fluid within the syrinx drained. If the tumour can be removed totally, a cure results. Where it is not possible to remove the tumour completely, the remnant is treated by irradiation therapy.