About Spinal Cord Tumors
The spinal cord is surrounded by tough fibrous covering called the dura. The spinal cord and dura are located within a bony canal created by the vertebral column. Tumors can arise in any of these spaces and are grouped according to location.
- Extradural (outside of the dura): typically the most common of spinal tumors, representing about 60%. The majority of these originate from the vertebrae.
- Intradural-extramedullary (between the spinal cord and the dura): representing 30% of spinal tumors
- Intramedullary (within the substance of the spinal cord itself): uncommon tumors representing approximately 10% of all spinal tumors. These occur most often in the cervical spinal cord and often associated with a dilated fluid cavity called a syrinx.
The location of the tumor can be identified on an MRI, of the spinal column.
The most common extradural tumors are metastatic - that is, they spread from some primary tumor site (like lung), through the blood stream, to the bones of the spinal column.
The most common intradural-extramedullary tumors are meningiomas and schwannomas. Meningiomas arise from the dura itself and a more common in women. Schwannomas arise from the lining of nerve roots.
The most common intramedullary tumors are:
- Astrocytoma: tumors from the support cells in the spinal cord
- Ependymoma: tumors from the cells that line the central spinal cord
- Hemangioblastoma: vascular tumors within the spinal cord
Patients with spinal tumors typically present with back pain at the level of the tumor that tends to be worse at night. Symptoms can be of long duration because these lesions grow slowly. Patients may develop weakness, numbness, difficulty walking, and bowel/bladder dysfunction.
A detailed neurological physical exam can localize the level of the spinal cord tumor. Individual muscle groups are tested for strength to determine any signs of weakness, sensation is tested for numbness, and reflexes are tested at the elbows, hands, knees, and ankles for abnormalities. An MRI (magnetic resonance imaging) study with and without contrast will definitively diagnose the condition.
Surgery is often performed on spinal tumors in order to obtain tissue for diagnosis, relieve pressure on the spinal cord, and stabilize the spine if necessary. A laminectomy (removal of bone overlying the spinal cord) is performed after radiographic confirmation of the appropriate spinal level. Extradural tumors can then be identified and removed. If the tumors is intradural, the dura is opened. An intraoperative microscope is used to excise the tumor which is then send for neuro-pathological examination. Subsequent treatment depends on the pathology diagnosis. Surgery is usually the only treatment necessary for benign tumors. Metastatic tumors and some gliomas may also be treated with postoperative radiation therapy.