A spinal tumor is an abnormal mass of tissue within or surrounding the spinal cord and spinal column. Spinal tumors can be benign or malignant. Primary tumors originate in the spine or spinal cord, and metastatic or secondary tumors result from cancer spreading from another site to the spine.
Spinal tumors are classified by the area of the spine in which they occur: cervical (neck), thoracic (middle back), lumbar (lower back) and sacral (bottom of the spine). They are also referred to by their location: anterior (front) and posterior (back). Clinically, they are divided into three major groups according to location: intradural-extramedullary, intramedullary and extradural.
Intradural-extramedullary tumors develop in the spinal cord’s arachnoid membrane (meningiomas), in the nerve roots that extend out from the spinal cord (schwannomas and neurofibromas) or at the spinal cord base (filum terminale ependymomas). Although meningiomas are often benign, they can be difficult to remove and may recur. Nerve root tumors are also generally benign, although neurofibromas may become malignant over time. Ependymomas at the end of the spinal cord can be large, and the delicate nature of fine neural structures in that area may complicate treatment.
Intramedullary tumors grow inside the spinal cord or individual nerves, most frequently occurring in the cervical (neck) region. They typically derive from glial or ependymal cells that are found through the interstitium of the spinal cord. Astrocytomas and ependymomas are the two most common types. They are often benign, but can be difficult to remove. Intramedullary lipomas are rare congenital tumors most commonly located in the thoracic spinal cord.
Extradural tumors are typically attributed to metastatic cancer of schwannomas derived from the cells covering the nerve roots. Occasionally, an extradural tumor extends through the intervertebral foramina, lying partially within and partially outside of the spinal canal.
Intramedullary tumors are rare, accounting for only 5 to 10 percent of all spinal tumors. Benign tumors such as meningiomas and neurofibromas account for 55 to 65 percent of all primary spinal tumors.
Meningiomas most frequently occur in women between the ages of 40 and 70. Primary tumors arising from the spinal cord, spinal nerve roots and dura are rare compared to tumors that arise in the brain.
The cause of most primary spinal tumors is unknown. Some of them may be attributed to exposure to cancer-causing agents. Spinal cord lymphomas, which are cancers that affect lymphocytes (a type of immune cell), are more common in people with compromised immune systems. In a small number of cases, primary tumors may result from presence of these two genetic diseases:
Neurofibromatosis 2 is a hereditary disorder in which benign tumors may develop in the arachnoid layer of the spinal cord or in the supporting glial cells. However, the more common tumors associated with this disorder affect the nerves related to hearing and can inevitably lead to loss of hearing in one or both ears.
Von Hippel-Lindau disease is a rare, multisystem disorder associated with benign blood vessel tumors (hemangioblastomas) in the brain, retina and spinal cord, and with other types of tumors in the kidneys or adrenal glands.
Metastatic Spinal Tumors
Metastatic spinal tumors are the most common type of malignant lesions of the spine, accounting for an estimated 70 percent of all spinal tumors. Common primary cancers that spread to the spine are lung, breast and prostate. Other cancers that spread to the spine include lymphoma, melanoma and sarcoma, as well as cancers of the gastrointestinal tract, kidney and thyroid.
Prompt diagnosis and identification of the primary malignancy is crucial to treatment. Many factors can affect outcome, including the nature of the primary cancer, the number of lesions, the presence of distant non-skeletal metastases and the presence and/or severity of spinal-cord compression.
- Back pain not attributable to injury, stress or physical activity
- Back pain that increases with activity and worsens at night
- Back pain that spreads to the hips, legs, feet or arms and worsens over time
Depending on the location and type of tumor, other signs and symptoms can develop, especially as a malignant tumor grows and compresses on the spinal cord, the nerve roots, blood vessels or bones of the spine. Impingement of the tumor on the spinal cord can be life threatening in itself. Additional symptoms can include the following:
- Loss of sensation or muscle weakness in the legs, arms or chest
- Difficulty walking, which may cause falls
- Decreased sensitivity to pain, head and cold
- Loss of bowel or bladder function
- Paralysis that may occur in varying degrees and in different parts of the body, depending on which nerves are compressed
- Scoliosis or other spinal deformity resulting from a large, but benign tumor
A thorough medical examination with emphasis on back pain and neurological deficits is the first step to diagnosing a spinal tumor. Imaging tests are required for an accurate and positive diagnosis.
- CT scan of the spine
- MRI of the spine
- Tissue biopsy
If the tumor is malignant, your doctor may order a whole body scan using nuclear technology, as well as a CT scan of the lungs and abdomen to determine the stage of the tumor. To confirm diagnosis, your doctor will compare laboratory test results and findings from these scans to your symptoms.
- Observation to determine whether the tumor is growing
- Radiation therapy
Indications for surgery vary depending on the type of tumor. Primary spinal tumors may be removed through complete en bloc resection for a possible cure.
For cases in which surgical removal is possible, preoperative embolization may be used to enable an easier procedure. The procedure involves the insertion of a catheter or tube through an artery in the groin. The catheter is guided up through the blood vessels to the site of the tumor, where it delivers a glue-like liquid embolic agent that blocks the vessels that feed the tumor. When the blood vessels that feed the tumor are blocked off, bleeding can often be controlled more easily during surgery, helping to decrease surgical risk.
A required period of post-surgery physical rehabilitation may involve a stay in a rehabilitation hospital for a period of time. In other cases, physical therapy may take place at an outpatient facility or at the patient's home. The total recovery time after surgery may be as short as three months or as long as one year, depending on the complexity of the surgery and the patient's overall health.
For patients with metastatic tumors, treatment is primarily palliative, with the goal of restoring or preserving neurological function, stabilizing the spine and alleviating pain. Generally, surgery is only considered as an option for patients with metastases when they are expected to live 12 weeks or longer, and the tumor is resistant to radiation or chemotherapy. Indications for surgery include intractable pain, spinal-cord compression and the need for stabilization of impending pathological fractures.
Source: American Association of Neurological Surgeons