Spinal tumour is an abnormal growth of cells in the spinal cord or surrounding the spinal cord and spinal column. The cells grow and multiply uncontrollably. Spinal tumours can be benign (non-cancerous) or malignant (cancerous).
These can classified as primary (originating in the spine or spinal cord) or secondary (or metastatic, resulting from cancer spreading from another site to the spine).
Spinal tumours are also referred according to the area of the spine in which they occur – cervical, thoracic, lumbar and sacrum. They can be classified according to the location in the spine – anterior (in the front) or posterior (in the back). Clinically, however, spinal tumour is classified is categorised into three major groups: intradural-extramedullary, intramedullary and extradural.
- Intradural-extramedullary spinal tumour: This form of tumour may develop in the following spaces of the spinal cord:
- Meningioma develops in the spinal cord’s arachnoid membrane. Most often benign, they can however be difficult to remove and have high chances of recurring.
- Schwannomas & Neurofibromas, in the nerve roots that extend out from the spinal cord; though generally benign, neurofibromas can become malignant over time.
- Filum terminale ependymomas, at the base of the spinal cord. These can be large and can be complicated to treat due to the fine neural structures in the region.
- Intramedullary spinal tumour: This form of spinal tumour develops inside the spinal cord or in individual nerves, most frequently in the cervical (neck) region. They are typically derived from glial or ependymal cells found throughout the interstitium of the spinal cord. Intramedullary tumours are of the following types:
- Astrocytomas & ependymomas, most common forms of intramedullary tumour, mostly benign but difficult to remove.
- Intramedullary lipomas, rare congenital tumours generally located in the thoracic spinal cord.
- Extradural spinal tumour: This form of tumour mostly develops from metastatic cancer or schwannomas derived from the cells that cover the nerve roots. An extradural tumour can sometimes extend through the intervertebral foramina, lying partly within and partly outside the spinal canal.
Metastatic spinal tumours
Metastatis or spread of cancer to bone most commonly occurs to the spinal column. The most common types of primary cancers that spread to the spine are the breast, lung and prostrate. Lung cancer is the most common cancer to metastasize to the bone in men, and breast cancer in women. Lymphoma, melanoma and sarcoma are other cancers that can spread to the spine, as also gastrointestinal tract cancer, and cancers of the kidney and thyroid.
Timely diagnosis and identification of primary malignancy is crucial for treatment. Prognosis of spinal metastatic cancers depends on the nature of the primary cancer, number of lesions, and presence and/or severity of spinal cord compression.
Paediatric spinal tumour: Though rare, spinal tumours in children can be challenging to treat. Spinal tumours in children may include the following:
- Osteoid osteoma
- Ewing sarcoma
- Aneurysmal bone cyst
- Eosinophillic granuloma
- Giant-cell bone tumour
- Mesenchymal chondrosarcoma
- Fibrous dysplasia
Doctors need to consider certain factors while determining treatment options as children have underdeveloped skeletal system, and also need to look at spinal stability and preservation of neurological function.
The most commonly occurring tumour of the central nervous system (CNS) is the intracranial (brain) tumour. Primary tumour arising from the spinal cord, spinal nerve roots and the dura is rare in comparison to CNS tumours of the brain. Most commonly occurring spinal tumour is the meningioma and neurofibroma, with the former being a common tumour occurring in women. Metastatic spinal tumours are most common forms of malignant lesions of the spine.
Though the cause of most primary spinal tumours is unknown, few can develop due to exposure to cancer-causing agents. Persons with compromised immune systems can develop spinal cord lymphomas.
In a small number of cases, primary tumours may result from two genetic diseases:
- Neurofibromatosis 2, in which benign tumours develop in the arachnoid layer of spinal cord or in the supporting glial cells.
- Von Hippel-Lindau disease, associated with benign blood vessel tumours in the brain, retina and spinal cord, and with tumours in the kidneys or adrenal glands.
Image Source: cancerresearchuk