The spine consists of a bony canal (the back bones) that encloses the spinal cord. Surrounded by protective membranes, the spinal cord is a thick white bundle of nerve tissue that travels from the base of the skull down the back. The spinal cord and the brain make up the central nervous system.
Along the length of the spinal cord, 31 pairs of spinal nerves extend through spaces between the vertebrae. They connect with nerves throughout the body, acting as conduits for critical messages between the brain and the entire body.
The spine can be affected by many different kinds of tumors. Malignant (cancerous) tumors can arise within the spine itself. Secondary tumors, which are actually much more common, begin as cancers in another part of the body, such as the breast and prostate, and then spread (metastasize) to the spine.
Not all growths are cancerous. But because the spinal cord is enclosed within the rigid, bony spinal column, any abnormal growth can cause problems by compressing the spinal cord and nerves, or compromising the structural integrity of the spine.
Types of Spine Tumors
Benign (nonmalignant, non-cancerous) spine tumors include:
Meningiomais a tumor that arises in the meninges, the layers of tissue that cover and protect the brain and spinal cord. Meningiomas compress the nerve tissues near them. Although these are typically slow-growing benign tumors, they can also be malignant and more aggressive. Meningiomas in the spinal cord can cause problems with neurologic function. Meningiomas make up about 25 percent of all spine tumors.
Osteochondromais a slow-growing tumor of the cartilage that typically occurs in the roof of the spine. It usually affects adolescents.
Osteoidosteomais a small bone tumor that causes night pain, and can lead to deformation of the spine. It usually affects adolescents.
Osteoblastomais a tumor that can be large, aggressive and painful, sometimes causing spine deformity and paralysis. It primarily occurs in children and adolescents.
Aneurysmal bone cystscan be large and typically cause pain and swelling. They mainly affect children and adolescents.
Giant cell tumoris commonly located at the base of the spine (sacrum). It often arises in children and young adults.
Hemangiomais a vascular mass that most often does not cause symptoms and requires no treatment. On rare occasions, hemangiomas can damage the vertebra and cause paralysis (paraparesis). It occurs most often in adults, arising within the vertebral body in the mid to upper (thoracic) spine.
Eosinophilic granulomais a tumor in the vertebrae of children and adolescents. In some cases, these are known to heal spontaneously.
Lipomais a benign tumor composed of normal fatty tissue located within an otherwise normal spinal cord. It arises most commonly within the thoracic spinal cord, and can cause neurological symptoms by compressing the nerves.
Hemangioblastomais a tumor that is usually benign but occasionally malignant. These tumors originate from tissues that make up the blood vessels. Although relatively rare in childhood, hemangioblastomas can occur at any age. In approxmiately 25 percent of cases, these tumors are associated with Von Hippel-Lindau syndrome, an inherited genetic condition. They can also be associated with a cyst in the spinal cord.
Malignant Spine Tumors
Some of the more common types of malignant spine tumors include:
A glioma is a primary brain or spinal cord tumor that arises from glial cells, which are the most common cells in the brain and spinal cord. Their main function is to support and protect the nerve cells (neurons).
Glial cells have three main types: astrocytes, oligodendrocytes and ependymal.
While neurons cannot multiply, glial cells have the power to divide and reproduce. Sometimes this process goes out of control, resulting in a tumor called a glioma.
Each type of glial cell creates its own type of glioma. Most gliomas come from abnormal astrocytes, and are called astrocytomas. The other types of gliomas include oligodendrogliomas and ependymomas. Sometimes, a tumor will have a combination of cell types.
Astrocytomas are tumors that occur mainly in the neck and upper back areas of the spinal cord. They can range in severity from benign (noncancerous) to malignant (cancerous). These tumors arise from star-shaped cells called astrocytes, a type of glial cell. The glial cells are the most common cells in the brain and spinal cord. Their main function is to support and protect the nerve cells (neurons).
Astrocytomas are most common among children and, in fact, are the most common pediatric spinal cord tumor that originates from supporting cells.
Chordomas are rare, slow-growing malignant tumors that typically arise in the spine and the base of the skull. Although chordomas can affect children and adolescents, they most often occur between 40 and 70 years of age. They may spread to other organs, including the lungs.
Chordomas develop from tissue that originally gave rise to the spine in the early stages of fetal development. Although this tissue is normally replaced by the spine, small areas can remain which can lead to chordomas.
Ependymomas are a rare type of glioma that develop from the ependymal cells found within the central canal of the spinal cord. They account for the majority of adult spine tumors and may occur in any part of the spine, and also in the brain.
Ependymomas can spread from the brain to the spinal cord via the cerebrospinal fluid that surrounds and protects the brain and spinal cord. About 40 percent of spine canal ependymomas arise within the filum terminale, a neurologically non-functioning structure at the tail end of the spinal cord.
People of all ages can develop these tumors.
Nerve sheath tumors
Nerve sheath tumors arise from the cells that surround nerves. They are generally categorized as either schwannomas or neurofibromas.
Nerve sheath tumors account for about 25 percent of intradural spinal cord tumors (located within the membrane surrounding the cord) in adults. Most are single schwannomas that can arise anywhere within the spine canal. With neurofibromas, these are typically associated with a genetic condition called neurofibromatosis, characterized by multiple tumors.
Only a small percentage of these intradural spine nerve sheath tumors are malignant.
Metastatic spine tumors
A metastatic or “secondary” spinal cord tumor arises when cancer cells break away from a primary tumor elsewhere in the body and spread to the spinal cord. Metastatic spine tumors are usually extradural in that that they grow outside the dura mater, a tough membranous layer that surrounds the spinal cord. These tumors can create pressure that affects the spinal cord and spine nerves.
Spine metastases occur most commonly in people with breast cancer, prostate cancer and multiple myeloma.