11 Oct Spinal Tumors
Spinal tumors are often referred to by the area of the spine in which they occur. These basic areas are cervical, thoracic, lumbar and sacrum. Additionally, they also are classified by their location in the spine—anterior (front) and posterior (back).
Clinically, they are divided into three major groups according to location: intramedullary, intradural-extramedullary and extradural.
Intramedullary tumors grow inside the spinal cord or on the individual nerves, most frequently occurring in the cervical (neck) region. They typically derive from glial or ependymal cells that are found throughout the interstitium of the cord. Astrocytomas and ependymomas are the two most common types, often benign, but can be difficult to remove. Intramedullary lipomas are rare congenital tumors most commonly located in the thoracic spinal cord.
Intradural-extramedullary tumors can 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.
Extradural tumors occur in the vertebral column, and grow either from the bone or disc elements of the spine. These lesions are typically attributed to metastatic cancer or 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. The spinal column is the most common site for bone metastasis.
Research indicates that 30% to 90% of patients with cancer will experience the spread of cancer to their spine. Common primary cancers that spread to the spine are lung, breast and prostate. Lung cancer is the most common cancer to metastasize to the bone in men, and breast cancer is the most common in women. Other cancers that spread to the spine include lymphoma, melanoma and sarcoma, as well as cancers of the gastrointestinal tract, kidney and thyroid. Nearly 5% to 10% of patients with systemic cancer suffer spinal metastases, and approximately 30% to 70% of patients with solid tumors have spinal metastatic disease. Breast, lung, prostate, andrenal cell carcinomas; lymphoma; and sarcoma account for 70% of all sources of spinal metastasis. The metastases occur in the vertebral body (60%), posterior elements (30%), or both (10%).