Spinal Cord Neoplasms 

Neoplastic disease that involves the spine with spinal cord compression may be devastating if unrecognized.

Primary spinal cord tumors arise from the different elements of the CNS, including neurons, supporting glial cells, and meninges. Anatomically, neoplasms of the spinal cord may be classified according to the compartment of origin, either intramedullary (inside the cord) or extramedullary (outside the cord). Additionally, cancers that metastasize to the vertebrae or surrounding tissues frequently cause spinal cord compression.

Metastatic lesions are featured in this discussion since they cause 85% of the cases of neoplastic spinal cord compression. The clinical presentation tends to be indistinguishable from that of primary cancers of the spine.

For the emergency physician, the cell origin of the tumor is less of a concern than the consequent syndromes of spinal cord dysfunction.

Metastatic spinal cord compression usually follows hematogenous dissemination of malignant cells to the vertebral bodies, with subsequent expansion into the epidural space. Spread into the epidural space may occur by means of tumor extension through the intervertebral foramina or hematogenous spread by way of the Batson venous plexus. Most frequently, metastatic seeding appears in the thoracic spine (accounting for about 70% of cases), with the lumbar spine being the next most involved site (20% of cases). The cervical spine is affected in approximately 10% of cases. Multiple spinal levels are affected in about 30% of patients.^[1]

Systemic cancers with a tendency for spinal cord metastasis include the following: breast, prostate, renal, or lung neoplasms; lymphoma; sarcoma; and multiple myeloma. Gastrointestinal and pelvic malignancies tend to affect the lumbosacral spine; lung and breast cancers are more likely to affect the thoracic spine.

Metastases to the substance of the cord (intramedullary) are relatively rare. Signs and symptoms tend to simulate those of epidural compression; however, the associated motor weakness is more likely to be unilateral. Principles of treating intramedullary cancer are similar to those for epidural spinal cord compression.

Leptomeningeal metastases spread by means of diffuse or multifocal seeding of the meninges from systemic cancer (eg, lung or breast cancer, melanoma, lymphoma). Consequent signs and symptoms may be referable to the spine or spinal cord. Evidence of spinal compromise may include lower extremity weakness, paresthesias, reflex asymmetry, and spinal pain.

Most primary intramedullary spinal cord tumors are astrocytomas or ependymomas.^[2] Intradural extramedullary tumors include schwannomas, neurofibromas, and meningiomas^[2] that affect the paravertebral area may spread and compress the cord through expansion. Additionally, an enlarging cancerous lymph node may compress the cord.

Hemangiomas (benign tumors of the blood vessels) are usually discovered incidentally and usually do not produce symptoms. However, symptoms emerge if pathologic vertebral fractures or epidural extension occurs.

Nerve tracts most vulnerable to mechanical pressure include the corticospinal and spinocerebellar tracts and the posterior spinal columns. Additionally, neoplasms may compromise the vascular supply, causing edema or ischemia. Less frequently, tumors may induce cyst formation or cavitation within the spinal cord.

Frequency

United States

Metastatic lesions that involve the spinal cord affect about 5-10% of patients with cancer.^[3] Approximately 15% of all primary CNS lesions arise from the spinal cord, with an estimated incidence rate of 0.5-2.5 cases per 100,000 population.

International

The international incidence rate parallels that of the United States.

Mortality/Morbidity

Most primary spinal cord cancers do not disseminate widely through the CNS or body. Consequent disability relates to the degree of cord impairment and anatomic level of cord injury.

Metastatic tumors that cause epidural cord compression and dysfunction are the most common causes of oncologic CNS injury. Mortality correlates with the prognosis of the primary cancer.

The severity of spinal cord compromise secondary to a tumor spans a wide range. Initially, symptoms may be limited to pain or minor sensory or motor disturbance. As the compression progresses, neurologic abnormalities become more pronounced, advancing to disability. Partial cord compression, such as Brown-Séquard syndrome, may evolve. In the advanced stage of compression, complete transverse sensory and motor paralysis with bowel and bladder incontinence occurs.

The disability of the patient at the initiation of therapy serves as the best predictor of ultimate disability in patients with epidural cord compression. Early detection of cord compression and early intervention is the goal.

Sex

A slight male predominance exists for primary spinal cord tumors.

Symptomatic hemangiomas occur most frequently in the thoracic region of teenaged girls.

Age

People older than 50 years are more likely to experience back pain secondary to a metastatic tumor. The incidence of primary spinal cord tumors peaks in people aged 30-50 years.

Certain CNS tumors, such as neuroblastoma, occur almost solely in pediatric patients.

Clinical syndromes produced by intramedullary tumors vary depending on the age of the individual. In children, gait disturbances prevail, with pain reported infrequently. Spinal cord neoplasms may manifest as scoliosis or torticollis in younger patients.

Pain is the most common early complaint of adult patients with spinal cord neoplasms, followed by the insidious progression of spinal cord dysfunction.