Practice Essentials
Neoplastic disease that involves the spine and results in spinal cord or cauda equina compression may have devastating neurologic and functional consequences.
Metastatic lesions are responsible for about 85% of neoplastic spinal cord compression cases, with the other 15% due to primary neoplastic lesions of the spine. The clinical presentation in compression caused by metastatic lesions tends to be indistinguishable from that caused by primary disease. For the emergency physician, however, the cell origin of the tumor is less of a concern than the consequent syndromes of spinal cord dysfunction. These patients require rapid diagnosis and treatment to prevent permanent complications (see Presentation, Workup, and Treatment).
Pathophysiology
Neoplastic disease can cause neurologic symptoms by compression of the thecal sac, spinal cord, or cauda equina, as well as compression of the attendant vascular supply, which results in cord edema and ischemia. The neural tracts most vulnerable to mechanical pressure include the corticospinal and spinocerebellar tracts and the posterior spinal columns. Infrequently, tumors may induce cavitation within the spinal cord.
Metastatic spinal cord comression
Metastatic spinal cord compression is due to invading lesion(s) in the epidural space, between the vertebral bones and the dura of the thecal sac, compressing the thecal sac, spinal cord, or cauda equina.
Systemic cancers with a tendency for spinal metastasis include the following:
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Breast cancer
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Prostate cancer
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Renal cancer
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Lung cancer
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Lymphoma (in both adults and pediatric populations)
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Sarcoma (eg, Ewing sarcoma in pediatric populations)
Metastatic spinal cord compression usually follows arterial hematogenous dissemination of malignant cells to the vertebral bodies, with subsequent expansion into the epidural space. Spread into the epidural space may also occur by means of tumor extension through the intervertebral foramina (as is common with lymphoma) or hematogenous spread to the vertebral bodies by way of the Batson venous plexus (particularly with prostate cancer). [1]
Most frequently, metastatic seeding involves 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] 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 in such cases tend to resemble those of epidural compression; however, if motor weakness is present, it 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 advanced systemic cancer (eg, lung or breast cancer, melanoma, lymphoma). Leptomeningeal metastasis presents as multifocal neurological deficits referable to the spinal cord.
Primary spinal cord tumors
Primary spinal cord tumors arise from the different elements of the central nervous system (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).
Most primary intramedullary spinal cord tumors are astrocytomas or ependymomas. [2] Intradural extramedullary tumors—including schwannomas, neurofibromas, and meningiomas [2] —that affect the paravertebral area may spread and compress the cord through expansion. Occasionally, an enlarging cancerous lymph node may also compress the cord.
Hemangiomas
Hemangiomas (benign tumors of the blood vessels) are usually discovered incidentally and usually do not produce symptoms. However, symptoms can emerge if pathologic vertebral fractures or epidural extension occurs.
Epidemiology
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 degree of disability 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- and age-related demographics
A slight male predominance exists for primary spinal cord tumors. Symptomatic hemangiomas occur most frequently in teenaged girls and typically involve the thoracic spine.
The incidence of primary spinal cord tumors peaks in people aged 30-50 years. People older than 50 years are more likely to experience back pain secondary to a metastatic tumor. 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.
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Patient with metastatic breast cancer; plain radiograph shows L4 vertebral collapse.
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MRI of plain film above showing intrusion of tumor and vertebral collapse into spinal canal.
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Patient with renal cell carcinoma; MR shows collapse of a thoracic vertebra with spinal cord impingement.
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Axial MR of patient in Media File 3 above with vertebral destruction and spinal cord impingement.
