A hemangioma is a common, benign tumor resulting from an overgrowth of blood vessels. While these vascular tumors can appear anywhere, they are most frequently noticed on the skin. When this growth occurs within the spine, it is called a spinal hemangioma, representing the most common benign tumor found in the spinal column. Most spinal hemangiomas are discovered incidentally during imaging tests for unrelated reasons, as they typically cause no symptoms. This article discusses their nature, identification, and management.
Defining Spinal Hemangiomas
A spinal hemangioma is a tangle of newly formed blood vessels within a vertebra. These lesions consist of proliferating capillary and venous structures that displace normal bone marrow within the vertebral body. They are most commonly found in the thoracic (mid-back) and lumbar (lower-back) regions.
Classified as primary spinal tumors, these lesions originate directly within the vertebral bone. They are benign vascular lesions characterized by a slow growth rate, often less than three millimeters over ten years.
The exact cause is not fully understood, but they are believed to arise from a developmental abnormality of the blood vessels. They are estimated to be present in 10 to 12 percent of the general population. While usually confined to the vertebral body, they can occasionally extend into the posterior arch or surrounding soft tissues.
Clinical Presentation and Symptoms
The vast majority of spinal hemangiomas remain completely asymptomatic throughout a person’s life. Their discovery is often an incidental finding on magnetic resonance imaging (MRI) or computed tomography (CT) scans ordered for other conditions.
When a spinal hemangioma becomes symptomatic, it is typically because the tumor has grown large enough to weaken the vertebral bone or press on nearby nervous structures. The most frequent complaint is localized back pain, varying from mild discomfort to severe pain. Pain occurs because the vascular growth causes the bone to expand or, in rare instances, leads to a vertebral compression fracture.
More concerning symptoms arise if the hemangioma extends into the spinal canal, causing compression of the spinal cord or nerve roots. This neural impingement can result in radicular pain, which radiates along the path of a nerve. Serious spinal cord compromise (occurring in less than two percent of cases) may present as neurological deficits, including muscle weakness, numbness, or difficulty with bladder or bowel control.
Diagnostic Procedures
Evaluation relies heavily on non-invasive imaging techniques. Initial screening may involve a simple X-ray, which can sometimes reveal characteristic changes in the bone structure, such as the coarse, lattice-like “corduroy sign.” X-rays are not sufficient for a definitive diagnosis or for assessing soft tissue involvement.
Computed Tomography (CT) scans offer a more detailed view of the bony architecture. CT is effective in showing the typical honeycomb pattern created by vascular channels within the bone and is useful for evaluating vertebral integrity and detecting compression fractures. However, CT provides limited information about the soft tissues surrounding the spine.
Magnetic Resonance Imaging (MRI) is the preferred method for confirming the presence of a spinal hemangioma and is crucial for comprehensive assessment. MRI is highly effective at distinguishing the hemangioma from other spinal tumors and visualizing the lesion’s growth into the spinal canal or its effect on the spinal cord and nerve roots. The characteristic appearance of the lesion on MRI, often showing a high fat content, helps radiologists differentiate it from more aggressive tumors.
Treatment and Management Strategies
Since the vast majority of spinal hemangiomas are benign and asymptomatic, the primary management strategy is “observation and monitoring,” often called watchful waiting. This involves periodic clinical evaluations and follow-up imaging to ensure the lesion is not growing or causing new symptoms. No active intervention is required for asymptomatic cases.
For the small percentage of patients who experience pain or neurological symptoms, an active treatment plan is required, tailored to the specific nature of the lesion. A common intervention for painful hemangiomas is vertebroplasty or kyphoplasty, which involves injecting bone cement into the affected vertebral body. This procedure stabilizes the weakened bone, reduces pain, and helps prevent further collapse.
Targeted Treatments
Other treatments aim to reduce the size or activity of the vascular tumor. Embolization is a minimally invasive technique where an interventional radiologist blocks the blood supply to the hemangioma using specialized materials. Radiation therapy can also be used to shrink the lesion and reduce local pain, particularly when the tumor is causing spinal cord compression. In rare instances where the hemangioma causes severe neurological deficits and has grown extensively into the spinal canal, surgical removal, such as a laminectomy to decompress the spinal cord, may be necessary.