A hemangioma is a common, benign, non-cancerous tumor characterized by an abnormal collection of blood vessels. When these vascular malformations develop in the spinal column, they are known as vertebral hemangiomas. Most vertebral hemangiomas are small, asymptomatic, and discovered incidentally. However, a rare subset is classified as aggressive. This aggressive variant demands attention because its rapid growth and tendency to expand can compromise the structural integrity of the vertebra and threaten the delicate neural tissues of the spinal cord.
Understanding Aggressive Vertebral Hemangiomas
Aggressive vertebral hemangiomas (AVH) represent approximately 1% of all spinal hemangiomas. They are distinguished by their pathological behavior and tendency toward extraosseous extension, meaning the tumor grows outside the confines of the bone. This abnormal growth often involves the entire vertebral body and can extend into posterior elements, such as the pedicles and neural arch.
The term “aggressive” is applied because the tumor causes significant vertebral expansion and cortical destruction. Unlike benign hemangiomas, AVH lesions have a high vascular-to-fat ratio, leading to faster proliferation of blood vessels. This overgrowth creates a soft tissue mass that can protrude into the spinal canal or the surrounding paravertebral space.
The resulting bone destruction and soft tissue expansion compromise the spinal column’s structure. This instability can cause a compression fracture, or the mass effect can directly compress the spinal cord. AVH is most frequently found in the mid-thoracic spine (T3–T9), where the spinal canal is naturally narrower, making the cord vulnerable to compression.
Clinical Presentation and Neurological Compromise
The onset of symptoms is often subacute, beginning with localized, persistent back pain that does not respond to typical rest or medication. This pain is caused by bone expansion and microfractures within the affected vertebra. The pain may be worse at night or when bearing weight, reflecting mechanical stress on the compromised spinal segment.
The most concerning feature of AVH is its potential to cause neurological compromise when the tumor mass or vertebral collapse presses on the spinal cord or nerve roots. Compression of a nerve root leads to radiculopathy, experienced as sharp, shooting pain, numbness, or tingling that radiates down an arm or leg.
When the tumor causes significant pressure on the spinal cord itself, myelopathy develops. Symptoms of myelopathy include progressive motor weakness in the limbs, such as difficulty walking or loss of fine motor control (paraparesis). Sensory changes, including numbness or an electric sensation, can also ascend or descend from the level of the lesion.
In severe, rapidly progressive cases, compression can lead to an acute neurological emergency, such as paraplegia (complete paralysis) or cauda equina syndrome. Signs include new or worsening bladder and bowel dysfunction, requiring immediate medical intervention.
Diagnostic Imaging and Confirmation
The diagnostic process begins with imaging studies to define the extent of the lesion and its relationship to neural structures. Magnetic Resonance Imaging (MRI) is the gold standard for evaluating aggressive vertebral hemangiomas. MRI provides excellent visualization of soft tissues, clearly showing the extraosseous component and the degree of spinal cord or nerve root compression.
Aggressive hemangiomas demonstrate a distinct signal pattern on MRI: hypointense (dark) on T1-weighted images and hyperintense (bright) on T2-weighted and STIR sequences. This pattern reflects the high vascularity and low fat content of the lesion, contrasting with benign hemangiomas. Intravenous contrast material further highlights the tumor’s rich blood supply through uniform enhancement.
Complementary to MRI, Computed Tomography (CT) scans assess the bony architecture and structural integrity of the vertebra. CT images effectively demonstrate bone expansion, cortical destruction, and the classic internal appearance of the hemangioma. This includes the “polka-dot sign” on axial views and the “corduroy sign” on sagittal views, caused by thickened vertical bone trabeculae.
If imaging features are ambiguous, a tissue biopsy may be necessary to confirm the diagnosis and exclude malignant tumors, such as metastasis or plasmacytoma. Pre-procedural imaging, including angiography, is often performed to map the tumor’s feeding vessels for surgical planning or embolization procedures.
Multidisciplinary Treatment Approaches
The management of aggressive vertebral hemangiomas is complex and requires a multidisciplinary team, typically involving spine surgeons, interventional radiologists, and radiation oncologists. The strategy is individualized based on the patient’s symptoms, neurological deficit, and extent of vertebral destruction.
For highly vascular tumors, a common initial step is preoperative embolization. Embolization is a minimally invasive procedure where an interventional radiologist blocks the blood vessels supplying the tumor. By injecting an embolizing agent (such as liquid embolic material or particles) into the feeding arteries, blood flow is significantly reduced. This procedure minimizes the substantial risk of life-threatening blood loss during subsequent surgical intervention.
Radiation therapy is an effective treatment option for AVH, especially for lesions causing pain or slowly progressive neurological deficits, or when surgery carries excessive risk. External beam radiation therapy (EBRT) or advanced techniques like Stereotactic Body Radiation Therapy (SBRT) can halt tumor growth, often resulting in pain relief and stabilization of neurological symptoms. Radiation is frequently used as an adjuvant treatment following surgical decompression to prevent local recurrence.
Surgery is the preferred option for patients with severe or rapidly progressing neurological deficits or significant spinal instability. The primary goals are spinal cord decompression and vertebral stabilization. Decompression involves removing the portion of the tumor pressing on the spinal cord, often through a laminectomy or a more extensive vertebral body removal (corpectomy).
Stabilization procedures are necessary after tumor removal to restore the spine’s structural integrity. This may involve placing metal instrumentation (rods and screws) and sometimes injecting bone cement (vertebroplasty) into the remaining vertebral body for immediate mechanical support. Combining surgical decompression with vertebroplasty reduces intraoperative blood loss and improves functional outcomes.