Aggressive vertebral hemangioma

Aggressive vertebral haemangiomata are a rare form of vertebral haemangiomata where significant vertebral expansion, extra-osseous component with epidural extension, disturbance of blood flow, and occasionally compression fractures can be present causing spinal cord and/or nerve root compression ^1,2. 

Epidemiology

It can occur at any age, with peak prevalence in young adults. They represent approximately 1% of spinal haemangiomas and are usually symptomatic ¹. 75% of these lesions occur in the thoracic spine between T3 and T9 vertebral segments ³.

Clinical presentation

Unlike typical vertebral haemangiomas which are almost always asymptomatic, aggressive type 'always' present with neurological manifestations due to the mass effect of the epidural component upon the spinal cord, nerve roots or both, leading to compressive myelopathy and/or radiculopathy ².

Pathology

They are composed of blood vessels with slow flowing, dilated venous channels surrounded by fat, infiltrating the medullary cavity ⁴.

Radiographic features

CT

They appear as hypodense expansile vertebral masses, with cortical defects and soft tissue extension and spinal cord/nerve root compression. The classic “polka dot” and “corduroy” signs of the vertebral body due to thickened vertebral trabeculae are also helpful ¹. They generally occupy the entire vertebral body, extend into the neural arch, expand the osseous margins, and contain a soft tissue component ¹.

MRI

Thickened trabeculae appear as low signal areas in both T1 and T2 images. The extraosseous component typically follows usual haemangioma in all pulse sequences with high T1 and T2 signals as well as uniform post-contrast enhancement. MRI is excellent at the assessment of cord or nerve root compression ¹.

Chemical shift imaging can be helpful to look for signal drop out to indicate intralesional fat.

Treatment and prognosis

Accurate preoperative diagnosis is essential because they are highly vascular with high tendency of intraoperative bleeding. Surgery is required in cases of rapid or progressive neurological symptoms like compressive myelopathy or radiculopathy. Endovascular embolisation prior to surgery to minimise intraoperative blood loss. Radiotherapy can be used in patients with slow progressive neurological deficits. Other emerging options in cases of aggressive hemangiomas include radiofrequency ablation with a hemostatic agent (FLOSEAL, Baxter, USA), and bone autograft placement ⁶. Minimally-invasive procedures may be successful in smaller lesions ⁵.

Differential diagnosis

• Plasmacytoma can sometimes mimic the appearances of an aggressive haemangioma.
• metastases: usually have decreased signal intensity on T1 and increased signal intensity on T2
• lymphoma: epidural component appears hypointense on T1 and less hyperintense on T2