Primary intraosseous hemangioma

Last revised by Yuichiro Hirano on 19 May 2023

Primary intraosseous hemangiomas, also known as hemangiomas of bone, are benign tumors of small and large caliber vascular channels arising within bone 4, seen most frequently in the vertebrae and next most frequently in the skull.

Given their non-neoplastic nature, some authors ref refer to these lesions as vascular malformations or hamartomas. They have not been included in the 2018 ISSVA classification 6.

Intraosseous hemangiomas are common, with vertebral hemangiomas seen in ~10% of the adult population 4. They are slightly less commonly encountered in men (M:F = 0.7:1) and most commonly seen in the 5th decade of life but can occur at any age 4.

Diagnostic criteria according to the WHO classification of soft tissue and bone tumors (5th edition) 4:

  • typical imaging appearances

  • on histology, thin-walled blood vessels with a lining of single non-atypical endothelial cells

These tumors are slow-growing and are most commonly asymptomatic (~99% 4) unless they exert mass effect on sensitive structures, present as a swelling or a palpable mass, especially in the skull, or when large and strategically located, they may present with a pathological fracture 4.

If they are high-flow lesions, shunt-related symptoms may also be present.

Primary intraosseous hemangiomas are slow-growing vascular tumors, usually located in the medullary cavity 4. The etiology and pathogenesis are unknown 4. Most commonly they are located in the vertebrae (of the thoracic spine 5), followed by the skull and facial bones, followed by long bones where they preferentially involve the metaphysis or diaphysis 4. They are classified as benign, but rarely may be locally aggressive.

Intraosseous hemangiomas come in four histologic types 1,2:

  1. intraosseous cavernous hemangioma

  2. intraosseous capillary hemangioma

  3. intraosseous arteriovenous hemangioma (may represent congenital arteriovenous malformations) 2

  4. intraosseous venous hemangioma

Histologically, intraosseous hemangiomas demonstrate hamartomatous vascular tissue within endothelium surrounding bone trabeculae and permeating marrow, but may also contain fat, smooth muscle, fibrous tissue, and thrombi 4.

It should be noted that it is difficult to distinguish between the various histological types on imaging, except for those with a large arterial component ref.

Plain radiographs are usually the first line of imaging and may be sufficient in vertebral or calvarial lesions. Findings include ref:

  • prominent trabecular pattern

  • sclerotic vertebra with vertical trabeculae: corduroy sign

  • lytic calvarial lesions with spoke-wheel appearance

  • irregular and lytic in long bones, with a honeycomb appearance

Usually appears as a mixed or sclerotic bone lesion with internal fat. CT allows for better visualization of thickened vertical trabeculation, which can give the polka-dot appearance on axial images and the corduroy sign on coronal and sagittal images 5.

Signal intensity is somewhat variable, depending largely on the amount of fat content:

  • T1

    • high is more common (lipid-rich)

    • intermediate to low signal intensity is seen in lipid-poor hemangiomas 3

  • T2: high

  • T1 C+ (Gd): enhancement is often present

  • STIR: intermediate or high

MRI is the ideal modality to demonstrate mass-effect complications, such as neural impingement and extraosseous extension.

Bone scintigraphy is usually normal but may show increased or decreased uptake ref.

If incidental with typical imaging appearances no work-up or follow-up is required 5. Treatment is reserved for symptomatic lesions, and a number of options exist ref:

Local recurrence rates are low 4.

When internal fat is present and the imaging findings are not typical, the following differential diagnosis can be considered 5:

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