Primary intraosseous haemangiomas, also referred to as vascular hamartomas, are haemangiomas seen most frequently in the vertebrae or skull, that come in four histological varieties (see below) 1-2.
Intraosseous haemangiomas are common, with vertebral haemangiomas seen in 10-15% of the adult population. They are more commonly encountered in men (M:F ratio of 2:1) and typically seen in the 4th to 5th decade of life.
These tumours are slow growing and are generally asymptomatic unless they exert mass effect on sensitive structures. Occasionally they may present as a swelling or a palpable mass, especially in the skull. When large and strategically located they may present with a pathological fracture.
If they are high-flow lesions, shunt-related symptoms may also be present.
Primary intraosseous haemangiomas are slow growing vascular neoplasms, usually located in the medullary cavity. They are classified as benign, but rarely may be locally aggressive.
Intraosseous haemangiomas come in four histologic types:
- intraosseous cavernous haemangioma
- intraosseous capillary haemangioma
- intraosseous arteriovenous haemangioma (may represent congenital arteriovenous malformations) 2
- intraosseous venous haemangioma
Histologically, intraosseous haemangiomas demonstrate hamartomatous vascular tissue within endothelium, but may also contain fat, smooth muscle, fibrous tissue, and thrombi.
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.
Location specific sub types
Plain radiographs are usually the first line of imaging and may be sufficient in vertebral or calvarial lesions. Findings include:
- 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 as an incidental finding, especially in the vertebrae.
Signal intensity is somewhat variable, depending largely on the amount of fat content.
- high is more common (fat rich)
- intermediate to low signal intensity is seen in fat poor haemangiomas
- 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.
Nuclear medicine bone scan
Usually normal but may show increased or decreased uptake.
Treatment and prognosis
Treatment is reserved for symptomatic lesions, and a number of options exist:
- radiation therapy
- embolization to reduce intraoperative blood loss
- surgical resection, especially if complicated by spinal cord compression
- intralesional ethanol injection
- 1. Sweet C, Silbergleit R, Mehta B. Primary intraosseous hemangioma of the orbit: CT and MR appearance. AJNR Am J Neuroradiol. 1997;18 (2): 379-81. AJNR Am J Neuroradiol (abstract) - Pubmed citation
- 2. Murphey MD, Fairbairn KJ, Parman LM et-al. From the archives of the AFIP. Musculoskeletal angiomatous lesions: radiologic-pathologic correlation. Radiographics. 1995;15 (4): 893-917. Radiographics (abstract) - Pubmed citation
The differential diagnosis for bone tumours is dependent on the age of the patient, with a very different set of differentials for the paediatric patient.
- bone-forming tumours
- cartilage-forming tumours
- chondromyxoid fibroma
- fibrous bone lesions
- bone marrow tumours
- other bone tumours or tumour-like lesions
- aneurysmal bone cyst
- benign fibrous histiocytoma
- giant cell tumour of bone
- Gorham massive osteolysis
- haemophilic pseudotumour
- intradiploic epidermoid cyst
- intraosseous lipoma
- musculoskeletal angiosarcoma
- musculoskeletal haemangiopericytoma
- primary intraosseous haemangioma
- post-traumatic cystic bone lesion
- simple bone cyst
- impending fracture risk