You are in: eMedicine Specialties > Radiology > MUSCULOSKELETAL Hemangioma, BoneArticle Last Updated: Mar 25, 2008AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  Author: Ishmael Chasi, MBChB, FRCR, Specialist Registrar, Department of Radiology, Freeman Hospital, UK Ishmael Chasi is a member of the following medical societies: Royal College of Radiologists Coauthor(s): Geoff Hide, MBBS, MRCP, FRCR, Consultant Musculoskeletal Radiologist, Department of Radiology, Freeman Hospital; Honorary Clinical Lecturer, Faculty of Medical Sciences, University of Newcastle upon Tyne Editors: Michael A Bruno, MD, Associate Professor, Departments of Radiology and Medicine, Pennsylvania State University College of Medicine; Director, Radiology Quality Management Services, Milton S Hershey Medical Center, Pennsylvania State University College of Medicine; Bernard D Coombs, MB, ChB, PhD, Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand; Theodore E Keats, MD, Professor, Departments of Radiology and Orthopedics, University of Virginia School of Medicine; Robert M Krasny, MD, Consulting Staff, Department of Radiology, The Angeles Clinic and Research Institute; Felix S Chew, MD, MBA, EdM, Professor, Department of Radiology, Vice Chairman for Radiology Informatics, Section Head of Musculoskeletal Radiology, University of Washington Author and Editor Disclosure Synonyms and related keywords: osseous hemangioma, cavernous hemangioma, capillary hemangioma INTRODUCTIONSection 2 of 11
  BackgroundBone hemangiomas are benign, malformed vascular lesions, overall constituting less than 1% of all primary bone neoplasms. They occur most frequently in the vertebral column (30-50%) and skull (20%), whereas involvement of other sites (including the long bones, short tubular bones, and ribs) is extremely rare. Bone hemangiomas are usually asymptomatic lesions discovered incidentally on imaging or postmortem examination and mostly encountered in the middle-aged. The symptoms are largely nonspecific and depend on the site, size, and aggressiveness of the tumors.1, 2 PathophysiologyBone hemangiomas usually occur in the medullary cavity, but uncommonly, surface-based hemangiomas are encountered in the cortex, periosteum, and subperiosteal regions.3 Gross pathology usually reveals well-demarcated, unencapsulated lesions with cystic red cavities. Microscopic examination shows hamartomatous proliferations of vascular tissue within endothelium-lined spaces. There are 4 histologic variants of hemangioma, classified according to the predominant type of vascular channel: cavernous, capillary, arteriovenous, and venous. These types can coexist. Bone hemangiomas are predominantly of the cavernous and capillary varieties. Cavernous hemangiomas most frequently occur in the skull,4, 5 whereas capillary hemangiomas predominate in the vertebral column; overall, the former type is most common in bone.6 Various types of nonvascular tissues may form the matrix within which the angiomatous tissue is interspersed, typically in cavernous hemangiomas. These include fat, smooth muscle, bone trabeculae, fibrous tissue, and clotted blood products. A greater proportion of fat in vertebral hemangiomas is associated with a reduced likelihood of symptoms. Conversely, neural compression is more likely to be associated with a greater proportion of hypervascular or hemangiomatous tissue. Hemangiomas are slow growing, and malignant degeneration is virtually unknown. Rarely, locally aggressive growth patterns are recognized; hemangiomas with these patterns can mimic malignant lesions. Epithelioid hemangiomas are benign vascular neoplasms usually occurring in the skin and superficial tissues. They are uncommonly encountered in bone. Cytologically, they may be confused with malignant tumors. Indentation or erosion of bone cortex with or without reactive bone formation may occur due to secondary involvement from soft-tissue hemangiomas. FrequencyUnited StatesVertebral hemangiomas are common, with a rate of 10-12% in autopsy series. Osseous hemangiomas are less frequent at other sites. Mortality/MorbidityComplications arising from osseous hemangiomas are rare, and their severity depends on the location of the lesions.
Related Medscape topic: RaceThere is no documented racial variation in the frequency of hemangiomas. SexOsseous hemangioma generally occurs more commonly in females than males, with a ratio of 3:2. AgeThe peak incidence is in the fifth decade, although osseous hemangiomas can be encountered at any age. The rare periosteal and other surface-based hemangiomas tend to occur in younger patients. AnatomyVertebral hemangiomas are the most common benign tumor of the spinal column, and they occur most frequently in the lower thoracic and upper lumbar spine. The lesions are most often solitary, but they may be multiple in up to one third of cases. Spinal hemangiomas are usually localized to the vertebral body, less frequently extending into or exclusively affecting the posterior arch. Clinical DetailsThe large majority of lesions are asymptomatic; clinically significant symptoms develop in only 1-2% of patients. Other more common causes of back pain, such as spondylosis or disk prolapse, should be excluded before ascribing the symptoms to hemangioma. When symptoms occur, they can be vague and nonspecific. Vertebral collapse and epidural and/or extraosseous extension can result in back pain. Neural compression can produce paralysis and/or paraplegia or bladder and bowel dysfunction, whereas radicular symptoms occur from nerve-root impingement. Calvarial lesions tend to be most significant clinically.7 Craniofacial hemangiomas may result in a palpable lump, although local pressure effects or aggressive growth patterns can cause pain. Localized swelling, limb hypertrophy, and pain can be characteristics of hemangiomas in the extremities. Hemorrhage can occur, usually in the setting of trauma, biopsy, surgery or other medical or dental interventions. Preferred ExaminationPlain radiography is useful for evaluation as the first-line imaging modality in most cases. Radiographic appearances differ depending on the anatomic site and histologic variant of the lesion. However, the radiographic hallmark of bone hemangiomas is a prominent trabecular pattern. Radiographic patterns may be nonspecific, necessitating further imaging or histology to achieve diagnosis. This is especially true in extraspinal hemangiomas occurring in an age group and location in which other more ominous diagnostic entities, such as myeloma or metastases, are more common. When plain radiographs do not suffice and appearances remain equivocal, cross-sectional imaging is crucial for further characterization of these lesions. CT is especially useful for assessing changes in bone trabeculae; the results support the plain radiographic findings and provide greater detail. The superior soft-tissue and bone marrow contrast resolution of MRI allows for better evaluation of extraosseous extension and depiction of the characteristic fatty content in vertebral hemangiomas and also flow patterns in general. The multiplanar capabilities of MRI are also crucial in defining the extent of neural involvement in the spine and planning therapeutic interventions.8 Limitations of TechniquesDespite the added diagnostic information available with CT and MRI, the angiomatous nature of many extraspinal lesions can be confirmed only with histologic analysis. DIFFERENTIALSSection 3 of 11
Aneurysmal Bone Cyst Bone Metastases Lymphoma, Bone Multiple Myeloma Osteosarcoma, Classic Paget Disease RADIOGRAPHSection 4 of 11
FindingsMost vertebral hemangiomas are small and cannot be seen on plain radiographs. The characteristic radiographic appearance is of a sclerotic or ivory vertebra with coarse, thickened vertical trabeculae giving a corduroy, accordion, or honeycomb appearance (see Images 1-4). This appearance is due to resorption of horizontal trabeculae, caused by vascular channels and consequent reinforcement of vertical trabeculae. This finding can be differentiated from Paget disease, in which picture framing of the vertebral body is seen due to prominent horizontal trabeculae. Similar findings may occur with lymphoma and metastases. Bulging of the posterior cortex or expansion of the vertebral body is sometimes present. Calvarial hemangiomas are usually round, osteolytic lesions that may demonstrate the characteristic sunburst, radiating spoke-wheel or weblike pattern of trabecular thickening. Radiographic appearances in craniofacial hemangiomas are often nonspecific. Mixed radiopacity, radiolucency, and honeycomb patterns are observed. Long-bone hemangiomas are usually lytic, with a spiculated pattern creating a latticelike or Irish-lace appearance. A honeycomb structure can also result from bubbly bone osteolysis. Irregular bone destruction can occur, simulating malignant lesions. Reactive sclerosis may be seen at the margins of the lesions; with surface-based hemangiomas, they may mimic osteoid osteoma. Epithelioid hemangiomas characteristically demonstrate well-defined lysis, and they may also exhibit surrounding sclerosis, cortical expansion, or destruction. Degree of ConfidenceRadiographic appearances of hemangiomas can be pathognomonic, especially with vertebral and calvarial hemangiomas. CT and MRI increase diagnostic confidence in equivocal cases. CT SCANSection 5 of 11
FindingsVertebral hemangiomas are typified by punctate sclerotic foci representing thickened vertical trabeculae seen in cross-section and giving a polka-dot appearance (see Image 5). This finding may be absent in patients with symptomatic lesions. Bulging of the posterior cortex and paravertebral soft-tissue extension is readily assessed on CT scans, as is bone destruction with aggressive hemangiomas. CT findings in nonvertebral hemangiomas confirm plain radiographic results but gives more detailed assessment of medullary, cortical bone, and extraosseous involvement. Degree of ConfidenceCT scanning is more sensitive than plain radiography. MRISection 6 of 11
FindingsMRI features largely depend on the proportion of fat and vascularity of the lesions. With T1-weighted MRIs, particularly in vertebral hemangiomas, areas of high fat content appear as areas of high signal intensity. On T2-weighted images, high signal intensity typically corresponds to the vascularity of hemangiomas (see Images 6-7). Low signal intensity on T1-weighted images indicates decreased marrow fat or a greater vascular component; such a finding may be correlated with more aggressive behavior and is also more characteristic in cases involving vertebral collapse. Thickened trabeculae demonstrate low signal intensity on MRIs obtained with all sequences (see Image 8). Extraosseous components tend not to show high signal intensity on T1-weighted images due to the paucity or absence of adipose tissue, but avid enhancement occurs with gadolinium enhancement due to the vascularity of the lesions. Epidural extension and neural involvement are well depicted with MRI (see Images 9-10). Gadolinium-based contrast agents (gadopentetate dimeglumine [Magnevist], gadobenate dimeglumine [MultiHance], gadodiamide [Omniscan], gadoversetamide [OptiMARK], gadoteridol [ProHance]) have recently been linked to the development of nephrogenic systemic fibrosis (NSF) or nephrogenic fibrosing dermopathy (NFD). For more information, see the eMedicine topic Nephrogenic Fibrosing Dermopathy. The disease has occurred in patients with moderate to end-stage renal disease after being given a gadolinium-based contrast agent to enhance MRI or MRA scans. Lesions in flat and long bones may show serpentine vascular channels. These demonstrate low signal intensity on T1-weighted images and high signal intensity on T2-weighted images with slow blood flow; they show low signal intensity on MRIs obtained with all sequences in conditions of high blood flow.9 Degree of ConfidenceComplicated symptomatic spinal hemangiomas may be difficult to differentiate from malignant lesions. NUCLEAR MEDICINESection 7 of 11
FindingsOsseous hemangiomas usually show normal uptake on isotope bone scans, but they may also demonstrate photopenia and mildly to moderately increased activity. Scintigraphy with labeled red blood cells usually demonstrates focally increased activity. Degree of ConfidenceSingle-photon emission CT images are more sensitive than planar images in depicting abnormal activity.10 ANGIOGRAPHYSection 8 of 11
FindingsAngiographic findings confirm the hypervascularity of the lesions. Angiography is usually performed in conjunction with embolization of symptomatic hemangiomas prior to surgery.11 INTERVENTIONSection 9 of 11
Hemangiomas should be treated only if symptomatic; treatment options depend on the site of the lesion, the severity of the symptoms, and the medical expertise available. Medical treatment and clinical observation can be used as first-line management, especially in patients with mild to moderate symptoms. Other treatment options are available when this does not suffice or when clinically appropriate.12, 13 Treatment modalitiesEmbolization Embolization of hemangiomas is performed prior to surgery; it helps reduce the vascularity of the lesions and, therefore, intraoperative blood loss. Embolization may also relieve cord compression by reducing lesion bulk. Surgery Surgery is usually reserved for refractory cases and in cases complicated by vertebral collapse with neural compression. It is ideally preceded by lesion embolization and may be combined with postoperative radiation therapy, especially when pain occurs with neurologic compression. The surgical options may entail lesion excision, decompressive laminectomy, resection of epidural extension, bone grafting, and use of metallic prostheses. Percutaneous vertebroplasty Percutaneous vertebroplasty was introduced in France in 1984. It was first used for the treatment of vertebral hemangiomas and, subsequently, osteoporotic and malignant vertebral collapse. Vertebroplasty is minimally invasive and provides stabilization of the vertebral body and prompt, lasting pain relief that allows for early mobilization of the patients. Vertebroplasty is ideal in the absence of cord compression or posterior arch and/or pedicle involvement, but it has also been used prior to surgical decompression to consolidate the vertebral body and reduce hemorrhagic complications.14, 15 Vertebroplasty may be used in combination with embolization or ethanol injection.16 Direct ethanol injection CT-guided direct injection of ethanol as a sclerosing agent has been used to treat vertebral hemangiomas complicated by cord and nerve root compression. This method has been shown to be effective and safe, providing symptomatic relief and lesion obliteration. Treatment by lesionVertebral lesions Controversial approaches to the management of these lesions are reflected by the range of treatment options available. Options include radiation therapy, embolization, surgical resection, vertebroplasty, and intralesional injection of a sclerosant. These approaches can be used alone or in combination. Radiation therapy is the most common treatment modality and an effective tool in the management of these lesions. It is used either as primary treatment for alleviating pain (probably as a result of its anti-inflammatory properties), for facilitating reossification, or for postsurgical care to prevent recurrence and relapse of symptoms. Obliteration of the lesion can occur with radiotherapy, but this effect is not prompt enough for cord compression. Calvarial lesions Curative marginal resection of these lesions can be achieved without local recurrence. Long-bone lesions Excision of the lesions and bone grafting are the mainstays of treatment of disease in the extremities. Special Concerns
MULTIMEDIASection 10 of 11
REFERENCESSection 11 of 11
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