Hemangioma of Bone Hemangioma of the skeletal system is rare and accounts for onlyabout 1% of all skeletal tumors. It is slightly more common infemales with the most common location being the skull, and spinalcolumn, and the least common location being the appendicularskeleton where it is seen typically in long bones such as thehumerus, femur and tibia. The presents of asymptomatic incidentalhemangiomas of the vertebral bodies at autopsy have been notedin as high as 10% of autopsy studies. The hemangioma is consideredA hamartomatous dysplastic process similar to fibrous dysplasia.It can be monstotic or polyostotic. The lesions occur during thedevelopmental years but are frequently not diagnosed until middleage when they are picked up as incidental findings, perhaps duringthe performance of an MRI study of the axial skeleton. Radiographically, the hemangioma is a lytic process with fairlygeographic borders and the lesions tend to have a motheaten or
honeycomb appearance in both the axial and long bones due toreactive bone formation surrounding the vascular spaces. In thecase of the axial skeleton, the characteristic radiographic feature isa vertically oriented honeycomb pattern. In flat bones, such as theiliac crest or the calvarium, the lesion may have a soap-bubblyor sunburst appearance, especially in the calvarium where theselesions are typically seen. Because of the osteoblastic response tothe vascular dysplasia, the radiographic appearance can be similarto that of an osteoid osteoma or an osteoblastoma. With MRIimaging, one may find a soft tissue component with the bony lesion,especially in the appendicular skeleton. Histologically, these lesionstend to be grossly bloody in appearance with large vascular sinusoidslined by a single layer of flat-appearing endothelial cells filledwith blood. Occasionally, one will see an epithelioid pattern tothe endothelial cells that gives them a more cube-like appearancesimilar to the histological appearance of an epithelioid low gradehemangioendothelioma.
As far as treatment is concerned, many of these smaller lesionsare incidental findings that require no treatment whatsoever. How-ever, with larger lesions, especially in the vertebral column, theremay be mechanical collapse associated with spinal cord compressionthat might necessitate curettement of the lesion with bone graftingand instrumentation. Also in the spinal area,larger lesions mayrequire embolization therapy prior to surgery to reduce hemorrhageat the time of exploration. Occasionally, low dose radiation therapycan reduce the lytic process produced by these dysplastic lesions.
Gorham’s Disease Gorham’s disease, sometimes referred to as disappearing bonedisease, is characterized by massive osteolysis in children or youngadults and is usually associated with the presence of benigncavernous hemangiomas or lymphangiomas of bone. This strangecondition usually affects a particular area (such as the spine or thehip) but can involve multiple bones of that area and tends to resolvespontaneously.
CLASSIC Case #15336 year maleGorham’s diseaseseen initially left hipSpontaneous osteolysisfemoral head and neck
CT scan 3 years later shows massive osteolysis both hips
Coronal T-1 MRI at time of initial disease in left hip
Initial axial T-2 MRI with high signal changes left hip
Bone biopsy left hip osteoidPhotomic shows changes similar to hemangiomatosis
Higher power showing capillary vascular pattern
Changes in right hip3 years after onsetin left hip
Case #839 12 year male with Gorham’s disease skull and spine
Hemangioendothelioma The hemangioendothelioma or epithelioid hemangioendotheliomais considered an intermediate grade vascular sarcoma arising fromendothelial cells. It occurs more commonly in males than femalesand is found typically in the femur, tibia ,axial skeleton and ribs.The most common age group is 20 thru 50 years. The lower gradelesions behave clinically very much like a hemangioma of bonebut the higher grade hemangioendotheliomas are more aggressive,require more aggressive treatment surgically, and can be helpedwith adjuvant radiation therapy.
CLASSICCase #15435 year femalelow gradehemangioendotheliomadistal femur
High Grade angiosarcoma of Bone High grade hemangiosarcoma of bone differs from the low gradehemangioendotheliomas of bone in that they are very aggressive,lytic, destructive tumors usually occurring in the lower extremitiesof young adults that carry an extremely poor prognosis becauseof the high incidence of pulmonary metastases. These lesions, asopposed to the hemangioendotheliomas, have very little osteoblasticresponse to the infiltrate and take on the radiographic appearance ofa high grade spindle cell sarcoma such as a malignant fibrous histio-cytoma or a fibrosarcoma of bone. As with the hemangioendo-thelioma, they can be multifocal in nature but the more aggressivelesions tend to be solitary and lytic with permeative lysis throughoutthe bone. There are only about 30 cases described in the worldliterature showing the extreme rarity of this lesion. This aggressivesarcoma requires aggressive surgical treatment along with radiationand chemotherapy with a 50% chance of a five year survival.
CLASSIC Case #159 21 year male with angiosarcoma pelvis
Hemangiopericytoma of Bone Hemagiopericytoma of bone is an extremely rare tumor arisingfrom the hemangiopericytes of Zimmerman, which are smoothmuscle contractile cells that lie outside the capillary tubes of thevascular system peripherally and control the flow of blood toperipheral tissue. Hemangiopericytomas can range from very lowgrade tumors, such as the glomus tumor seen in the distalphalanges of young adults, to the more aggressive, malignanthemangiopericytoma seen in the more proximal parts of the body,such as the pelvis, spine or femur. The later can behave like asarcoma and metastasize to the lung. There have only been a fewcases of this tumor reported in the literature in large bones.
CLASSIC Case #160 25 year female with benign hemangiopericytoma talus
Parosteal Lipoma Lipid tumors of bone, unlike soft tissue fatty tumors, are extremelyrare clinical entities. The most common of these rare tumors is theparosteal lipoma that is usually found lying on the surface of themetaphyseal portion of a long bone such as the humerus, femur ortibia. They usually occur in middle-aged patients with no sexdominance. Radiographically these lesions stand out because ofan exophytic bony spur arising from the surface of the metaphysealbone similar to the appearance of a small osteochondroma or bonespur, or in larger cases they can take on the appearance of a parostealsarcoma. However, the diagnostic feature of the parosteal lipomais the presence of a radiolucent cap of benign fatty tissue surroundingthe bone spur that extends out into the soft tissue a distance of 3-5cm. These lesions are very benign, are usually asymptomatic and donot require surgical treatment, similar to the situation with a softtissue lipoma.
CLASSICCase #16364 year femaleparosteal lipomadistal humerus spur
Intramedullary Lipoma Intramedullary lipomas are extremely rare conditions with approx-imately 30 cases in the world literature. They are usually locatedin the central area of the diaphysis of a long bone such as the femur,tibia, or fibula. For some reason, a large 30% of cases of this raretumor are seen in the os calcis. These lesions are usually asympto-matic and picked up as an incidental finding. They take on theradiographic appearance of fibrous dysplasia of a long bonebecause of slight fusiform dilatation of the surrounding cortex,which is slightly thinned out and in the central area there is evidenceof degenerative calcification and occasionally even bone formationin the lipoma. However, a T-1 weighted MRI image will show thehigh signal features of a lipoma to help differentiate the tumor fromfibrous dysplasia that has a low signal on a T-1 weighted image.These lesions are asymptomatic and do not require surgical treatment.There is no threat to the patient of pathologic fracture.
CLASSIC Case #16640 year femaleintramedullary lipomahumerus