4. Hemangioma of Bone
Hemangioma of the skeletal system is rare and accounts for only
about 1% of all skeletal tumors. It is slightly more common in
females with the most common location being the skull, and spinal
column, and the least common location being the appendicular
skeleton where it is seen typically in long bones such as the
humerus, femur and tibia. The presents of asymptomatic incidental
hemangiomas of the vertebral bodies at autopsy have been noted
in as high as 10% of autopsy studies. The hemangioma is considered
A hamartomatous dysplastic process similar to fibrous dysplasia.
It can be monstotic or polyostotic. The lesions occur during the
developmental years but are frequently not diagnosed until middle
age when they are picked up as incidental findings, perhaps during
the performance of an MRI study of the axial skeleton.
Radiographically, the hemangioma is a lytic process with fairly
geographic borders and the lesions tend to have a motheaten or
5. honeycomb appearance in both the axial and long bones due to
reactive bone formation surrounding the vascular spaces. In the
case of the axial skeleton, the characteristic radiographic feature is
a vertically oriented honeycomb pattern. In flat bones, such as the
iliac crest or the calvarium, the lesion may have a soap-bubbly
or sunburst appearance, especially in the calvarium where these
lesions are typically seen. Because of the osteoblastic response to
the vascular dysplasia, the radiographic appearance can be similar
to that of an osteoid osteoma or an osteoblastoma. With MRI
imaging, one may find a soft tissue component with the bony lesion,
especially in the appendicular skeleton. Histologically, these lesions
tend to be grossly bloody in appearance with large vascular sinusoids
lined by a single layer of flat-appearing endothelial cells filled
with blood. Occasionally, one will see an epithelioid pattern to
the endothelial cells that gives them a more cube-like appearance
similar to the histological appearance of an epithelioid low grade
hemangioendothelioma.
6. As far as treatment is concerned, many of these smaller lesions
are incidental findings that require no treatment whatsoever. How-
ever, with larger lesions, especially in the vertebral column, there
may be mechanical collapse associated with spinal cord compression
that might necessitate curettement of the lesion with bone grafting
and instrumentation. Also in the spinal area,larger lesions may
require embolization therapy prior to surgery to reduce hemorrhage
at the time of exploration. Occasionally, low dose radiation therapy
can reduce the lytic process produced by these dysplastic lesions.
145. Gorham’s Disease
Gorham’s disease, sometimes referred to as disappearing bone
disease, is characterized by massive osteolysis in children or young
adults and is usually associated with the presence of benign
cavernous hemangiomas or lymphangiomas of bone. This strange
condition usually affects a particular area (such as the spine or the
hip) but can involve multiple bones of that area and tends to resolve
spontaneously.
146. CLASSIC
Case #153
36 year male
Gorham’s disease
seen initially left hip
Spontaneous osteolysis
femoral head and neck
147. CT scan 3 years later shows massive osteolysis both hips
161. Hemangioendothelioma
The hemangioendothelioma or epithelioid hemangioendothelioma
is considered an intermediate grade vascular sarcoma arising from
endothelial cells. It occurs more commonly in males than females
and is found typically in the femur, tibia ,axial skeleton and ribs.
The most common age group is 20 thru 50 years. The lower grade
lesions behave clinically very much like a hemangioma of bone
but the higher grade hemangioendotheliomas are more aggressive,
require more aggressive treatment surgically, and can be helped
with adjuvant radiation therapy.
209. High Grade angiosarcoma of Bone
High grade hemangiosarcoma of bone differs from the low grade
hemangioendotheliomas of bone in that they are very aggressive,
lytic, destructive tumors usually occurring in the lower extremities
of young adults that carry an extremely poor prognosis because
of the high incidence of pulmonary metastases. These lesions, as
opposed to the hemangioendotheliomas, have very little osteoblastic
response to the infiltrate and take on the radiographic appearance of
a 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 aggressive
lesions tend to be solitary and lytic with permeative lysis throughout
the bone. There are only about 30 cases described in the world
literature showing the extreme rarity of this lesion. This aggressive
sarcoma requires aggressive surgical treatment along with radiation
and chemotherapy with a 50% chance of a five year survival.
210. CLASSIC Case #159
21 year male with angiosarcoma pelvis
242. Hemangiopericytoma of Bone
Hemagiopericytoma of bone is an extremely rare tumor arising
from the hemangiopericytes of Zimmerman, which are smooth
muscle contractile cells that lie outside the capillary tubes of the
vascular system peripherally and control the flow of blood to
peripheral tissue. Hemangiopericytomas can range from very low
grade tumors, such as the glomus tumor seen in the distal
phalanges of young adults, to the more aggressive, malignant
hemangiopericytoma seen in the more proximal parts of the body,
such as the pelvis, spine or femur. The later can behave like a
sarcoma and metastasize to the lung. There have only been a few
cases of this tumor reported in the literature in large bones.
243. CLASSIC Case #160
25 year female with benign hemangiopericytoma talus
268. Parosteal Lipoma
Lipid tumors of bone, unlike soft tissue fatty tumors, are extremely
rare clinical entities. The most common of these rare tumors is the
parosteal lipoma that is usually found lying on the surface of the
metaphyseal portion of a long bone such as the humerus, femur or
tibia. They usually occur in middle-aged patients with no sex
dominance. Radiographically these lesions stand out because of
an exophytic bony spur arising from the surface of the metaphyseal
bone similar to the appearance of a small osteochondroma or bone
spur, or in larger cases they can take on the appearance of a parosteal
sarcoma. However, the diagnostic feature of the parosteal lipoma
is the presence of a radiolucent cap of benign fatty tissue surrounding
the bone spur that extends out into the soft tissue a distance of 3-5
cm. These lesions are very benign, are usually asymptomatic and do
not require surgical treatment, similar to the situation with a soft
tissue lipoma.
284. Intramedullary Lipoma
Intramedullary lipomas are extremely rare conditions with approx-
imately 30 cases in the world literature. They are usually located
in 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 rare
tumor are seen in the os calcis. These lesions are usually asympto-
matic and picked up as an incidental finding. They take on the
radiographic appearance of fibrous dysplasia of a long bone
because of slight fusiform dilatation of the surrounding cortex,
which is slightly thinned out and in the central area there is evidence
of degenerative calcification and occasionally even bone formation
in the lipoma. However, a T-1 weighted MRI image will show the
high signal features of a lipoma to help differentiate the tumor from
fibrous 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.