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Canine Hemangiosarcoma
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Dr. Kimberly Cronin
Overview
Hemangiosarcoma is a malignant cancer of the cells that form blood vessels.
Because these tumors start
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Pale gums of a dog with abdominal
bleeding from a ruptured tumor.
click on image for larger view
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in blood vessels, they are
frequently filled with blood. Consequently, when a blood-filled tumor ruptures,
it can cause problems with internal or external bleeding. Hemangiosarcoma
is considered to be a very aggressive tumor and can spread rapidly to other
organs.
Hemangiosarcoma is more common in dogs than in cats. It usually occurs
in middle-aged to older dogs 9 to 11 years of age, and German shepherds
appear to be predisposed to developing this cancer.
The most common primary location of this cancer in dogs is the spleen.
Other primary locations include the heart, liver, skin, and bone; however,
it can start in any location where blood vessels are present. These tumors
usually spread to the lungs, liver, spleen and heart.
Signs of this disease are usually the result of the tumor rupturing,
which causes bleeding.
This may occur without any warning, and the symptoms will depend upon
where the tumor is located.
When the tumor is located in the spleen or liver, the signs are usually
due to rupture of the tumor and subsequent bleeding into the abdomen. This
causes anemia, weakness and if the bleeding is severe, collapse. The gums
may appear to be pale or white. In relatively few animals the diagnosis
is made before the tumor ruptures.
When this type of tumor occurs in the heart, it can cause symptoms,
such as weakness, collapse, difficulty breathing, exercise intolerance
and fluid build-up in the abdomen. This is usually due to the development
of fluid around the heart, called pericardial effusion. A thin sack, called
the pericardium, normally surrounds the heart. In pericardial effusion
the sack fills up with fluid and prevents the heart from beating effectively.
With hemangiosarcoma, the pericardium fills up with blood due to rupture
of the tumor.
When the tumor occurs in the skin, a mass or lump can usually be felt
in or under the skin. The mass may become ulcerated and bleed. When the
tumor occurs in a bone, it can cause pain and discomfort. In some locations,
such as a rib, the tumor can be felt as a firm swelling in the bone.
What to Watch For
Anemia, weakness and collapse
Pale or white gums
Difficulty breathing
Exercise intolerance
Fluid build-up of the abdomen
Mass or lump under the skin
Swelling in the bone
Pain in the bones
Diagnosis
Diagnostic tests that may be needed to recognize hemangiosarcoma and
to direct treatment include:
Complete blood count (CBC) including platelet numbers
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An abdominal tap or abdominocentesis may
be needed to recognize hemangiosarcoma.
click on image for larger view
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Clotting tests
Serum chemistry panel and urinalysis
Abdominal radiographs (X-rays) and/or ultrasound
Abdominal tap
Chest X-rays
Ultrasound of the heart
Electrocardiogram (EKG)
Pericardial tap
Biopsy
Treatment
The treatment and prognosis depends upon the location of the tumor. When
the tumor occurs in an internal organ such as the spleen or heart, the
chances of long-term survival are poor. Treatment is more successful when
this cancer occurs in the skin. Exposure to the sun may play a role in
the development of this type of skin cancer. Dogs with poorly-pigmented
skin and sparse hair coats, such as the whippet, saluki, bloodhound and
English pointer, are more likely to develop this form of hemangiosarcoma.There
is no known cause of hemangiosarcoma in other locations. In humans, exposure
to certain chemicals such as vinyl chloride has been implicated as a cause.
Treatment for hemangiosarcoma may include the following:
Stabilization
Intravenous fluids
Blood transfusion
Pericardial tap
Surgery
Chemotherapy
Radiation therapy
Home Care and Prevention
Seek veterinary attention promptly if your pet develops pale gums, signs
of weakness or collapse. Have any new lumps on your pet evaluated by your
veterinarian.
Minimize your pet's exposure to the sun, especially dogs that are poorly
pigmented and have a sparse hair coat.
Information In-depth
Hemangiosarcoma must be differentiated from other diseases that might
cause similar clinical signs. For example, diseases of the heart such as
an irregular heart rhythm can cause pets to show signs of weakness or collapse.
There are several other malignant tumors that can appear as a mass in the
spleen including:
Fibrosarcomas
Malignant fibrous histiocytomas
Undifferentiated sarcomas
Osteosarcomas
These tumors can also rupture leading to bleeding from the spleen and
the development of anemia. Some systemic cancers may involve the spleen either
in addition to other sites or as the primary site. The two most common cancers
where this occurs are lymphosarcoma and mast cell tumor. Although not common,
other tumors can spread or metastasize to the spleen causing similar signs
as hemangiosarcoma.
Other diseases that can cause similar signs include:
Hemangioma, which is the benign counterpart of hemangiosarcoma.This
tumor can cause the same clinical signs as hemangiosarcoma but does not
spread to other areas of the body. This tumor type is rare.
Splenic torsion. The spleen can become twisted, which can lead
to enlargement of the spleen and possible rupture.
Hematoma of the spleen. A blood clot can form in the spleen causing
anemia and/or a mass in the spleen. Although generally there is a history
of trauma, this can also occur without any known injury.
Aortic body tumor, which is the most common other tumor of the
heart. This can occur in the same location as hemangiosarcoma and cause similar
signs. Ultrasound of the heart may not be able to differentiate between hemangiosarcoma
and other tumor types such as an aortic body tumor.
Idiopathic pericardial effusion. This condition in dogs causes
fluid build-up around the heart. The cause is unknown but it can be managed
by periodic removal of the fluid or surgery. Other types of tumors can also
cause pericardial effusion.
Veterinary Care In-depth
Diagnosis
A complete blood count (CBC), including evaluating platelet numbers,
will allow your veterinarian to check
whether anemia (a low red blood cell count) is present or not. In addition
to causing anemia, hemangiosarcoma can also cause a low platelet count.
Platelets are needed in order for clotting to occur, so when the platelet
count is low, there is an increased risk of bleeding.
Dogs with hemangiosarcoma can also have changes in other clotting tests.
The risk of bleeding may be increased when the clotting tests are abnormal.
This information is important for your veterinarian when surgery is being
considered.
Serum chemistry panel and urinalysis tests are run to identify
any underlying diseases such as kidney or liver disease.
Abdominal radiographs (X-rays) or ultrasound are sometimes performed
to identify if there is a mass present in the abdomen.However, when there
has been bleeding into the abdomen, X-rays become difficult to evaluate.
An ultrasound of the abdomen will allow the liver and spleen to be evaluated
in greater detail than X-rays. It should be kept in mind that older dogs
frequently have nodules in the liver and spleen that are considered aging
changes and this does not mean that cancer is present.
An abdominal tap may be performed to confirm the presence of free
blood in the abdomen. Unlike blood in blood vessels, free blood in the
abdomen does not clot. The blood can also be examined under a microscope
for the presence of cancerous cells in the fluid. However, the absence of
cancerous cells does not preclude the diagnosis of hemangiosarcoma.
Pericardial tap When there is free fluid around the heart, it
is often possible to remove a portion of this fluid using a needle and syringe.
This is called a pericardial tap. A pericardial tap is often done with the
assistance of an ultrasound so that there is less risk of puncturing the
heart.
Chest X-rays may be routinely taken in any dog suspected of having
cancer. The lungs are one of the most common sites of spread of hemangiosarcoma.
In addition, the size and shape of the heart can be evaluated to see if
there are signs of either a mass in the heart or pericardial effusion.
An ultrasound of the heart may be performed to allow identification
of either a mass in the heart or fluid around the heart. However, ultrasound
may not be able to identify small masses in the heart. An ultrasound of
the heart also allows evaluation of heart function, which is important if
chemotherapy is planned.
An EKG allows for identification of any irregular heart rhythms
(arrhythmias) that may be secondary to hemangiosarcoma in the heart. Arrhythmias
are common in dogs that have tumors in the spleen or that have just undergone
removal of the spleen.
Biopsy
A biopsy may be necessary to make a definite diagnosis. If only a small
sample is taken or if the tumor is very abnormal, it may not be possible
to confirm that it is hemangiosarcoma. In the case where only a small sample
is submitted, additional biopsies may be needed. In the case where the tumor
is abnormal, special stains can be used to confirm that it is hemangiosarcoma.
The type of biopsy depends upon the location of the tumor.
When the tumor occurs in the spleen, the entire spleen is usually removed
and submitted for biopsy. In addition, all other organs in the abdomen
are usually examined and biopsies taken of any tissue that looks abnormal.
The liver is usually examined carefully since it is common for hemangiosarcoma
to spread to this site.
It is more difficult to obtain a diagnosis when the tumor occurs in the
heart than in the spleen. Generally the only way to get a biopsy in this
location is to enter the chest cavity surgically.
When the tumor occurs in the skin or in the tissues directly below the
skin, several types of biopsies can be obtained. A small piece of the tumor
can be obtained to confirm the diagnosis prior to any further treatment.
It is also possible in some cases to remove the entire tumor for biopsy.
When the tumor occurs in a bone, generally only a small sample of the
bone is taken to obtain a diagnosis.
Treatment
Stabilization is usually needed when the tumor causes internal bleeding
or a build-up of fluid around the heart. The symptoms can be life threatening;
pets that have bleeding into the abdomen can go into shock and require
emergency care. Dogs that have a build-up of fluid around the heart can
show signs of heart failure and collapse.
Intravenous fluids may be administered. This usually involves placement
of a catheter and rapid administration of intravenous fluids.
Transfusions may be performed. If a dog is very anemic, a blood transfusion
may be required to stabilize the patient. A transfusion can consist of
either whole blood or just red blood cells.
When the tumor causes pericardial effusion, it may be necessary to remove
the fluid around the heart to allow the heart to beat more effectively.
A pericardial tap is the procedure by which fluid is removed from around
the heart.Generally, once the fluid is removed, the patient improves, although
he must be monitored for recurrence of the fluid. Periodic removal of the
fluid may be needed.
Surgery
Surgery may be performed, and the type will depend upon the location
of the tumor. In some cases emergency surgery is required to stabilize a
patient when the tumor is bleeding.
When the tumor occurs in the spleen, a splenectomy is performed. This
involves removing the entire spleen. The spleen can be removed without having
an adverse effect on health. At the time of surgery other organs, particularly
the liver, should be examined and a biopsy taken of any abnormal tissue.
By removing the spleen, the source of bleeding is removed and the patient
stabilized. Potential complications following removal of the spleen include:
infection, continued bleeding, failure of the incision to heal and an abnormal
heart rhythm.
When the tumor occurs in the heart, it is almost always found on only
one chamber of the heart, the right atrium. It may be possible to remove
the tumor surgically. The outer covering of the heart, the pericardium, can
also be removed to prevent future build-up of fluid around the heart.
Potential complications of this surgery include bleeding, infection,
failure of the surgery site to heal, introduction of air into the chest
cavity causing difficulty breathing and an abnormal heart rhythm.
When the tumor occurs in the skin or in the tissues immediately below
the skin, surgery is required. It is important that normal tissue surrounding
the tumor be removed, along with the mass, because cells from this tumor
frequently infiltrate the surrounding tissues. Failure to remove these cells
will result in the tumor regrowing.
When the tumor occurs in the bone, it may be possible to remove the tumor
by removing the bone itself. This is possible only in certain locations
such as a leg or a rib. In some cases, it is only possible to get a biopsy
of the tumor.
Chemotherapy
Due to the early spread of this tumor, chemotherapy is frequently recommended
in addition to other treatments. The only exception to this is when the
tumor is localized to the very uppermost layer of the skin. Then surgical
removal of the tumor may be all that is required.
The most commonly used chemotherapy drug is doxorubicin. This drug is
administered intravenously once every three weeks. Dogs handle this drug
well and the risk of serious side effects is low, between 5 to 10 percent.
Potential side effects include gastrointestinal problems, including nausea,
vomiting, diarrhea or loss of appetite, and a drop in the white blood cell
count, leaving a pet susceptible to infection. If multiple treatments of this
drug are given, cumulative side effects include heart problems. In order to
prevent the cumulative side effects, the number of treatments is limited to
six or less.
In dogs, a heart evaluation (ultrasound and EKG) is recommended prior
to giving the drug and before the fifth and sixth treatment.
Other drugs that are used in the treatment of hemangiosarcoma are cyclophosphamide
and ifosphamide. Cyclophosphamide is frequently given either with doxorubicin
or immediately after. When ifosphamide is used, it is alternated with doxorubicin.
Both of these drugs can cause gastrointestinal side effects and a drop
in the white blood cell count. In addition, they can cause an irritation
in the lining of the bladder causing blood in the urine and straining to
urinate. If the drug irritates the bladder the signs will usually resolve
in a few days to a few weeks.
Radiation
Radiation Therapy
Radiation therapy may be performed and involve the following:
Full course radiation therapy. This type of radiation therapy
is used when a tumor involving the skin or underlying tissues cannot be
completely removed. In order for full course radiation to be effective,
all visible evidence of the tumor must be removed first with surgery. In
this situation, 16 to 19 treatments of radiation may be given over a four
to six week period of time. The side effects include hair loss and redness
and ulceration of the skin. These side effects are present only for a three
to four week period of time and can be managed with medications.
Palliative radiation therapy. This type of radiation therapy can
be used to control symptoms such as pain when the tumor cannot be entirely
removed with surgery. It involves giving a few large doses of radiation therapy
to the tumor over a two to three week period of time.Side effects are very
few and is most commonly used when the tumor occurs in the bone.
Prognosis may vary. The recommended course of treatment and outcome depends
upon the location of the tumor.
Hemangiosarcoma of the spleen is aggressive. The recommended treatment
is surgery (to remove the spleen) and chemotherapy. If the only treatment
is removal of the spleen, the survival time is short (between one to two
months). If chemotherapy is given after surgery the survival time is improved
and is about six months.
When the hemangiosarcoma is in the liver, the treatment recommendations
and outcome are similar to that of the spleen.
When the hemangiosarcoma is in the heart, the recommended treatment is
to remove the tumor if possible and follow-up with chemotherapy. With surgery
alone, the survival time is less than four months. With chemotherapy, the
survival time is extended to six months or more.
If the tumor occurs in only the upper layer of the skin the outcome is
excellent. In that situation, the only required treatment is complete removal
of the tumor with surgery. When the tumor involves the deeper layers of
the skin or the underlying tissues, there is a greater potential for spread
of the tumor to other organs. The recommended treatment is to remove the
entire tumor with surgery and to follow-up with chemotherapy. If the entire
tumor cannot be removed with surgery but is reduced to the level where the
tumor cannot be felt, radiation therapy is recommended in addition to the
surgery and chemotherapy. In this situation, survival times are between eight
to 12 months with treatment.
Hemangiosarcoma of the bone is an aggressive tumor. The most common bones
affected are the ribs, forelimbs and vertebrae. The recommended treatment
is removal of the affected bone if possible followed by chemotherapy. In
situations where the affected bone cannot be removed, palliative radiation
therapy can be given to control pain. The survival time for hemangiosarcoma
of the bone with treatment is around six months.
Follow-up
Seek veterinary attention promptly if your pet develops pale gums or
signs of weakness or collapse. These may be symptoms of hemangiosarcoma
or other potentially serious conditions.
Have any new lumps on your pet evaluated by your veterinarian. Hemangiosarcoma
of the skin or underlying tissues can be difficult to distinguish from
less serious skin tumors. Early detection may increase the possibility
of successful treatment.
Restrict your pet's activity after surgery until suture removal. Monitor
the incision for any signs of redness, swelling or discharge. Keep your
pet from chewing or scratching at the incision.
If your pet receives chemotherapy monitor him for changes in appetite
and activity. The most common side effects of chemotherapy are appetite loss,
vomiting and/or diarrhea. Mild signs can frequently be managed at home with
diet changes.Anti-nausea or anti-diarrhea medications can also be prescribed.
Your veterinarian should be notified if the signs are severe or last longer
than a few days. Rarely, your veterinarian may recommend hospitalization
to prevent dehydration.
Signs of infection include loss of appetite, fever and extreme tiredness.
Infections in patients with low white blood counts are serious and require
intravenous antibiotics.
Minimize your pet's exposure to the sun, especially for dogs that are
poorly pigmented and have a sparse haircoat. Hemangiosarcoma of the skin
can be caused by excessive exposure to the sun.
"This article has been provided courtesy of PetPlace.com
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online source for pet news, health,
and wellness information."
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THE PET HEALTH LIBRARY
Hemangiosarcoma
Hemangiosarcoma
is a malignant tumor of blood vessel cells. With the exception of
the skin form, which can often be eliminated by surgery, a diagnosis
of hemangiosarcoma is bad news. This tumor is associated with serious
internal bleeding and rapid internal spread. Fortunately, it is not completely
without therapy options and, as long as expectations are realistic,
temporary remissions are possible.
Hemangiosarcoma can theoretically arise from any tissue
where there are blood vessels (which amounts to anywhere in the body)
but there are three classical locations which account for most presentations:
Skin and subcutaneous forms
Splenic forms
Heart-based forms
The Skin Form
The skin form of hemangiosarcoma are the best types to
have as they are the most easily removed surgically and thus have
the greatest potential for complete cure.
The skin forms of hemangiosarcoma are classified as either
dermal and subcutaneous (also called hypodermal.) The true skin form
looks like a rosy red or even black growth on the skin. This form is
associated with sun exposure and thus tends to form on non-haired or
sparsely haired skin, such as on the abdomen, or on areas with white
fur. Dogs with short white haired fur (such as Dalmatians and pit bull
terriers) are predisposed to the development of this tumor. Approximately
1/3 of cases will spread internally in the malignant way we usually associate
with cancer so it is important to remove such growths promptly.
What To Know When a Skin Growth Biopsy Comes Back as
Hemangiosarcoma
The biopsy report will indicate whether or not the growth
was completely excised. If the tissue completely surrounding the growth
is normal, this indicates that the growth has been removed completely
and that it should not grow back.
If one wants to be absolutely positive that no tumor spread
has yet occurred, the following non-invasive (but not inexpensive)
testing is necessary.
Chest radiographs - hemangiosarcoma tends to spread to
the lungs. Advanced tumor spread can be picked up with this simple
test. (Spots of tumor spread must be 3cm in diameter to be large enough
to be visible on a radiograph.)
Ultrasound of the belly - specifically the spleen.
Even a small splenic hemangiosarcoma should be detectable with ultrasound.
Ultrasound of the heart - even a small heart-based
hemangiosarcoma should be detectable with ultrasound.
Subcutaneous or Hypodermal Hemangiosarcoma
The overlying skin is often totally normal on top of a
subcutaneous hemangiosarcoma and often the surgeon is surprised to
find a dark red blood growth under the skin when the tumor is removed.
Since up to 60% of hypodermal hemangiosarcomas spread internally
the above three tests to rule out tumor spread are more important.
If no sign of tumor spread is found after chest radiographs
have been taken and ultrasound of the heart and belly are clear, prognosis
is substantially better than if secondary tumor is found; however,
additional treatment with chemotherapy is recommended if cure is the
goal.
Surgery alone has been associated with a 172-day (approximately
6 months) median survival time.
Hemangiosarcoma of the Spleen
The spleen is a fairly deep-seated abdominal organ
that tends to go unnoticed unless it develops a growth of unusual
enlargement. Splenic growths have the unfortunate tendency to break
open and bleed profusely regardless of whether they are benign or malignant.
While a splenectomy (removal of the spleen) certainly ends the prospect
of this type of life-threatening sudden bleed, splenic hemangiosarcoma
is still a rapidly spreading malignancy.
When a splenic mass is detected, it may not be possible
to tell prior to splenectomy whether or not the mass is malignant or
not (though certainly basic testing is performed in an attempt to
determine this.)
Read about splenectomy
to review the details of splenic mass evaluation. Chemotherapy after
removal of the splenic hemangiosarcoma is reviewed here so see the
hemangiosarcoma link on the splenectomy page when you are ready to
return for more information.
25% of dogs with splenic hemangiosarcoma also have a heart-based
hemangiosarcoma.
Survival time with surgery alone is 19 to 65 days for splenic
hemangiosarcoma.
Heart-Based Hemangiosarcoma
Like the splenic hemangiosarcoma, the heart-based hemangiosarcoma
tends to exert its life-threatening effects by bleeding.
The heart is enclosed in a sac called the pericardium.
When the hemangiosarcoma bleeds, the blood fills up the pericardium
until it is so full that the heart inside is under so much pressure
that it has no room to fill with the blood it has to pump.
On chest radiographs the heart is globoid (spherical).
In fact, the actual heart is of normal shape but all that can be
seen on the radiograph is the large round heart shadow of the pericardium
filled to capacity with blood. Ultrasound is needed to truly see the
effusion.
This condition, if allowed to progress, results in an emergency
circulating collapse called a "pericardial tamponade" and can only
be relieved by tapping the pericardium with a needle and withdrawing
the excess fluid.
63% of heart-based hemangiosarcomas have evidence of tumor
spread at the time of their discovery.
Survival time for surgery alone (removing the pericardium
and snipping off the heart-based hemangiosarcoma) is approximately
4 months. In a study presented in the Journal of the American Veterinary
Medical Association in February 2005, 23 dogs with this type of tumor
were studied. Of the dogs that had surgery, approximately half of them
had some sort of post-operative complication, though most complications
were minor and 87% survived and were released to go home from the hospital.
Eight of these dogs received chemotherapy in addition to surgery and
these individuals had much longer survival times (median survival of
175 days vs. 42 days for dogs who had surgery without chemotherapy).
Chemotherapy is necessary to create a substantial improvement
in survival time. The most current protocol involves injectable Adriamycin
(Doxorubicin) every 3 weeks and oral cyclophosphamide at home for
3 days out of the week.
Chemotherapy of Canine Hemangiosarcoma With Doxorubicin
and Cyclophosphamide
J Vet Intern Med 7[6]:370-376 Nov/Dec'93 Clinical Study
29 Refs Karin U. Sorenmo CMV, K. Ann Jeglum VMD, and Stuart C. Helfand
DVMDept. of Clinical Studies, VHUP, 3850 Spruce Street, Philadelphia,
PA 19104.
Sixteen dogs with a histologic diagnosis of hemangiosarcoma
were treated with surgery and doxorubicin/ cyclophosphamide. The patients'
characteristics, i.e., age, size, and breed, were similar to those
of previous studies. Historic controls for surgery alone were used
to evaluate efficacy of the chemotherapy. The results show a trend
of improved survival in dogs with localized disease (Stage I) receiving
combination therapy. The median survival was 250 days, with a mean
of 403 days. The survival times for dogs with stage I, II, and III disease
was also improved with combination therapy, when compared to historical
controls treated with surgery alone. The overall median survival was
202 days with a mean of 285 days. Toxicities included mild to moderate
neutropenia (9 of 16) and clinical signs, such as lethargy, anorexia,
vomiting, diarrhea, and fever (13 of 16). Three dogs had severe neutropenia
requiring hospitalization and supportive care. One dog died from sepsis
and related complications. Chemotherapy with doxorubicin and cyclophosphamide
appears to improve survival with acceptable morbidity in patients with
early stage disease. (Author Abstract)
Date
Published: 5/25/2003 12:57:00 PM
Copyright
2003 - 2007 by the Veterinary Information Network, Inc. All rights
reserved.
This work was originally published by Veterinary
Information Network, Inc. (VIN)
and is republished with VIN's permission.
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The above information is simply informational.
It's intent is not to replace the advice of a veterinarian nor to assist
you in making a diagnosis of your pet. Please consult with your own veterinarian
for confirmation of any diagnosis. Your pets life may depend on it.
