Hemangiosarcoma is a malignant tumor of blood vessel cells.  This tumor is associated with serious internal bleeding and involves rapid internal spread.

It can come from any tissue where there are blood vessels, however, there are three classical locations :

            -           Skin and Subcutaneous forms

            -           Splenic forms

            -           Heart Base forms

The Skin Form

They are the most easily removed surgically.  They 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.  It is associated with sun exposure and tends to form on non-hair or sparsely haired skin like on the abdomen, or on areas with white fur.  Dogs with short white haired fur such as Dalmations, pit bull terriers and Albino Dobermans are predisposed to this tumor.  1/3 of cases will spread internally malignantly.

            * A biopsy will indicate whether or not the growth was “completely exiced” (cut out).

To be absolutely positive there has been no spread following surgery, the following tests are necessary.

• Chest x-rays - Hemangiosarcoma tends to spread to the lungs.  Any spots must be 3cm in diameter to be large enough to be visible by x-ray

• Ultrasound of the belly - specifically the spleen.  Even a small tumor will be visible

• Ultrasound of the heart - a small tumor should be easily visible by ultrasound

The Subcutaneous or Hypodermal Form

The overlying skin is often totally normal to the naked eye on top of a subcutaneous hemangiosarcoma.  Often the surgeon is surprised to find a dark red blood growth under the skin once the tumor has been removed.

Up to 60% of these tumors spread internally and the above test are even more important to ensure the tumor has been removed.  If no sign of the tumor spreading is found after chest ultrasound or heart ultrasound, and the belly is clear, prognosis is much better.  Additional treatment with chemotherapy may be recommended if cure is the goal.  6 months or 172 days is the median survival time with surgery alone.

Hemangiosarcoma of the Spleen

The spleen is a fairly deep-seated abdominal organ which tends to go undetected unless it develops a growth of significant size.  Splenic growths have the unfortunate tendancy to break or burst open and bleed profusely regardless whether they are benign or malignant because of the blood supply to that organ.  Splenic hemangiosarcoma is a rapidly spreading malignancy and removal of the spleen will reduce the life-threatening prospect of a sudden bleed.  25% of dogs with splenic hemangiosarcoma also have a heart-based hemangiosarcoma.  Survival time even with surgery is approximately 19 - 65 days.

Heart-Based Hemangiosarcoma

This type of tumor 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 so full that the heart inside is under so much pressure, it has no room to fill with blood it has to pump.  On chest x-ray, the heart is “globiod” meaning spherical.  In fact the actual heart is normal shape but all that can be seen is the round heart shadow of the pericardium filled with blood.  An ultrasound is the only true way to see the effusion.  If allowed to progress, this condition results in an emergency circulating collapse called a “pericardial tamponade” and is relieved by tapping the pericardium using a needle to extract the excess fluid.   63% of heart-based hemangiosarcomas have tumor spread at the time of discovery.  Survival time with surgery alone is approximately 4 months. 

Chemotherapy is recommended to create an improvement in survival time.