Hemangiosarcoma is a very aggressive, rapidly growing form of cancer that affects the blood vessels.

They can form anywhere in the body, but more than half of the cases originate in the spleen; this condition is also known as “splenic angiosarcoma.” This form of cancer can develop in patients of any age, but mainly affects those over 50 years of age.

It is a very rare form of cancer, with less than 200 cases diagnosed annually. This condition is more prevalent in animals—particularly dogs—than in humans.

Signs & Symptoms

Long-term exposure to certain environmental hazards and chemicals, including arsenic, vinyl chloride, and thorium dioxide, has been linked to a number of cases of hemangiosarcoma. Patients who have been exposed to these types of chemicals—often used in certain types of industry—are at particular risk for developing this form of cancer.

Symptoms are often mistaken for those of other conditions, which can make rapid diagnosis and treatment very difficult. Distinctive symptoms typically include abdominal pain or splenomegaly (an enlargement of the spleen).

Patients with this condition also run a high risk of splenic rupture, which can result in severe blood loss and often death. This condition develops in the spleen and will often spread to the lungs and/or liver.

Diagnosis & Treatment

The highly aggressive nature of this form of cancer, and lack of symptoms until it has progressed fairly significantly, makes it very difficult to treat. A physician will usually conduct a thorough physical exam, followed by scans that might include a CT or CAT, MRI, or x-rays.

These scans can help to determine the size and precise location of the mass; an MRI can provide a more detailed image of the tumor that can help to determine the progression of the condition. The size, location, and stage of the tumor will then determine the best course of treatment.

A combination of chemotherapy and a splenectomy, surgery to remove the tumor on the spleen, have been the most successful. A splenectomy itself can give the patient a survival time of 1-3 months; the addition of chemotherapy can extend the survival rate to 5-7 months.

Prognosis

Hemangiosarcoma is an extremely rare but highly progressive form of cancer that metastasizes, or spreads, very quickly. Even with aggressive treatment, most patients have a survival rate of approximately 6 months.