Skin Angiosarcoma

Skin angiosarcoma is a rare and aggressive cancer that develops in the lining of blood vessels and lymph vessels, most commonly appearing on the head, neck, and scalp, often resembling a bruise that grows and changes over time.

Table of contents

• What is Skin Angiosarcoma?
• How Common is This Disease?
• Signs and Symptoms
• Causes and Risk Factors
• Diagnosis
• Treatment
• Prognosis and Outlook

What is Skin Angiosarcoma?

Skin angiosarcoma is a rare type of cancer that begins in the cells that line blood vessels or lymph vessels in the skin. These cells, called endothelial cells (cells that normally form the inner lining of blood and lymph vessels), start to grow and multiply abnormally, forming tumors that can spread quickly to other parts of the body^[1][2].

Skin angiosarcoma belongs to a larger group of cancers called soft tissue sarcomas (cancers that develop in the soft tissues of the body, such as blood vessels, muscles, fat, and connective tissue). Among all soft tissue sarcomas, angiosarcomas represent only about 1 to 2 percent^[3][4].

Skin angiosarcoma is known for being aggressive, meaning it tends to grow quickly and has a high risk of spreading to other organs through the bloodstream or lymphatic system (a network of vessels and tissues that helps remove waste and fight infection)^[2][4]. The lungs and liver are the most common sites where the cancer spreads^[6].

How Common is This Disease?

Skin angiosarcoma is extremely rare. In the United States, approximately one person in every million is diagnosed with angiosarcoma each year^[2][3]. The disease can occur at any age, but it is most commonly diagnosed in older adults, particularly those over 60 years old. About 85 percent of cases occur in people older than 60^[6][15].

Men are slightly more likely than women to develop skin angiosarcoma^[2]. The disease most often affects white individuals^[6].

The rate of skin angiosarcoma has been changing over time. While the disease is decreasing in people younger than 50 years, it is increasing in people older than 70^[6][15]. The increase in older women may be related to the growing use of radiation therapy for breast cancer treatment^[6].

Signs and Symptoms

The symptoms of skin angiosarcoma depend on where the cancer is located on the body. The most common location is the skin on the head and neck, especially the scalp^[1][2].

When skin angiosarcoma affects the head, neck, or other skin areas, it may appear as^[1][2]:

• A raised area that looks like a bruise
• Reddish or blue small lumps that spread and grow larger over time
• A purplish area that looks like a rash or bruise and may be raised
• A bruise-like spot that grows larger instead of fading
• An area that bleeds easily when scratched or bumped
• Swelling in the skin around the affected area
• A sore that does not heal or continues to grow

Skin angiosarcoma often does not cause pain, which can make it easier to overlook^[2][16]. The average tumor size is about 4 to 5 centimeters, though some can grow larger than 10 centimeters^[6].

The appearance of skin angiosarcoma can be confusing because it often looks like a harmless bruise. This similarity to other, less serious skin conditions can lead to delayed diagnosis^[6][7].

Causes and Risk Factors

The exact cause of most skin angiosarcomas is not known^[1][19]. However, researchers have identified several factors that can increase the risk of developing this cancer.

Radiation therapy is one of the most important risk factors. Skin angiosarcoma can develop in areas that were previously treated with radiation, typically appearing about 8 to 10 years after the radiation treatment^[2][13]. This is most commonly seen in women who received radiation therapy for breast cancer^[6][15].

Chronic lymphedema (long-term swelling caused by a buildup of lymph fluid in tissues) is another risk factor. This condition can develop after surgery, particularly after breast surgery that removes lymph nodes. About 5 percent of all angiosarcomas are associated with chronic swelling in the arms or legs^[2][13].

Exposure to certain chemicals has been linked to angiosarcoma, particularly in the liver, but this is less commonly associated with skin angiosarcoma. These chemicals include vinyl chloride, arsenic, and thorium dioxide. In some cases, angiosarcomas may not appear until 10 to 40 years after exposure^[2][13].

Certain genetic conditions may also increase the risk. Some people with genetic changes in specific genes, such as the POT1 gene, may be more likely to develop angiosarcoma^[3]. Familial syndromes including neurofibromatosis 1, BRCA1 or BRCA2 mutations, Maffucci syndrome, and Klippel-Trenaunay syndrome have been associated with increased risk^[6].

The high rate of skin angiosarcoma on the head and neck may be related to increased blood vessel density and greater exposure to ultraviolet light in these areas^[6].

Diagnosis

Diagnosing skin angiosarcoma involves several steps to confirm the presence of cancer and understand how far it has spread.

A healthcare provider will begin with a physical examination, carefully looking at and feeling the affected area to understand the condition^[10][22].

A biopsy (a procedure to remove a small sample of tissue for testing) is essential for diagnosis. The healthcare provider removes a sample of the suspicious tissue, which is then examined in a laboratory under a microscope. Special tests on the tissue sample can provide detailed information about the cancer cells^[3][10][22].

Imaging tests help doctors understand the size and location of the tumor and whether it has spread to other parts of the body. These tests may include^[3][10][22]:

• MRI (magnetic resonance imaging), which uses magnets and radio waves to create detailed images
• CT scan (computed tomography), which uses X-rays to create cross-sectional images of the body
• PET scan (positron emission tomography), which shows how tissues and organs are functioning

The specific tests used will depend on each person’s situation and the location of the suspected cancer^[10][22].

Treatment

Treatment for skin angiosarcoma depends on the location of the cancer, its size, whether it has spread to other areas, and the overall health of the patient^[10][22].

Surgery is the main treatment for skin angiosarcoma. The goal is to remove all of the cancer along with some surrounding healthy tissue to ensure complete removal. This border of healthy tissue is called a margin^[3][10][22]. Sometimes surgery is not possible if the cancer is very large or has spread to other parts of the body^[10][22].

Radiation therapy uses high-energy beams, such as X-rays and protons, to kill cancer cells. It is often used after surgery to kill any remaining cancer cells. Radiation therapy may also be used as the main treatment if surgery is not possible^[3][10][22]. However, radiation therapy may pose risks for patients whose angiosarcoma developed after previous radiation treatment^[6][15].

Chemotherapy uses drugs or chemicals to kill cancer cells. It may be used if the cancer has spread to other areas of the body. Sometimes chemotherapy is combined with radiation therapy when surgery is not an option^[3][10][22]. Specific chemotherapy drugs that have shown effectiveness include paclitaxel, anthracycline-based regimens, and gemcitabine-based regimens^[11].

Targeted drug therapy attacks specific chemicals present within cancer cells. By blocking these chemicals, targeted treatments can cause cancer cells to die^[10][22]. Some patients may benefit from drugs like pazopanib, which targets vascular signaling^[11].

Immunotherapy is an emerging treatment approach that uses the body’s immune system to fight cancer. While research on immunotherapy for skin angiosarcoma is still limited, early findings suggest it may be promising for some patients. Skin angiosarcoma shares certain immune characteristics with other skin cancers that respond well to immunotherapy^[4][12].

Because skin angiosarcoma is aggressive and often comes back after treatment, doctors typically treat it with a combination of approaches^[3].

Prognosis and Outlook

Skin angiosarcoma has a challenging outlook, with 3-year survival rates as low as 40 percent and 5-year survival rates as low as 17 percent^[6][15]. However, survival rates have improved from 1985 to 2014, likely due to earlier diagnoses and more effective treatments^[6].

Several factors can affect prognosis^[3][6][15]:

• Where the tumor is located in the body
• Whether the cancer has spread to other parts of the body
• How much of the tumor was removed during surgery
• The size of the tumor (tumors larger than 5 centimeters have a worse outlook)
• Location on the scalp and neck (associated with worse outcomes)
• The patient’s age (older age is associated with worse outcomes)
• The presence of multiple skin lesions

Many people with angiosarcoma are not diagnosed until their cancer has already spread to other parts of the body, which often results in a worse prognosis^[3][23].

The cancer has a high rate of coming back after treatment, with recurrence occurring in approximately 16 to 35 percent of patients^[6]. Because of this, long-term monitoring is important for anyone who has been treated for skin angiosarcoma.

It is important to discuss prognosis with your healthcare provider, as every person’s situation is different and newer treatments continue to be developed^[3].