What Is Kaposi Sarcoma?

Kaposi sarcoma (KS) is a cancerous tumor. It commonly appears in multiple locations on the skin and around one or more the following areas:

  • nose
  • mouth
  • genitals
  • anus

It can also grow on the internal organs. It’s due to a virus called the Human herpesvirus 8, or HHV-8.

According to the American Cancer Society, Kaposi sarcoma is an “AIDS-defining” condition. That means that when KS is present in someone who’s HIV-positive, their HIV has progressed to AIDS. Generally, it also means their immune system is suppressed to the point that KS can develop.

However, if you have KS, that doesn’t necessarily mean you have AIDS. KS can develop in an otherwise healthy person as well.

There are several types of KS:

AIDS-Related Kaposi Sarcoma

In the HIV-positive population, KS appears almost exclusively in homosexual men rather than others who contracted HIV through intravenous drug use or through receiving a transfusion. Controlling the HIV infection with antiretroviral therapy has made a large impact on the development of KS.

Classic Kaposi Sarcoma

Classic, or indolent, KS develops most often in older men of southern Mediterranean or Eastern European descent. It typically appears first on the legs and feet. Less commonly, it can also affect the lining of the mouth and gastrointestinal (GI) tract. It slowly progresses over many years and often isn’t the cause of death.

African Cutaneous Kaposi Sarcoma

African Cutaneous KS is seen in people living in sub-Saharan Africa, likely due to the prevalence of HHV-8 there.

Immunosuppression-Related Kaposi Sarcoma

Immunosuppression-related KS appears in people who have had kidney or other organ transplants. It’s related to immunosuppressive medications given to help the body accept a new organ. It may also be related to the donor organ containing HHV-8. The course is similar to classic KS.

Cutaneous KS looks like a flat or raised red or purple patch on the skin. KS often appears on the face, around the nose or mouth, or around the genitals or anus. It may have many appearances in different shapes and sizes, and the lesion may change quickly over time. The lesion may also bleed or ulcerate when its surface breaks down. If it affects the lower legs, swelling of the leg can also occur.

KS can affect internal organs like the lungs, liver, and intestines, but this is less common than KS that affects the skin. When this happens, there are often no visible signs or symptoms. However, depending on the location and size, you may experience bleeding if your lungs or gastrointestinal tract is involved. Shortness of breath can also occur. Another area that may develop KS is the lining of the inner mouth. Any one of these symptoms is a reason to seek medical attention.

Even though it often progresses slowly, KS can ultimately be fatal. You should always seek treatment for KS.

The forms of KS that appear in men and young children who live in tropical Africa are the most serious. If they’re left untreated, these forms can result in death within a few years.

Because indolent KS appears in older people and takes many years to develop and grow, many people die of another condition before their KS becomes serious enough to be fatal.

AIDS-related KS is usually treatable and not a cause of death by itself.

Your doctor can usually diagnose KS by a visual inspection and by asking some questions about your health history. Because other conditions might look similar to KS, a second test may be necessary. If there are no visible symptoms of KS but your doctor is suspicious you may have it, you may need more testing.

Testing for KS can occur through any of the following methods, depending on where the suspected lesion is:

  • A biopsy involves the removal of cells from the suspected site. Your doctor will send this sample to a lab for testing.
  • An X-ray can help your doctor look for signs of KS in the lungs.
  • An endoscopy is a procedure for viewing inside of the upper GI tract, which includes the esophagus and stomach. Your doctor can use a long, thin tube with a camera and a biopsy tool on the end to see the inside of the GI tract and take biopsies or tissue samples.
  • A bronchoscopy is an endoscopy of the lungs.

There are several ways to treat KS, including:

  • removal
  • chemotherapy
  • interferon, which is an antiviral agent
  • radiation

Talk with your doctor to determine the best treatment. Depending on the situation, observation may also be recommended in some instances. For many people with AIDS-related KS, treating AIDS with antiretroviral therapy may be enough to also treat the KS.


There are a few ways to remove KS tumors surgically. Surgery is used if someone only has a few small lesions, and it may be the only intervention needed.

Cryotherapy may be done to freeze and kill the tumor. Electrodesiccation can be done to burn and kill the tumor. These therapies treat only the individual lesions and can’t keep new lesions from developing since they don’t affect the underlying HHV-8 infection.


Doctors use chemotherapy with caution because many patients already have a reduced immune system. The most commonly used drug to treat KS is doxorubicin lipid complex (Doxil). Chemotherapy is usually only used when there’s a large skin involvement, when KS is causing symptoms in the internal organs, or when small skin lesions don’t respond to any of the removal techniques above.

Other Treatments

Interferon is a protein that naturally occurs in the human body. A doctor can inject the medically developed version to help patients with KS if they have a healthy immune system.

Radiation is targeted, high-energy rays aimed at a particular part of the body. Radiation therapy is only useful when the lesions don’t appear over a large part of the body.

KS is curable with treatment. In most cases, it develops very slowly. However, without treatment, it can sometimes be fatal. It’s always important to discuss treatment options with your doctor

Don’t expose anyone to your lesions if you think you may have KS. See your doctor and begin treatment right away.

You shouldn’t touch the lesions of anyone who has KS.

If you’re HIV-positive, have had an organ transplant, or are otherwise more likely to develop KS, your doctor may suggest highly active antiretroviral therapy (HAART). HAART reduces the likelihood that people who are HIV-positive will develop KS and AIDS because it fights the HIV infection.