Kaposi’s Sarcoma (KS)

Medically Reviewed by Jabeen Begum, MD on February 16, 2024
8 min read

Kaposi’s sarcoma (KS) is a type of cancer that grows in the lining of your blood vessels and lymph vessels. The cells can form tumors on your skin and in your mouth, nose, eyes, and anus. These tumors appear on your skin as purple, brown, or red patches (also called lesions). 

. These skin lesions usually appear on your face or legs and do not cause symptoms. However,  KS can spread to your lungsliverstomachintestines, and lymph nodes, the glands that help your body fight infection. When they're present in your digestive tract, lungs, or liver, they can be dangerous and affect your breathing or cause bleeding.

You could have several symptoms, depending on which parts of your body are affected by the disease.


The most visible signs of KS are lesions on your skin: flat, painless patches or nodules that appear red or purple on light skin and bluish, brownish, or black on dark skin. Unlike bruises, they don't change color when you press on them. They aren't itchy, and they don't drain. They're not dangerous.

New spots may show up each week. For some people, these lesions change slowly. They may grow into raised bumps or merge together.

Mucous membranes

KS lesions can form inside your mouth and throat, causing trouble eating or swallowing. They might also happen on your eyes and under your eyelids.

Lymph nodes

When lesions block the flow of lymphatic fluid around your body, they can lead to severe swelling in your arms, legs, face, or scrotum.

Respiratory tract

Lesions inside your lungs may cause serious coughing and shortness of breath.

Digestive tract

Lesions in your stomach and intestines can lead to bleeding and blockages. You may have:

  • An upset stomach
  • Vomiting
  • Belly pain
  • Diarrhea
  • Bloody or black poop
  • Low red blood cell counts (anemia)

Spots or lesions on the skin are typically the first signs of KS. These lesions can be flat (called patches), raised (called plaques), or bumps (called nodules). They can range from purple, red, or brown in color and appear in one area or many areas, most commonly including the face, legs, and feet. If the lesions appear on your groin or legs, they can block the flow of fluids and lead to swelling in your feet and legs.

If your doctor suspects you have KS, they may perform a skin biopsy to look at your CD4 cell count. A low CD4 cell count can indicate KS.

There are four types of KS:

  • Epidemic or AIDS-associated. This is the most common kind in the U.S. It affects people who have HIV, the virus that causes AIDS. It’s known as an AIDS-defining illness because it’s on the CDC’s list of conditions that mean someone’s HIV infection has officially become AIDS.
  • Classic (Mediterranean). This type affects older people of Mediterranean, Middle Eastern, or Eastern European descent. It's more common in men or people assigned male at birth (AMAB). People with classic KS usually don't get new lesions as often, and the lesions don't grow as quickly compared to other KS types. If you have classic KS, your immune system is weaker than normal, but not as weak as in those with endemic KS.
  • Endemic (African). Children and young people from Africa get this kind of KS. Being infected with Kaposi sarcoma-associated herpesvirus (KSHV) is more common in Africa, so there's an increased risk of KS. Other conditions in Africa, such as malnutrition and malaria, that cause weakened immune systems can play a role in developing KS. Endemic KS usually affects younger people (under 40 years of age) and can advance fast.
  • Immunosuppressive (iatrogenic or transplant-related). This kind affects people who have had organ transplants and thus their immune system is suppressed. If you've received a transplant, you'll need to take drugs to be sure your immune system doesn't reject the new organ. If you're already infected with KSHV, taking these drugs can increase your risk of getting KS.

KS develops in people who've already been infected with KSHV; however, most people with the virus won't get KS.

People with HIV have weakened immune systems -- the body's main line of defense against germs and illnesses -- so they're more likely to get certain cancers, including Kaposi's sarcoma.

Most severe cases happen when someone has AIDS, but skin lesions can show up earlier. They're a sign that your immune system isn't at full strength and they can get worse if you have other infections.

You're also at risk if you've received an organ transplant or have a weakened immune system because of other factors, such as age.

Antiretroviral therapy (ART) for HIV can also treat KS, especially early on. Anti-HIV drugs have lowered the rate of KS cases by 80%-90% from the early 1980s.

KS is caused by the herpes virus HHV-8, also called KSHV. It spreads mainly through saliva, such as during sexual contact or in interactions between a mother and child.

People with healthy immune systems can carry the virus without any problems. But it triggers cancer in people with weakened immune systems.

KS affects eight times more men or people AMAB than women or people AFAB. Among people who have HIV, men or people AMAB who have sex with other men or people AMAB are more likely to have the virus and to get KS.

Additional risk factors include:

  • Age. If you're in the age group of 40-70 years, you are at a higher risk of developing KS.
  • Unprotected sex. Usually, HIV and HHV-8 are spread through bodily fluids, so the risk of infection is greater if you have unprotected sex.
  • Ethnicity. People living in certain areas of Africa are more at risk of developing endemic KS, and those of Mediterranean or Jewish descent are more at risk of classic KS.
  • Immune deficiency. If you're taking an immunosuppressant medication after an organ transplant or have HIV or AIDS, you're at a higher risk of developing KS.


Your doctor may diagnose KS just by looking at your skin. To confirm it, they may take a sample of tissue from a spot and look at it under a microscope, which is called a biopsy. They might also do tests including:

  • Fecal occult blood test. This looks for blood in your stool, which might mean KS is hurting your digestive tract.
  • Endoscopy/colonoscopy. If you’re having stomach trouble or belly pain, your doctor might want to look in your stomach with a lighted tube called an endoscope or in your intestines with a colonoscope.
  • Bronchoscopy. If you have trouble breathing, they might look into your airways with a thin tube called a bronchoscope.
  • Imaging tests. A CT scan or an X-ray can tell whether the cancer has spread to your lungs, lymph nodes, or other parts of your body.

Treatment for KS will depend on how many lesions you have, how big they are, where they are, and how well your immune system is working.

In many cases, ART is the best way to treat active KS. It may even clear up skin lesions.

If you have just a few lesions, your doctor can cut or freeze them off. It’s not a cure for KS, but it can make your skin look better.

If you have lots of lesions or the virus is affecting many areas of your body, you might get radiation therapy. This kills the cancer cells or keeps them from growing. A machine directs radiation toward the lesions on your skin, or your doctor may put radioactive needles, seeds, or wires inside you near the cancer.

If KS has spread, you'll need medications that go through your whole body to kill the cancer. Chemotherapy drugs for KS include:

Chemotherapy can have side effects, including hair loss, vomiting, and fatigue. It can also lower the number of platelets and white blood cells and raise your chances of an infection.

Another type of drug treatment, called biologic therapy, works by boosting your immune system. Your doctor may prescribe interferon alfa (Intron A) if your CD4 cell count (a type of white blood cell) is over 200 and you have a fairly healthy immune system.

Clinical trials are testing targeted therapies such as monoclonal antibody therapy and tyrosine kinase inhibitors. These treatments are aimed at attacking the cancer and keeping it from growing without hurting healthy cells.

Some complications of having KS include: 

  • Second cancer. People with classic KS can get a second cancer such as non-Hodgkin's lymphoma.
  • Anemia. The internal bleeding that can be caused by KS (the type that affects your digestion) can lead to anemia.


Treatment can usually keep KS under control for many years. The lesions may shrink and fade, but they might not go away.

Overall, about 75% of people who have KS live at least 5 years after diagnosis. If the cancer hasn’t spread, about 81% live at least 5  years after being diagnosed. In people whose cancer has spread to nearby areas, the 5-year survival rate is 65%. The rate is 47% if the cancer has spread farther away.

There’s no vaccine to protect against HHV-8. The best way to avoid getting KS is to avoid things that put you at higher risk of HIV, such as having unprotected sex or injecting drugs with used needles. Medications called pre-exposure prophylaxis (PrEP) can also make you less likely to get HIV.

If you have HIV, preventing KS should be possible with ART, especially if you start it when your CD4 count is still high. If you have advanced HIV, or AIDS, a test can tell if you also have HHV-8. ART will lower the chances that it will become KS.

If you’ve had an organ transplant, some anti-rejection drugs can also lower your chance of getting KS.

Kaposi's sarcoma is a rare condition that can be a symptom of HIV/AIDS or the result of taking medication after an organ transplant. There are four types of KS, and the impact on your immune system, location, number, and size of lesions can vary and determine the proper treatment. It's important to speak to your doctor as soon as you develop early signs of KS.

  • How long does it take for Kaposi's sarcoma to develop? How quickly KS progresses depends on the type of KS you have. For most of the types, symptoms worsen within a few weeks or months, but others can develop. over many years.
  • How many people have died from Kaposi's sarcoma? The number of deaths from KS has decreased a lot in recent years, to about 6 cases per 1 million people. This decrease is due to improvements in treatments for HIV/AIDS. In the U.S., about 1 in 200 people who receive a transplant develop KS. In 2020, about 15,086 people worldwide died from KS.
  • How do you clean Kaposi's sarcoma? In many cases, antiretroviral therapy is the best way to treat active KS. It may even clear up skin lesions. If you have just a few lesions, your doctor can cut or freeze them off. It’s not a cure for KS, but it can make your skin look better.