Kaposi Sarcoma: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Kaposi Sarcoma?
An oncologist, a doctor who treats cancer, usually leads care for Kaposi sarcoma. A dermatologist (a skin doctor) may check skin spots. People with HIV may also see an infectious disease doctor. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is Kaposi sarcoma?
Kaposi sarcoma, or KS, is a type of cancer. It starts in the cells that line your blood vessels or lymph vessels. Lymph vessels are small tubes that carry a clear fluid through the body.
KS causes lesions, which are patches of abnormal tissue. The lesions are usually red or purple. They can grow on the skin, in the lymph nodes, in the lining of the mouth, nose, and throat, and in other organs. The lesions may begin in more than one place at the same time. This makes KS different from other cancers.
Symptoms
KS usually starts as one or more red, purple, or brown spots on the skin of the legs and feet. They are most often on the ankles or the soles of the feet. Over time, lesions may form in other parts of the body. Lesions may not cause symptoms. Problems are more likely as lesions grow bigger and become more numerous. Possible problems include:
- Painful swelling in the legs, when lesions block the flow of lymph and blood.
- Belly pain and diarrhea, when lesions in the stomach or intestines bleed.
- Shortness of breath, when lesions in the lungs bleed.
Causes and who gets it
KS is caused by infection with a virus called human herpesvirus-8, or HHV-8. It is also called Kaposi sarcoma-associated herpesvirus. Most people infected with this virus do not get KS. KS is more likely when the immune system is weak. The immune system is the body's defense against germs. There are 4 main types:
- Epidemic, or HIV-related, KS. It develops in people who have HIV. It is the most common type in the United States.
- Iatrogenic, or transplant-related, KS. It develops in people who take medicines to weaken the immune system after an organ transplant.
- Classic KS. It happens mainly in older people of Mediterranean, Eastern European, and Middle Eastern heritage. It is more common in men than in women.
- Endemic, or African, KS. It occurs in people who live in Sub-Saharan Africa.
How doctors diagnose it
Your health care provider will ask about your medical and family history and do a physical exam. Tests may include:
- A chest x-ray, to look for KS in the lungs.
- A biopsy, which removes a small piece of tissue so a pathologist (a doctor who studies tissue) can check it for cancer.
- An endoscopy, which uses a thin tube with a light and a lens to check the stomach and intestines.
- A bronchoscopy, which uses a similar tube to check the lungs.
If you do have KS, you will likely need blood and imaging tests to find out if the cancer has spread to other parts of the body.
Treatment
Your treatment depends on the type of KS you have, how many lesions you have and where they are, and what problems they cause. Treatment can often keep KS under control for many years.
For people with HIV-related KS, taking HIV medicines may be enough to treat the KS. Highly active antiretroviral therapy, or HAART, is a mix of several drugs that lessen the damage HIV causes to the immune system. For transplant-related KS, changing the dose of the medicines or switching medicines may help. Follow your transplant doctor's instructions about any medicine change. Some people will need more treatment. Options include:
- Radiation therapy, which uses high-energy x-rays to kill cancer cells.
- Surgery.
- Cryosurgery, which uses an instrument to freeze and destroy abnormal tissue.
- Chemotherapy, which is cancer-fighting medicine.
- Immunotherapy.
Treatment for KS may cause side effects, so ask your care team what to expect.
When to see a doctor
See a doctor if you notice new red, purple, or brown spots on your skin or inside your mouth. Also tell your doctor about painful leg swelling, belly pain, or diarrhea.
Call 911 or go to the emergency room if you have severe trouble breathing, cough up blood, have severe belly pain or pressure, vomit blood, or have bleeding that will not stop.
If you have HIV or had an organ transplant, ask your doctor how often to be checked.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Such a doctor can review new skin spots, order first tests, and help coordinate care between your cancer, HIV, or transplant doctors. They can also follow your overall health over time.
Common questions
Is Kaposi sarcoma caused by a virus?
Yes. KS is caused by infection with human herpesvirus-8, or HHV-8. Most people who have this virus do not get KS. It is more likely in people with a weakened immune system.
Does Kaposi sarcoma only affect the skin?
No. It often shows up on the skin or in the mouth. It can also develop in the lymph nodes, lungs, or digestive tract. KS can be much more serious when it affects internal organs.
Can HIV medicine treat Kaposi sarcoma?
Yes, for some people. For people with HIV-related KS, taking HIV medicines may be enough to treat it. Others need additional treatment.
Sources
- MedlinePlus - Kaposi Sarcoma
- National Cancer Institute - Kaposi Sarcoma Treatment (PDQ)
- American Cancer Society - Kaposi Sarcoma
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
