Reviewed by: HU Medical Review Board | Last reviewed: October 2020 | Last updated: February 2021
Kaposi sarcoma (KS) is a form of cancer that affects the skin, mouth, lymph nodes, and other organs. It causes lesions, or patches, of abnormal cells to grow in these areas. These patches contain cancer cells and blood vessels.1
How is Kaposi sarcoma related to HIV?
KS is caused by infection with the human herpesvirus-8 (HHV-8). HHV-8 is a common virus, but most people who are infected do not get KS. However, people living with HIV are at higher risk of KS because HIV attacks immune cells. When your immune system is damaged, it cannot fight off infections as well.1,2
Treating HIV can reduce your risk of developing KS. Highly active antiretroviral therapy (HAART) is the use of multiple drugs to treat HIV. It can reduce your risk of developing KS because it prevents HIV from damaging your immune system. However, it does not completely prevent KS. It is important to keep up with your medicines even if you are diagnosed with KS. Staying on your drugs can help prevent KS from worsening.2,3
KS is considered an AIDS-defining illness. Not everyone living with HIV has AIDS. The virus can stay in the body for many years before it causes symptoms and develops into AIDS. When someone living with HIV develops KS, they are considered to have AIDS. This is because KS can only happen when HIV has significantly damaged the immune system.3
Signs and symptoms
KS creates purple or red lesions on the skin of the legs and feet, and in the mouth and nose. It may also affect lymph nodes.
Lymph nodes are collections of immune cells that are located throughout the body, like in the neck, underarms, and groin. If they are affected, they may swell and feel like small bumps under the skin. If KS progresses and becomes severe, it may also affect the digestive tract or the lungs.4
How is Kaposi sarcoma diagnosed?
Your doctor will first ask you about your symptoms and examine your skin. They may then order a biopsy to remove a piece of a lesion so it can be studied under the microscope.
If your doctor thinks you might have lesions on your lungs or in your digestive tract, they may order a chest X-ray or an endoscopy, where doctors use a small camera that moves down your throat to look at your intestines.2
Once you are diagnosed with KS, your doctor may order more tests to have a more thorough look. These tests include blood tests and imaging tests like CT scans or PET scans. CT scans are similar to X-rays, but they show your organs. PET scans are used to find cancer cells all over the body.2
KS treatment varies according to where the lesions are on the body and how advanced they are. Your doctor may choose to remove the lesions by excision (cutting them out) or electrodessication (drying them with a special tool). Cryosurgery is another option that uses extremely cold substances like liquid nitrogen to remove the tissue.2
Other treatment options include radiation, chemotherapy, or biologic therapy. Biologic therapies are drugs that are made to fight off specific cells like cancer cells.2