Kaposi's sarcoma

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at April 24, 2016
StartKaposi's sarcoma

Kaposi's sarcoma is a form of cancer that is named after Moritz Kaposi, a dermatologist from the late 1800s. It typically affects immunocompromised people. The early stages of Kaposi's sarcoma cause few serious symptoms, but it can develop into a life-threatening illness.


Definition & Facts

Kaposi's sarcoma is a general term used to describe cancerous tumors caused by an infection with a human herpesvirus 8, and it is divided into four categories.

  • Classic Kaposi's sarcoma mainly develops among older, middle aged people from the Mediterranean and Middle Eastern Areas.
  • Endemic Kaposi's sarcoma is prevalent among people in equatorial Africa, where many younger people and children develop it due to a weakened immune system
  • Iatrogenic Kaposi's sarcoma occurs when a person receives an organ transplant and is required to take immunosuppressant drugs.
  • AIDS-associated Kaposi's sarcoma is a form of the cancer that happens among patients with HIV or AIDS.

Symptoms & Complaints

The primary symptom of Kaposi's sarcoma is the presence of lesions occurring in the soft tissues. These lesions are mottled shades of red, brown, black, and purple, and they are typically raised and slightly bumpy. The lesions normally are not physically painful, and they normally appear first on the face and legs.

The lesions can spread to the mouth, back, feet, and genitalia. When lesions appear in the gastrointestinal tract, they can result in many digestive issues, and the lesions can sometimes cause internal bleeding. Lesions that grow in the lungs may obstruct breathing, and lesions in the mouth can cause difficulty eating or difficulty speaking.

In addition to the tumorous lesions, people with Kaposi's sarcoma may suffer from weight loss, fever, cough, shortness of breath, diarrhea, bloody coughing, bloody bowel movements, pain, or shortness of breath.

The symptoms of Kaposi's sarcoma vary depending on the type that a person has. The classic version results primarily in leg and foot lesions that do not grow or spread quickly, and the endemic version spreads quickly over the skin and lymph nodes without lesions growing on other organs.

For both AIDS-associated and iatrogenic Kaposi's sarcoma, people can get gastrointestinal or lung lesions without skin lesions ever appearing. AIDS-associated Kaposi's sarcoma spreads extremely rapidly and causes severe symptoms.


Kaposi's sarcoma is caused by the human herpesvirus 8, but not all people infected with this virus end up developing Kaposi's sarcoma. The virus can be transmitted through kissing, other saliva exchanges, organ transplants, and blood transfusions.

The human herpesvirus 8 can cause cells to overproduce by altering the genes in individual cells, making them divide quickly and live too long. Though research scientists do not know the precise reason that the virus becomes cancerous, it is far more common among people with weakened immune systems.

When the person infected by the virus is immunocompromised due to old age, malaria, HIV, organ transplants, or other illnesses, cells infected with herpesvirus 8 begin to multiply too quickly, and they can eventually turn into cancerous cells.

Diagnosis & Tests

The first stage of diagnosis for Kaposi's sarcoma is a complete physical examination and medical history. Unlike other forms of cancer, Kaposi's sarcoma tends to develop in multiple places at once, so it is often diagnosed after a thorough medical examination that reveals many tiny tumors on the skin.

To correctly diagnose the cause of a lesion, the doctor will do a biopsy if the patient has skin lesions. Sometimes the biopsy will remove the entire lesion, but normally the physician will just remove a tiny sample that can then be tested to see if the cells have characteristically elongated shapes, amounts of human herpesvirus 8, and abnormally dense blood vessels.

However, biopsy of lesions on the interior of the body can result in heavy bleeding, so a doctor may just use a bronchoscopy or gastrointestinal endoscopy to examine a patient who does not have skin lesions. The presence of the characteristic lesions along with testing positive for the human herpesvirus 8 is enough to diagnose the condition without doing a biopsy.

Treatment & Therapy

Treatment for Kaposi's sarcoma focuses on treating the individual lesions while attempting to boost the overall health of the patient. It is not completely curable, but modern scientific advancements are able to greatly slow or stop the progression of the lesions. For patients with AIDS-associated Kaposi's sarcoma, antiretroviral therapy for HIV treatment can shrink the size of the lesions.

People who just have generally poor immune systems due to illness or transplant often have a slowed progression once the source of the dysfunctional immune system is treated. Sometimes, the lesions might even go away after transplant patients quit taking immunosuppressant drugs. For those who just have a few small lesions on their skin, radiation therapy or cryosurgery can be used to treat each local region individually. However, if surgery is done to remove the lesion, another may appear in the same spot.

Light therapy that involves strong rays of light being beamed onto lesions and retinoid treatment that involves putting creams with vitamin A derivatives onto the lesions have a small measure of success in shrinking lesions. People with lesions within their body may need chemotherapy drugs to treat the lesions.

Prevention & Prophylaxis

The best way to avoid getting Kaposi's sarcoma is to avoid being infected with the human herpesvirus 8. The best way to do that is to avoid anything that might put you in contact with infected saliva, including washing your hands regularly, avoiding locations where the virus is common, and practicing safe sex.

For people who are already infected with the virus, taking antiviral drugs or specific drugs to treat herpes infections can stop them from developing Kaposi's sarcoma.