Cancer begins when normal cells begin to change and grow uncontrollably, forming a mass called a tumor. A tumor can be benign (noncancerous) or malignant (cancerous, meaning it can spread to other parts of the body). Kaposi’s sarcoma is a rare type of skin cancer. It generally develops in tissue below the skin surface or in the mucous membranes of the mouth, nose, or anus. Kaposi’s sarcoma lesions usually appear as raised blotches or nodules that may be purple, red, or brown.
There are several types of Kaposi’s sarcoma:
Classic Kaposi’s sarcoma. Classic Kaposi’s sarcoma traditionally occurs in older men of Jewish or Mediterranean descent. Lesions typically appear in the lower part of the body, particularly the legs, ankles, or soles of the feet. Classic Kaposi’s sarcoma is more common in men than women, and lesions may develop over a period of 10 to 15 years.
Endemic Kaposi’s sarcoma. Endemic (or African) Kaposi’s sarcoma usually develops in people living in equatorial Africa. In many cases identical to classic Kaposi’s sarcoma, endemic Kaposi’s sarcoma usually occurs at a younger age. A particularly aggressive form has been known to develop in children who have not yet reached puberty, usually involving the lymph nodes and other organs. Generally, endemic Kaposi’s sarcoma causes skin lesions that do not produce any symptoms and do not spread to other parts of the body.
Acquired Kaposi’s sarcoma. Acquired (or immunosuppressive treatment-related or transplant-related) Kaposi’s sarcoma develops in people who have received an organ transplant and are taking drugs to suppress their immune system, so their body will not reject the transplanted organ. As a result of the treatment, secondary diseases or infections can occur. Kaposi’s sarcoma is 150 to 200 times more likely to develop in people who have received an organ transplant than the general population. Most of the time, acquired Kaposi’s sarcoma only affects the skin, but the disease can spread to the mucous membranes or other organs.
Epidemic Kaposi’s sarcoma. Epidemic Kaposi’s sarcoma causes lesions to arise in multiple sites on the body and may affect the lymph nodes and organs, such as the liver, spleen, lungs, and in the digestive tract. Acquired immune deficiency syndrome (AIDS) is a disease of the immune system caused by infection with the human immunodeficiency virus (HIV). Today, Kaposi’s sarcoma is found most often in homosexual men with HIV/AIDS, with most cases related to an infection with the human herpesvirus 8 (HHV-8). Kaposi’s sarcoma in people with HIV/AIDS is often referred to as epidemic Kaposi’s sarcoma. For more information, read the Guide to HIV/AIDS-Related Cancer.
Statistics
Kaposi's sarcoma develops in less than 1% of the general population, with about one in 200 transplant recipients in the United States developing the disease. Previously, approximately one in four homosexual males with HIV/AIDS developed Kaposi's sarcoma. This number has decreased over recent years due to more effective treatment of HIV/AIDS.
Cancer statistics should be interpreted with caution. These estimates are based on data from thousands of cases of this type of cancer, but the actual risk for a particular individual may differ. It is not possible to tell a person how long he or she will live with Kaposi’s sarcoma.
Source: American Cancer Society and the National Cancer Institute.
basic cancer terms used in this section.
Last Updated: October 01, 2009
