Reviewed by Dr. Clement J. Cheng
Sarcoma is a cancer that develops in connective tissues such as bone, fat, cartilage, blood vessels, muscle, or fibrous tissue (related to ligaments and tendons). Kaposi’s sarcoma (KS) gets its name from Dr. Moritz Kaposi, who first described it in 1872.
Before the AIDS epidemic, experts believed that KS affected elderly men of Jewish or Mediterranean heritage, organ transplant patients, and young adult African men. In the past 20 years, though, the majority of KS cases have developed in association with HIV and AIDS, especially among gay men.
Because KS is a cancer that arises as a consequence of an infectious disease of the immune system, the severity of AIDS-related KS varies from patient to patient. For some people, KS is not a serious condition. For others, it may be a life-threatening complication. In this case, aggressive therapy is available.
KS lesions may be the first sign that a person with HIV has developed AIDS. HIV-infected people should have regular physical exams to keep abreast of KS and other manifestations of AIDS.
Lesions begin as flat or slightly raised colored spots. They can develop anywhere on the body, but appear most often on the legs, nose, feet, ears, mouth, and genitals. Over time, the lesions turn into larger nodules of deeper color. In dark-skinned people, the lesions are usually a darker brown or black. Lesions are rarely tender or sore.
KS occurs at higher rates among men than among women. The people at highest risk are male homosexuals and bisexuals infected with HIV. Other risk factors include the presence of other sexually transmitted diseases, and having a high number of sex partners.
Scientists are unsure of exactly what causes KS, though viruses such as HIV may play a direct or indirect role. The virus itself may produce chemical substances that cause direct changes in some cells. Subsequently, the cells can spread out of control and produce the lesions associated with KS. Or, HIV may weaken the immune system enough to allow other viruses to create lesions.
