Kaposi's sarcoma is a type of cancer caused by the virus human herpes virus 8. The tumors appear as red or purple patches on the skin, mouth, lungs, liver, or gastrointestinal tract.
First described in 1872, Kaposi's sarcoma was considered rare and relatively harmless until the AIDS epidemic began. An aggressive form of the disease, AIDS-related Kaposi's sarcoma, occurs in people with severely weakened immune systems. It is now the most common type of Kaposi's sarcoma.
The four types of Kaposi's sarcoma are
Classic Kaposi's sarcoma. This is a rare, slow growing skin tumor, usually affecting males of Italian or Eastern European Jewish ancestry. People with this form of the disease may develop non-Hodgkin lymphoma or another cancer before the skin lesions appear or later in life.
African Kaposi's sarcoma. Although extremely rare in the rest of the world, the disease occurs more often in young males in certain African countries. Usually it is a slow-growing tumor, but in some cases, it can be aggressive, invading bone and tissue under the skin.
Immunosuppressive-treatment-related Kaposi's sarcoma. People who are taking immunosuppressive medication after an organ transplant may develop this form of the disease. It sometimes improves if the medication is reduced or changed.
AIDS-related Kaposi's sarcoma. This disease affects people with HIV/AIDS. It usually appears as a rapidly progressing tumor affecting the skin, lymph nodes, gastrointestinal tract, lungs, liver, or spleen. Nearly all cases involve homosexual or bisexual men. The incidence of type of Kaposi's sarcoma is decreasing due to highly active retroviral therapy (HAART) for people with HIV/AIDS.