Kaposis sarcoma (KS) is a type of cancer that can form masses in the skin, in lymph nodes, in the mouth, or in other organs. The skin lesions are usually painless, purple and may be flat or raised. Lesions can occur singly, multiply in a limited area, or may be widespread. Depending on the sub-type of disease and level of immune suppression, KS may worsen either gradually or quickly. KS is caused by a combination of immune suppression (such as due to HIV/AIDS) and infection by Human herpesvirus 8 (HHV8 – also called KS-associated herpesvirus (KSHV)).Four sub-types are described: classic, endemic, immunosuppression therapy-related (also called iatrogenic), and epidemic (also called AIDS-related). Classic KS tends to affect older men in regions where KSHV is highly prevalent (Mediterranean, Eastern Europe, Middle East), is usually slow-growing, and most often affects only the legs. Endemic KS is most common in Sub-Saharan Africa and is more aggressive in children, while older adults present similarly to classic KS. Immunosuppression therapy-related KS generally occurs in people following organ transplantation and mostly affects the skin. Epidemic KS occurs in people with AIDS and many parts of the body can be affected. KS is diagnosed by tissue biopsy, while the extent of disease may be determined by medical imaging.Treatment is based on the sub-type, whether the condition is localized or widespread, and the persons immune function. Localized skin lesions may be treated by surgery, injections of chemotherapy into the lesion, or radiation therapy. Widespread disease may be treated with chemotherapy or biologic therapy.
In those with HIV/AIDS, highly active antiretroviral therapy (HAART) prevents and often treats KS. In certain cases the addition of chemotherapy may be required. With widespread disease, death may occur.The condition is relatively common in people with HIV/AIDS and following organ transplant. Over 35% of people with AIDS may be affected. KS was first described by Moritz Kaposi in 1872. It became more widely known as one of the AIDS-defining illnesses in the 1980s. KSHV was discovered as a causative agent in 1994. Signs and symptoms
KS lesions are nodules or blotches that may be red, purple, brown, or black, and are usually papular.They are typically found on the skin, but spread elsewhere is common, especially the mouth, gastrointestinal tract and respiratory tract. Growth can range from very slow to explosively fast, and is associated with significant mortality and morbidity.The lesions are painless, but become cosmetically disfiguring or interruptive to organs. Skin
Commonly affected areas include the lower limbs, back, face, mouth, and genitalia. The lesions are usually as described above, but may occasionally be plaque-like (often on the soles of the feet) or even involved in skin breakdown with resulting fungating lesions. Associated swelling may be from either local inflammation or lymphoedema (obstruction of local lymphatic vessels by the lesion). Skin lesions may be quite disfiguring for the patient, and a cause of much psychosocial pathology. Mouth
The mouth is involved in about 30% of cases, and is the initial site in 15% of AIDS-related KS.