Kaposi’s sarcoma (KS) is a disease in which cancer (malignant) cells are found in the tissues under the skin or mucous membranes that line the mouth, nose, and anus. KS causes red or purple patches (lesions) on the skin and/or mucous membranes and spreads to other organs in the body, such as the lungs, liver, or intestinal tract.

If there are signs of KS, a doctor will examine the skin and lymph nodes carefully (lymph nodes are small bean-shaped structures that are found throughout the body; they produce and store infection-fighting cells). The doctor also may order other tests to see if the patient has other diseases. The chance of recovery (prognosis) depends on what type of Kaposi’s sarcoma the patient has, the patient’s age and general health, and whether or not the patient has AIDS.

Source: National Cancer Institute