Kaposi sarcoma is a cancer that causes lesions to grow in the skin; the mucous membranes lining the mouth, nose, and throat; lymph nodes; or other organs. The lesions are usually purple and are made of cancer cells, new blood vessels, red blood cells, and white blood cells.
Kaposi sarcoma is different from other cancers in that lesions may begin in more than one place in the body at the same time.
While most people infected with human herpesvirus-8 (HHV-8) or Kaposi sarcoma herpesvirus (KSHV) do not get Kaposi sarcoma, this virus is found in the lesions of all patients with this form of cancer. The people infected with HHV-8 who are most likely to develop Kaposi sarcoma have immune systems weakened by disease or by drugs given after an organ transplant.Kaposi Sarcoma Treatment (PDQ®)
Source: National Cancer Institute