What is Kaposi's sarcoma? Kaposi's sarcoma (KS) is a tumor that typically presents with skin lesions. It develops from the cells lining blood vessels as well as the lymphatic system. Kaposi's sarcoma first moved into the spotlight as an AIDS-defining illness prior to the use of modern medications to control HIV (Human Immunodeficiency Virus). However, through further study over the years, much more has been learned about Kaposi's sarcoma. For example, in 1994, it was discovered that infection with the human herpes virus 8 (HHV-8) was responsible for Kaposi's sarcoma. Although it is necessary to be infected with HHV-8 in order to develop KS, the vast majority of people with HHV-8 infection actually will never develop the disease. This is because our immune systems are very adept at controlling the virus and keeping it from causing the development of tumors. Kaposi's sarcoma is classified ... read more on Kaposi's Sarcoma: The Basics