Until the early 1980s, Kaposi's Sarcoma was very rare and found mainly in older men of Mediterranean or African origin (Classic KS) or patients who had organ transplants (Immunosuppressive treatment related KS). With the impact of AIDS it has become more common (Epidemic KS).
Knowledge of Kaposi's Sarcoma entered the awareness of the general public with the release of the film Philadelphia, in which Tom Hanks portrayed a lawyer who was fired after his employers found out he was HIV-Positive due to visible lesions.
Because of their highly visible nature, external lesions are sometimes the presenting symptom for HIV infection. Unfortunately, by the time lesions appear the body's immune system has already been greatly weakened. HIV is not fatal in and of itself, but weakens and can eventually destroy the body's natural immune system, allowing Kaposi's and other kinds of "opportunistic infection" which appear when the immune system has become ineffective.
External lesions are not often fatal. Internal lesions which affect the internal organs are much more often fatal. With recent medical advances, however, Kaposi's has become less common.
See also: Taxol