Kaposi’s sarcoma is a rare type of cancer caused by a virus.
It affects the skin and mouth, and sometimes the internal organs.
Kaposi’s sarcoma is mostly seen in people with an advanced HIV infection.
It can also affect people with a weakened immune system for another reason, such as after having an organ transplant.
Kaposi’s sarcoma is caused by a virus called the human herpesvirus 8 (HHV-8), also known as the Kaposi’s sarcoma-associated herpesvirus (KSHV).
The virus is thought to be spread during sex, through blood or saliva, or from a mother to her baby during birth.