Karposi's sarcoma?

Originally Published: May 1, 1994 - Last Updated / Reviewed On: November 26, 2007
Share this
Dear Alice-

I've never had an HIV test and it's not something that I'd particularly like to go through, for psychological reasons of course. I've always practiced safer sex, which leads to my query: over the past several months, I've developed two spots on my legs which are now, well, purple. One began as a large egg-shaped bump, presumably a bruise, etc.; and the other began, I believe, as a bug bite, which developed into a large cyst that had to be drained. My concern, however, is that these two spots, even considering their origins, could signal the advent of KS. Could you kindly tell me how KS begins, as either flat purple spots, or as I've described?

Thanks in advance.

Dear Anxious,


Kaposi's sarcoma, or KS, is a rare form of cancer in which the tumors occur in the walls of the blood vessels. The disease is caused by human herpesvirus-8 (HHV8), also known as Kaposi's sarcoma-associated herpesvirus (KSHV). KS is an example of an opportunistic infection: the virus takes advantage of weakened immune systems (such as those of people with HIV) and leads to cancer, but is usually not harmful to healthy people). HIV-positive people with Kaposi's sarcoma are considered to have developed AIDS.


AIDS-related KS initially causes lesions (spots) on the skin that do not heal. While lesions themselves are usually painless, they can lead to pain in nearby healthy tissues. The lesions may also develop inside the body and cause further, potentially life-threatening problems. Symptoms of KS can include:


  • purple, brown, or black lesions on the skin and/or inside the mouth, nose and eyelids
  • swelling in the extremities and/or enlarged lymph nodes (if lesions block the lymph vessels)
  • abdominal pain (if lesions spread to the digestive tract)
  • persistent cough, difficulty breathing, and/or coughing up blood (if lesions spread to the respiratory system)

Keep in mind that many people with HIV will not have any symptoms for years, even without treatment. Additionally, KS-like symptoms can be signs of health issues other than HIV. In general, symptoms are never enough to determine whether a person has HIV — getting tested is the only way to know for sure. AIDS must be diagnosed by a health care provider depending on whether a patient meets a very specific set of criteria (see What is AIDS? for more information).  


If you've always practiced safer sex (using condoms for vaginal, anal, and oral sex), you're at a much lower risk of contracting HIV. Again, getting tested in the only way to know for sure whether or not you have the HIV-virus (and thus whether AIDS is even a possibility). If you are at Columbia, confidential testing for all students is available through the Gay Health Advocacy Project (GHAP); visit their website for walk-in hours and more information. Find more information about HIV-testing in the Q&A Should I get tested for HIV?

While testing itself can definitely be stressful for some people, you also seem to be anxious about your symptoms and their cause. Testing, along with talking with your health care provider about your symptoms, will help you find a definitive answer. Many HIV-testing sites offer results in 24 hours or less and provide counselors who can talk with you about your testing anxiety and any other concerns you have about HIV/AIDS. Given your history of safer sex, you might consider looking into other, more common causes of skin abnormalities, such as an allergic rash, reaction to detergents or soaps, injury, or reaction to bug bites.

Best of luck,