Kaposi sarcoma is a rare tumor that has numerous types, the most common of which is associated with advanced HIV.
All forms of Kaposi sarcoma (KS) are caused by a type of herpesvirus, Kaposi sarcoma herpesvirus (KSHV).
Most people with KSHV do not develop Kaposi sarcoma unless their immune system is suppressed.
The incidence of Kaposi sarcoma increased 20-fold during the spread of HIV in the early 1990s and this type of cancer is still seen most often in people with late-stage HIV, as well as in people taking immunosuppressant medications.
What is it?
Kaposi sarcoma is a type of cancer caused by a virus.
Kaposi sarcoma is a multicentric vascular tumor, meaning that it involves blood vessels and affects soft tissue in multiple areas of the body.
It originates in the endothelial cells that line blood vessels and lymphatic vessels, causing these to grow at a faster rate and to survive for longer than normal.
There are four main types of Kaposi sarcoma:
Classic KS: This occurs mainly in older adults of Mediterranean, Eastern European, and Middle Eastern descent. It is more common in males than females.
Epidemic KS: This is the most common form of KS.
Endemic KS: Also known as African Kaposi sarcoma, this form is relatively common in equatorial Africa and can affect children and adults independently of HIV transmission.
Iatrogenic KS: This is also known as immunosuppressive treatment-related Kaposi sarcoma, immunosuppressive Kaposi sarcoma, or transplant-related Kaposi sarcoma.
Kaposi sarcoma is an illness in people infected with stage 3 HIV, also known as AIDS, and the most common malignancy associated with the syndrome.
The appearance of Kaposi sarcoma lesions has historically triggered a diagnosis of late-stage HIV.
There have been reports more recently, however, of Kaposi sarcoma occurring in people whose HIV is being well managed with antiretroviral medications, and whose viral load is undetectable.
This has led some physicians to question whether Kaposi sarcoma should still be considered a diagnostic factor in stage 3 HIV.
Typical Kaposi sarcoma lesions
Image credit: Anatomy & Physiology, Connexions Web site, 2013 – Kaposi sarcoma lesions
Kaposi sarcoma lesions before Interferon treatment
Image credit: National Cancer Institute, 1987 – Kaposi sarcoma before
Kaposi sarcoma lesions after Interferon treatment
Image credit: Image credit: McLeod, 2008 – Kaposi sarcoma after
Kaposi lesions under a microscope
Image credit: CFCF, 2009 – Kaposi sarcoma
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