Definition
Kaposi’s sarcoma is a cancer that is characterized by the formation of vascular conglomerates in the skin. These become visible in the form of blue and reddish lumps or spots, which can be as large as the palm of your hand. The sarcoma is named after its first descriptor Moritz Kaposi, who classified it in the 19th century as “Idiopathic multiple pigment sarcoma of the skin”. The disease usually develops in cases of immune deficiency, as is the case with AIDS patients or people with other autoimmune diseases. The course of the disease varies: There are harmless courses that do not cause any symptoms for years, as well as highly aggressive courses that can quickly become fatal.
Causes
The trigger of Kaposi’s sarcoma is the Human Herpes Virus 8 (HHV-8). As this virus was only discovered in the nineties, the first describer was not yet able to establish a connection to the genesis of the disease. HHV-8 belongs to the group of herpes viruses and is transmitted sexually and perinatally, i.e. during birth.
Transmission by smear infection, i.e. through the exchange of body fluids, is also possible. At this point it should be mentioned that HHV-8 infection is necessary for the development of Kaposi’s sarcoma, but at the same time there must be other genetic peculiarities or even an impairment of the immune system. On the one hand, there is the classic form of Kaposi’s sarcoma.
This form is mainly contracted by men over 60 who are of Italian, Jewish or Eastern European origin. In this case, the course of the disease can be classified as mild. On the other hand, the endemic Kaposi sarcoma has been described in Africa, which occurs independently of HIV and can also affect small children.
By far the most common form is the AIDS-associated Kaposi sarcoma. In this case there is an immunodeficiency. If the person infected with HHV-8 is an immunocompetent person, his immune system manages to keep the virus in check and the person does not develop any symptoms.
It is only when the immune deficiency becomes pronounced that the virus breaks out and causes the malignant vascular conglomerates of the skin. Since Kaposi’s sarcoma is particularly common in HIV infection and AIDS (20,000 times more common than in healthy individuals), it has also been described as an “AIDS-defining disease”. The largest risk group for the AIDS disease, and thus also for Kaposi’s sarcoma, are homosexual men. However, it must also be said that with the development of highly effective HIV drugs, the number of Kaposi’s sarcoma has decreased.