Kaposi sarcoma presents as red to purplish spots (macules) and raised bumps (papules and nodules). They are generally first seen on the skin, commonly on legs or feet. They also occur in the mouth. Initially, the lesions are small and painless but they can ulcerate and become painful. Their visible presence may cause considerable anxiety. Kaposi sarcoma lesions can also occur internally; in the gut, lungs, genitals and lymphatic system. These internal lesions may cause symptoms e.g. discomfort with swallowing, bleeding, shortness of breath, swollen legs, etc.
The exact cause of KS is not entirely understood. Early on, it was thought that KS was a form of cancer. However, scientists now believe it is caused by the herpes virus HHV8. And since HHV8 can be transmitted via sexual contact, the risk of developing KS is thought to be spread from person to person as well. The health of a person's immune system appears to have some affect on whether KS will develop.
In fact, KS has also been identified in HIV negative organ transplant patients who were receiving immunosuppressive therapy. The good news is that while KS is common, the incidence seems to be decreasing.
Kaposi's sarcoma is a cancer that causes patches of abnormal tissue to grow under the skin, in the lining of the mouth, nose, and throat or in other organs. The patches are usually red or purple and are made of cancer cells and blood cells. The red and purples patches often cause no symptoms, though they may be painful. If the cancer spreads to the digestive tract or lungs, bleeding can result. Lung tumors can make breathing hard.
Transplant-related (or acquired) Kaposi sarcoma develops in people whose immune systems have been suppressed after an organ transplant. Usually a transplant patient must take drugs to prevent the immune system from rejecting the newly transplanted organ. Because these drugs weaken the body's defenses, other diseases or infections can take hold. Kaposi sarcoma is 150 to 200 times more likely to develop in transplant patients than in the general population. Often, transplant-related KS affects only the skin. In some cases, though, the disease can spread to the mucous membranes or other organs.
Before the AIDS epidemic, KS usually developed slowly.
In AIDS patients, though, the disease moves quickly. Treatment depends on where the lesions are and how bad they are. Treatment for the AIDS virus itself can shrink the lesions. However, treating KS does not improve survival from AIDS itself.
KS is caused by an excessive proliferation of spindle cells thought to have an endothelial cell origin. Molecular studies suggest that KS originates from a single cell clone rather than a multifocal origin. Human herpes virus 8 (HHV-8) genomic sequences have been identified by polymerase chain reaction in more than 90% of all types of KS lesions (including epidemic and endemic forms), suggesting a causative role. These sequences additionally have been associated with body cavity-based lymphomas, Castleman disease, and leiomyosarcomas that occur in individuals infected with HIV.
Kaposi's sarcoma consists of characteristic skin lesions that range from flat to raised purple plaques. These tumors have a rich network of small blood vessels, and red blood cells moving slowly through these channels lose their oxygen, changing from red to blue. The mixture of red and blue cells gives the KS lesion a characteristic purple color. There are several forms of KS, based on cause rather than appearance. The "classic" Kaposi's sarcoma, found mainly in Mediterranean males and mid-European Jews, has always been rare.
