Kaposi sarcoma is a multifocal neoplasm of reticuloendothelial cells. It was first described by Moritz Kaposi in 1872.
The skin lesions may be nodular, papular or blotchy and the colour may be red, purple, brown or black. These characteristics may also be seen under or on mucous membranes. The most common sites of the lesions are the throat, nose and mouth and unless they are swollen or inflamed, they are usually painless.
In some cases, there is superimposed bacterial infection. In transplant recipients, the tumor spreads. On rare occasions, lesions occurring in the respiratory tract or the oesophagus may bring about obstruction .
Even though KS can be detected from the appearance of lesions and the risk factor of the patient, definitive diagnosis can only be made by biopsy and microscopic examination. When KSHV protein LANA is detected in the tumor cells, the diagnosis is confirmed .
Again patients with HIV infection will need to undergo CD4 lymphocyte counts and plasma HIV viral-load studies.
Kaposi Sarcoma is generally incurable and can only be controlled using palliative treatments. All underlying causes will however be treated where possible such as immunosuppression and immunodeficiency. For AIDS related KS or epidemic KS, beginning HAART will often lead to a reduction of lesions in more than 40% of cases . However, the KS will continue to grow in some instances even with the use of antiretrovirals.
When there are only a few lesions, the treatments that can be considered include: Radiotherapy, cryothrapy or cryosurgery.
Surgery has the risk of KS occurring on the edges of the wound and is often only appropriate for small lesions on the surface. To prevent KS occurring on edges, electrodessication with curettage can equally be used.
Prognosis is dependent on the variation of KS, how deeply the immune system is affected, presence of dissemination and whether or not the KS is recurrent . Since the AIDS death rate declined in the 1990s however, there has been a reduction in the severity of KS conditions and the general occurrence.
As stated above, the KS disease is caused by infection with a virus known as the Kaposi sarcoma herpes virus, KSHV or the human herpesvirus 8 (HHV8). The KSHV virus is similar to the Epstein-Barr virus known to cause mononucleosis and other varieties of cancer.
With KS, the endothelial cells become infected with KSHV. The presence of the virus brings in genes that cause excessive cell divisions and make the cells live longer than normal. A combination of these changes, end up turning them into cancerous cells.
Infection with the KSHV virus is more common than the KS disease condition and many people who get infected with this virus do no go on to develop KS. In fact a greater percentage of people with KSHV do not show any symptoms . For KS to occur KSHV must be present but in many cases the virus on its own does not bring about KS. People who develop KS have a weak immune system that may be caused by HIV infection, organ transplant, older age etc.
Kaposi Sarcoma was rare in the United States before the AIDS epidemic. In recent times, the figures have gone back to pre-epidemic figures.
In Africa however, the incidence of KS is quite high with 37.7 cases per 100,000 men and 20.5 cases per 100,000 women. The highest incidence of Kaposi sarcoma in Europe is seen in Sicily with 30 cases per million for men and 5.4 cases per million in women .
Regardless of the name, KS is not truly considered to be a sarcoma as sarcomas often arise from a mesenchymal tissue. On the other hand, KS is a cancer of the lymphatic endothelium forming vascular channels that are filled with blood cells. The filled vascular channels are what give the resultant KS tumor its bruise like appearance. In KS cancer cells, KSHV proteins are uniformly detected .
KS lesions have tumor cells with a characteristically abnormal elongated shape known as spindle cells. The most typical feature of Kaposi sarcoma is the presence of spindle cells that form slits containing red blood cells. Pleomorphism is often absent and Mitotic activity is only moderate. The tumor is very vascular and contains irregular blood vessels that are abnormally dense. This is what gives the tumor its dark colour. Inflammation around this tumor may produce swelling and pain.
HHV8 is found in all lesions of KS regardless of whether it is HIV related, classic, endemic or iatrogenic .
There are still doubts till date as to how Kaposi sarcoma herpes virus is acquired but it is commonly believed to be transmitted through the saliva of an infected person. Therefore the first step is to avoid body fluids from individuals diagnosed with the KSHV. However, keep in mind that the KS condition will only develop if there are other enabling factors .
Kaposi sarcoma (KS) is a cancer of the connective tissue caused by the human herpes virus 8. This virus is now known as the Kaposi sarcoma associated virus (KSHV) . The condition is basically a malignant lesion that is characterised by neoplastic cells and abnormally growing blood vessels. Named by the Hungarian dermatologist Moritz Kaposi who discovered it in 1872, its viral gene sequence was only determined recently in 1995-1996. The lesions from KS may begin in more than one place at the same time making it different to other neoplasms.
The different types of KS include:
Kaposi sarcoma (KS) is a cancer of the skin that can also affect other parts of the body. The condition is caused by a virus and it is mostly seen in individuals that have an immune system that is not as strong as should be. The condition is relatively common with individuals living with AIDS and is seen around the world.
On its own, KS isn't life threatening but a lot depends on how deeply the immune system has been affected. There is no conclusive treatment for it but when there are a few lesions, radiotherapy may be used. One important part of management of this condition is regular support by health professionals. To prevent Kaposi sarcoma, patients with a disease that affects the immune system should stay away from body fluids from patients of the KS condition.