Kaposi Sarcoma (KS) is a type of disorganised growth of blood vessels. It was first described in 1872 by Moritz Kaposi.
KS is caused by an infection with a virus called human herpesvirus-8 (HHV-8). This virus alters the genes on the cells that line blood vessels and the lymphatic system, causing an increase in division rate and a longer cell-life. As a result, there is an abnormal increase in production of new blood vessels.
There are four variants of KS.
Classic Type: It is most common type and often seen in older males of Mediterranean or eastern European heritage. Skin lesions are primarily seen on the legs. It usually follows an inactive clinical course.
Iatrogenic Type: It appears secondary to the use of immunosuppressive medication, and may be seen in organ transplant recipients.
AIDS related KS: Occurs in patients with Acquired Immunodeficiency Syndrome (AIDS). It can be disseminated but effective HIV treatment may control the disease.
Endemic Type (African): Most commonly seen in African males, the clinical course ranges from slow progression to rapid internal organ dissemination. There is a variant that affects children with rapid aggressive disease.
Lesions appear as painless, bluish-red flat patches on the skin resembling bruises. These lesions may increase in size progressively and form plaques and nodules. With enough time, they may become brown, and the skin may thicken or form ulcers. In some cases, KS may spread to other parts of the body.
There are many growths of the blood vessels which may look like KS such as tufted angioma, Kaposiform haemangioendothelioma and bacillary angiomatosis. In order to make a definitive diagnosis, a skin biopsy.
KS is a difficult condition to treat. In many patients, obtaining a complete cure may be difficult and recurrence rates are high. Nevertheless, lesions may have a significant impact on quality of life and self-esteem and there are treatment options available. The treatment alternatives for KS depend on the clinical type, the extent and location, and which organ system is involved.
For KS confined to the skin, the treatment options include:
- Cryotherapy (Freezing therapy)
- Laser surgery (Pulsed dye laser or ablative laser)
- Surgical Excision
- Photodynamic therapy
- Intralesional injection
On the other hand, for widespread skin lesions, stubborn lesions or in the setting of internal organ involvement, systemic treatment may be a better option.
For patients with KS and changes to their immune system (either through immune-suppressing medications or the HIV virus), improving the function of the immune system can help treating the KS.