Kaposi’s Sarcoma - Types, Signs, Symptoms, Diagnosis, Treatment and Prevention

What Is Kaposi's Sarcoma?

Kaposi's sarcoma (KS), a type of cancer, results in tumors or masses in the lymph nodes, skin, and other organs. These tumors originate in the lining of blood vessels or lymph vessels. These lesions are usually painless and appear as purplish spots on the feet, legs, face, genital area, mouth, or lymph nodes. In severe cases, tumors may develop in the lungs and digestive tract.

Infection with a virus called human herpesvirus 8 (HHV-8) is the underlying cause of Kaposi's sarcoma. But infection with HHV-8 does not always result in this condition. In people with a healthy immune system, HHV-8 infection does not usually result in any symptoms because our immunity keeps the virus under control. On the other hand, HHV-8 infection in people with weak immune systems can possibly trigger Kaposi's sarcoma.

Also, those infected with the human immunodeficiency virus (HIV), which is the virus that causes AIDS (acquired immunodeficiency syndrome), are most at risk of Kaposi's sarcoma. As HIV damages the immune system, it allows the cells that are infected with HHV-8 to multiply exponentially and out of control. Organ transplant recipients are also at risk because of the immune system-suppressing drugs they take to prevent transplant rejection.

Diagnosis is made by conducting a tissue biopsy, and the extent of the disease is determined by imaging. The treatment depends on the type of KS, how well the patient's immune system is functioning, and if the condition is localized or widespread. Localized lesions in the skin are treated surgically or with chemotherapy or radiation therapy. More widespread lesions need chemotherapy or biologic therapy. AIDS patients need highly active antiretroviral therapy (HAART). Severe cases might be fatal.

Moritz Kaposi described this illness in 1872. As over 35 % of AIDS patients are affected with KS, it was known as one of the AIDS-defining illnesses in the 1980s. The causative virus was discovered in 1994.

What Are the Types of Kaposi's Sarcoma?

There are four types of Kaposi's sarcoma:

1. Classic Kaposi's Sarcoma - It commonly affects older adults (especially men), they are slow-growing, and the lesions are seen in the legs.

2. Endemic Kaposi's Sarcoma - This type occurs in young adults (more men) in Africa and is often aggressive.

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3. Immunosuppression Therapy-Related Kaposi's Sarcoma - It generally occurs in individuals who have had organ transplantation. This type mostly affects the skin.

4. Epidemic Kaposi's Sarcoma - This type of KS occurs in AIDS patients and can affect multiple areas of the body.

What Are the Signs and Symptoms of Kaposi's Sarcoma?

Depending on the parts of the body that are affected by the disease, the signs and symptoms include:

1. Skin - The skin lesions appear as flat spots and are usually red, purple, or bluish on light skin and black or brownish on dark skin. They are generally painless and are not itchy; neither do they drain pus or fluid. These lesions do not change color when pressed like bruises. Every week, new spots might occur, and in some, the spots may grow into a bump or merge together to form a bigger spot.

2. Lymph Nodes - Lesions in the lymph vessels can block the flow of lymphatic fluid in the body, leading to serious swelling in the legs, hands, face, or scrotum.

3. Respiratory Tract - Lesions inside the lungs or anywhere in the respiratory tract can cause coughing and difficulty breathing.

4. Mucous Membranes - Lesions due to Kaposi's sarcoma can also be seen in the soft tissue lining the inside of the mouth and throat. When such lesions form a bump, they can interfere with chewing and swallowing. Lesions can also occur on the underside of the eyelids and eyes.

5. Digestive Tract - Lesions in the lining of the stomach and intestines can cause internal bleeding and blockages. The symptoms that the patient might experience include indigestion, vomiting, stomach pain, diarrhea, blood in stools, and anemia.

KS in the internal organs like the lungs and gastrointestinal tract are rare when compared to KS, which affects the skin. Even though the condition progresses slowly, it can ultimately be fatal if not treated.

How Does a Doctor Diagnose Kaposi's Sarcoma?

For Kaposi's sarcoma that affects the skin, the doctor can generally diagnose it by just looking at the lesion. As other conditions, such as bacillary angiomatosis, fibrous histiocytoma, hemosiderotic hemangioma, interstitial granuloma annulare, pyogenic granuloma, and arteriovenous malformations also look similar to KS, a confirmatory test is a must.

The following tests are done to diagnose Kaposi's sarcoma:

1. Biopsy - A small sample of cells is collected from the suspected site. This collected sample will then be sent to a laboratory for testing.

2. X-ray - A chest X-ray will help diagnose Kaposi's sarcoma affecting the lungs.

3. Endoscopy - In this procedure, the upper part of the gastrointestinal tract is viewed using a long, thin tube (endoscope) with an attached camera. The stomach and a part of the small intestine are looked for abnormalities, and if needed, a biopsy can be taken from suspected areas.

4. Bronchoscopy - Here, a thin tube (bronchoscope), which is passed through the nose to the lungs, is used to view the lining of the lungs and to take a biopsy sample.

5. Fecal Occult Blood Test - This test is used to detect blood in stools, which can indicate KS of the digestive tract.

6. Imaging Tests - A CT (computed tomography) or MRI (magnetic resonance imaging) scan might be needed to determine how widely cancer has spread.

What Are the Treatment Options for Kaposi's Sarcoma?

Factors like the type of Kaposi's sarcoma, the number and location of lesions, signs and symptoms, and the overall health of the patient influence Kaposi's sarcoma treatment.

The treatment options include:

1) Removal of Lesions - If the patient has only a few small lesions, then the tumors might be removed surgically, either by cryotherapy, where the tumor is killed by freezing, or electrodesiccation, where it is killed by burning. Surgical removal of lesions only treats individual lesions and does not stop the development of new lesions, as the underlying HHV-8 infection is not addressed.

2) Chemotherapy - Drugs to kill tumors are used only when the skin lesions are widespread or when the internal organs are affected. As most KS patients already have a weak immune system, chemotherapy is used with caution. Doxorubicin, Vinblastine, and Paclitaxel are the most commonly used chemotherapeutic drugs for KS.

3) Interferon - Interferon, an antiviral drug, is a protein naturally found in the body. The synthetic version of this protein is injected in patients with KS, provided their immune system is healthy.

4) Radiation - In case the patient has many lesions or many parts of the body affected, radiation therapy using high-energy rays is used to kill cancer cells or keep them from growing.

For most AIDS patients with KS, treatment of AIDS with highly active antiretroviral therapy (HAART) is sufficient to treat KS too.

Can Kaposi's Sarcoma Be Prevented?

No vaccine can protect you against HHV-8. So the best way to prevent KS is by avoiding things that increase the risk of HIV, such as unprotected sex and using injectable drugs. AIDS or HIV patients can reduce the risk of KS by taking antiretroviral drugs. Organ transplant patients can reduce the risk of KS by using some anti-rejection drugs.

Conclusion:

KS progresses slowly and can be treated. But without treatment, it can be fatal. If you have KS, avoid exposing the lesions to anyone. For more information, consult a specialist online now.