General Information About Kaposi Sarcoma

Kaposi sarcoma is a disease in which malignant lesions (cancer) can form in the skin, mucous membranes, lymph nodes, and other organs.

Kaposi sarcoma is a cancer that causes lesions (abnormal tissue) to grow in the skin; the mucous membranes lining the mouth, nose, and throat; lymph nodes; or other organs. The lesions are usually purple and are made of cancer cells, new blood vessels, red blood cells, and white blood cells. Kaposi sarcoma is different from other cancers in that lesions may begin in more than one place in the body at the same time.

Human herpesvirus-8 (HHV-8) is found in the lesions of all patients with Kaposi sarcoma. This virus is also called Kaposi sarcoma herpesvirus (KSHV). Most people with HHV-8 do not get Kaposi sarcoma. People with HHV-8 are more likely to develop Kaposi sarcoma if their immune system is weakened by disease, such as human immunodeficiency virus (HIV), or by drugs given after an organ transplant.

There are several types of Kaposi sarcoma. The two types discussed in this summary include:

• Classic Kaposi sarcoma.
• Epidemic Kaposi sarcoma (HIV-associated Kaposi sarcoma).

Tests that examine the skin, lungs, and gastrointestinal tract are used to diagnose Kaposi sarcoma.

In addition to asking about your personal and family health history and doing a physical exam, your doctor may perform the following tests and procedures:

• Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body. This is used to find Kaposi sarcoma in the lungs.
• Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer.

  One of the following types of biopsies may be done to check for Kaposi sarcoma lesions in the skin:

  • Excisional biopsy: A scalpel is used to remove the entire skin growth.
  • Incisional biopsy: A scalpel is used to remove part of a skin growth.
  • Core biopsy: A wide needle is used to remove part of a skin growth.
  • Fine-needle aspiration (FNA) biopsy: A thin needle is used to remove part of a skin growth.

  An endoscopy or bronchoscopy may be done to check for Kaposi sarcoma lesions in the gastrointestinal tract or lungs.

  • Endoscopy for biopsy: A procedure to look at organs and tissues inside the body to check for abnormal areas. An endoscope is inserted through an incision (cut) in the skin or opening in the body, such as the mouth. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue or lymph node samples, which are checked under a microscope for signs of disease. This is used to find Kaposi sarcoma lesions in the gastrointestinal tract.
  • Bronchoscopy for biopsy: A procedure to look inside the trachea and large airways in the lung for abnormal areas. A bronchoscope is inserted through the nose or mouth into the trachea and lungs. A bronchoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue samples, which are checked under a microscope for signs of disease. This is used to find Kaposi sarcoma lesions in the lungs.

After Kaposi sarcoma has been diagnosed, tests are done to find out if cancer cells have spread to other parts of the body.

The following tests and procedures may be used to find out if cancer has spread to other parts of the body:

• Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease.
• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, such as the lung, liver, and spleen, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
• PET scan (positron emission tomography scan): A procedure to find malignant lesions in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant lesions show up brighter in the picture because they are more active and take up more glucose than normal cells do. This imaging test checks for signs of cancer in the lung, liver, and spleen.
• CD34 lymphocyte count: A procedure in which a blood sample is checked to measure the amount of CD34 cells (a type of white blood cell). A lower than normal amount of CD34 cells can be a sign the immune system is not working well.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis and treatment options depend on the following:

• The type of Kaposi sarcoma.
• The general health of the patient, especially the patient's immune system.
• Whether the cancer has just been diagnosed or has recurred (come back).