If your healthcare provider thinks you might have Kaposi sarcoma (KS), you will need certain exams and tests to be sure. Diagnosing KS starts with your healthcare provider asking you questions. He or she will ask you about your medical history, your symptoms, risk factors (especially if you might have a weakened immune system, such as due to HIV infection), and family history.
Your healthcare provider will also give you a physical exam, paying special attention to any lesions (changes, sores, or lumps) on your skin or inside your mouth. Pictures of any lesions may be taken. You might also have a digital rectal exam (DRE). This is because KS lesions can form inside the rectum. To do this exam, your provider puts a gloved, lubricated finger into your rectum to feel for lesions. Your stool may also be checked for blood.
What tests might I need?
If symptoms or the exam suggest you might have KS, you may need more tests. You may have 1 or more of the following tests:
Your doctor will likely want to test small pieces (samples) of the changed areas. This is called a biopsy. A biopsy is often needed to confirm the diagnosis of KS. Depending on where the area is, different types of biopsies might be done.
The area may be in an easy-to-reach place, such as on your skin or inside your mouth. Then part or all of the area might be removed with minor surgery. Numbing medicine (local anesthesia) will be used. Then your doctor will remove a tiny piece or all of the lesion.
The area may be inside the body, such as in a lung or in your digestive tract. Then the area might be biopsied during an endoscopic procedure. Endoscopy is done by putting a long, thin, lighted tube into your body. For example, lesions in the lungs can be biopsied during a bronchoscopy. For this, a tube is put down your throat and into your lung. Lesions in the esophagus can be biopsied during an upper endoscopy. In this case, a tube is put down your throat and into your esophagus. These types of procedures are usually done while you are under sedation. Sedation is medicine to relax you and make you sleepy during the procedure. Numbing medicine might be used as well.
The biopsy samples are sent to a lab. A doctor called a pathologist, who specializes in looking at cells, checks them under a microscope to see if cancer is present.
If you have symptoms that might be from KS or another serious health problem, imaging tests might be done to look inside your body. For example, if you have symptoms like shortness of breath or coughing up blood, your healthcare provider might want to do a chest X-ray to look at your lungs.
Other types of imaging tests are not often needed to diagnose KS.
If your healthcare provider thinks you might have KS, you will likely have blood tests. For example, your doctor will want to test your blood to see if you are infected with HIV, the virus that causes AIDS. KS is much more common in people who are HIV-positive. If you are HIV-positive, your doctor will probably want to check your CD4 count and HIV viral load, which can help show how well controlled the infection is. This might affect your treatment.
Other blood tests can be used to check your overall health and how well your organs are working, such as your liver and kidneys.