Kaposi Sarcoma: Diagnosis

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 on your skin or inside your mouth. You might also have a digital rectal exam (DRE). For this exam, your provider inserts a gloved, lubricated finger into your rectum to feel for lesions and check for blood in your stool.

What tests might I need?

You may have 1 or more of the following tests:

• Biopsy of suspicious areas

• Imaging tests

• Blood tests

Biopsy

If symptoms or an imaging test suggest you might have KS, your doctor will likely want to get small samples of the suspicious areas. This is called a biopsy. A biopsy is typically 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 the 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.

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, in which a long, thin tube is put into your body. For example, lesions in the lungs can be biopsied during a bronchoscopy, when a tube is put down your throat and into your lung. Lesions in the esophagus can be biopsied during an upper endoscopy, when a tube is put down your throat and into your esophagus. These types of procedures are usually done while you are under sedation. 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.

Imaging tests

If you have symptoms that might be due to KS (or another serious health problem), imaging tests might be done to look inside your body. For example, if you have symptoms such as shortness of breath or coughing up blood, your doctor might want to get a chest X-ray to look at your lungs. Other types of imaging tests are used less often to look for KS. 

Blood tests

If your doctor thinks you might have KS (or if you have already been diagnosed with KS), blood tests will likely be done. For example, your doctor will likely want to test your blood to see if you are infected with HIV, the virus that causes AIDS (if you have not been tested already). 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.

Getting your test results

When your healthcare provider has your test results, he or she will contact you. Your provider will talk with you about other tests you may need if Kaposi sarcoma is found. Make sure you understand the results and what follow-up you need.