Kaposi's sarcoma - Diagnosing Kaposi's sarcoma

Before diagnosing Kaposi's sarcoma, your GP will ask you about your general health and carefully examine your skin.

If you have HIV or AIDS, the examination may be carried out by a member of your local HIV clinic who has experience of treating Kaposi's sarcoma. They may take digital photos of any suspected lesions and send them to specialists, such as a cancer specialist (oncologist) or a skin specialist (dermatologist).

If it's thought you may have Kaposi's sarcoma, you'll be referred for other tests to confirm the diagnosis, such as a skin biopsy.

If you don't have HIV or AIDS, you will be referred to a specialist who treats skin cancer.

Further tests

Some of the tests used to diagnose Kaposi's sarcoma are described below.

Biopsy

A biopsy is the most effective way of confirming a diagnosis of Kaposi's sarcoma. It involves taking a small sample of cells from an affected area of skin, which is then checked for Kaposi’s sarcoma cells at a laboratory.

Read more about how a biopsy is performed.

Endoscopy

An endoscopy may be carried out if it's thought you have Kaposi's sarcoma in your digestive system. It involves inserting a thin, flexible tube called an endoscope down your throat.

This allows the specialist to look inside parts of your digestive system, such as your bowel, liver and spleen, for any abnormalities or signs of Kaposi's sarcoma. A biopsy may be taken if anything suspicious is found.

If you have an endoscopy, you'll be given a mild sedative to help you relax. A local anaesthetic will be sprayed on to your throat to prevent discomfort as the tube is passed down.

A similar method can be used to examine your lungs if it's believed you have Kaposi's sarcoma in your lungs. This is known as a bronchoscopy.

Imaging scans

A computerised tomography (CT) scan and/or a magnetic resonance imaging (MRI) scan may be recommended if it's thought Kaposi's sarcoma has spread to your lymph nodes or other parts of your body.

For example, you may have a CT or MRI scan if you have symptoms of breathlessness that may be caused by Kaposi's sarcoma spreading to your lungs.

A CT scan works by taking a series of X-rays to build up a three-dimensional picture of the inside of the body. You may be given a radioactive dye to drink before the CT scan so that particular areas of your body can be seen in greater detail.

An MRI scan uses powerful magnets and radio waves to build up a detailed image of the inside of your body. Before having an MRI scan, you must tell your doctor if you have a pacemaker or any metallic implants in your body

Stages of Kaposi's sarcoma

Staging is a medical term that describes how far a cancer has spread at the time it is diagnosed. The higher the stage, the more advanced the cancer and the further it has spread.

A number of different staging systems are used for Kaposi's sarcoma. Some are specifically designed for specific types, such as HIV-related Kaposi's sarcoma.

A staging system for all types of Kaposi's sarcoma is outlined below:

stage 1 – the cancer is limited to one section of the body, such as your legs, and there's little or no spread inside your body
stage 2 – the nodules have begun to grow upwards out of your skin, as well as deeper into the underlying layers of skin, damaging affected areas
stage 3 – the cancer has spread into multiple lymph nodes but the internal organs, such as the lungs and digestive system, are unaffected
stage 4 – the cancer has spread into the internal organs