As Paget's disease of the nipple is usually a sign of breast cancer, it's very important you see your GP if you notice changes to the tissue or skin of your breast.

In particular, you should tell your GP if you notice any changes to:

• the skin of your nipple or areola (the darker area of skin around the nipple)
• your breasts, particularly lumps in your breast

Paget's disease of the nipple can sometimes be confused with eczema, a skin condition that also causes red, itchy and dry skin.

Therefore, you should visit your GP for a diagnosis rather than assuming you have eczema. Paget's disease is a form of breast cancer and the sooner it's diagnosed, the better the outcome is likely to be.

Your GP will examine both breasts, even if you only have a problem with 1 of them. They may also ask you:

• about your symptoms and how long you've had them
• whether you've had breast cancer or have a family history of it
• your age and whether you've had the menopause (when a woman's monthly periods stop)
• whether you're taking any medication, including hormone replacement therapy (HRT), which is used to treat some of the symptoms of the menopause, or the oral contraceptive pill
• how much alcohol you drink
• how much you weigh and if you've recently gained weight

If your GP thinks you may have breast cancer, they'll refer you to a specialist breast clinic for tests.

At the breast clinic you'll have tests to find out whether you have breast cancer and, if you have, what type of breast cancer.

Staff at the clinic may photograph your breasts to record their current appearance and help identify any further changes that may occur.

Tests you might have at the clinic may include:

• an examination of your breasts to check for lumps or other abnormalities
• a mammogram
• an ultrasound scan, which is the first line of investigation used in younger women, and those who are pregnant or lactating
• a skin biopsy will be carried out if Paget's disease is suspected (a punch biopsy of the skin of the nipple and/or areola)

Mammogram

A mammogram is a simple procedure that uses X-rays to create an image of the inside of your breasts. It can identify early changes in your breast tissue when it may be difficult to feel a lump.

Younger women often have denser breasts than older women, which can make identifying changes more difficult. Mammograms may not be as effective in women under 35 years of age. If you're under 35, your doctor may suggest you have a breast ultrasound instead (see below).

However, if Paget's disease of the nipple is confirmed, mammography will become an important part of pre-surgery assessment.

During a mammogram, the radiographer will position 1 of your breasts on a flat X-ray plate. A second X-ray plate will press down on your breast from above, temporarily compressing and flattening it between the 2 plates.

An X-ray will be taken, which will give a clear image of the inside of your breast. The procedure will then be carried out on your other breast.

Having a mammogram can be slightly uncomfortable or even painful, but it only takes a few minutes. The image that's produced will be looked at by 2 people, called film readers, image readers or radiologists, for signs of cancer.

Breast ultrasound

If you're under 35 years of age, a breast ultrasound may be recommended instead of a mammogram. This is because your breast tissue may be too dense for a mammogram. Your doctor may also suggest a breast ultrasound if they need to find out whether a lump in your breast is solid or contains liquid.

You may also have an ultrasound scan if you're pregnant or lactating.

Ultrasound uses high-frequency sound waves to produce an image of the inside of your breasts. An ultrasound probe or sensor will be placed over your breasts to create an image on a screen. The image will show any lumps or abnormalities that are present.

Skin biopsy

A skin biopsy is often used to confirm a diagnosis of Paget's disease of the nipple. A small tissue sample will be taken from your nipple or the skin around it. The sample will be examined under a microscope and tested to see if it's cancerous.

If a diagnosis of breast cancer is confirmed, a number of other tests can be carried out to help determine what types of treatment might be used.

Read more about further tests for breast cancer.