Warning notification:Warning

Unfortunately, you are using an outdated browser. Please, upgrade your browser to improve your experience with HSE. The list of supported browsers:

  1. Chrome
  2. Edge
  3. FireFox
  4. Opera
  5. Safari

Diagnosis - Breast cancer in women

You may be diagnosed with breast cancer after routine breast screening, or you may have symptoms that you've seen your GP about.

Seeing your GP

See your GP as soon as possible if you notice any symptoms of breast cancer. This could be an unusual lump in your breast or any change in the appearance, feel or shape of your breasts.

Your GP will examine you. If they think your symptoms need further assessment, they'll refer you to a specialist breast cancer clinic.

Tests at the breast cancer clinic

If you have suspected breast cancer you'll be referred to a specialist breast cancer clinic for tests.

This referral will be because of your symptoms or because your mammogram has shown an abnormality.

Mammogram and breast ultrasound

If you have symptoms and have been referred to a specialist breast unit by your GP, you'll probably be invited to have a mammogram if you are over 35 years old. This is an X-ray of your breasts. You may also need an ultrasound scan.

If your cancer was detected through the BreastCheck screening programme, you may need another mammogram or ultrasound scan.

Ultrasound uses high-frequency sound waves to produce an image of the inside of your breasts. It helps to determine the nature of a lump or of the abnormality. It may be needed to find out if a lump in your breast is solid or contains liquid.

Dense breast tissue

Your breasts are made up of thousands of tiny glands (lobules) that produce milk. This glandular tissue contains a higher concentration of breast cells than other breast tissue, making it denser.

Dense breast tissue can make a mammogram difficult to read. Lumps or areas of abnormal tissue are harder to spot.

Younger women tend to have denser breasts. This is why mammography is not routinely performed in women under 35 years. As you get older, the amount of glandular tissue in your breasts decreases and is replaced by fat. This means your breasts become less dense.


A biopsy is where a sample of tissue cells is taken from your breast and tested to see if it's cancerous.

You may also need a scan and a needle test on lymph nodes in your armpit (axilla) to see if these are also affected.

Biopsies can be taken in different ways, and the type you have will depend on what your doctor knows about your condition.

Needle biopsy is the most common type of biopsy. A small sample of tissue is taken from a lump in your breast using the ultrasound machine to help the doctor to sample the correct part.

You'll have a local anaesthetic. You'll be awake during the procedure, but your breast will be numb.

Your doctor may suggest that you have a mammogram guided needle biopsy. This is called a stereotactic biopsy. This is usually guided by a mammogram to obtain a more precise and reliable diagnosis of cancer.

This also can distinguish it from any non-invasive change, particularly ductal carcinoma in situ (DCIS).

Stage and grade of breast cancer

When your breast cancer is diagnosed, the doctors will give it a stage. The stage describes the size of the cancer and how far it has spread, and helps to predict the outlook.

Stage of breast cancer

Ductal carcinoma in situ (DCIS) is sometimes described as stage 0. Other stages of breast cancer describe invasive breast cancer:

  • stage is – the tumour is "in situ" and there's no evidence of invasion (pre-invasive)
  • stage 1 – the tumour measures less than 2cm and the lymph nodes in the armpit aren't affected; there are no signs that the cancer has spread elsewhere in the body
  • stage 2 – the tumour measures 2-5cm, the lymph nodes in the armpit are affected, or both; there are no signs that the cancer has spread elsewhere in the body
  • stage 3 – the tumour measures 2-5cm and may be attached to structures in the breast, such as skin or surrounding tissues, and the lymph nodes in the armpit are affected; there are no signs that the cancer has spread elsewhere in the body
  • stage 4 – the tumour is of any size and the cancer has spread to other parts of the body (metastasis)

Tests to find out the stage

More tests may be needed to determine the stage of the cancer.

Computerised tomography (CT) scans, or chest X-ray ultrasound scans of abdomen and bone may be needed to check if the cancer has spread outside of the breast area. Your doctor will discuss with you if these are needed.

An MRI scan of the breast may be needed to clarify the results. It may be also used to assess the extent of the condition within the breast.

Content supplied by the NHS and adapted for Ireland by the HSE

Page last reviewed: 16 May 2019
Next review due: 16 May 2022

This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.