Breast lumps

A breast lump is any swelling, thickening or lump that you can feel in your breast tissue or armpit that was not there before. Most breast lumps are not cancer, but any new lump should always be checked by a GP.

What causes breast lumps?

Breast lumps have many possible causes, including:

• Fibroadenoma – a harmless, firm lump made of fibrous and glandular tissue, most common in women in their 20s and 30s
• Breast cyst – a fluid-filled sac that can form in the breast, often around the time of the menopause
• Fibrocystic changes – normal changes in your breast tissue linked to your hormones, often more noticeable just before your period
• Breast infection or abscess (a collection of pus) – more common if you're breastfeeding or if you smoke
• Fat necrosis – scar tissue that can form after an injury to the breast, or after breast surgery
• Intraductal papilloma – a small, wart-like growth inside a milk duct
• Breast cancer – a less common cause, and the reason any new lump needs checking.

Are there different types of breast lumps?

Breast lumps can feel very different from one another, and how a lump feels can offer some clues, though it cannot tell you for certain what is causing it.

• Smooth and easy to move under the skin – often, but not always, linked to a cyst or fibroadenoma
• Hard, fixed in place, or a different texture to the rest of your breast – can be more concerning, though this does not always mean cancer
• Tender or painful, especially around your period – usually linked to hormonal changes rather than cancer
• Painless – can still, in rare cases, be a sign of cancer, so should still be checked.

The size of a lump does not show whether it's cancer. Lumps of any size can turn out to be harmless or cancerous, so it's the lump itself, not how big it is, that needs to be checked.

How are breast lumps diagnosed?

If you see a GP about a breast lump, they'll usually ask about your symptoms and family history, then examine your breasts. If they're not sure what's causing the lump, they'll refer you to a breast clinic for further tests.

1. Breast examination – a doctor or nurse feels the lump and the surrounding breast tissue.
2. Imaging scan – usually a mammogram (a breast X-ray) or an ultrasound scan, sometimes both.
3. Biopsy, if needed – a fine needle is used to take a small sample of cells from the lump, which is checked under a microscope in a laboratory.

These tests are often carried out during the same visit, sometimes called a one-stop clinic. You'll usually be told your scan results on the same day, though biopsy results take about a week or longer.

How are breast lumps treated?

Treatment depends entirely on what's causing the lump. Many breast lumps do not need any treatment at all and settle down on their own.

• Fibroadenoma – usually needs no treatment, though it can be removed if it's large, growing or bothering you
• Cyst – drained with a fine needle if it's large or uncomfortable
• Infection or abscess – treated with antibiotics (medicine that clears the infection). An abscess may also need the pus drained with a needle
• Cancer – if a lump is confirmed as cancer, treatment may include surgery, chemotherapy (medicine that destroys cancer cells) or radiotherapy (high-energy rays that destroy cancer cells).

When should you see a doctor?

Always see a GP if you notice a lump in your breast or armpit, even if you think you already know what's causing it.

• A new lump or swelling in your breast or armpit
• A lump that feels harder, or different, from the rest of your breast or from your other breast
• Your nipple turning inwards, or new discharge that isn't breast milk
• Dimpling, puckering or redness of the skin on your breast
• A change in the size or shape of your breast
• Pain in one specific part of your breast that does not go away.