For many women, feeling a lump in their breast can be quite a frightening experience. For most women, their first thought is cancer. However, it should be realised that most breast lumps are not cancerous. In fact, only about one of every 10 breast lumps turn out to be cancer – most breast lumps are benign (not malignant) tumours or cysts that do not spread to other parts of the body.
It’s important to know how your breasts normally feel so that you are aware of any changes or lumps that develop. You should see your doctor if you notice:
- any change in the size, look or feel of your breasts;
- the development of a lump or lumps; or
- nipple discharge.
Causes of benign breast lumps
There are several causes of benign (non-cancerous) breast lumps – see below. Remember, always check any breast lump you find with your doctor.
Fibroadenomas are a common cause of breast lumps, and occur mainly in women aged around 15-30 years. Made up of a mix of fibrous (containing or resembling fibres) tissue and glandular (coming from a gland) tissue, they are painless, round, and have a smooth, firm feel. Their size can vary – they may feel like a marble or be several centimetres wide.
A fibroadenoma can generally move freely under the breast tissue – because of this movement it is sometimes called a ‘breast mouse’. They generally do not change in size.
Fibroadenomas can occur on their own or there may be more than one. Having a fibroadenoma does not increase your risk of getting breast cancer.
Fibrocystic breast changes
Also known as fibrocystic disease, fibrocystic breast changes are most common in women of childbearing age and often disappear after menopause. As the name suggests, the changes are a combination of breast cysts and thickened, fibrous tissue in the breasts. The changes may occur in both breasts, one breast, or just one area of breast tissue.
Benign fibrocystic changes can cause a lump or lumps in the breast(s). Fibrous tissue may feel firm, hard or rubbery, and cysts feel firm, round and mobile. Breast lumps may be tender, especially just before your period. The size of the lump(s) can also change with your menstrual cycle.
In women with fibrocystic breast changes, the breasts can also generally feel sore and tender.
Simple breast cysts are benign (non-cancerous) fluid-filled sacs that occur in the breasts of some women, most commonly those aged 35-50 years. Breast cysts feel smooth and round, and may move when you apply pressure with your fingertips.
Breast cysts can be painful or tender to the touch, especially during the week before a woman’s menstrual period. They can also change size over time or during the menstrual cycle (often getting bigger and more tender just before your period) and may disappear and reappear. Sometimes women with a breast cyst have nipple discharge.
Intraductal papillomas (also sometimes known as benign milk duct tumours) are a wart-like growth in one of the milk ducts – the tubes that carry milk to the nipple. They usually grow just behind and near the edge of the nipple.
Intraductal papillomas usually result in small lumps that can be painful. They can cause a discharge from the nipple, which may be clear or contain blood.
Intraductal papillomas are not cancerous and generally don’t increase a woman’s risk of getting breast cancer.
Milk cyst (galactocoele)
A milk cyst (galactocoele) can develop in women who are breast feeding or have recently stopped breast feeding. It is a collection of breast milk, and is usually felt as a smooth, round movable mass. Milk cysts may feel uncomfortable.
A breast abscess is a collection of pus in the breast that usually occurs as a complication of mastitis in women who are breast feeding. Breast abscesses cause a painful lump or swelling in the breast that may get bigger quickly. Women with mastitis and a breast abscess usually have a fever and feel generally unwell. Other symptoms include redness, warmth, swelling, and tenderness in the affected area of the breast.
Sometimes, breast abscesses develop in women who are not breast feeding. Your risk of developing a breast abscess may be increased if you have had a recent breast injury or surgery, cracked nipples or a nipple piercing.
A lipoma is a benign growth of fat cells that can appear in most areas of the body, including the breasts. Lipomas are felt as a soft, doughy lump that can move when you press them with your fingertips. They are usually not painful.
Fat necrosis is a type of scar tissue that can cause painless breast lumps that may feel firm and have an irregular edge. Fat necrosis results from breast injuries, breast surgery or radiotherapy to the breast, and most often affects older women with larger breasts.
Breast lumps: tests and diagnosis
Your doctor will ask about the breast lump and perform a physical examination, including examination of your breasts when you are sitting up and lying down. They will look at the appearance of both breasts and nipples, and feel for any lumps. They will also feel for any enlarged lymph nodes under your arms and in your neck.
There are a number of tests that can be used to help work out the cause of a breast lump. Your doctor will probably recommend imaging tests initially, which may include the following.
- Breast ultrasound — this test uses high frequency sound waves and is often used to determine if the lump is fluid-filled (this is usually harmless) or solid. Ultrasound is also recommended to investigate breast masses in younger women, because it is more sensitive than mammography in young women who usually have dense breast tissue.
- Mammogram — this is an X-ray of the breast used to detect abnormalities. A mammogram is usually recommended to investigate any breast lump in older women. This type of testing is also often used as a screening test for women without symptoms.
Depending on the results of the imaging tests, further tests may be recommended, including the following.
- Fine needle aspiration — this is where a needle is inserted directly into the lump to remove fluid. The fluid may sometimes be sent to a laboratory for examination under a microscope. Depending on the location of the breast lump, the needle may be guided by ultrasound.
- Biopsy — this is where a sample of breast tissue is taken and then microscopically examined. This test is considered to be the most accurate way of determining the cause of the lump. The sample may be taken using a needle (fine needle aspiration biopsy or core needle biopsy) or done surgically (surgical or open biopsy), sometimes under X-ray or ultrasound guidance.
These tests may be done by your doctor or by a radiologist (medical imaging specialist). Alternatively, your doctor may refer you to a breast surgeon for investigation.
See your doctor as soon as possible if you discover a breast lump. The majority of breast masses are benign, and for those that are malignant (cancerous), an early diagnosis is important.