Benign breast disease

How common is benign breast disease?

Any symptom in the breast causes natural anxiety. Breast cancer is the most common cancer in women in the developed world, with around 50,000 cases diagnosed each year in the UK.¹ Around 3% of primary care consultations relate to breast symptoms but the vast majority of these represent benign breast diseases, with the average full-time GP diagnosing 1-2 cases each year.²

When to worry about a breast lump

Current guidelines from the National Institute for Health and Care Excellence (NICE) advise consideration of referral for all unexplained breast lumps in patients aged 30 or over, with the urgency being dependent on age and other features.³ Benign breast disease may present with other symptoms, however, such as pain, nipple discharge, nodularity and swelling. It may fall to the GP to differentiate which of these represent benign disease and which may suggest malignancy, and therefore which need further investigation and with what degree of urgency. Most breast clinics aim to see women referred with breast symptoms within two weeks, whether referred under the suspected cancer pathway or not, but this may depend on your local pathway.

See also the separate Breast Lumps and Breast Examination article for information about features of the history and examination which are important to establish during assessment of breast symptoms.

Types of benign breast diseases

Histologically, benign breast diseases can be divided into three groups which provide an idea regarding potential future cancer risk:⁴

• Non-proliferative disorders - no increased risk.

• Proliferative disorders without atypia - mild to moderate increase in risk.

• Atypical hyperplasias - substantial increase in risk (relative risk in the order of 4.1-5.3).

Clinically, classification by common presenting features may be more helpful:

• Physiological swelling and tenderness.

• Nodularity.

• Breast pain (not usually associated with malignancy).^{2 3}

• Palpable breast lumps.

• Nipple discharge including galactorrhoea.

• Breast infection and inflammation - usually associated with lactation.

Breast pain and galactorrhoea are covered elsewhere and will not be considered further in this article.

Benign breast swelling and tenderness

Puberty

Breast enlargement, sometimes initially unilateral, is the first obvious sign of puberty in girls. Breast buds may initially be unilateral. Pubertal breast development is known as thelarche.

Isolated premature thelarche can occur. Breast development may occur in girls aged <3 years and can then spontaneously regress. This is often seen in girls under the age of 3 years and is caused by maternal oestrogens in the early months. There is fairly static breast development before true puberty eventually occurs at the normal time. It is a benign condition confirmed by:

• Absence of any other signs of puberty.

• Normal growth with appropriate bone age (ie no growth spurt).

• Minimal increase in breast tissue with time (can even decrease).

• Appropriate uterine dimensions for age (ultrasound) with normal endometrial echo and no vaginal bleeding.

Unless there are features of true precocious puberty (such as premature pubic hair) then just reassurance is required.

Some breast development in boys is also common in puberty, occurring in nearly half. It usually settles and disappears on its own over a year or two.⁵ True gynaecomastia is discussed in a separate article.

Cyclical mastalgia⁶

The breasts are active organs that change throughout the menstrual cycle and some degree of tenderness and nodularity in the premenstrual phase is so common that it may be considered as normal, affecting up to two thirds of all menstruating women with 10% of women having moderate to severe pain. It rapidly resolves as menstruation starts. Conditions to exclude by history and examination are infection, pregnancy and malignancy.

Pregnancy

Normal changes to the breasts during pregnancy and breast-feeding include:

• Tenderness, discomfort or pain.

• Increase in size.

• Areolar and nipple changes: darkening of colour, enlargement of nipples, enlargement of the Montgomery glands on the areola.

• Leaking of colostrum or milk.

When problems arise during breast-feeding there may be sore or cracked nipples, thrush, engorgement, etc.

Benign breast disease and nodularity⁷

Fibrocystic change is the most common benign breast disorder and most often presents with pain and nodularity. This usually affects women aged 20-50 and appears to be hormonal in aetiology. Any of the histological types listed above may be found and where there is proliferative change (with or without atypia) it seems there is an associated increased risk of developing breast cancer.⁸ Women present with lumpiness of the breast and varying degrees of pain and tenderness:

• The symptoms are greatest about one week before menstruation and decrease when it starts.

• Examination may reveal an area of nodularity or thickening, poorly differentiated from the surrounding tissue and often in the upper outer quadrant of the breast.

• If the changes are bilaterally symmetrical, they are rarely pathological. If there is asymmetry it is acceptable to review the patient after one or two menstrual cycles, seeing her mid-cycle.

• If symptoms persist then referral should occur.

• Mammography is often used in older patients; however, for younger ones with denser breasts, ultrasound is usually better.

• Treatment is with analgesia and a good, well-fitting bra.

For other possible treatments, see the separate Breast Pain article.

Palpable breast lumps

Many breast lumps are benign, especially in younger patients. Most benign lumps will be either cysts or fibroadenomas.

Broadly speaking, a benign mass is usually three-dimensional, mobile and smooth, has regular borders and is solid or cystic in consistency. A malignant mass is usually firm in consistency, has irregular borders and may be fixed to the underlying skin or soft tissue. There may also be skin changes or nipple retraction. However, current guidelines recognise that it is not always possible to make an accurate diagnosis on the basis of examination alone and therefore all unexplained lumps should be referred for assessment in a specialist breast clinic, with those in patients aged 30 or above being sent via the two-week wait suspected cancer pathway.^{3 9}

Breast cysts⁷

Cysts are most common between the ages of 35 and 50. They are palpable as discrete lumps and may be recurrent. They cannot be reliably distinguished from solid tumours on clinical examination. They often do not need aspiration, as they may settle spontaneously; however, guidelines advise all should be referred to a breast clinic for imaging.^{3 9}

Fibroadenomas^{7 10}

These are benign tumours that are common in young women, with incidence peaking at 20-24 years of age. They are the most common type of breast lesion. Fibroadenomas arise in breast lobules and are composed of fibrous and epithelial tissue. They present as firm, non-tender, highly mobile palpable lumps. Hormones seem to be involved in aetiology, and hormone replacement therapy (HRT) increases the incidence.

As with all unexplained lumps, referral should be made to a specialist breast clinic. Women are assessed by the triple assessment of examination, imaging (first-line choice is ultrasound before age 40, mammogram after) and needle biopsy (not necessarily required under the age of 25).⁹ They are often treated with surgical excision but this may not be necessary if they are small and the diagnosis is confirmed. Most stop growing at about 2 or 3 cm. Complex and multiple fibroadenomas are associated with an increase in the risk of breast cancer.

Juvenile fibroadenomas can occur in teenage girls.

Phyllodes tumour

This is a rare tumour that tends to occur in women aged between 40 and 50 years. It can be difficult to distinguish from a fibroadenoma. It may be benign, borderline or malignant. A benign tumour may reappear after excision and may become malignant.

Treatment is wide excision, including some normal breast tissue. Follow-up is needed, although practice varies on how this is done and there are no national guidelines.¹¹

Intraductal papilloma

This is a benign, warty lesion usually located just behind the areola.

• A small lump or a sticky, possibly blood-stained discharge may be noticed.

• Women aged in their 40s are more likely to have just one but younger women may have multiple lesions.

• Triple assessment is required in a specialist breast clinic, with examination, imaging and biopsy.

Atypical hyperplasia

This is a benign hyperplasia which can occur in the ducts or the lobes.

• Lobular carcinoma in situ may develop.

• Where there is atypical hyperplasia, there is approximately a 29% risk of breast cancer over 25 years.¹⁰

• Risk is increased where there is a positive family history of breast cancer.

• Follow-up is required where atypical hyperplasia has been detected.

Sclerosing adenosis

This is a benign condition of sclerosis within the lobules.

• It may cause a lump, pain or be found on routine assessment.

• It can be very difficult to distinguish from malignancy and biopsy is often advised.

• Once diagnosed, it does not need follow-up as it does not have malignant potential.

Fat necrosis

Fat necrosis is more likely to occur in larger, fatty breasts in overweight or obese women but can occur in any woman and even occasionally in men.

• It usually follows trauma.

• The lump is usually painless and the skin around it may look red, bruised or dimpled.

• Biopsy may be required; however, if the diagnosis is confirmed, no further management is indicated.

Duct ectasia and periductal mastitis

See the separate Mammary Duct Ectasia and Periductal Mastitis article.

Infection

Infection (mastitis) may be associated with lactation or, more rarely, occur at other times.

With lactation

See the separate Puerperal Mastitis article. Breast ducts become blocked with engorged milk, and bacteria enter from cracks in the nipple.

• There may be engorgement of the breast and axillary lymphadenopathy.

• Warm compresses and analgesia such as ibuprofen or paracetamol may give some relief.

• Encourage the woman to continue breast-feeding.

• A penicillinase-resistant antibiotic such as flucloxacillin is required where first-line measures have not succeeded.

• An abscess may develop in the peripheral part of the breast tissue.

• A localised abscess will require incision and drainage, followed by antibiotics.

• Swabs should be sent for culture.

Without lactation

Spontaneous peripheral abscesses in non-lactating women are often associated with diabetes and immune compromise. Smoking and nipple rings can predispose women to non-lactational mastitis.

• Non-lactational mastitis produces peri-areolar abscesses, usually resulting from obstruction with cellular debris and lipid-laden material. Bacteria enter from the skin and produce periductal inflammation and abscess formation.

• There is a chronic recurrent course with noncyclical mastalgia, nipple discharge or retraction, peri-areolar abscess, subareolar mass or cellulitis of the overlying skin.

NB: inflammatory breast cancer causes pain, redness and induration of the skin, usually affecting the dependent portion of the breast. Symptoms progress very rapidly and within a month the breast may have the peau d'orange appearance.

Anyone in whom presumed mastitis does not resolve completely and who has residual breast change needs referral to exclude inflammatory or other types of breast cancer.

Referral³

Refer people via the suspected cancer pathway referral (to be seen within two weeks) to a specialist breast clinic if they are:

• Aged ≥30 and have an unexplained breast lump with or without pain; or

• Aged ≥50 with any of the following symptoms in one nipple only:

  • Discharge

  • Retraction

  • Other changes of concern

Consider referral via the suspected cancer pathway referral (to be seen within two weeks) to a specialist breast clinic in people who:

• Have skin changes that suggest breast cancer; or

• Are aged ≥30 with an unexplained lump in the axilla.

Consider non-urgent referral in people aged <30 with an unexplained breast lump with or without pain.