A 45 year old woman presents with unilateral bloodstained nipple discharge. On examination, there is no palpable breast lump and no axillary or supraclavicular lymphadenopathy.

What you should cover

History

Discharge colour-Although discharge colour is a not an accurate diagnostic tool, bloodstained discharge is always abnormal and one should have a high index of suspicion for a serious underlying pathology.¹ Galactorrhoea, the inappropriate secretion of breast milk in men or women who aren't breast feeding, is likely to be endocrine in origin.

Unilateral or bilateral-Discharge from both breasts usually indicates a systemic cause; either physiological (such as lactational), endocrine (such as prolactinoma, hypothyroidism) or iatrogenic (such as medications). Unilateral discharge indicates a local cause, such as a ductal papilloma, breast cyst, or ductal carcinoma.

Associated symptoms-Nipple discharge can occur as an isolated complaint or as part of a constellation of local or systemic symptoms. Discharge associated with a palpable breast lump or new-onset nipple inversion should alert the clinician to suspect breast malignancy. An abscess causing nipple discharge may show local or systemic signs of infection. If the discharge is secondary to hypothyroidism, they may exhibit other features of this condition, such as weight gain or cold intolerance.

Medications-Commonly prescribed medications that can cause galactorrhoea include antipsychotics, antidepressants, oral contraceptives, antiemetics such as metoclopromide, and opioids.²

Other patient factors-The age of the patient can guide the clinician to likely causes. Among premenopausal women and girls, discharge is more commonly physiological, lactational, medication related, or secondary to a ductal papilloma.² Lactation can also continue for up to six months after childbirth or cessation of breast feeding and will resolve spontaneously. Perimenopausal and postmenopausal discharge is more likely due to a papilloma, duct ectasia, or breast cancer.² If the patient is male, the discharge is abnormal.

These features of a patient's history cannot confidently exclude cancer; rather they allow the clinician to make an assessment of the likelihood that the discharge is secondary to an underlying malignancy.

Examination

Inspection

Ask the patient to raise her arms above her head to accentuate skin tethering or asymmetry of the breasts suggesting an underlying breast cancer. Check for peau d'orange (skin oedema, giving rise to an "orange peel" appearance). Although erythematous skin usually indicates mastitis or a breast abscess, the rare diagnosis of inflammatory breast cancer should be considered, especially if there are no other signs of sepsis.

The bottom line

• If a patient is over 50 years old with discharge, retraction, or other changes of concern affecting one nipple only, refer urgently to a breast clinic for review within two weeks

• Beware of inflammatory breast cancer or Paget's disease of the breast, which may be confused with mastitis, breast abscess, or unilateral eczema

Look for skin pathologies causing weeping of the skin that may be mistaken for nipple discharge, such as atopic eczema or contact dermatitis from detergents. Cellulitis, candidal infections, and mastitis can also produce weeping of the skin.³Always consider Paget's disease of the breast; an intraductal carcinoma presenting as unilateral eczema that invariably starts at the nipple and spreads outwards.

Palpation

Perform a breast examination including all four quadrants of the breast and the axillary tail, as well as the axillae and supraclavicular regions to identify any masses or lymphadenopathy. Pay special attention to the central breast below the nipple to identify a cause for the discharge. Palpate around the areola circumferentially to see if the discharge can be expressed.

Red flags based on NICE guidelines for suspected cancer⁴

• Refer for an appointment within two weeks if any of the following features apply:

  -Age ≥50 with unilateral nipple discharge, retraction or other changes of concern (such as localised tethering or new asymmetry of the breasts)

  -Age ≥30 with an unexplained breast lump

  
  

• Consider referral for an appointment within two weeks if any of these apply:

  -Skin changes that suggest breast cancer (such as peau d'orange or unilateral nipple eczema unresponsive to topical treatment)

  -Age ≥30 with an unexplained axillary lump.

What you should do

The history and examination will identify if any of the above red flags are present. The presence of any red flag symptom warrants urgent referral to a breast clinic for review within two weeks. If an endocrine cause (such as prolactinoma or hypothyroidism) is possible, check serum prolactin and thyroid stimulating hormone levels. Patients less than 50 years old and without red flag features, troublesome symptoms, or endocrine causes can be managed, at least initially, in primary care by offering periodic review and advising the patient to return if red flag symptoms occur.⁵

This is part of a series of occasional articles on common problems in primary care. The BMJ welcomes contributions from GPs.

Contributors: PLZL and NG were responsible for article concept, design, drafting, and revision. DH was responsible for design, drafting, and revision. PLZL and NG are accountable for ensuring that questions related to the accuracy or integrity of the work are appropriately investigated and resolved, and are guarantors for the article's content.

Competing interests: We have read and understood BMJ policy on declaration of interests and have no relevant interests to declare.

Provenance and peer review: Not commissioned; not externally peer reviewed.

How to advise patients

Nipple discharge is common, and most women can express a few drops of fluid. Many conditions and medications can cause nipple discharge, and in most women the cause will be benign. It is unusual for discharge to be the first symptom of breast cancer. However, even though breast cancer is unlikely, it is important that we refer you to the breast clinic to ask a specialist for their opinion if:

• You are over 50 years old and the discharge comes from one nipple

• You also have a breast lump, one nipple that is inverted, changes to the skin of your breast, a lump in your armpit, or other changes of concern.

For more information, see www.nhs.uk/conditions/nipple-discharge/Pages/Introduction.aspx