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Nipple Discharge


Mary Ann Kosir

, MD, Wayne State University School of Medicine

Last full review/revision Sep 2020| Content last modified Sep 2020
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Nipple discharge is a common complaint in women who are not pregnant or breastfeeding, especially during the reproductive years. Nipple discharge is not necessarily abnormal, even among postmenopausal women, although it is always abnormal in men. Spontaneous unilateral nipple discharge, regardless of color, is considered abnormal.

Nipple discharge can be serous (yellow), mucinous (clear and watery), milky, sanguineous (bloody), purulent, multicolored and sticky, or serosanguineous (pink). It may occur spontaneously or only in response to breast manipulation.

Pathophysiology of Nipple Discharge

Nipple discharge may be breast milk or an exudate produced by a number of conditions.

Breast milk production in nonpregnant and nonlactating women (galactorrhea Galactorrhea Galactorrhea is lactation in any men or in women who are not breastfeeding. It is generally due to a prolactin-secreting pituitary adenoma. Diagnosis is by measurement of prolactin levels and... read more ) typically involves an elevated level of prolactin, which stimulates glandular tissue of the breast. However, only some patients with elevated prolactin levels develop galactorrhea.

Etiology of Nipple Discharge

Most frequently, nipple discharge has a benign cause (see table Some Causes of Nipple Discharge Some Causes of Nipple Discharge Nipple discharge is a common complaint in women who are not pregnant or breastfeeding, especially during the reproductive years. Nipple discharge is not necessarily abnormal, even among postmenopausal... read more Some Causes of Nipple Discharge ). Cancer (usually intraductal carcinoma or invasive ductal carcinoma) causes < 10% of cases. The rest result from benign ductal disorders (eg, intraductal papilloma, mammary duct ectasia, fibrocystic changes The term breast mass is preferred over lump for a palpably discrete area of any size. A breast mass may be discovered by patients incidentally or during breast self-examination or by the clinician... read more ), endocrine disorders (eg, pituitary tumor, hypothyroidism), liver disorders, breast abscesses or infections, or use of certain drugs. Of these causes, intraductal papilloma is probably the most common; it is also the most common cause of a bloody nipple discharge without a breast mass.

Endocrine causes involve elevation of prolactin levels, which has numerous causes.


Evaluation of Nipple Discharge


History of present illness should include the following:

Review of systems should seek symptoms suggesting possible causes, including the following:

Past medical history should include possible causes of hyperprolactinemia, including chronic renal failure, pregnancy, liver disorders, and thyroid disorders, as well as history of infertility, hypertension, depression, breastfeeding, menstrual patterns, and cancer. Clinicians should ask specifically about drugs that can cause prolactin release such as oral contraceptives, antihypertensive drugs (eg, methyldopa, reserpine, verapamil), H2-antagonists (eg, cimetidine, ranitidine), opioids, and dopamine D2 antagonists (eg, many psychoactive drugs, including phenothiazines and tricyclic antidepressants).

Physical examination

Physical examination focuses on the breasts. The breasts are inspected for symmetry, dimpling of the skin, erythema, swelling, color changes in the nipple and skin, and crusting, ulceration, or retraction of the nipple. The breasts are palpated for masses and evidence of lymphadenopathy in the axillary or supraclavicular region. If there is no spontaneous discharge, the area around the nipples is systematically palpated to try to stimulate a discharge and to identify any particular location associated with the discharge.

A bright light and magnifying lens can help assess whether the nipple discharge is uniductal or multiductal.

Red flags

Certain findings are of particular concern:

  • Spontaneous discharge

  • Age 40

  • Unilateral discharge

  • Bloody or guaiac-positive discharge

  • Palpable mass

  • Male sex

Interpretation of findings

Important differentiating points are

  • Whether a mass is present

  • Whether the discharge involves one or both breasts

  • Whether the discharge is bloody (including guaiac-positive)

If a mass is present, cancer must be considered. Because cancer rarely involves both breasts or multiple ducts at presentation, a bilateral, guaiac-negative discharge suggests an endocrine cause. However, if the discharge is guaiac-positive, even if bilateral, cancer must be considered.

Presence of any of the following requires follow-up with a surgeon who is experienced with breast disorders:

  • A breast mass

  • A bloody (or guaiac-positive) discharge

  • A spontaneous unilateral discharge

  • History of an abnormality on a mammogram or an ultrasound scan


If endocrine causes are suspected, the following are measured:

  • Prolactin level

  • Thyroid-stimulating hormone (TSH) level

If discharge is guaiac-positive, the following is done:

  • Cytology

If there is a palpable mass, evaluation as for breast mass is done, usually beginning with

  • Ultrasonography

Lesions that appear cystic are sometimes aspirated, and solid masses or any that remain after aspiration are evaluated with mammography followed by imaging-guided biopsy.

If there is no mass but cancer is otherwise suspected or if other tests are indeterminate, the following is done:

  • Mammography

Abnormal results are evaluated by biopsy-guided imaging. If mammography and ultrasonography do not identify a source and the discharge is spontaneous and comes from a single duct or breast, ductography (contrast-enhanced imaging of the milk duct) can be done.

Treatment of Nipple Discharge

Treatment of a nipple discharge is based on the cause.

If the cause is benign and the discharge is persistent and annoying, the terminal duct can be excised on an outpatient basis.

Key Points

  • Nipple discharge is most often benign.

  • Bilateral, multiductal, guaiac-negative discharge is usually benign and has an endocrine etiology.

  • Spontaneous, unilateral discharge requires diagnostic testing; this type of discharge may be cancer, particularly if it is bloody (or guaiac-positive).

  • Presence of a breast mass, a bloody (or guaiac-positive) discharge, or history of an abnormality on a mammogram or an ultrasound scan requires follow-up with a surgeon who is experienced with breast disorders.

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