NIPPLE DISCHARGE

Nipple discharge occurs when fluid inside the milk ducts is elicited by expression of the nipple or when it spontaneously flows from the nipple. Nipple secretions can be expressed in up to 85% of women and are generally the by products of ductal epithelial cells that are undergoing cellular turnover

The reported incidence in this population of patients is between 3% and 7.4%. Most of these patients will have a benign process, although 5%-20% of patients presenting with pathologic discharge will have a malignancy. Most patients with the complaint of nipple discharge do not actually have a pathologic condition. Differentiating between physiologic and pathologic nipple discharge is critical to identify patients in need of a diagnostic work-up and treatment plan.

Physiological Discharge:
Exogenous or endogenous hormones, medications, stress, direct stimulation, or endocrine abnormalities can cause physiologic nipple discharge. In cases where a hormonal influence is pathologic, as is the case with prolactinoma, the ductal system itself has no abnormality so the resultant discharge is classified as physiologic. Physiologic discharge is commonly bilateral, non-spontaneous, and involving multiple ducts because the cause is central, such as medications or hormones, versus an intraductal lesion. Physiologic discharge is often more viscous than pathologic discharge with coloration varying from milky to yellow, gray, brown, or dark green.

Pathologic nipple discharge:
It is caused by an abnormality of the duct epithelium. It is therefore commonly unilateral, spontaneous or at least easily expressible, and from a single duct. The fluid produced by the lesion collects in the dilated duct and is subsequently released when the plug is removed or the duct is compressed. Pathologic nipple discharge is usually serous, bloody or clear, and has a watery consistency. Patients presenting with pathologic discharge are very likely to have benign disease probably a proliferative lesion such as a papilloma or ductal hyperplasia.
4% to 14.3% of patients with pathologic nipple discharge are also found to have cancer.

Diagnostic Evaluation:
The characteristics of the fluid and history of presentation of the discharge are the most important clinical factors that determine the need for surgical removal of the duct. The laterality, spontaneity, number of ducts involved, colour, and consistency of the discharge should be recorded. Physical exam should include a breast exam, assessing
or palpable masses, lymphadenopathy, skin changes, and nipple inversion or lesions.
Investigations:
The role of investigations is to rule out or confirm the presence of cancer.
Occult Blood and Cytology:
Occult Blood or heam-positive discharge has been associated with an increased incidence of cancer. The ability to detect malignancy by cytological examination of nipple discharge ranges from 8% to 82%
Cytology examination is not recommended for pregnant patients due to the difficulty in differentiating normal from abnormal proliferative change

Mammography & Ultrasound:
It is recommended for patients in the appropriate age group if physiologic or indeterminate discharge is the presenting symptom.
In the face of normal mammography, many women with pathologic nipple discharge will go on to have ultrasound evaluation of the effected breast in an attempt to localise the lesion causing the discharge. If an identified peripheral lesion can be visualised by ultrasound, needle localisation or ultrasound-guided fine needle aspiration fine needle aspiration may be performed.

MR galactography:
It can identify abnormalities in patients with pathologic nipple discharge when other localising studies have failed. It is a non-invasive alternative to patients with pathologic nipple discharge and may provide information in suspected cancer cases where breast conservation will be attempted.

Management:
If cancer is identified then it will be treated as for cancer.
Multiple duct involvement:
If the discharge is minimal all that is needed is reassurance. However if the patient is troubled by copious discharge or if they are found to have proliferative lesions like papillomatosis then operation to eliminate discharge can be offered. Because the discharge is frequently bilateral and involving multiple ducts, major duct excisions are usually the only surgical option. The procedure is called subareolar excision. The patient should be informed that breast tenderness or nodularity that may accompany the discharge is likely to remain after the procedure. Surgery could also result in decreased nipple sensation and the inability to breast feed, particularly if bilateral excisions are required.
Single duct Involvement:
Microdochectomy has been described as a technique that allows the removal of only the abnormal duct with preservation of surrounding normal breast tissue. The technique involves identifying and cannulating the discharging duct preoperatively by ductography. Blue dye is then injected into the abnormal ductal system through the cannula placed during the preoperative ductogram.

Follow Up:
Patients with physiologic nipple discharge should be educated regarding the findings of pathologic nipple discharge and encouraged to return if such symptoms occur.

Pathologic nipple discharge is almost always associated with a proliferative lesion that should be surgically removed to prove absence of malignancy. Even if atypia or cancer is not found at the time of duct excision, these patients are at higher risk for developing a future cancer than other asymptomatic patients. Close follow-up is essential for patients with nipple discharge in whom no proliferative abnormality is found at duct excision, and also for patients found to have peripheral papillomas.

Click here to see nipple discharge referral guidelines

Click here to see management of nipple discharge

If you require further advice or information please contact the
Macmillan Breast Care Nurses, Hazel Ricard and Hilary Rickwood on 020 8565 5885