Nipple discharge is the third most common breast complaint
for which women seek medical attention, after lumps and breast pain.
A woman's breasts have some degree of fluid secretion
activity throughout most of the adult life. The difference between lactating (milk producing) and non-lactating breasts is
mainly in the degree or amount of secretion and to a smaller degree in the chemical composition of the fluid. In non-lactating
women, small plugs of tissue block the nipple ducts and keep the nipple from discharging fluid.
During breast exam, fluid may be expressed from the
breasts of 50% to 60% of Caucasian and African-American women and 40% of Asian-American women.
The majority of nipple discharges are associated with
non-malignant changes in the breast such as hormonal imbalances. However, any woman with a suspicious or worrisome nipple
discharge (see below) should consult her physician.
Nipple
Discharge is of Concern if it is:
1. bloody or watery (serous) with
a red, pink, or brown color
2. sticky and clear in color or
brown to black in color (opalescent)
3. appears spontaneously without
squeezing the nipple
4. persistent
5. on one side only (unilateral)
6. a fluid other than breast milk
Causes of Nipple Discharge
Milky discharge (cloudy, whitish or almost clear in
color, thin, non-sticky) is the most common type of discharge. Most milky discharge is caused by lactation or increased mechanical
stimulation of the nipple due to fondling, suckling or irritation from clothing during exercise or activity. Drugs or hormones
that stimulate prolactin secretion can cause spontaneous, persistent production of milk (galactorrhea). Prolactin is the hormone
produced by the pituitary gland that starts the growth of the mammary glands and triggers production of milk. Some pituitary
tumors cause excess prolactin secretion that can lead to milky nipple discharge, usually from both breasts (bilateral). Opalescent
discharge that is yellow or green in color is normal.
Most bloody or watery (serous) nipple discharge (approximately
90%) is due to a benign condition such as papilloma or infection. A papilloma is
a non-cancerous, wart-like tumor with a branching or stalk that has grown inside the breast duct. Papillomas frequently involve
the large milk ducts near the nipple. Multiple papillomas may also be found in the small breast ducts further from the nipple.
Of the benign conditions that cause suspicious nipple
discharge, approximately half is due to papilloma and the other half is a mixture of benign conditions such as fibrocystic
conditions or duct ectasia (widening and hardening of the duct due to age or damage). Most opalescent discharge is due to
duct ectasia or cyst.
Suspicious nipple discharge is due to a malignant (cancerous)
lesion just ten percent (10%) of the time. Discharge caused by a malignant condition is almost always on one side only (unilateral).
Discharge that is coming from both breasts (bilateral) is usually benign. Papilloma usually causes discharge from a single
breast duct.
Nipple Discharge in Men
Both male and female adolescents may experience a milky
discharge during puberty. Nipple discharge in the adult male is more often associated with a malignant condition than in the
female. Mammography should be performed and biopsy should be performed if a mass or mammographic abnormality is found.
Bloody Discharge During Pregnancy
Bloody discharge during pregnancy/lactation is fairly
common and usually not related to papilloma. During pregnancy and lactation, breast tissue grows rapidly and this can lead
to duct irritation that causes bloody nipple discharge. This discharge should not interfere with nursing. If the discharge
persists after lactation has stopped, it should be evaluated further.
Examination for Nipple Discharge
A blood test of prolactin levels is often made to determine
hormonal causes of excessive milky discharge (galactorrhea). A hormone imbalance, pituitary tumor, and certain drugs such
as sedatives, tranquilizers, hormone replacement or birth control pills may cause excessive prolactin levels.
If there is a suspicious nipple discharge (see above criteria),
an examination by a physician should be performed. Clinical
breast exam (CBE) is first performed. If a discharge can be produced during
the examination, some of the fluid may be collected and examined under a microscope to see if any blood cells or cancer cells
are present. This test is called a nipple smear. The discharge may also be examined for signs of infection such as pus. Papillomas
may be seen with microscopic examination of a nipple discharge, but this test may be inconclusive.
If the discharge is bloody or serous, a mammogram is
often the first test to be performed. Even when no cancer cells are found in a nipple discharge, it is not possible to rule
out breast cancer or other condition such as papilloma.
If a patient has a suspicious mass together with nipple
discharge, evaluation of the mass should be performed using mammography, adjunctive imaging and biopsy as necessary. If these
tests are negative and show no malignancy, nipple smear should be evaluated.
Some papillomas are near the nipple and are large enough
to be felt. In these cases, a needle biopsy can be done to test for malignancy or diagnose papilloma.
In some cases, a galactogram (also called a ductogram) is performed to aid in diagnosing the
cause of an abnormal nipple discharge such as intraductal papilloma. However, a ductogram that does not show an abnormality
does not exclude the fact that a significant lesion may be present.
Treatment for Persistent Nipple
Discharge
The standard treatment for nipple discharge that has
no hormonal involvement is duct excision. Duct excision is usually performed on an outpatient basis with local anesthesia.
The procedure is usually done through a small circular incision near the areolar border around the nipple. It is not uncommon
for the pathology found to be so microscopic that it is invisible without the assistance of a microscope. Typically, nursing
ability and nipple sensation are notpreserved after duct excision. Breast-feeding in the other breast should have no affect
from the duct excision in the opposite breast.
There is usually not a significant change in breast
size/shape after duct excision since only a small amount of tissue is removed. There is no evidence of increased future risk
of breast cancer from the procedure. Some suggest that there may be a slight increase in risk of breast cancer for patients
with a papilloma, but this possibly higher risk has nothing to do with the treatment chosen.
Conclusion:
The above information and statistics are general guidelines.
If you have nipple discharge that is worrisome, please do not hesitate to contact your physician or healthcare provider about
it. However, keep in mind that most nipple discharge is not caused by breast cancer.
References:
Lois F. O'Grady, MD, et al., A Practical
Approach to Breast Disease, Boston: Little, Brown and Company, 1995, pp. 131-139.
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