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.
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
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
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
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
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.
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.
Lois F. O'Grady, MD, et al., A Practical Approach to Breast Disease, Boston: Little, Brown and Company, 1995, pp. 131-139.