Breast Nipple Discharge
Objectives: Upon completion of this course the participant will be able to demonstrate a knowledge of nipple discharges, the causes, diagnostic techniques and treatments available.
Background: Nipple discharge is a symptomatic problem that causes many women both discomfort and anxiety. Tremendous advances have been made in the management of breast problems, mainly through advances in diagnostic breast imaging.
Pathophysiology: The causes of nipple discharge are not well understood. However, nipple discharge is most commonly associated with endocrine alterations and/or medications. These often result in duct ectasia and/or fibrocystic changes in the breast. Changes are often bilateral and may lead to bilateral discharge from one or several nipple ducts.
An unusual cause of nonmalignant nipple discharge is duct ectasia with periductal galactophoritis, which is inflammation around dilated milk ducts. The most common cause of clinically significant discharge is intraductal growth of the ductal epithelium, due to hyperplasia, micropapillary proliferation, solitary papillomas, and/or ductal carcinoma (both in situ and invasive). Most of the intraductal changes that lead to nipple discharge are situated within 1-4 cm of the nipple.
Frequency:
- In the US: The frequency of nipple discharge is 1-3% in patients referred to breast clinics, but frequencies as high as 3-8% are reported.
Mortality/Morbidity:
- Most patients have surgically reversible, nonsignificant nipple discharge.
- In those in whom an occult malignancy is the cause, the mortality rate is the same as that in patients with other breast cancers. That is, patients have a good prognosis if latent breast cancer is detected early.
- With respect to morbidity, surgery may result in minor cosmetic defects.
Race: Nipple discharge occurs in people of all races.
Sex:
- Nipple discharge can occur in both males and females, although it occurs predominantly in females.
- When nipple discharge occurs in young males, it usually represents duct ectasia. The histologic features in these patients are similar to those of gynecomastia in mammary ducts, without associated endocrinologic abnormalities.
- Researchers have reported that the incidence of breast cancer is significantly higher in men with nipple discharge than in women with nipple discharge.
Age: Nipple discharge can occur in patients of all ages, from infants to adults.
- Non–clinically significant nipple discharge more commonly occurs in women using contraceptives or those undergoing hormone replacement therapy [HRT].
- Non–clinically significant nipple discharge also occurs in women who are taking medications that have estrogenlike effects on the breast epithelium.
Clinical Details: The most common types of nipple discharge are bilateral, emanate from several ducts in the same nipple, and vary in color from white to brown. To be clinically significant, nipple discharge must be true, spontaneous, persistent, and nonlactational. Surgically significant discharge is clear (ie, watery), serous (ie, clear yellow), serosanguineous, or sanguineous (ie, bloody).
The likelihood of malignancy increases when the discharge is unilateral and arises from a single duct, when it is accompanied by a palpable mass, when it is associated with a positive mammographic or galactographic finding and a positive cytologic result, or when the patient is older than 50 years.
Clinically significant nipple discharge is most commonly secondary to intraductal growths, ranging from hyperplasias to malignancies. Researchers have reported that when clinical, cytologic, and breast imaging findings show no evidence of malignancy, nipple discharge spontaneously resolves in as many as 73% of patients within 5 years.
Cytologic smears of secreted fluid obtained from women who are taking oral contraceptives can demonstrate dysplastic changes; however, the findings appear to be reversible when the medication is stopped or changed.
Preferred Examination: Mammography, although typically unrevealing, is the first examination that should be performed in a patient with clinically significant nipple discharge. (Annual screening mammography should be performed in all women who are 40 years or older.) Subsequent to negative mammographic findings, galactography or ductography is the procedure of choice. Galactography involves the retrograde injection of water-soluble radiopaque contrast material into a discharging duct with subsequent mammographic imaging.
Technique for galactography
The nipple is inspected to identify the orifice of secretion, and the direction and path of that duct is ascertained by gently pressing on the breast from different directions toward the nipple.
After the nipple is sterilized, a ductography cannula (ie, a needle with a blunt end) is gently inserted into the secreting orifice; both straight and right-angled cannulas are used.
Approximately 0.2-0.8 mL of water-soluble contrast material is slowly injected by using a 1- or 3-mL syringe. The injection is discontinued if the patient experiences pain or burning or if resistance is met.
Extravasation may occur due to the forceful contrast injection or the perforation of the wall as a result of vigorous cannula insertion. If extravasation occurs, it may cause focal burning/pain, or it can be asymptomatic. In such cases, the patient is treated with mild analgesics, and the procedure is performed in 1-3 weeks.
After the injection of contrast material, craniocaudal and lateral mammograms are obtained. Additional magnification, oblique, and rolled views are acquired as needed to visualize the ductal system.
Other tests
Hemoccult tests can be used to assess the nipple discharge fluid to confirm or exclude the presence of occult blood.
Cytologic tests of the fluid can be performed; however, false-positive rates and significant false-negative rates have been reported (2.6% and 17.8%, respectively, in Leis' series.)
Sonography is not typically used unless the nipple discharge is accompanied by a palpable mass or a positive mammographic finding. Sonography may be useful in presurgical localization if galactography reveals a dilated duct larger than a few millimeters in width. Modern high-resolution ultrasonographic techniques are becoming more sensitive for the visualization of intraductal changes. Tiny solitary papillomas can sometimes be visualized by using this sophisticated technology (see
Images 9-10).MRI may play an adjunctive role in aiding the differentiation of benign and malignant ductal abnormalities. However, a prospective study of MRI compared with galactography and sonography is necessary before its role is determined.
Fiber-ductoscopy is an experimental technique that may eventually play a role in the evaluation of nipple discharge. At this endoscopic examination, a thin, flexible, silica fiber-ductoscope is inserted into the duct through the secreting duct orifice at the surface of the nipple, and the intraluminal findings are viewed on a television monitor. The technique is still in its infancy, and its role in the evaluation of nipple discharge has yet to be determined.
Limitations of Techniques: Galactography is not indicated unless the nipple discharge is spontaneous, unilateral, and expressed from a single pore. If discharge cannot be expressed at the time of galactography, the affected duct cannot be identified or cannulated.
High-resolution ultrasonography is relatively new and expensive. This examination is not available at all breast-imaging centers. In addition, it is operator-dependent and requires expertise for the identification of small intraductal structures.
MRI and fiber-ductoscopy remain experimental techniques in the
evaluation of nipple discharge. Further studies are required before their
roles are determined.
Papillomas
Findings: Galactography involves the retrograde
injection of contrast medium into a discharging duct, with subsequent
mammographic imaging of the breast in at least 2 planes. The contrast
agent–filled ducts should decrease in width from the nipple inward. An
increase in duct diameter suggests duct ectasia.
A contrast-agent filling defect in an otherwise well-filled duct
suggests an intraductal growth. Solitary papillomas are usually seen as
single lobulated contrast-agent filling defects within a duct (see In instances in which the passage of radiographic contrast medium stops
abruptly, the ductal lumen is totally obstructed, and visualization of its
proximal portion is precluded. The obstruction could be due to a large
papilloma, though malignancy cannot be excluded. Ductal carcinoma in situ
is often apparent as irregular duct walls (see Images
1-2), in contrast to the smooth walls associated with normal ducts.
Hyperplasia also can appear as continuous irregular duct walls. A
ductogram that reveals irregular duct walls should always be investigated
further, because the differential diagnosis includes hyperplastic
micropapillary changes and malignancy.
Duct compression due to an extrinsic mass decreases the ductal
diameter, which takes on the shape of a cone or funnel.
Degree of Confidence: When radiographs show obvious
contrast-agent filling defects in the examined ducts that are not due to
artifact (eg, air bubbles), the findings always correspond with
intraductal growths at pathology. The degree of confidence for other
findings is more variable and corresponds to individual experience and the
technical quality and success of a ductographic examination.
The absence of convincing visible pathologic findings on a ductogram
does not exclude local pathophysiologic changes. Therefore, some
physicians advocate close interval follow up, however, others prefer
surgical ductal excision.
False Positives/Negatives: To the author's knowledge,
no large studies have been conducted to define the positive or negative
predictive values of galactography. In the author's experience, which
encompasses more than 2 decades with approximately 100 ductograms
performed annually, intraductal contrast-agent filling defects at
ductography have always corresponded with intraductal epithelial growths
at histopathology; therefore, ductography has no false-positive findings.
Most defects (98%) represent solitary intraductal papillomas or
papillomatosis. Fewer than 2% of pathologic findings on ductograms are
associated with intraductal malignancies at surgery. In the few patients
with biopsy-proven intraductal malignancies, galactography demonstrates
irregular ducts and never solitary contrast-agent filling defects.
In the published data as well as in the author's experience, a negative
galactographic finding does not exclude intraductal disease. In patients
with clear or sanguineous discharge and negative ductographic findings,
abnormalities may still be proven at surgery. In approximately 10% of
patients with these findings, histopathology demonstrates micropapillary
epithelial proliferations; the corresponding false-negative rate for
pathologic findings at galactography is 10%. In less than 1% of cases,
histopathology demonstrates atypical ductal hyperplasias or intraductal
malignancies; the corresponding false-negative rate for neoplastic changes
at galactography is <1%. Findings: Magnetic resonance (MR) galactography
remains under investigation and is not the method of choice in evaluating
nipple discharge.
Findings: Ultrasonography is an indispensable
complementary diagnostic tool in the investigation of breast
abnormalities. However, ultrasonography is not commonly indicated for the
evaluation of nipple discharge. Sonography is an adjunctive tool for
breast evaluation when more specific indications, including an abnormal
mammographic finding or a palpable clinical finding, are present. With
technologic advances in high-resolution ultrasonography, it may have a
role in breast ductal evaluation in the future.
Intervention: Spontaneous, unilateral nipple discharge
from a single ductal orifice warrants investigation if the secretion is
clear and watery or if it is serosanguineous and contains blood.
Medical/Legal Pitfalls:
Caption: Picture 2.
Nipple discharge evaluation. Close-up view of ductogram in Image 1.
Caption: Picture 4.
Nipple discharge evaluation. Close-up view of the ductogram in Image
3. Caption: Picture 6.
Nipple discharge evaluation. Close-up view of the ductogram in Image
5. Caption: Picture 8.
Nipple discharge evaluation. Close-up view of the ductogram in Image
7. Caption: Picture 10.
Nipple discharge evaluation. Additional sonogram obtained in the
same patient as in Image 9.
REFERENCES MEDCEU
Continuing Education Courses CEU for Nurses and Healthcare
Professional
Other Problems to be Considered:
Papillomatosis
Intraductal hyperplasias
Intraductal
malignancies
