Nipple discharge and cancer
Nipple discharge refers to the secretion from one or both breasts, which can be spontaneous or occur when the nipple is manually stimulated. The discharge can vary in color, including clear, milky, brown, green, yellow, pink, or bloody. While nipple discharge is common and often benign, certain characteristics may raise concerns for underlying malignancies, particularly when the discharge is unilateral, occurs in older women, or is associated with a mass or blood.
Galactorrhea, a milky discharge typically caused by high prolactin levels, is the most prevalent type of nipple discharge and can be triggered by specific medications. Although many women experience some form of discharge, it is rarely indicative of breast cancer, with only 1 to 5 percent of cancer diagnoses involving this symptom. Diagnostic approaches may include clinical breast exams, mammography, and other imaging techniques to assess the discharge further. Treatment often involves cessation of stimulation to the breast, adjustment of medications when necessary, and evaluation of any suspicious discharge. Understanding the underlying causes of nipple discharge can help in determining its significance and appropriate management.
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Subject Terms
Nipple discharge and cancer
ALSO KNOWN AS: Breast discharge
RELATED CONDITIONS: Galactorrhea, mastitis, papilloma, Paget's disease of the breast, intraductal breast carcinoma
DEFINITION: Nipple discharge refers to secretions from one (unilateral) or both (bilateral) breasts. Discharge can be spontaneous or appear only when expressed through squeezing and “milking” the nipple, and it can be occasional or constant. It can be clear, milky, brown, green, yellow, pink, or deeply bloody.
Risk factors: Nipple discharge is more likely to be the result of underlying malignancy when it is a unilateral discharge, occurs in a woman past reproductive age, is associated with a mass, or contains blood. Older women with nipple discharge are much more likely to have a malignancy than younger women.
Etiology and the disease process: High levels of the hormone prolactin can cause galactorrhea, which is a milky discharge. Galactorrhea is the most common nipple discharge. Medications that commonly cause galactorrhea include psychotropics, oral contraceptives, and antiemetics.
Incidence: Nipple discharge is very common and usually benign. As many as two-thirds of women are able to express fluid with manual manipulation. Though more common in women, men may occasionally exhibit nipple discharge. Though common, discharge is rarely an indication of breast cancer.
Symptoms: Discharge may be spontaneous or occur only with manual expression or “milking” of the nipple. It may be a few drops of fluid or a continual leakage.
Screening and diagnosis: A clinical breast exam includes taking a history of breast nipple discharge and examining the nipples with gentle squeezing to see if fluid is expressed. Milky fluid in breastfeeding women is of no concern as long as the woman does not have symptoms of infection (breast is painful to the touch, redness is present, milk has a foul odor or has changed color). Many women continue to express milk long after they stop breastfeeding. Other testing includes a cytologic discharge examination, mammography, breast ultrasound, and ductoscopy. A computed tomography scan may be ordered to investigate the possible presence of a pituitary tumor, and a blood test can rule out hypothyroidism and hyperprolactinemia. A benign tumor centrally located in the milk duct called an intraductal papilloma often causes nipple discharge, but these are not cancerous.
Treatment and therapy: Often, discharge will resolve if all stimulation of the breast is ceased. This means the woman must avoid the urge to check to see if the discharge is still occurring. Sometimes, drugs that cause increased prolactin need to be adjusted, and any nipple discharge that is suspicious in terms of malignancy must be evaluated. Nipple discharge can also be a symptom of disorders in other hormone-producing glands, and those conditions may need treatment.
Prognosis, prevention, and outcomes: Prognosis and outcomes depend on the type of discharge. Prevention can often be managed by decreasing medications that increase prolactin and avoiding a cycle of stimulation of the nipple. Only between 1 and 5 percent of cancer diagnoses include the presence of discharge.
Bibliography
Mazza, Danielle. Women's Health in General Practice. 2nd ed. Elsevier Australia, 2011.
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Onstad, Michaela, and Ashley Stuckey. "Benign Breast Disorders." Breast Disorders. Spec. issue of Obstetrics and Gynecology Clinics of North America, vol. 40, no. 3, 2013, pp. 459–74.
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