In order of decreasing frequency, the following are the most common causes of nipple discharge in the nonlactating breast duct ectasia, intraductal papilloma, and carcinoma. The important characteristics of the discharge and some other factors to be evaluated by history and physical examination are listed in Table.
Spontaneous, unilateral, serous or serosanguineous, discharge from a single duct is usually caused by an intraductal papilloma or, rarely, by intraductal cancer. A mass may not be palpable. The involved duct may be identified by pressure at different sites around the nipple at the margin of the areola. Bloody discharge is suggestive of cancer but is more often caused by a benign papilloma in the duct. The cytologic examination may identify malignant cells, but negative findings do not rule out cancer, which is more likely in women over age 50 years. In any case, the involved bloody duct and a Mass. if present should be excised. A Ductogram (a mammogram of a duct after a radiopaque dye has been injected) is of limited value since the excision of the suspicious ductal system is indicated regardless of findings. Ductscopy, evaluation of the ductal system with a small scope inserted through the nipple, has been attempted but is not effective management.
In premenopausal women, spontaneous multiple duct discharge, unilateral or bilateral, most noticeable j List before menstruation, is often due to fibrocystic condition. The discharge may be green or brownish. Papillolnatosis and ducta] ectasia are usually detected only by biopsy. 1f a mass is present, it should be removed. A milky discharge from multiple ducts in the nonlactating breast may occur from hyperprolactinemia. Serilm prolactin levels should be obtained to search for a pituitary tumor. Thyroid-stimulating hormone (TSH) helps exclude causative hypothyroidism. Numerous antipsychotic drugs and other drugs may also cause a milky discharge that ceases on discontinuance of the medication.
Oral contraceptive agents or estrogen replacement therapy may cause clear, serous, or milky discharge from a single duct, but multiple duct discharge is more common. In the premenopausal woman, the discharge is more evident just before menstruation and disappears on stopping the medication. If it does not stop, it is from a single duct and is copious exploration should be performed since this may be a sign of cancer.
A purulent discharge may originate in a subareolar abscess and require removal of the abscess and the related lactiferous sinus.
When localization is not possible, no mass is palpable, and the discharge is Nonbloody, the patient should be reexamined every 3 or 4 months for a year, and a mammogram and an ultrasound should be performed. Although most discharge is from a benign process, patients may find it annoying or disconcerting. To eliminate the discharge, Proximal duct excision can be performed both for treatment and diagnosis.