Pathologic nipple discharge is either (1) bloody or (2) spontaneous, unilateral, and originates from a single duct. Normal physiologic discharge is usually nonbloody, from multiple ducts, can be a variety of colors (clear to yellow to green), and requires breast manipulation to produce.
- Pathologic discharge is serous, serosanguineous, bloody, or watery. The presence of blood can be confirmed with a guaiac test.
- Cytologic evaluation of the discharge is not generally useful.
- Malignancy is the underlying cause in 10% of patients.
- If physical examination and mammography are negative for an associated mass, the most likely etiologies are benign intraductal papilloma, duct ectasia, or fibrocystic changes. In lactating women, serosanguinous or bloody discharge can be associated with duct trauma, infection, or epithelial proliferation associated with breast enlargement.
- A solitary papilloma with a fibrovascular core places the patient at marginally increased risk for the development of breast cancer. Patients with persistent spontaneous discharge from a single duct require a surgical microdochectomy, ductoscopy, or major duct excision.
- Microdochectomy: Excision of the involved duct and associated lobule. Immediately before surgery, the involved duct is cannulated, and radiopaque contrast is injected to obtain a ductogram, which identifies lesions as filling defects. The patient is then taken to the operating room, and the pathologic duct is identified and excised, along with the associated lobule.
- Ductoscopy utilizes a 1-mm rigid videoscope to perform an internal exploration of the major ducts of the breast. Once a ductal lesion is identified, this single associated duct with the lesion is excised.
- Major duct excision may be used for women with bloody nipple discharge from multiple ducts or in postmenopausal women with bloody nipple discharge. It is performed through a circumareolar incision, and all of the retroareolar ducts are transected and excised, along with a cone of tissue extending up to several centimeters posterior to the nipple