Which nipple discharge characteristics are concerning?

• A. Bilateral milky discharge only
• B. Clear, non-spontaneous discharge
• C. Uniductal, spontaneous, or bloody discharge
• D. Pus-like discharge

Answer: (C)

Unilateral, spontaneous discharge that is bloody is the most concerning pattern because it points to a localized ductal process such as an intraductal papilloma or even breast cancer; the spontaneous nature means it isn’t just a result of squeezing or manipulation, and the presence of blood adds a red flag for pathology inside the duct system. By contrast, bilateral milky discharge is usually physiologic or related to hyperprolactinemia, clear, non-spontaneous discharge is often benign and can occur with nipple stimulation or duct changes, and pus-like discharge suggests infection or inflammatory duct changes but does not carry the same specific alarm for a single-duct lesion. If this pattern is observed, it warrants clinical evaluation with history, physical exam, and appropriate imaging.