Spontaneous unilateral serous or serosanguineous discharge from a single duct can be due to which conditions?

• A. Ectatic duct
• B. Intraductal papilloma
• C. Intraductal cancer
• D. All of the above

Answer: (D)

Spontaneous leakage from a single duct points to a localized intraductal process rather than a diffuse breast change. A duct that is dilated and inflamed (duct ectasia) can spill serous fluid through the opening. A papillomatous lesion inside a duct (intrEaductal papilloma) often causes unilateral discharge that can be serous or blood-tinged. Malignant processes confined to the duct, such as intraductal cancer (DCIS), can also present with spontaneous serous or serosanguineous discharge from a single duct. Because each of these distinct intraductal conditions can produce this same clinical finding, the differential includes all of the above. This presentation rightly prompts imaging and, if indicated, ductal biopsy or excision to determine the exact cause.