Bloody Nipple Discharge: Causes, Diagnosis & Treatment

Question
Hello. I am 26 years old, and a few days ago I noticed a VERY DARK almost black looking discharge from one nipple, and from only one hole in the nipple. After touching the discharge and looking at it better, I realized that it was blood. What is this????

Answer
That should be examined with: 1. Exfoliative cytology of your discharge, 2. Mammography & galactography (mammography with an x-ray contrast fluid injected into the milk duct from which your discharge comes) of the discharging breast (and mammography of the other breast too). 3. Ultrasound and MRI breast scans of both your breasts. 4. Needle biopsies of any unclear breast lesions seen. With this a diagnosis on which further decisions can be made should be possible. It does not necessarily mean anything dangerous but it can be so any such condition must be checked for.