A discharge from the nipple of a nonlactating breast is often the first indication to the patient of a lesion of the breast. It is frequently the cause of consultation with the physician. Palpation of the breast may reveal a tumor which may or may not be the source of the discharge or may not reveal any changes at all. In the former instance, the correct interpretation of the significance of the discharge may be a deciding factor in the differential diagnosis, while in the latter it may be an aid in reaching an opinion as to the character of the lesion.
A review of the literature indicates that the significance of a serohemorrhagic or hemorrhagic discharge from the nipple has been a matter of dispute among clinicians for some time. A thin serous or bloodstained discharge is regarded by many as indicative of an intracanalicular papilloma; a frank bloody
MILLER EM, LEWIS D. THE SIGNIFICANCE OF A SEROHEMORRHAGIC OR HEMORRHAGIC DISCHARGE FROM THE NIPPLE. JAMA. 1923;81(20):1651-1657. doi:10.1001/jama.1923.02650200001001