Nipple discharge is a common breast complaint. A majority of nipple discharge is benign

In favor of benign: bilateral, multiductal, occurs with breast manipulation

Concerning: spontaneous, bloody, unilateral, uniductal, associated with a mass, >40yo

Physiologic:

straw colored, green, brown

galactorrhea (milk)- can be normal up to 6 months after breast feeding

Pathologic:

Bloody- papilloma (52-57%), this is from ductal lining

Ductal ectasia (14-32%)

Malignancy (typically DCIS)