What is the significance of a nipple discharge?
Nipple discharges that are non bloody, non palpable and not seen by either mammography or by ultrasound are uncommonly of significance unless they are a nuisance by messing up clothing. Most cancers that involve the nipple ducts are bloody, palpable and/or imaged via mammography or by ultrasound. The greenish and yellowish dischages are usually associated with retroareolar cysts or hyperplastic ducts and can usually be followed. Bloody discharges are almost always biopsied to rule out an underlying cancer or papilloma even if the palpable and imaging exams are otherwise normal. Milky discharges may proceed to a galactorrhea evaluation to rule out a prolactin secreting tumor. A crusting nipple with or without discharge may need to be evaluated and biopsied for Paget\’s disease. The definitive diagnosis of a suspicious discharge is made by a biopsy of the retroareolar ducts. Nipple discharge cytology may be of benefit in the early investigation but is never definitive.
