Nipple discharge

• Physiologic

• Discharge only with compression
• Multiple duct involvement
• Bilateral
• Fluid may be clear, yellow, white or dark green

• Pathologic

• Spontaneous discharge
• Bloody
• Unilateral
• Associated with a mass

• Physiologic/Endocrinologic Discharge

• Lactation

• Milk produced in presence of postpartum exocrin, parathyrin, thyroxine, cortisol, growth hormone and placental lactogen
• Milk secreted via stimulation of lobular and ductal epithelium by PRL
• Milk ejected via stimulation of muscular walls of lactiferous ducts by oxytocin
• Oxytocin and PRL secreted by pituitary in response to nipple stimulation

• Galactorrhea:

• Milk secretion unrelated to pregnancy/lactation
• Usually due to hyperprolactin state, though can be idiopathic with normal prolactin (PRL)
• Can occur via:

1. Chronic breast stimulation (nipple manipulation, rubbing on bra)
2. Oral Contraceptive Pills (OCPs) – E can stimulate PRL secretion
3. Drugs that inhibit dopamine (loss of tonic inhibition of PRL)
4. Hypothalamic/pituitary disease interfering with DA release
5. Prolactinoma
6. Hypothyroidism
7. Chronic renal failure
8. Chest wall injury – healing wound stimulates PRL release

• Pathologic Discharge

• Intraductal papilloma: monotonous proliferation of papillary cells growing into the lumen

• Fluid typically straw-colored, transparent, sticky

• Duct ectasia: distention of subareolar ducts
• Fibrocystic disease: associated irritation within the duct
• Papillomatosis: formation of multiple papillomas

• Associated with small increase in breast cancer risk

• Intraductal hyperplasia: increased number of epithelial cells lining the ducts

• Cells appear benign but associated with small increase in breast cancer risk

• Breast cancer: risk much increased if mass associated with abnormal discharge