Nipple discharge

Nipple discharge in non-lactating women can be classified as either galactorrhea or non-milky nipple discharge. Galactorrhea is usually caused by hyperprolactinemia and is associated with endocrine disorders or medication. Most of the causes of non-milky nipple discharge are benign, with less than 15% of cases related to cancer. The diagnostic approach is based on patient history and the characteristics of the discharge. Spontaneous, unilateral, and/or bloody nipple discharge, especially in women older than 40 years, should raise suspicion of malignancy. Treatment depends on the underlying disorder.

Physiological nipple discharge

• Definition: bilateral nipple discharge, typically milky
• Etiology
  • Lactation
  • Galactorrhea: milk production in non-breastfeeding women or men ; ^[1]
    • Discharge varies in color (clear, white, yellowish, or greenish)
    • Endocrine causes include hyperprolactinemia and primary hypothyroidism
    • Discharge may also be only unilateral
  • Chronic nipple stimulation; (e.g., piercings; , tight clothing, etc.)

Pathological nipple discharge

• Definition: unilateral, non-milky nipple discharge
• Etiology
  • Benign causes: intraductal papilloma (52–57% of cases); , mammary duct ectasia; , fibrocystic changes, breast abscess
  • Malignancy; : 5–15% of cases (mostly ductal carcinoma in situ)

Patient history and clinical breast examination

• Features that should raise concern for malignancy
  • Discharge that is unilateral, uniductal, persistent, spontaneous, and/or bloody or serosanguineous
  • Presence of a breast mass
  • Presence of risk factors for breast cancer (e.g., advanced age, positive family history)

Further diagnostics

Biopsy is mandatory if malignancy is suspected.

• Galactorrhea
  • See “Therapy” in hyperprolactinemia.
  • In the case of normoprolactinemic galactorrhea: reassurance and avoidance of nipple stimulation
• Non-milky nipple discharge: : Treatment depends on the underlying disorder and can be found under respective causes (e.g., terminal ductal excision in the case of intraductal papilloma).