Nipple Discharge

Differential Diagnosis

Common Diagnoses

  • Pregnancy
  • Duct Papilloma
  • Duct Ectasia
  • Acute Mastitis/Breast Abscess
  • Areolar Abscess (Infected Gland of Montgomery)

Occasional Diagnoses

  • Oral Contraceptives
  • Intraduct Carcinoma
  • Neonatal and Peripubertal Galactorrhoea (Also Post-Lactation)
  • Hyperprolactinaemia (Drugs, Prolactinoma, Hypothyroidism)
  • Duct Epithelial Proliferation
  • Galactocoele

Rare Diagnoses

  • Periductal (Plasma Cell) Mastitis
  • Mechanical Stimulation
  • Invasive Carcinoma
  • Tuberculous Abscess
  • Mamillary Duct Fistula
  • Paget’s Disease of Nipple
  • Comedo Mastitis

Ready Reckoner

Key distinguishing features of the most common diagnoses

Pregnancy PapillomaEctasiaMastitisAreolar Abscess
Hot Tender SegmentNoNoNoYesYes

Possible Investigations

Likely:None (referral for specialist assessment in suspicious cases)

Possible: Pregnancy test, prolactin level, TFT

Small Print:Swab of purulent discharge.

  • Pregnancy test if pregnancy suspected
  • Swab purulent discharge: May help guide antibiotic therapy
  • Prolactin level and TFT: To check for hyperprolactinaemia or hypothyroidism in galactorrhoea.
  • Excision biopsy will be performed if a suspicious lump is palpable. In cases of doubt, mammography may help; surgical exploration may also be undertaken if pressure on an area of one breast consistently elicits discharge.

Top Tips

  • Women presenting with breast discharge are likely to be afraid there may be an underlying cancer. To ‘reassure’ properly, make sure you address this anxiety.
  • If the discharge is bilateral, then serious breast disease is highly unlikely.
  • In a woman of child-bearing age with bilateral serous discharge, enquire specifically about pregnancy – this possibility may be deliberately concealed or genuinely overlooked by the patient.
  • If a pre-menopausal woman is amenorrhoeic with bilateral discharge and pregnancy has been excluded, remember the possibility of hyperprolactinaemia.

Red Flags

  • Refer urgently any patient aged 50 or more with a unilateral discharge, retraction or other nipple symptoms of concern.
  • If a lump is palpable, or pressure on a certain area of the breast consistently produces the discharge, refer for probable excision biopsy.
  • Bright red blood from one nipple is usually caused by duct papilloma or ectasia – but can be caused by carcinoma and therefore requires prompt referral.
  • Nipple discharge in a male is always abnormal, except occasionally in pubertal boys. Investigate or refer as appropriate

Published: 2nd August 2022 Updated: 10th April 2024

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