What imaging studies are recommended for evaluating blood nipple discharge?

Imaging Studies for Blood Nipple Discharge

For patients with bloody nipple discharge, diagnostic mammography with ultrasound is the recommended initial imaging approach, with age-specific considerations determining which modality to use first. 1

Age-Based Imaging Algorithm

Women ≥40 years or Men ≥25 years

• First-line imaging: Diagnostic mammography or digital breast tomosynthesis (DBT)
• Complementary imaging: Breast ultrasound
• Both modalities rated 9/9 (usually appropriate) by the American College of Radiology 1

Women 30-39 years

• Either diagnostic mammography/DBT or ultrasound can be used as initial examination (both rated 9/9)
• Choice between modalities based on institutional preference 1
• For men in this age group, mammography with complementary ultrasound is recommended

Women <30 years

• First-line imaging: Breast ultrasound (rated 9/9)
• Mammography/DBT only if:
  • Ultrasound shows suspicious findings
  • Patient has genetic predisposition to breast cancer (BRCA+)
  • Mammography rated 5/9 (may be appropriate) in this age group 1, 2

Imaging Characteristics and Performance

Mammography

• Sensitivity for detecting malignancy: 15-68%
• Specificity: 38-98% 1
• Limitations:
  • May miss small lesions
  • May miss lesions without calcifications
  • May miss completely intraductal lesions 1
• Additional views with spot compression and magnification may be needed to better evaluate the subareolar region 1

Ultrasound

• Advantages:
  • Better visualization of retroareolar region
  • Can detect intraductal abnormalities not visible on mammography
  • Particularly effective for papillomatous lesions 3
  • Non-invasive and does not require contrast
• Special techniques to improve visualization:
  • Peripheral compression
  • Two-handed compression
  • Rolled nipple technique
  • Use of standoff pad or abundant warm gel 2
• Can visualize echogenic intraductal tumors in 69% of cases with nipple discharge 3

When Initial Imaging is Negative

If mammography and ultrasound are negative but clinical suspicion remains high:

1. MRI breast with contrast:

   • Can detect underlying causes in 19-96% of cases when conventional imaging is negative 2
   • High negative predictive value (87-98.2%) for excluding malignancy 4
   • Excellent for visualizing dilated ducts and their contents
   • Can identify lesions >3cm beyond the nipple 2

2. Ductography (Galactography):

   • Alternative to MRI
   • Involves retrograde filling of milk duct with contrast material
   • Better than ultrasound for visualizing the duct system and detecting calcification 5
   • Can guide preoperative wire localization if a suspicious lesion is identified 2

Important Clinical Considerations

• Bloody discharge requires thorough evaluation regardless of age due to 5-21% risk of underlying malignancy 1
• Male patients with nipple discharge have a high incidence (23-57%) of breast cancer and require rigorous evaluation 1
• Pathologic discharge is typically:
  • Spontaneous
  • Unilateral
  • From a single duct
  • Clear, serous, serosanguineous, or bloody 2

Common Pitfalls to Avoid

• Relying solely on mammography without ultrasound, especially in dense breasts
• Dismissing clear fluid discharge as benign without thorough evaluation, even with normal imaging 2
• Inadequate surgical excision due to lack of thorough preoperative imaging 2
• Relying solely on cytology of nipple discharge (negative results should not stop further evaluation) 2

Follow-up After Imaging

• If imaging identifies a suspicious lesion: proceed to image-guided core needle biopsy (preferred over fine needle aspiration) 1, 2
• If imaging is negative but discharge persists: surgical duct excision may be considered for bothersome discharge 2
• MRI's high negative predictive value may allow for surveillance as an alternative to surgery in select cases 6