What is the approach to evaluating nipple discharge?

Evaluation of Nipple Discharge

The approach to evaluating nipple discharge should first differentiate between physiologic and pathologic discharge, with no imaging needed for physiologic discharge while pathologic discharge requires mammography/DBT and ultrasound as first-line imaging modalities. 1

Differentiating Physiologic vs. Pathologic Discharge

Physiologic Discharge

• Bilateral discharge 1
• Originates from multiple ducts 1
• White, green, or yellow in color 1
• Occurs only when provoked (not spontaneous) 1
• No association with breast cancer 1
• No radiologic investigation needed if routine screening mammography is up to date 1

Pathologic Discharge

• Spontaneous (occurs without manipulation) 1
• From a single duct orifice 1
• Unilateral 1
• Serous or bloody 1
• Associated with underlying malignancy in 3-29% of cases 1, 2

Evaluation Algorithm for Pathologic Nipple Discharge

For Women ≥40 Years or Men ≥25 Years

1. Initial Imaging: Mammography or Digital Breast Tomosynthesis (DBT) 1

   • First-line imaging modality 1
   • Additional spot compression and magnification views may be needed to evaluate subareolar region 1
   • Sensitivity for malignancy: 15-68%, specificity: 38-98% 1

2. Complementary Ultrasound 1

   • More sensitive than mammography but lower specificity 1
   • Useful for identifying intraductal lesions 1
   • Special techniques (peripheral compression, 2-hand compression, rolled-nipple) may be needed for successful imaging of nipple and retroareolar region 1
   • Can guide biopsy of suspicious lesions 1

For Women 30-39 Years

• Either mammography/DBT or ultrasound as initial examination (based on institutional preference) 1
• The other modality should be added as complementary imaging 1

For Women <30 Years

• Ultrasound as initial examination 1
• Add mammography/DBT only if:
  • Ultrasound shows suspicious findings 1
  • Patient has predisposition to breast cancer 1

Additional Imaging Considerations

When Initial Imaging is Negative

• MRI may be considered 1, 3

  • Higher sensitivity than galactography 2
  • Overall sensitivity up to 96% 2
  • Provides physiologic information in addition to morphologic detail 1
  • Does not require duct cannulation 1

• Ductography (Galactography) 1

  • Historically used for identifying intraductal lesions 1
  • Invasive and may cause discomfort/pain 1
  • Technical failure rate of 10-15% 1, 2
  • Can guide preoperative wire localization 1

Tissue Sampling

• Image-guided core needle biopsy (CNB) is preferred over fine-needle aspiration (FNA) 1
  • Superior sensitivity, specificity, and correct histologic grading 1
  • Performed when a suspicious lesion is identified on imaging 1

Common Pathologies

• Benign intraductal papilloma - most common cause (35-48%) 1

  • Mammographic findings: asymmetrically dilated ducts, circumscribed subareolar mass, or grouped microcalcifications 1

• Ductal ectasia - second most common cause (17-36%) 1

• Malignancy - less common but important to exclude 1

  • DCIS: presents with nipple discharge in up to 12% of cases 1
  • Mammographic findings: fine linear, discontinuous branching microcalcifications in ductal distribution 1
  • Higher risk in men (23-57% of nipple discharge cases are malignant) 1

Clinical Pearls and Pitfalls

• A negative mammogram reduces risk of carcinoma to 3%, while negative mammogram AND ultrasound reduces risk to approximately 0% 1

• False-positive ultrasound results may occur due to:

  • Volume averaging with ductal wall in tortuous ducts 1
  • Intraductal and periductal fibrosis 1
  • Adherent blood clots or inspissated secretions 1

• Nipple discharge cytology has limited utility with false negative rates over 50% 2

• Surgery is no longer considered the standard approach for all pathologic nipple discharge cases 2