What is the recommended approach for a breast discharge workup?

Breast Discharge Workup

Initial Clinical Characterization

The first and most critical step is to determine whether the nipple discharge is physiologic or pathologic, as this fundamentally dictates all subsequent management. 1

Physiologic Discharge Characteristics

• Bilateral presentation 1, 2
• Multiple ducts involved 1, 2
• Non-spontaneous (requires manipulation or compression) 1, 2
• White, green, yellow, or clear in color 1, 2
• No imaging is indicated for physiologic discharge 1, 2

Pathologic Discharge Characteristics

• Spontaneous occurrence 1, 2
• Unilateral presentation 1, 2
• Single duct involvement 1, 2
• Bloody, serous, or serosanguineous appearance 1, 2

Management Algorithm for Physiologic Discharge

For women under age 40 with physiologic discharge: observation only, with patient education to stop breast compression and report any development of spontaneous discharge. 1, 2

For women age 40 or older with physiologic discharge: mammography if not up to date, then observation with the same patient education. 1

• No ultrasound, MRI, ductography, or biopsy is appropriate 1, 2
• Re-evaluation in 3-6 months if discharge persists despite stopping compression 2

Imaging Algorithm for Pathologic Discharge

Age 40 Years or Older (Including Men Age 25 or Older)

Diagnostic mammography or digital breast tomosynthesis (DBT) is the initial examination, with ultrasound added as a complementary study. 1

• Both modalities rated as "usually appropriate" (rating 9/9) by ACR 1
• Men with pathologic discharge have high breast cancer incidence, warranting mammography/DBT first 1

Age 30-39 Years

Either mammography/DBT or ultrasound may be used as the initial examination based on institutional preference, with the other modality as complementary. 1

Age Under 30 Years

Ultrasound is the initial examination. 1

• Add mammography/DBT only if ultrasound shows suspicious findings or patient has predisposition to breast cancer 1
• Mammography has low yield in this age group due to breast density and low cancer risk 1

Management Based on Imaging Results

BI-RADS Category 1-3 (Negative, Benign, or Probably Benign)

When imaging is negative or benign, management options include duct excision or follow-up with physical exam after 6 months and imaging for 1-2 years. 1

• Ductogram or MRI are optional to guide duct excision 1
• Sampling before imaging is not recommended 1
• If clinical suspicion increases during follow-up, tissue biopsy is recommended 1

BI-RADS Category 4 or 5 (Suspicious or Highly Suggestive of Malignancy)

Tissue biopsy is required. 1

• If biopsy findings are benign, ductogram is optional but surgical duct excision is still necessary 1
• If findings indicate malignancy, treat according to breast cancer guidelines 1

Role of Advanced Imaging

MRI

MRI is not usually appropriate as an initial examination but may be useful when standard imaging (mammography and ultrasound) is negative in cases of persistent pathologic discharge. 1

• MRI aids in diagnosis of suspected ductal disease 1
• Can identify lesions missed by conventional imaging 3
• Important caveat: MRI has limitations and may miss small intraductal lesions; negative MRI does not exclude all pathology 4

Ductography

Ductography is not appropriate as an initial examination but should be considered when conventional imaging is negative and pathologic discharge persists. 1, 4

• Can detect underlying abnormalities in 14-86% of cases when conventional imaging is negative 4
• Particularly valuable for localizing intraductal lesions preoperatively 4, 5
• Must be performed when discharge is actively present to successfully cannulate the discharging duct 4
• If ductography cannot be performed, proceed directly to major duct excision 4

Critical Pitfalls to Avoid

• Never perform sampling before imaging 1
• Do not assume bilateral green or clear discharge is always benign—monitor for change to spontaneous, unilateral, or single-duct characteristics 2
• Do not rely solely on mammography for pathologic discharge—sensitivity is low because lesions are typically small, retroareolar, and without calcifications 3
• Do not assume negative MRI excludes pathology—up to 20% of lesions may be beyond detection 4
• Do not perform "blind" major duct excision without attempting ductography when technically feasible, as this risks incomplete excision 4

Malignancy Risk Factors

The likelihood of cancer increases with: 6

• Watery, bloody, pink, or yellow discharge (in order of increasing risk) 6
• Presence of palpable mass 6
• Unilateral and single-duct presentation 6
• Positive mammogram, galactogram, or cytology 6
• Age over 50 years 6
• Overall cancer risk with pathologic discharge is approximately 5-14% 1, 3