What are the indications for a breast biopsy in a patient with abnormal breast symptoms or screening results?

Indications for Breast Biopsy

Breast biopsy is indicated for any imaging finding classified as BI-RADS category 4 or 5 (suspicious or highly suggestive of malignancy), regardless of clinical findings, and for clinically suspicious lesions even when imaging is negative. 1

Primary Indications Based on Imaging Assessment

BI-RADS Category-Based Indications

• BI-RADS 4 or 5 lesions require tissue biopsy regardless of whether they are detected on screening mammography, diagnostic mammography, or ultrasound 1
• BI-RADS 3 (probably benign) lesions do not require immediate biopsy but need short-interval follow-up imaging at 6 months, then every 6-12 months for 1-2 years; biopsy is indicated if the lesion increases in size or changes characteristics 1
• BI-RADS 0 (incomplete assessment) requires additional diagnostic imaging before determining biopsy necessity 1

Complex or Complicated Cysts

• Complex cysts (BI-RADS 4) containing both solid and cystic components require ultrasound-guided biopsy or surgical excision 1
• Complicated cysts that increase in size on follow-up imaging warrant biopsy 1
• Recurrent cysts after aspiration should undergo image-guided biopsy 1

Clinical Indications Requiring Biopsy

Palpable Masses

• Any palpable mass in women ≥30 years requires diagnostic mammogram and ultrasound; if imaging shows BI-RADS 4-5, proceed to biopsy 1, 2
• Palpable masses with negative imaging (BI-RADS 1) may still require tissue biopsy or close observation if clinically suspicious, as negative imaging does not exclude malignancy 1, 3
• In one study, 1.2% of palpable abnormalities with negative imaging proved malignant, with all cancers occurring in the clinically suspicious group 3

Skin Changes

• Skin or nipple biopsy is mandatory for suspected inflammatory breast cancer (peau d'orange, erythema) or Paget's disease (nipple eczema, scaling, ulceration) even with negative mammography 1
• If imaging shows BI-RADS 1-3, perform punch biopsy of skin or nipple first 1
• If imaging shows BI-RADS 4-5, core needle biopsy with or without punch biopsy is preferred 1

Nipple Discharge

• Duct excision (with or without ductography) is indicated for persistent, spontaneous, unilateral, single-duct discharge that is clear, serous, sanguineous, or serosanguineous when imaging shows BI-RADS 1-3 or benign/indeterminate biopsy results 1
• If imaging shows BI-RADS 4-5, proceed directly to tissue biopsy 1

Asymmetric Thickening or Nodularity

• Biopsy is indicated if imaging shows BI-RADS 4-5 or if clinical findings progress despite initially benign imaging 1
• If BI-RADS 1-3 with benign clinical assessment, reexamine in 3-6 months with imaging; biopsy if progression occurs 1

Histologic Indications for Excisional Biopsy

Core needle biopsy showing certain high-risk or indeterminate lesions requires excisional biopsy due to underestimation of cancer risk 1:

• Atypical ductal hyperplasia (ADH) - studies show significant underestimation of cancer 1
• Lobular carcinoma in situ (LCIS) or atypical lobular hyperplasia (ALH) - though select concordant cases may be observed 1
• Papillary lesions 1
• Radial scars 1
• Mucin-producing lesions 1
• Potential phyllodes tumors 1
• Benign results that are image-discordant 1

Important Clinical Caveats

When Imaging Should Not Delay Biopsy

• Clinical suspicion trumps negative imaging - there are situations where biopsy is warranted even with BI-RADS 1-3 if clinical examination is highly suspicious 1, 2
• Imaging should precede biopsy in most situations to avoid alteration of imaging findings, but this should not delay biopsy when clinical concern is high 1, 2

Age-Specific Considerations

• Women <30 years with palpable masses may be observed for 1-2 menstrual cycles if clinical suspicion is low; if mass persists, ultrasound is performed and biopsy indicated based on findings 1
• Women ≥30 years with palpable masses should not be observed without imaging; proceed directly to diagnostic mammogram and ultrasound 1, 2

Breast Pain Alone

• Breast pain as the only symptom (cyclic, diffuse, nonfocal) with negative clinical exam and current negative screening mammogram does not require biopsy 1
• Focal breast pain requires age-appropriate diagnostic imaging; biopsy only if imaging shows BI-RADS 4-5 1
• Cancer risk with pain alone is low (1.2-6.7%) 1