What is the recommended approach for evaluating a breast nodule?

Evaluation of a Breast Nodule

For any breast nodule, proceed immediately with diagnostic imaging—diagnostic mammography for women ≥30 years (followed by targeted ultrasound) or ultrasound alone for women <30 years—as physical examination alone is unreliable and cannot distinguish benign from malignant lesions. 1, 2

Initial Clinical Assessment

History and Physical Examination

• Document patient age, menopausal status, personal history of breast disease, family history of breast/ovarian cancer, and any breast symptoms (skin changes, nipple discharge, pain) 3, 4
• Perform systematic visual inspection with the patient sitting, hands on hips to contract pectoralis muscles, assessing for asymmetry, skin changes (erythema, peau d'orange, dimpling), and nipple changes (retraction, scaling) 3, 4
• Palpate with patient supine, ipsilateral arm overhead, using finger pads in overlapping circular motions with three pressure levels (light, medium, deep) covering the entire breast tissue pentagon and all nodal basins (axillary, supraclavicular, infraclavicular) 3, 4

Critical point: Physical examination cannot reliably distinguish cysts from solid masses (only 58% accuracy) or benign from malignant lesions—imaging is mandatory in nearly all cases 2, 5

Imaging Algorithm Based on Age

Women Under 30 Years

• Start with targeted breast ultrasound as the initial study to avoid unnecessary radiation exposure 1, 2
• Add diagnostic mammography only if ultrasound findings are suspicious or inconclusive 1

Women 30-39 Years

• Either ultrasound or diagnostic mammography may be performed first, depending on clinical suspicion 2
• Complete evaluation with the complementary modality 1

Women ≥40 Years

• Begin with bilateral diagnostic mammography (not screening mammography) to characterize the palpable lesion, screen the remainder of both breasts, detect calcifications/architectural distortions, and provide baseline documentation 1, 2
• Follow immediately with targeted ultrasound of both breasts to identify additional lesions, characterize solid versus cystic nature, evaluate bilateral axillae, and guide potential biopsy 1, 2

Rationale: Mammography alone has 86-91% sensitivity for palpable abnormalities, but combined mammography and ultrasound provide >97% negative predictive value when both are negative or benign 1, 2

Management Based on Imaging Results (BI-RADS Classification)

BI-RADS 1-2 (Negative or Benign)

• Simple cyst on ultrasound: Return to routine clinical follow-up only—no further imaging, short-interval follow-up, or biopsy needed 1, 2
• Return to routine screening mammography in 1 year 1

BI-RADS 3 (Probably Benign)

• Solid mass with benign features (circumscribed margins, oval shape, horizontal orientation, homogeneous hyperechogenicity, or thin echogenic pseudocapsule with <4 gentle lobulations): Short-interval ultrasound follow-up at 6 months, then every 6-12 months for 1-2 years 3, 1, 2, 5
• Malignancy risk <2% 3

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

• Proceed directly to core needle biopsy (preferred over fine needle aspiration) 3, 1, 2
• Use ultrasound-guided core biopsy whenever the lesion is visible on ultrasound—provides real-time needle visualization, no breast compression, no radiation exposure, and allows axillary evaluation 1, 2
• Obtain at least 2-3 cores from each suspicious lesion 1
• BI-RADS 4 lesions have 3-94% malignancy risk; BI-RADS 5 lesions have ≥95% malignancy risk 3

Critical Post-Biopsy Requirements

Concordance verification is mandatory—ensure agreement between pathology results, imaging findings, and clinical examination 1, 2

• If concordant and benign: Return to appropriate follow-up based on pathology (some high-risk lesions like atypical ductal hyperplasia may require surgical excision) 1
• If discordant: Pursue additional tissue sampling or surgical excision immediately 1, 2
• If malignant: Refer for treatment according to breast cancer guidelines; consider preoperative MRI for extent of disease evaluation in select circumstances 1

Pathology Requirements

For core needle biopsy specimens, the pathology report should include 3:

• Histologic type and grade
• Estrogen receptor (ER), progesterone receptor (PgR), and HER2 status by immunohistochemistry or FISH/CISH
• Proliferation markers (Ki67 labeling index)
• Vascular/lymphovascular invasion if present

Common Pitfalls to Avoid

• Never delay imaging evaluation—physical examination alone is unreliable and cannot exclude malignancy 2
• Never assume benignity based solely on clinical features such as cyclic changes, soft texture, or patient age 2
• Never perform biopsy before imaging—biopsy-related changes (hematoma, architectural distortion) will confuse subsequent image interpretation 2
• Never rely on a single imaging modality—mammography and ultrasound provide complementary information 1, 2
• Do not order MRI, PET, or molecular breast imaging as initial evaluation—these have no role in routine workup of a palpable mass 2
• Never accept "probably benign" pathology that contradicts suspicious imaging—discordance mandates repeat biopsy or surgical excision 1, 2