What diagnostic tests are used to confirm breast cancer in a patient with a suspected lump or abnormality, considering their age, family history, and previous breast-related issues?

Diagnostic Tests for Breast Cancer

The diagnosis of breast cancer requires bilateral diagnostic mammography combined with targeted ultrasound of the breast and regional lymph nodes, followed by ultrasound- or stereotactic-guided core needle biopsy to confirm the diagnosis and assess biomarkers. 1, 2

Initial Clinical Evaluation

Before imaging, obtain the following specific information:

• Complete family history of breast/ovarian cancer in first- and second-degree relatives, including age at diagnosis and Ashkenazi Jewish ancestry 2
• Menopausal status (measure serum estradiol and FSH if uncertain) 2
• Physical examination with bimanual palpation of both breasts, all regional lymph node basins, assessment for hepatomegaly, and bone tenderness 2
• Laboratory tests: complete blood count, liver function tests, renal function, alkaline phosphatase, and calcium 1, 2

Imaging Protocol by Age

For Patients ≥30 Years Old:

Start with bilateral diagnostic mammography PLUS ultrasound of both breasts and regional lymph nodes 1, 2. This is the standard approach regardless of breast density.

For Patients <30 Years Old:

Begin with ultrasound alone, then proceed to diagnostic mammography only if ultrasound shows suspicious findings or clinical suspicion is high 1, 2. Mammography has low yield in this age group due to breast density and low cancer prevalence 1.

When to Add Breast MRI

MRI is not routine but should be obtained in these specific scenarios:

• Strong family history of breast cancer or proven BRCA mutations 1, 2
• Breast implants present 1
• Lobular cancer suspected 1
• Suspicion of multifocality/multicentricity 1
• Large discrepancy between conventional imaging and clinical examination 1
• Before and during neoadjuvant chemotherapy 1
• Dense breast tissue in young patients with genetic/familial predisposition 1

The American Cancer Society recommends annual MRI plus mammography for high-risk women (≥20% lifetime risk or BRCA mutations) starting at age 25-30 2. MRI detects an additional 4-5 cancers per 100 high-risk women but also leads to increased benign biopsies 3.

Tissue Diagnosis Requirements

Core needle biopsy is mandatory and must be performed under image guidance (ultrasound or stereotactic) 1, 2. Fine needle aspiration is insufficient.

The pathology report must include:

• Histological type and grade 1, 2
• Estrogen receptor (ER) status 1, 2
• Progesterone receptor (PgR) status 1, 2
• HER2 status 1, 2
• Proliferation measure (Ki67) 1, 2

Obtain a minimum of 2-3 cores during the biopsy procedure 2. Place a marker (surgical clip or carbon) into the tumor at biopsy to ensure correct surgical site identification 1.

Lymph Node Assessment

Evaluate lymph nodes by:

• Clinical examination 1
• Ultrasound of regional nodes 1, 2
• Ultrasound-guided fine needle aspiration or core biopsy of suspicious lymph nodes 1

Staging for Metastatic Disease

Routine comprehensive staging is NOT recommended for asymptomatic early breast cancer, as distant metastases are very rare 1.

Obtain additional staging studies (chest CT, abdominal CT/ultrasound, bone scan) only if:

• Clinically positive axillary nodes present 1
• Large tumors (≥5 cm) 1
• Aggressive tumor biology 1
• Constitutional symptoms (night sweats, weight loss) suggesting metastatic disease 2
• Clinical signs, symptoms, or laboratory values suggesting metastases 1

Common Pitfalls to Avoid

Do not skip core biopsy in favor of fine needle aspiration—core biopsy is essential for assessing biomarkers and confirming invasive disease, especially if systemic therapy is planned 1.

Do not order routine tumor markers or comprehensive staging in asymptomatic patients with early disease—this does not benefit patients and increases costs 1.

Do not rely on mammography alone in young women or those with dense breasts—sensitivity drops to 50% in these populations 3. Always add ultrasound 1, 2.

If ER/PgR and HER2 are negative on biopsy, retest them on the surgical specimen to account for tumor heterogeneity 1.

Special Presentations

Nipple Discharge Without Mass:

For persistent, spontaneous, unilateral, single-duct, clear or bloody discharge:

• Perform age-appropriate diagnostic mammography and ultrasound 1
• If imaging is BI-RADS 1-3, consider ductogram or MRI to guide duct excision 1
• If imaging is BI-RADS 4-5, perform tissue biopsy 1

Skin Changes:

For erythema, peau d'orange, or nipple eczema/scaling:

• Consider inflammatory breast cancer or Paget's disease 1
• Obtain skin biopsy—negative mammogram does not exclude Paget's disease 1