Is a complete breast ultrasound (US) useful as a supplementary test in a patient with heterogeneously dense breast tissue on mammogram and retropectoral saline implants (breast implants)?

Breast Ultrasound is Useful as a Supplementary Test in Patients with Dense Breasts and Breast Implants

Complete breast ultrasound is recommended as a supplementary test for this 43-year-old female patient with heterogeneously dense breasts and retropectoral saline implants to improve cancer detection beyond mammography alone. 1

Rationale for Supplemental Ultrasound Screening

Dense Breast Tissue Considerations

• Mammography has decreased sensitivity in women with dense breast tissue (as low as 30% in extremely dense tissue) 1
• Dense breast tissue is both a risk factor for developing breast cancer and increases the risk of cancer not being detected on mammography 1
• Heterogeneously dense breast tissue (BI-RADS category 3) significantly reduces mammographic sensitivity for detecting non-calcified lesions 1

Implant-Related Considerations

• Retropectoral saline implants can further complicate mammographic interpretation by obscuring portions of breast tissue 1
• Ultrasound can effectively evaluate breast tissue around implants and help determine implant integrity 1
• For patients ≥40 years of age with saline implants, ultrasound is complementary to diagnostic mammography or digital breast tomosynthesis (DBT) 1

Benefits of Supplemental Ultrasound

1. Improved Cancer Detection:

   • Studies show ultrasound detects an additional 3.0-7.7 cancers per 1,000 examinations (median 4.2) in women with dense breasts 2
   • Meta-analysis indicates ultrasound detects approximately 29% of all screen-detected cancers that are mammographically occult 3
   • Cancer detection rate of 0.3% with whole-breast ultrasound in women with dense breasts and negative mammography 4

2. Early Detection of Invasive Cancers:

   • Supplemental ultrasound primarily detects small, invasive cancers that are node-negative 5
   • Mean tumor size detected by ultrasound alone is approximately 9.9mm, with 90% having negative lymph node status 5

3. Evaluation Around Implants:

   • Ultrasound can effectively visualize breast tissue adjacent to implants that may be obscured on mammography 1
   • Can help distinguish between implant-related findings and breast parenchymal abnormalities 1

Potential Limitations and Considerations

1. Increased Biopsy Rates:

   • Supplemental ultrasound is associated with additional 11.7-106.6 biopsies per 1,000 examinations (median 52.2) 2
   • Positive predictive value (PPV) for ultrasound-prompted biopsies ranges from 8.4-13.7%, which is lower than for mammography-prompted biopsies 5

2. Milk Calcifications:

   • The patient's milk calcifications in grouped distribution are best evaluated by mammography, not ultrasound 1
   • Ultrasound complements mammography but does not replace it for evaluation of calcifications 6

Implementation Recommendations

1. Comprehensive Approach:

   • Complete breast ultrasound should be performed by a trained technologist or radiologist 4
   • Average examination time is approximately 10 minutes 4
   • Special attention should be paid to areas that may be obscured by the implants on mammography

2. Interpretation:

   • Abnormal findings should be corroborated by a fellowship-trained breast-imaging radiologist 4
   • Findings should be integrated with mammographic results for comprehensive evaluation

In this 43-year-old patient with heterogeneously dense breasts, milk calcifications, and retropectoral saline implants, supplemental complete breast ultrasound is clinically indicated to maximize cancer detection and provide optimal screening.