Additional Mammographic Views for Breast Asymmetry
The additional mammographic views recommended for breast asymmetry are spot compression views and magnification views, collectively referred to as diagnostic mammography. 1
Diagnostic Mammography Components
When a screening mammogram identifies breast asymmetry, the standard approach involves:
- Spot compression views: These are the primary additional views used to determine whether the asymmetry persists as a true finding or disappears, indicating it was merely summation artifact from overlapping normal breast tissue 2
- Magnification views: These are particularly helpful when evaluating any associated microcalcifications that may accompany the asymmetry 2
- Lateral or rolled views: These may be added to help localize the asymmetry in three-dimensional space and further differentiate summation artifacts from real lesions 3, 4
Algorithmic Approach to Evaluation
The diagnostic workup follows this sequence:
- Initial diagnostic mammography with spot compression views to characterize whether the asymmetry persists 1, 2
- Magnification views if microcalcifications are present 1, 2
- Targeted ultrasound of the area of concern should be performed concurrently to identify potentially benign causes or a target for biopsy 2, 3
Important Clinical Context
The term "diagnostic mammography" distinguishes this evaluation from screening mammography, which consists of only 2 standard x-ray images of each breast, whereas diagnostic mammography includes these additional specialized views 1
Key Caveat
Spot compression views are essential because they help determine if the asymmetry represents summation artifact (overlapping normal tissue that mimics an abnormality) or a true lesion requiring further evaluation 2, 3. Rolled views can be particularly effective, successfully identifying summation artifacts in approximately 75% of cases 4.
Clinical Significance
The absence of a sonographic correlate should not preclude biopsy if the mammographic findings remain suspicious after complete diagnostic evaluation 2, 3. Developing asymmetry—a focal asymmetry that is new or increased compared to prior mammograms—carries a positive predictive value for cancer of 12.8% at screening and 42.9% when biopsy is recommended 2.