Seven Takeaways from New Review of Common Mammography Misses

In a new review, researchers discuss an array of factors that can contribute to missed breast cancers in the interpretation of mammograms, offering insights on reader factors as well as subtle lesion characteristics.

Here are seven takeaways from the recently published review in Insights into Imaging.

1. Noting that 12 to 45 percent of missed breast cancer cases present with architectural distortion, the researchers emphasized scrutiny of anterior and posterior mammary fat lines and possible tethering of breast architecture. They pointed out that digital breast tomosynthesis (DBT) offers strong detection in cases involving architectural distortion.

2. Pointing out the challenge of grouped microcalcifications that may be obscured by overlapping structures, the review authors suggested that high-resolution monitors, digital magnification views and AI-CAD software may enhance detection of this subtle finding.

3. While acknowledging that the majority of isodense asymmetries are benign, the researchers noted a 27 percent positive predictive value (PPV) with developing asymmetries and that coexisting microcalcifications or architectural distortion should raise the index of suspicion in these cases. In order to improve differentiation of asymmetries from tissue overlap, the review authors recommended magnification and spot compression views as well as DBT and breast ultrasound.

4. The review authors also cautioned about overreliance on lesion stability as correlating with benign assessments. They said that invasive lobular carcinoma and low-grade ductal carcinoma are marked by slow growth, which commonly manifests in an infiltrative or diffuse pattern. When there is raised suspicion of these cases, the researchers emphasized assessment of morphological features in contrast to lesion stability when weighing the need for additional imaging.

5. Citing research that suggests between nine to 38 percent of breast cancers appear on a single mammographic view, the review authors advocated increased focus on asymmetries that may correlate with palpable abnormalities. The researchers also called for extended views and spot compression in these cases and consideration of DBT or ultrasound.

6. Noting that axillary regions, retro-areolar areas and inframammary folds often fall outside of the standard search pattern for mammography interpretation, the review authors acknowledged that common blind spots for subtle lesions include the inner half of the breast and the retroglandular clear space on the craniocaudal (CC) view. They also emphasized scrutiny of the area adjacent and anterior to the pectoralis major muscle on the mediolateral oblique (MLO) view.

7. Cautioning against satisfaction of search, the researchers pointed out that multifocal or multicentric disease may occur in six to 60 percent of breast cancer cases. Accordingly, the review authors advocated the use of standard checklists for mammography interpretation. They also suggested a structured survey of the imaging to assess for additional abnormalities prior to focusing on the primary finding.