Subtle Finding Analysis in False Negative Results on Screening Mammogram and US: An Institute Study

Abstract

Objective: To determine the percentage and evaluate the subtle findings of false negative results on mammogram and ultrasonography (US) screening.
Methods: A retrospective study involved twelve breast cancer patients who had a negative result of malignancy on both the initial mammogram and US with an equal number of benign or negative cases mixed. One radiologist randomly reviewed all mammograms and US images without any knowledge of the final diagnosis, noting mammographic characteristics of breast density composition, lesion type, size, and morphology according to (BIRADS-LEXICON).
Results: The incidence of prospectively false-negative rates was 7.3% (7 of 9,582). The type of subtle findings characterized on the prior mammogram included a macrolobulated mass in one of seven lesions (14.3%), a macrolobulated mass with amorphous microcalcification in one (14.3%), amorphous microcalcification alone in one (14.3%), and asymmetrical breast density on one-view mammogram in two (28.6%). There were two of seven lesions with negative mammogram and positive US findings.
Conclusion: There is a small subset of breast cancer, called subtle findings, which can be perceptible but sometimes there are no definite malignant findings on the image interpretation. An understanding of the characteristics of subtle findings in false-negative screens may be a valuable aid in increasing the sensitivity of breast cancer detection.