False-Positive Findings at Contrast-Enhanced Breast MRI: A BI-RADS Descriptor Study

False-Positive Findings at Contrast-Enhanced Breast MRI: A BI-RADS Descriptor Study
Pascal A. T. Baltzer, Matthias Benndorf, Matthias Dietzel, Mieczyslaw Gajda, Ingo B. Runnebaum, and Werner A. Kaiser
AJR 2010;194:1658-1663

Link to Journal

The ratio of mass to non-mass lesions differed significantly (p < 0.001) between benign (1.2:1) and malignant (7:1) findings. Seventeen mass and 14 nonmass lesions were false-positive, and 105 mass and 15 nonmass lesions were true-positive. Among mass lesions, it was possible to differentiate malignant and benign lesions on the basis of margin (smooth, irregular, or spiculated) and dynamic enhancement features (p < 0.05). Among nonmass lesions, only stippled enhancement had a significant difference between the subgroups (p < 0.05). Tumor diameter had no influence on the correct diagnosis of nonmass lesions (p = 0.301). Conversely, among mass lesions, false-positive lesions were smaller than true-positive lesions (p = 0.01).

CONCLUSION. Nonmass lesions were the major cause of false-positive breast MRI findings. BI-RADS descriptors are not sufficient for differentiating benign and malignant non-mass lesions