A matrix of morphology and distribution of calcifications in the breast: Analysis of 849 vacuum-assisted biopsies.

Objective: The purpose of this retrospective analysis was to evaluate the likelihood of malignancy in prospectively categorized BI-RADS 4 and BI-RADS 5 calcifications.

Material And Methods: This analysis included 849 women who underwent vacuum biopsy for BI-RADS 4 (with the subgroups 4A, 4B and 4C) or BI-RADS 5 calcifications between February 2007 and May 2015. Calcifications were classified according to the morphology and distribution descriptors of the BI-RADS lexicon (BI-RADS 4th edition lexicon). A standardized scheme (matrix) was used to combine the characteristics of the grouped calcifications with the BI-RADS assessment category.

Results: Overall, 275/849 (32%) lesions were found to be malignant. 285/327/208/29 calcified lesions were prospectively classified as BI-RADS 4A/4B/4C/5 indicating a risk for malignancy of 16%/27%/55%/90%, respectively. The morphology descriptors predicted the risk for malignancy as follows: typically benign (n=55): 2%; indeterminate (n=676): 27%; typically malignant (n=118): 80%. The distribution descriptors correlated with a malignant histology as follows: diffuse (n=0); round or oval (n=261): 22%; regional (n=398): 33%; segmental (n=106): 42%; linear or branching (n=85): 55%. There was a significant difference between the descriptor categories (p<0.0001).

Conclusion: A standard scheme combining the morphology and distribution characteristics proved to be a helpful tool in diagnosis of calcifications, bridging the gap between description and classification of these lesions.