ABSTRACT
PURPOSE: To investigate the usefulness of a standardized reporting and data system in improving the positive predictive value of mammography in breast calcifications. MATERIALS AND METHODS: Using the Breast Imaging Reporting and Data System lexicon developed by the American College of Radiology, we defined 5 descriptive categories of breast calcifications and classified diagnostic suspicion of malignancy on a 3-grade scale (low, intermediate and high). Two radiologists reviewed 117 mammographic studies selected from those of the patients submitted to surgical biopsy for mammographically detected calcifications from January 1993 to December 1997, and classified them according to the above criteria. The positive predictive value was calculated for all examinations and for the stratified groups. RESULTS: Thirty-five of 36 cases classified as low-grade suspicion at mammography were benign at histology, while the extant one was a microinvasive lobular carcinoma in situ. Of 44 cases of intermediate-grade suspicion, 21 were benign while 23 were malignant lesions. All the 37 cases graded as highly suspicious were actually carcinomas. The positive predictive value was 0.52 for the whole series, 0.02 in the low suspicion group, 0.52 in the intermediate suspicion group and finally 1.0 in the high suspicion group. If the low suspicion cases had not undergone surgical biopsy, the positive predictive value would have been 0.74, with a single false-negative. DISCUSSION AND CONCLUSION: Defining a standardized system for assessing and describing breast calcifications helps improve the diagnostic accuracy of mammography in clinical practice.
