LIKELIHOOD OF MALIGNANT DISEASE FOR VARIOUS CATEGORIES OF MAMMOGRAPHICALLY DETECTED, NONPALPABLE BREAST-LESIONS

To determine the likelihood of malignant disease for mammographically detected, nonpalpable breast lesions, we defined 11 morphologic catego ries and retrospectively reviewed the mammograms in 859 cases in which biopsy was performed after a wire localization procedure at our insti tution during 1989 and 1990. Within each category, the total number of lesions and the percentage of cases with a surgical pathologic diagno sis of malignant involvement were as follows: benign calcification, 25 (0% malignant); indeterminate calcification, 200 (22%); malignant cal cification, 39 (92%); smooth mass, 84 (1%); irregular mass, 337 (40%); architectural distortion, 45 (47%); asymmetric breast tissue, 37 (3%, or 1 case of asymmetrically prominent ducts); smooth mass with calcif ication, 3 (0%); irregular mass with calcification, 68 (66%); architec tural distortion with calcification, 14 (57%); and asymmetric breast t issue with calcification, 7 (29%). The overall rate of malignant invol vement for the 859 cases was 34%. If follow-up examinations rather tha n biopsies had been done for the lesions categorized as benign calcifi cation, smooth mass, smooth mass with calcification, and asymmetric br east tissue (excluding asymmetrically prominent ducts), the overall po sitive predictive value would have increased from 34 to 41%, and 148 b iopsies would have been deferred (17% of all biopsies). If morphologic criteria are applied to the evaluation of mammographically detected, nonpalpable lesions, the rate of malignant disease at biopsy may reach 40%. This rate correlates with that in recent large series.