Radiology of nonpalpable breast lesions

: The authors reviewed 619 consecutive cases of breast nonpalpable lesions detected with mammography in which wire-directed open biopsy or stereotaxic biopsy was performed from 1984 to 1993. The ratio of benign to malignant biopsy findings was 4:1 for the whole series. The positive predictive value (PPV) of different radiologic pattern was determined. Biopsy is advised in the presence of patterns such as strongly suspect microcalcifications (granular or branching morphologic features), stellate masses, parenchimal distortion, opacities with undefined borders and asymmetric density, which yielded higher PPVs (26%, 93%, 92%, 35%, 42% and 19% respectively). However, follow-up with mammography is advised in probably benign lesions (opacity with regular borders and clusters of round or oval particles of calcifications), which yielded lower PPVs (1.5% and 3%). By decreasing the number of biopsies of probably benign lesions and thereby substantially reducing costs, this approach may help to widespread use of mammographic screening.