Gray-scale sonography of solid breast masses: diagnosis of probably benign masses and reduction of the number of biopsies.

PURPOSE: To identify probably benign breast masses using gray-scale sonography and to see if this strategy could reduce the number of biopsies of breast masses. METHODS: This retrospective study included 229 masses in 203 women who underwent sonographically guided percutaneous biopsy. Masses with a negative predictive value for malignancy >98% were retrospectively considered probably benign, and the potential impact of gray-scale sonography in reducing the number of biopsies if these masses were not biopsied was assessed. Assessments were performed considering all masses as a group as well as various subgroups. RESULTS: Round, ellipsoid, or lobulated masses with 3 or fewer lobulations, circumscribed margins, a longitudinal-anteroposterior diameter ratio > or =1.0 and no marked hypoechogenicity, posterior acoustic shad owing, internal microcalcifications, or altered surrounding breast tissue were considered probably benign. The sensitivity of gray-scale sonography to identify this subgroup was 98%, with a negative predictive value of 99%. If these masses were not biopsied, there would be a 42% reduction in the number of biopsies considering all masses, a 36% reduction for masses classified as Breast Imaging Reporting and Data System category 4, and a 59% reduction for masses exclusively analyzed with sonography. CONCLUSIONS: It is possible to identify probably benign breast masses using gray-scale sonography, and thereby to reduce the number of biopsies performed.