Objective: The purpose of this study was to assess the utility and efficacy of second-look breast sonography in the evaluation of abnormalities identified on presurgical breast magnetic resonance imaging (MRI) examinations.
Methods: A retrospective review was performed of 152 presurgical breast MRI examinations having 196 unsuspected abnormalities to identify findings that underwent subsequent breast sonography. Eligible examinations had a suspicious abnormality identified on presurgical MRI and documentation of the location and size of the finding on MRI and subsequent second-look sonography. Fourteen examinations not meeting the criteria were excluded, with 182 abnormalities remaining. Patient medical records were reviewed.
Results: Seventy percent (128 of 182) of breast MRI lesions were visible at second-look sonography; 30% (54 of 182) were sonographically occult. Ninety-five percent (121 of 128) of sonographically visible abnormalities underwent breast biopsy. Pathologic examinations of sampled sonographically visible lesions revealed 39 cancers, 9 high-risk lesions, 72 benign lesions, and 1 lesion not specified at surgery; 23% (9 of 128) of cancers were in the contralateral breast. Fifty-four lesions were sonographically occult. Needle biopsy was performed for 93% (50 of 54) of occult lesions, revealing 8 cancers, 1 high-risk lesion, and 41 benign lesions; 3 of the benign lesions did not have sufficient pathologic specimens but were benign at follow-up. Magnetic resonance imaging guidance was used in 86% (43 of 50) of these biopsies. One contralateral cancer was identified in the sonographically occult subset. Of the 182 lesions that underwent second-look sonography, 20% (36 of 182) had a change in management.
Conclusions: Second-look sonography has value in the evaluation of abnormalities found on breast MRI. We found enhancements in 70% (128 of 182), yielding 39 cancers.