Sonographic evaluation of mammographically detected microcalcifications without a mass prior to stereotactic core needle biopsy

PURPOSE: The purpose of this prospective study was to evaluate the clinical usefulness of sonographically re-evaluating areas of microcalcification found mammographically before undertaking stereotactic core needle biopsy (SCNB). METHODS: Patients with nonpalpable breast lesions appearing as microcalcifications on mammograms and who had been referred to us for SCNB were re-evaluated sonographically before the procedure. None of the breast lesions had been associated with a density on the mammograms, and the initial sonographic evaluations had been negative. Using the mammograms for correlation, we meticulously re-evaluated the areas of microcalcifications sonographically using a high-frequency linear-array transducer. The sonographic and histopathologic results were then reviewed and correlated. The sonographic findings and visibility of the mammographically detected microcalcifications were analyzed by the 2-tailed Fisher's exact test and the chi-square test. RESULTS: Sixty-six patients, who had 68 cases of microcalcifications, were enrolled. Thirteen of the 66 patients underwent surgery, and 9 of the 13 were found to have breast carcinoma. In the sonographic re-evaluation before SCNB in these 9 patients, an associated soft tissue mass was demonstrated in 5 patients but not in the other 4. Sonographic re-evaluation also revealed abnormalities in 24 of 68 cases (35.3%), in contrast to the negative findings on the initial sonography. Using the chi-square test to identify a trend, we found that the percentage of cases that were sonographically visible was highest for clustered benign microcalcifications and lowest for segmental benign microcalcifications (p < 0.0001). CONCLUSIONS: In breast lesions that appear as microcalcifications without an associated mass on mammograms, pre-SCNB sonographic re-evaluation with a high-frequency transducer can depict microcalcifications, particularly the clustered ones, and can detect small associated masses. Although the absence of a sonographically detectable mass in areas of mammographically detected microcalcifications does not guarantee the absence of cancer, the presence of an associated mass on sonography should warrant close follow-up in the case of negative results to avoid a delay in the diagnosis of breast carcinoma.