This study was performed to determine the negative predictive value of sonography with mammography in evaluating palpable breast lesions.
Four hundred twenty patients with 455 palpable breast lesions were retrospectively identified from our mammography database as having negative mammographic and sonographic results. For patients diagnosed with breast cancer, images and medical records were reviewed to determine whether the palpable lesion evaluated on sonography and mammography corresponded to the patient's breast cancer. On the basis of the number of breast cancers that correlated to the palpable areas imaged, the negative predictive value of sonography with mammography was determined.
Sixty-two of the 420 patients in the study group were already diagnosed with breast carcinoma, and eight new carcinomas were diagnosed during the study period. Only one of six ipsilateral cancers corresponded to a palpable lesion that had a negative imaging evaluation. This lesion was diagnosed as an invasive lobular cancer, hard and fixed at physical examination. Imaging and clinical follow-up of the remaining patients showed no abnormality at the sites of previously investigated palpable abnormalities. The mean imaging follow-up was 25 months. The negative predictive value of sonography and mammography in the setting of a palpable lesion was 99.8%.
The negative predictive value of sonography with mammography is high, and together these imaging modalities can be reassuring if follow-up is planned when the physical examination is not highly suspicious. However, if the physical examination is suspicious, biopsy should not be delayed.