Biopsy of amorphous breast calcifications: Pathologic outcome and yield atstereotactic biopsy

PURPOSE: To assess the pathologic outcome of amorphous breast calcification s and the success of stereotactic biopsy for such lesions. MATERIALS AND METHODS: From July 1995 through February 2000, biopsy of all clustered amorphous calcifications not clearly stable for at least 5 years or in a diffuse scattered distribution was recommended. Logistic regression analysis was used to stratify the risk of malignancy by patient risk facto rs, calcification distribution, and stability. RESULTS: Calcifications were retrieved from 150 biopsies; 30 (20%) proved m alignant and included 27 ductal carcinomas in situ and three low-grade inva sive and intraductal carcinomas (2-5 mm). Another 30 (20%) yielded high-ris k lesions, including 21 atypical ductal hyperplasia, eight atypical lobular hyperplasia, and one lobular carcinoma in situ. In 150 lesions, stereotact ic biopsy was performed on 113 and aborted in 10. Calcifications were retri eved from all 113 stereotactic biopsies. Of those with calcification retrie val, there were three histologic underestimates (accuracy, 97%). Stereotact ic biopsy spared a surgical procedure in 57 (46%) of 123 patients. Needle l ocalization was required for 23 (15%) of 150 patients due to poor conspicui ty. Five (45%) of 11 biopsies performed in women with ipsilateral breast ca ncer showed malignancy (P =.025). When multiple lesions of amorphous calcif ications were present in one breast, sampling of one reliably predicted the outcome of others. CONCLUSION: We found a substantial rate of ductal carcinoma in situ and hig h-risk lesions associated with amorphous calcifications. Stereotactic biops y can be successfully performed for the majority of subtle amorphous calcif ications; however, only a minority were spared a surgical procedure.