Malignancy rates of stereotactic biopsies of two or more distinct sites of suspicious calcifications in women without known breast cancer.

OBJECTIVE: To determine the malignancy rate in women without a concurrent breast cancer diagnosis at presentation who underwent stereotactic biopsies of distinct sites of suspicious calcifications.

METHODS: This retrospective study included 280 women without a concurrent breast cancer diagnosis who underwent 587 stereotactic biopsies of two or more distinct sites of suspicious calcifications in one or both breasts at our institution from 2010 to 2015.

RESULTS: The overall malignancy rate was 27.9% (78/280, 95% CI, 22.7%-33.5%) at the patient level and 18.7% (110/587, 95% CI, 15.7%-22.1%) at the lesion level. Eighteen had invasive cancers (mean [range] diameter, 0.5 cm [0.1-1.7]; six grade I, ten grade II, two grade III), one of whom had multifocal and another bilateral malignancy. Sixty had ductal carcinoma in situ. Of the 171 with all calcifications of the same morphology, 139 (81.3%) had all calcifications in the same pathology category (benign, high-risk, or malignant).

CONCLUSION: The malignancy rate is substantial in women who undergo stereotactic biopsies of two or more distinct calcification sites. Given the nearly 20% rate of dissimilar histopathology between calcification sites with similar morphology, if only one site is biopsied and results in a malignant pathology, biopsy of the additional calcifications is warranted. Even if the pathology result of the one site biopsy is benign, biopsy of additional sites may perhaps still be necessary.