Fig. 1.

Distribution of benign lesions by subtype, according to pathology reports. Fibroadenomas comprised 49% and 43% of the benign lesions imaged prebiopsy and postbiopsy, respectively, and 21% and 22% of each sample, respectively, were characterized by fibrocystic change. Subtype information was not available from pathology reports for $\sim 12\%$ and 7% of the benign lesions imaged prebiopsy and postbiopsy, respectively.