Figure 3a. Developing benign asymmetric tissue. (a) Mediolateral view of the deep upper part of the breast on a baseline mammogram. (b) Mammogram of the same area as in a obtained 1 year later shows amorphous tissue (arrow) that was not present on the prior image. (c) Sagittal fat-suppressed, three-dimensional spoiled gradient-echo postcontrast MR image (26.9/3.1) shows no abnormal enhancement of this tissue (arrow). (d) Photomicrograph of an excisional biopsy specimen of this asymmetric tissue reveals ductal hyperplasia (straight arrows) and extensive pseudoangiomatous stromal hyperplasia (large area delineated by curved arrows). (Hematoxylin-eosin stain; original magnification, x150.)