Figure 5b. Diabetic mastopathy in a 26-year-old woman with long-standing insulin-dependent type 1 diabetes mellitus who presented with a palpable mass. (a) Craniocaudal mammogram of the left breast shows subtle foci of asymmetric density in the outer quadrant at the location of the palpable mass (arrows). (b) US image reveals an irregular hypoechoic mass with ill-defined margins and discrete acoustic shadowing. (c) Photomicrographs (original magnification, x400 [left] and x200 [right]; H-E stain) reveal extensive collagenous stromal fibrosis (*) accompanied by the characteristic perivascular (left) and periductal (right) lymphocytic inflammatory infiltration.