Digital Atlas of Breast Pathology by Meenakshi Singh, MD © - Department of Pathology, Stony Brook University Medical Center

Angiosarcoma,low grade,  high power.
The nuclei are more hyperchromatic and bulge into the vascular space differentiating this from a benign hemangioma; however, mitotic figures are not present signifying its low-grade designation. Solid aggregates of endothelial-like cells are surrounded by vascular spaces.