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

Intracystic papillary carcinoma, high power.
In contrast to papillomas, the epithelial cells in papillary carcinoma grow in a more haphazard fashion showing uneven stratification and loss of polarity. Myoepithelial cells are absent.