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

Microinvasive carcinoma with adjacent high grade DCIS, low power.
Note the small groups of invasive tumor cells in the right hand side of the photomicrograph. Some of these clusters have irregular shapes reminiscent of conventional invasive carcinoma. The microinvasive foci have attracted a lymphocytic reaction. Microinvasion is most often associated with a high-grade intraductal carcinoma.