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

Microglandular adenosis with adjacent atypical lobular hyperplasia.
The microglandular adenosis (upper right) is a problematic diagnosis as it does not contain myoepithelial cells and therefore is difficult to differentiate from tubular carcinoma. Differentiation is thus made generally at low power on the apparent infiltrating character. Atypical lobular hyperplasia (lower left) is noted by distended lobules with relatively benign-appearing cells.