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

Lobular neoplasia cells involving foci of florid hyperplasia.
The areas of lobular neoplasia obliterate the lumen and contain a less cohesive population of monotonous cells (left side of photomicrograph). Areas involved by florid hyperplasia do not completely fill the lumen, creating irregularly shaped spaces.