REFERENCE AND ABSTRACT TO CLASSICAL ARTICLE. The mouse mammary tumorsystem(model) was intensively studied for many years by Professor Kenneth DeOme and his associates at the Cancer Research Laboratory at the University of California at Berkeley. Precancerous hyperplastic alveolar nodules, readily identified in whole mounts of mouse mammary glands, were studied in detail.
In order to search for similar lesions in women(ref), 196 whole breasts were sliced in the parasaggital plane at a thickness of 2-3 mm, obtaining fifty to one hundred slices per breast. The slices were next defatted, stained with hematoxylin, cleared in methyl salicylate, sealed in plastic bags and examined at low powers (5-10 x) (subgross level of observation) with a dissecting microscope. For each breast in the study all lesions were classified, counted and photographed. Differential counts of lesions were correlated with age and clinical history. Histology slides of each lesion, stained with hematoxylin and eosin, were compared with the subgross phototgraphs. Striking similarities between mouse andhuman were observed. The purpose of this presentation is to offer the data in a form useful to current investigators.
REFERENCE AND ABSTRACT TO CLASSICAL ARTICLE. 
To lecture images: 1-16.
To lecture images: 17-32.
To lecture images: 33-48.
To lecture images: 49-64.
To lecture images: 65-75.
To lecture images: 61-68. Histology self test. Can you predict the subgross appearance?
To lecture images: 69-75. Subgross self test. Can you predict the histological appearance?
To ductal carcinoma-in-situ, comedo type.
To infiltrating duct carcinoma
To lobular carcinoma-in-situ.
To ductal carcinoma-in-situ, micropapillary (cribriform) type.
To apocrine metaplastic cysts, possible markers for increased risk.
To atypical lobules, type A (ALA).
To TDLU.