Pathology is the study of abnormalities or diseases in an organism. A complete and correct identification and interpretation of abnormalities is crucial, if we are to understand the complex effects of experiments on the organism and all its organs and tissues. Distinguishing spontaneous background pathology from true experimental results is one of the key challenges. Many abnormalities can be detected by histopathology with light microscopy using hematoxylin and eosin staining, and can be further investigated with special stains and additional methods. Histotechnicians process the tissues, cut and stain tissue slides, and optimize methods to allow light microscopic analysis of tissue slides by pathologists. Comparative pathologists use their medical knowledge of both mouse and human physiology, anatomy and pathology, to translate scientific findings in animal models to the human species.
H&E staining on various lung lesions of mice with conditional deletion of Pten and Cdkn2ab. Figure 2C from Cancer Cell, 2016, Ferone et al., SOX2 Is the Determining Oncogenic Switch in Promoting Lung Squamous Cell Carcinoma from Different Cells of Origin.
Early stromal recruitment in mouse and human classic lobular carcinoma of the mammary gland. Figure 6 from Cell Reports, 2016, Boelens et al., PTEN Loss in E-Cadherin-Deficient Mouse Mammary Epithelial Cells Rescues Apoptosis and Results in Development of Classical Invasive Lobular Carcinoma.