The more that we use whole slide analysis, the more we are amazed that anyone tolerates the old way of doing things: doing image analysis or manual reads on small “representative” sample areas. Let’s look at a mouse spleen example.
Histology pattern recognition was tested on mouse spleen sections in an effort to quantitate normal splenic tissue components that are commonly altered in amount during physiologic or toxicologic adaptations. The pathologist identified 5-10 regions per slide for each lesion of interest, and then applied the analysis across the entire slide.
In the top figures, the lymphoid tissue across the whole spleen is 30.1%. But in a “representative” sample below, the lymphoid tissue comprises 46.9% – this is a 56% error!
Use the tissue, the whole tissue, and nothing but the whole tissue when running image analysis. Otherwise you will have some ‘expleening’ to do.