Theoretical aspects of diagnostic histopathology and their relation to morphometry

The theoretical aspects of diagnostic histopathology are discussed and their relationship to morphometry is examined. In diagnostic pathology, one tends to look at certain structural features, overlooking other details regarded as unimportant. In fact, the pathologist is continuously reducing the images under observation into a new simplified reality, based on a theoretical model (concept). The model is composed of features in a structural interrelation that is thought to be specific for the pathologic diagnosis being considered. The pathologist also selects appropriate regions for study in order to enhance the possible successful application of the appropriate criteria for the given diagnosis; the diversity of different tissues within, between and at different levels requires a vast experience in order to select the appropriate criteria in a specific situation. Analytical histopathology and morphometry require a more conscious construction of a model comprising the concept of the pathologic process and the criteria for its diagnosis. The theoretical background subconsciously used in the pathologist's daily practice is thus the essential knowledge for the application of morphometry in diagnostic histopathology, the basis on which elements for measurement or counting and on which compartments for calculation are selected.