[Histomorphology of inflammation]

Progress in biochemistry of inflammation, particularly in the identification of mediators of inflammation, has considerably deepened our understanding of the histomorphology of inflammatory lesions. In surgical pathology, the traditional histologic differentiation between specific and non-specific inflammation still plays a certain role. This differentiation, on the other hand, has lost significance since it became evident that specific inflammatory reactions, such as epithelioid cell granuloma formation, can be observed in diseases of completely different etiology. Consequently, the histological picture does not reflect the activity of a particular etiologic agent but rather images the action of mediators of inflammation. Which mediators are released depends not only on the inducing agent but also on numerous other factors. This holds true for specific as well as non-specific inflammation and also for immunopathologic (allergic) reactions. In most instances the modulating effect of the fine structure of tissues (e.g. capillary angioarchitecture) on the intensity, type and course of inflammatory processes is covered by other predominating influences. The most important new aspect in the histomorphology of inflammation is the possibility--nowadays--of interpreting histological patterns of inflammation in terms of known pathomechanisms.