[About eosinophilic infiltration in cellular tissue (author's transl)]

With this paper, we want to settle the part of eosinophilia in the definition of diseases as entities. Consequently, we emphasize the contribution of eosinophils in the histological diagnosis. Eosinophilic infiltration is the main marker of several lesions. We review successively some of these entities. They belong to tumoral or inflammatory (without or with vasculitis) pathology. The function of eosinophils must improve our knowledge about the significance of all these lesions (parasitic infestation, hypersensitivity...). These physiopathological mechanisms must be helpful to draw some new borders between these different entities.