[Bronchial lympho-epithelial nodules in the rat. Definition and morphological characteristics in optical and electron microscopy (author's transl)].

Among the bronchial lymphoid tissue, lympho-epithelial nodules are an original component, easily distinguished from other structures, particularly from lymphoid cell infiltrates. Such structures are encountered in many species and may be characterized by a flattened epithelium, containing a few ciliated cells, devoid of mucus producing cells, and infiltrated with lymphocytes. Inter and intracellular vacuoles are described in the lympho-epithelium and the underlying mucosa. Electron microscope studies support the view that lymphoepithelium has a "trapping" function of particulate matter, more direct evidence is however attempted. Peripheral lymphatic vessels and high endothelium veins contribute to the important lymphocyte transfer. An hypothesis of capacity for antigenic recognition of the lymphoepithelial nodule is discussed.