Epithelioid Cell: A New Opinion on Its Nature, Parentage, Histogenesis, Cytomorphogenesis, Morphofunctional Potency, Role in Pathogenesis and Morphogenesis of Tuberculous Process

It is known that during an embryogenesis form a well-defined for each type of organism the number of cell types, each of which has its own specific morphophysiological characteristics. Some cells operate only at certain stages of embryonic development and then disappear as a result of apoptotic death, while others are unique for adult organism. However, in researching of granulomas formed in some granulomatous diseases have been described cells are not found in a healthy organism. To such cells referred «basophilic hystiocytes» in rheumatic disease, Mikulich cells in scleroma, epithelioid cells (ECs), formating ECs granulomas in a number of infectious, including tuberculosis, as well as some allergic and autoimmune diseases. It was shown that ECs forming in nidus of the inflammation in granulomatousis diseases of different etiology. Suppose that ECs do not enter number of differentiated cell-like types neither embryonic not adult organism; they occur only at particular pathological statuses and forming ECs-granulomas. This granulomas determine clinicomorphologic essence of many granulomatousis diseases in man. Moreover, the ECsgranulomas form in different groups animals, relating to different branches of "phylogenetic tree". Thus, ECs formation in the nidus of inflammation can be related to one of most ancient mechanisms of cell-like response on imbalance of the "antigenic-structural" homeostasis in organism. The concept of ECs origin from cells of macrophages (Mphs) family till now is considered conventional, which some theoretical fundamentals were placed in workers of Ashoff L. (1924) and Maksimov А. (1926). Affirms that ECs transform from Mphs located in the nidus where the pathological process flows past and under some conditions directly from monocytes of a blood. This concept is based on the hypothesis that in a basis of the differentiation resulting in to derivation ECs from Mphs in reply to particular pathogenic stimulus lie the changes of genic activity and that in a basis of this transformation resulting in to formation ECs lie epigenetic changes, and the phenomenon can be considered as “intra-tissue transdetermination” (Shvemberger, 1976). Important thus to mark that till now is not obtained sufficiently convince facts touching not only the