[Criteria of organ specificity of a tumor]

On the basis of literature the markers of organ and tissue tumour specificity are reviewed. Signs of specific cell differentiation, similarity of tumour cells to the homologous cells of normal tissues are found electron-microscopically, histochemically (immunohistochemically and histoenzymochemically) in many organ-nonspecific tumours. Carcinoma cells with the ultrastructural features of organospecificity can be considered to be the cells-markers of the organ appurtenance of the tumor. Biological tumour markers (oncofetal antigens, ectopic hormones and enzymes) revealed until now in the serum and secretes of a tumour-bearing host, are not specific for a tumour of a single type. The search of criteria of tumour organospecificity (so-called biological, ultrastructural and histochemical markers) is necessary for precise tumour verification, determination of its histo- and cytogenesis and its primary location.