[Some fundamental notions of oncomorphology in the light of modern molecular biology advances].

Introduction of molecular biological studies into oncomorphology has made investigators reconsider many fundamental notions of the histogenesis, morphogenesis, and microscopic structure of human neoplasms. Tumor cell differentiation is a more dynamic process, a less fixed concept; hence it is necessary to do away with the rigid frameworks of cancer nosological entities and with a number of postulates on tumor histogenesis, including the rudiments of blastemic tissue changed during embryogenesis. The morphogenesis of a tumor has proven to be frequently determined by the variants of the specific translocations that may, in addition to its miscroscopic structure, affect a great variety of the clinical manifestations of disease. The molecular portrait of a tumor, the result of gene expression peculiarities can substitute for traditional cancer nosological entities although new classifications should be based on advances in oncomorphology.