The Rôle of the Neural Crests in the Embryonal Adenosarcomas of the Kidney

The malignant tumors of multiple tissues or adenosarcomas of the child9s kidney form a group the appearance of which, in spite of an extreme polymorphism, is still characteristic enough so that their diagnosis is easily made by any experienced histologist. Classical Data on the Structure of the Adenosarcomas Renal Blastema: The diagnosis of renal adenosarcoma depends upon the existence of a special tissue complex, the varied aspects of which can easily be related one to another in the same fashion as are stages of histogenic development. In its primitive state this complex has a mesenchymatous foundation which is highly vascularized, with stellate cells forming a loose network through the interstices of which run collagen fibers. In this basic tissue are collections of cells, compressed one against the other, which are so poor in cytoplasm that their rounded or oblong nuclei are almost contiguous. These dense collections are not vascularized; they have the appearance of nodules or of irregularly ramifying cords beaded with swellings. Their peripheries are always vague and indefinite throughout their extent, formed by cells which are more and more widely separated, branching and in continuity with the surrounding mesenchymatous network. In places these borders appear distinct and the nodules or cords seem to push back the loose mesenchyme about them; but an examination with high magnification shows after all a symplastic continuity between the cell groups and the loose mesenchyme which surrounds them in such a fashion that the compact masses and the basic mesenchyme form a whole and seem to correspond to two states of a single tissue.