ADENOMATOID TUMORS OF THE BLADDER REPRODUCING RENAL STRUCTURES (NEPHROGENIC ADENOMAS)
ADENOMATOID TUMORS OF THE BLADDER REPRODUCING RENAL STRUCTURES (NEPHROGENIC ADENOMAS)
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DOI：
10.1016/s0022-5347(17)68693-2
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发表时间：
1950-01-01
影响因子：
6.6
通讯作者：
KUHLENBECK, H
中科院分区：
文献类型：
--
作者：
FRIEDMAN, NB;KUHLENBECK, H
The urinary bladder and adjacent structures of the genito-urinary tract have a complex developmental history, both phylogenetic and ontogenetic. Entoderm and mesoderm, the latter evaginated from the metanephric and the mesonephric duct, join to form the peculiar epithelial lining of the bladder, generally known as transitional epithelium, but perhaps more suitably designated as urothelium. In its characteristic stage of differentiation, which is frequently not sufficiently emphasized in the standard histology texts, transitional epithelium or urothelium consists of two layers (Schaffer, 1927). The single surface layer has large, cuboid, often binucleate cells. The basal layer is pseudostratified, consisting of rounded and elongated pear-shaped cells all of which are anchored with a cytoplasmic process to the reticular tissue of the propria. Detached cells of this type represent the tailed epithelial cells found in urinary sediments. In the stretched organ the surface cells flatten, and the basal cells lose their pseudostratified arrangement and become arrayed in a single layer (fig. 1). Urothelium in its pure form is thus a two-layered epithelium with two functional patterns. In the contracted state the basal layer is single but pseudostratified, the surface layer single and cuboid; in the distended state the basal layer becomes simple and the surface layer flattened. Transitions between the typical form of urothelium and modifications of stratified squamous or columnar epithelium occur, contributing to the considerable doubt about the exact nature of" transitional epithelium" as is evident from a study of the literature. Since both mesodermal and entodermal derivatives develop into urothelium, the histogenesis of that type of tissue is another exemplification of the well known fact that the germ layers are by no means specific as far as differentiation of tissues is concerned. Nevertheless certain predominant histogenetic potencies may well be inherent in each germ layer, and the distinction of entodermal, mesodermal, and ectodermal tissues appears justified and has definite but limited usefulness.In the histogenesis of bladder tumors, the hidden potencies of the germ layers become manifest. Entodermal potencies may find their expression in the formation of allantoid tumors and those with enteric structure (Colby, 1925); mesodermal potencies in the development of endometriosis (O'Conor and Greenhill, 1945; Phillips, 1934), or in the formation of tumors containing structures of endometrial type.
