Nephroid XXXX of the urinary tract. A survey of the literature, with the contribution of 5 new immunohistochemically studied cases, including one case examined by electron microscopy.

@entity1358 @entity4648 @entity420
Nephroid @entity4648 is an unusual lesion confined to the lamina propria of the lower urinary tract. It is defined by a characteristic histologic picture of tubular structures, formed by a single layer of cuboidal cells, surrounded by a thick basement membrane. Two main theories concerning the histogenesis of the condition have been proposed: embryonic origin, or @entity4648 . Five cases of @entity1358 were studied light-microscopically and by immunohistochemistry for the content of Tamm Horsfall's uromucoprotein. In addition, one case was examined by electron microscopy. The results were compared to current knowledge of the lesion obtained from a survey of the literature, with special reference to histogenesis. Morphologically, one case of @entity1358 was associated with @entity420 . It is concluded that @entity1358 arises as a metaplastic lesion, nearly always in previously traumatized urothelial mucosa. The natural history of the typical @entity1358 is benign, but a possible relationship to @entity420 , representing the malignant counterpart of the lesion, is discussed in relation to the histological findings, suggesting a rare but possible malignant potential of @entity1358 . The diverse nomenclature used for this histologic entity needs re-evaluation and should be changed to: @entity1358 .
