Renal papillary morphology in infants and young children.

The morphology of the renal papillae was studied in a series of necropsy kidneys from infants and young children, and related to experimental data obtained in piglets. As in the piglet, extensively fused papillae of the type associated with intrarenal reflux occurred almost exclusively at the upper and lower poles of the kidney. However, the incidence of this kind of papilla was much lower in the children's kidneys, and in over a quarter of the specimens examined only cone-shaped papillae were found; this latter type of papilla is never associated with intrarenal reflux in the piglet.