Normal and near normal caliceal patterns in reflux nephropathy

Distorted, clubbed calices associated with focal renal scars or areas of more diffuse parenchymal loss make up the accepted urographic diagnostic criteria of chronic reflux nephropathy. It is widely believed that this diagnosis should not be suggested in the absence of the above findings and that scarring with normal calices indicates a vascular aetiology. This study describes five children with marked renal parenchymal loss all of whom have normal or near normal calices underlying the areas of parenchymal thinning and all of whom show severe vesico-ureteric reflux on micturating cystography. We suggest that these patients represent examples of true reflux nephropathy and that normal or near normal caliceal patterns may be seen underlying areas of renal parenchymal damage in this condition. No localised scars were seen in association with normal calices and we suggest that the marked tissue distortion caused by localised indented scars plays a significant part in producing the caliceal appearances more usually seen in reflux nephropathy. Other possible mechanisms responsible for the maintenance of relatively normal caliceal architecture are also discussed.