Renal dysplasia in nephrectomy specimens from adolescents and adults.

In a review of 156 total or partial nephrectomy specimens from patients over the age of 12 years, renal dysplasia was found 14 times. The cases were divided initially into five groups on the basis of the predominant pathological changes, namely (1) dysplasia (14 cases), (2) chronic pyelonephritis (31 cases), (3) calculous inflammation (58 cases), (4) hydronephrosis (35 cases), and (5) miscellaneous (18 cases). The diagnosis of dysplasia was made on gross and microscopic criteria and included 12 of segmental dysplasia, one of total dysplasia, and one multicystic dysplastic kidney. The principal differential diagnosis is from the irregularly scarred chronic pyelonephritic kidney. The criteria for the separation of the two are emphasized and, in particular, the distinction from those pyelonephritic kidneys with aglomerular scars. A high incidence of anomalies of drainage was found in association with dysplasia, but such were not always present. It was not thought that intrarenal reflux in infancy was an aetiological factor. Six of the cases presented with urinary infection, but only two had hypertension. It was thought that acquired glomerular damage was more important in the aetiology of hypertension than segmental glomerular agenesis.