Renal dysplasia
Renal dysplasia refers to abnormal and incomplete development of the kidney, which may be segmental, for instance, in the upper part of a duplex kidney, or affect the entire kidney. Dysplasia is by definition a histological diagnosis, but in most patients diagnosis is made on the basis of evaluation with ultrasound and renography. This typically shows cysts and/or a small kidney with decreased corticomedullary differentiation and a reduced split renal function. The latter can also be found in other conditions, such as hypoplasia, vascular insults, renal post-infectious damage, or polycystic kidney disease, making it difficult to establish the diagnosis and thereby estimate the incidence of renal dysplasia. The clinical consequences of renal dysplasia depend upon the residual renal function and may range from hypertension to chronic kidney disease.