Renal Dysplasia: Differential Diagnosis

Differential Diagnosis: Multicystic kidney dysplasia (MKD) with urinary obstruction has to be distinguished from hydronephrosis without dysplasia. In pure hydronephrosis, there is extreme thinning of the renal medulla, whereas in hydronephrotic dysplastic kidney, the cortex is more severely affected. Dysplastic kidney also shows collarettes of primitive smooth muscle around immature ducts and tubules. This feature is absent in pure hydronephrosis. Additional entities in the differential diagnosis include primary renal neoplasms that may be cystic (Wilms tumor, mesoblastic nephroma), sporadic glomerulocystic kidney disease, tuberous sclerosis and polycystic kidney disease.

This image from a case of MKD shows portion of a large cyst and immature disorganized renal parenchyma in the cyst wall.