80 Cystic Dysplastic Kidney

Clinical Presentation

Initial abdominal sonogram in a male infant presenting with history of in utero oligohydramnios

Figure 80A

Figure 80B

Radiologic Findings

A highly echogenic kidney is evident on longitudinal (Fig. 80A) and transverse (Fig. 80B) ultrasound images with loss of the normal corticomedullary differentiation. Note the kidney is much more echogenic than the adjacent liver. A few small, peripheral, anechoic cysts are seen. Both kidneys have similar appearances and are small for age.

Diagnosis

Bilateral (cystic) renal dysplasia

Differential Diagnosis

Autosomal dominant polycystic kidney disease (normal kidneys usually seen in early childhood and rarely manifest with identifiable cysts in infancy)
Autosomal recessive polycystic kidney disease (large echogenic kidneys are seen without resolvable cysts)
Multicystic dysplastic kidney (MCDK) (unilateral disorder with multiple large cysts without identifiable normal renal parenchyma in a nonfunctioning kidney)
Acute tubular necrosis (causes enlarged kidneys without any cystic change)