Infant with prenatal diagnosis of left multicystic dysplastic kidney

US of kidney agenesis and seminal vesicle cyst / Zinner syndrome
Sagittal US of the left renal fossa (above) demonstrated that no left kidney was present in the left renal fossa or pelvis. Transverse ultrasound of the bladder (below) demonstrated a cystic structure adjacent to the left side of the bladder.

The diagnosis was left kidney agenesis and a left seminal vesicle cyst, which is Zinner syndrome.