Pediatric Renal Cyst

Etiology: Occurs in a kidney with otherwise normal renal parenchyma
Imaging US Simple cyst:
— Most common
— Anechoic, thin-walled, no septations or calcification or Doppler flow
Imaging US Complex cyst:
— Less common
— Thick wall, septations, calcification, Color Doppler flow
DDX:
Complications:
Treatment:
Clinical: Rarer in children than in adults but increases in incidence with age

Radiology Cases of Renal Cyst

Radiology Cases of Simple Renal Cyst

CT of simple renal cyst — Coronal (left) and axial (above right) images from a CT with contrast of the abdomen obtained soon after the injection of contrast (nephrographic phase) show a claw sign in the right kidney encasing a large round low density lesion in the lower pole of the right kidney. The Hounsfield unit of the cystic lesion was that of water. Axial delayed image (excretory phase) from the same exam (below right) shows no contrast in the cystic structure.

CT and ultrasound of a simple renal cyst — Axial (above left) and coronal (above right) CT with contrast of the abdomen show a round low density lesion in the upper pole of the right kidney. Sagittal US of the right kidney (below) shows an anechoic lesion in the upper pole of the right kidney that has a thin wall and no internal septations or calcifications.

Radiology Cases of Septated Renal Cyst

CT of pediatric septated renal cyst — Axial (above) and coronal (below) CT with contrast of the abdomen show a round low density lesion in the superior pole of the right kidney that has a thin septation within it.