Renal milk of calcium cyst


Key learning points:

  • typically an incidental finding that does not require further treatment
  • most frequently seen in calyceal diverticulae but can also occur in renal cysts
  • on abdominal radiographs has a "full moon" appearance on supine projections, which changes "half moon" appearance on erect project
  • on ultrasound has dependent echogenic material within a hypoechoic cyst