Renal milk of calcium cyst

Case contributed by Dr Henry Knipe


Epigastric pain ?perforation.

Patient Data

Age: 35
Gender: Female

Ill-defined rounded opacity on the supine film projects over the upper pole of the right kidney demonstrates layering on the erect projection. 

No evidence of pneumoperitoneum. 


Ultrasound confirms finding of echogenic structure with dependent echogenic material, consistent with milk of calcium cyst. 


CT confirms presence of a renal cyst, likely calyceal in origin, with dependent calcification. 

Case Discussion

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
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Case information

rID: 31487
Published: 13th Oct 2014
Last edited: 14th Aug 2019
System: Urogenital
Inclusion in quiz mode: Included

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