Daily Archives: July 26, 2019

Renal milk of calcium cysts

Renal milk of calcium refers to the viscous colloidal suspension of calcium salts found either within a calyceal diverticulum or within a simple renal cyst. Unlike stones, milk of calcium is typically asymptomatic and does not require intervention. In fact, shock wave lithotripsy is ineffective for the treatment.

The etiology of milk of calcium is unclear; however, it may be related to urine stagnation (obstruction) and infection. As a colloid suspension, the calcium salts gravitate to the most dependent portion of the cavity. This layering (gravitational) effect leads to the radiological finding of crescent-shaped dense lesion with a fluid level at the upper border of the stone and may change positions with patients’ position. This finding is reported in KUB, ultrasound and more evident on CT scan. Acoustic shadowing is usually absent but may be seen with larger depositions. Reverberation artefact is seen sometimes.