Presentation
Known urolithiasis, microhaematuria.
Patient Data
Non-enhancing lesion adjacent to a renal calyx, that mainly shows homogeneously hyperdense attenuation values with some sedimented denser gravel or debris. There is also a small calculus in the lower calyx, best seen on the MIP.
Case Discussion
Renal milk of calcium cysts are rare. They typically arise in calyceal diverticula and contain a suspension of crystals. Sedimentation of denser material is a typical feature but may be missed after a change of position (as in CT). Treatment is normally not necessary, but they have to be differentiated from calculi within the collecting system 1.