An intrarenal opacity resisting extracorporeal shock wave lithotripsy.

Milk of calcium renal stone refers to an entity described in connection to a similar condition in gallbladder disease. The intrarenal accumulation of calcium carbonate imitates a calcific density and frequently is located within a caliceal diverticulum or a pyelogenic cyst. Symptomatology, if present, mainly refers to a continuous flank distress but colicky pain complaints are rare. The diagnosis is radiological. The typical impression of a shifting fluid level is apparent when comparing x-rays with the patient in the supine position, and in the upright and lateral projections. When extracorporeal shock waves are applied on this target no fragmentation is achieved. Although the calcium content will account for a difference in acoustical impedance, neither a cleavage nor a fracture plane can be generated within the fluid calcium salt deposits.