<prompt> Management of 4 cm size renal staghorn calculus.Extracorporeal shock wave lithotripsy ESWLPercutaneous nephrolithotomy PCNLPyeloplastyOpen pyelolithotomy  <response>: ANS. B Management of renal calculi Stones 6 mm--conservative treatment Stones from 6 mm to 2 cm: ESWL Stones 2 cm: PCNL For stones at lower renal calyx: Do PCNL For staghorn calculi: ESWLPCNL Sandwich techniqueShapes of urinary stonesLeucine stones--spherical-shapedTyrosine stones--needle-shaped 