Randall's plaques, plugs and the clinical workup of the renal stone patient.

Renal stone patients are generally considered to be affected with the idiopathic form of calcium nephrolithiasis. It is debated whether a comprehensive diagnostic evaluation should be performed in first stone patients. There is a substantial number of first or mildly recurrent stone formers who do not undergo any work-up to investigate stone etiology and in whom stone etiology is unknown. In this setting, the endourological approach can provide the treating physician with diagnostic information based on the presence of Randall's plaques and/or ductal plugs, thus triggering the need for further clinical investigations.