Abstract

SUMMARYIn summary, I have reviewed in its simplest aspects the evidence now at hand from experimental, clinical and pathologic studies into the cause of urinary calculi. I have proposed and supported the thesis that instead of arising from crystalline deposition from the free urinary stream after excretion, stone arises from a precedent lesion in the surface epithelium of the urinary tract with subsequent deposition of crystalline matter at the site of this lesion. An attempt has been made to show how the various mechanisms of stone formation assume their respective activities on such a pathologic basis.Admittedly there are many gaps in our knowledge as to the cause of such localizing lesions in the urinary epithelium and our concepts of the various mechanisms producing a stone forming urinary tract are all too inadequate. Nevertheless as we take stock of the evidence which we have, the result of research for the past twenty-five years, we, must come to think of stone formation in a new light. It is a pathologic process involving localized injury to the surface epithelium of the urinary tract by metabolic, toxic or bacterial agency with the subsequent deposition of crystalline matter when and where such sites are exposed to a supersaturated urinary stream capable of concomitantly precipitating crystalline and colloid material thereon.