THE CLASSIFICATION AND CHEMICAL PATHOGENESIS OF URINARY CALCULI

Abstract

A new basis for the classification of urinary stones is presented, based chiefly upon the presence or absence of the metallic elements Ca and Mg. Since the metals have more physiologic significance than the inorganic anions, this method of classification may be readily correlated with present-day views as to the chemical pathogenesis of stones. The chemical mechanism responsible for the formation of each class of stone is discussed. In 100 consecutive specimens the findings were as follows: uric acid, 10; NH4-urate, 1; cystine, 1; CaC2O4, 50; Ca phosphate-carbonate, 9; Mg-containing, 29. Inorganic stones which contained Ca but no Mg were found as a rule to be independent of infection. Stones which contained Mg occurred in the presence of infection, and on culture of the urine, in some cases, a urea-splitting organism was isolated.