Not true about `Struvite Stones' is -
better k/a staghorn calculus
these are triple phosphate stones
common in infected urine
usually seen in acidic urine
Ans. is 'd' ie Usually seen in acidic urine Struvite stone tends to grow in alkaline urine* esp. when proteus organisms are present which split urea to ammonia". Types of Renal Calculus a) Calcium oxalate calculus (Most common*) - they have hard, small and jagged surface b) Phosphate calculus - calcium phosphate but can be combined calculus* ie Calcium amnomium magnesium phosphate also k/a struvite stones. - smooth and diy white and soltitary*. - seen in alkaline urine esp with proteus infection which split urea to ammonia. - this type of calculus may enlarge to fill all or most of the renal collecting system forming a staghorn calculus*. c) Uric acid and urate calculus - these are radioluscent* - Form in acidic urine - Most responsive to lithotripsy d) Cystein stones uncommon, seen in cystinuria - appear only in acidic urine* - they are pink to yellow when first removed but they change colour to a greenish hue when exposed to air. extremely hard stones - are relatively resistant to fragmentation by ESWL e) Xanthine calculi - are radioluscent* - are secondary to a congenital deficiency of xanthine oxidase f) Indinavir calculi Indinavir is a protease inhibitor used in AIDS patients. It results in calculi in --6% pt. who use. indinavir. Indinavir calculi are radioluscent. Rare Calculi Silicate stones - associated with the long term use of antacids containing silica Triamterene stones associated with antihypeensive medications containing trimterene are radioluscent