Morphological and chemical study of urinary calculi.

Of 50 patients with urinary calculi, upper tract stones were common between 15-44 and lower tract stones between 0-14 and above 44 years of age. Urinary calculi contained calcium, phosphate, oxalate, urate/uric acid, ammonium, magnesium and carbonate. The frequency of occurrence of each of these radicals in sixty stones was 93.33, 83.33, 61.67, 51.67, 25.00 and 13.33% respectively. Five (27.78% ) out of eighteen different combinations of acidic and basic radicals seen in the stones, analysed were of pure lithiasis and the rest were mixed. The most frequent combination observed in upper urinary tract stones was calcium oxalate and calcium phosphate. The cut surface of the stones revealed that 60% stones were featureless. Only vesical stones made of Ammonium urate, Ammonium urate +calcium phosphate and Ammonium urate + Calcium phosphate + Calcium oxalate were laminated and contained well defined nucleus (JPMA 36: 300. 1986).