Acute renal failure due to bilateral pieloureteral stone impaction in a 10-month-old boy.

[cystinuria]

Urolithiasis (UL ) can present with its classic signs and symptoms , such as flank or abdominal pain and gross hematuria . However , atypical complaints can be more common in younger children . We report here a case of bilateral ureteropelvic junction (UPJ ) stones in a 10 -month -old boy who only showed nonspecific symptoms at the time of presentation . The initial blood test revealed renal failure (serum creatinine 3 .4 mg /dl ), hyperkalemia (6 .4 mEq /l ), hyperphosphoremia (9 .4 mEq /l ) and mild metabolic acidosis . Medical treatment for electrolyte disorders was started . The ultrasonography revealed impacted stones in both ureteropelvic junctions . A pigtail catheter was placed in each ureter . High urine flow was promptly achieved after the pigtail procedure , and the serum creatinine level dropped quickly from 4 .5 to 0 .32 mg /dl . Quantitative determination of urinary amino acids by ion exchange chromatography showed high cystine levels of 8 .43 mmol /g creatinine . Outpatient follow-up was scheduled every 3 months to monitor patient compliance with potassium citrate . In the first 6 months , the patient underwent three febrile urinary tract infections (UTIs ). Since both pigtail catheters were removed , he has been free of UTIs and stones . Our case emphasizes the need for considering UL in infants who complain with unclear signs , because UL can only show nonspecific symptoms in children younger than 1 year old . Since cystinuria can cause loss of renal function due to urinary system obstruction and UTI , an early diagnosis and a close follow-up are the key to achieving the best long -term outcome .