54th ESPN Annual Meeting, Ljubljana, Slovenia, 22 June 2022, vol.37, pp.2939
Introduction: Urolithiasis is a non-malignant condition that can affect
any part of the urinary tract. Kidney stone formation is affected by factors
such as climate, dietary habits, drugs, occupation, fluid intake, genetic
predisposition, urinary tract infections and malformations in the urinary
tract.
Material and methods: With this case report, the surprising reason for
the formation of silicate stone which is extremely rare was explained.
Results: A 7-year-old female patient who had a bone marrow transplant
due to aplastic anemia two years ago was admitted to hospital with the
complaint of stone in the urine. The patient with left flank pain noticed a
0.4x0.5mm gray-beige stone in her urine.
Upon presentation, her physical examination was normal. Laboratory
examination revealed normal kidney function test and blood gas analysis.
For urine; tubular phosphate reabsorption was 95.8%, fractional excretion
of sodium was 0.2%; urine protein/creatinine was 0.08 mg/mg, calcium/
creatinine was 0.01 mg/mg, oxalate/creatinin 0.01 mg/mg, citrate/
creatinin 0.35 mg/mg. Urine density was measured as 1007, and urine
pH was measured in fresh urine by dipstick as 6. The urine output was 3.6
ml/kg/hour. Abdominal ultrasonography was normal. She was using only
ursodeoxycholic acid as a drug for 18 months because of post-transplant
hyperbilirubinemia.
In the stone analysis performed by X-ray diffraction method, dolomite
(CaMg(CO3)2) mineral accompanied by calcium was observed in addition to the quartz mineral (SiO2). The ursodeoxycholic acid tablet form
that the patient was using was changed to the syrup form which is silicon
dioxide free. Also hydration and a salt-restricted diet are recommended in
the treatment and no new stone formation was observed in the follow-up.
Conclusions: The fact that the disease is very rare causes curiosity on this
subject. The importance of performing stone analysis as short as possible
becomes clear once again. When prescribing drugs to the patient, not only
the side effects of the active substance should be taken into consideration,
but also the possible side effects of the excipients in the drug content
should be evaluated.