Abstract: PUB023
A Rare Case of Staghorn Calculi Complicated by Bilateral Xanthogranulomatous Pyelonephritis
Session Information
Category: Trainee Case Report
- 402 Bone and Mineral Metabolism: Clinical
Authors
- Chang, Michael, Montefiore Medical Center, Bronx, New York, United States
- Dellacerra, Gary, Montefiore Medical Center, Bronx, New York, United States
- Sharma, Deep, Montefiore Medical Center, Bronx, New York, United States
- Stern, Joshua M., Montefiore Medical Center, Bronx, New York, United States
- Nauka, Peter, Montefiore Medical Center, Bronx, New York, United States
- Chen, Wei, Montefiore Medical Center, Bronx, New York, United States
Introduction
Staghorn calculi are usually unilateral and typically occur in women. Chronic obstruction and infection of staghorn calculi can cause xanthogranulomatous pyelonephritis (XGP), a rare destructive granulomatous process of renal parenchyma. We describe a case of bilateral staghorn calculi in a man complicated with XGP and worsening renal function.
Case Description
A 64-year-old man with bilateral staghorn calculi and chronic kidney disease (CKD) stage 4 was admitted for fatigue and worsening renal function. He tested positive for COVID-19 by nuclei acid-based test. Serum creatinine increased from 3.5 (2 months ago) to 6.2 mg/dL. Renal ultrasound showed dilated left calyces and large shadowing calculi without hydronephrosis. History was notable for persistently alkaline urine (urine pH >6.5), 100% carbonate apatite (dahllite) on stone analysis, and urinary tract infection with Proteus mirabilis. CT imaging revealed bilateral staghorn calculi with “bear paw” signs (left > right), a typical appearance of XGP [Figure]. Compared to a CT scan completed 10 months ago, the left kidney was enlarged with greater low-attenuating spaces indicating worsened XGP; the right kidney decreased in size with less stone burden corresponding to the right percutaneous nephrolithotomy performed 7 months prior. AKI was thought to be related to COVID-19, and surgical intervention was deemed unnecessary. Bilateral XGP likely increased his risk of AKI and hampered renal recovery, and he was subsequently initiated on hemodialysis.
Discussion
In this rare case of staghorn calculi progressed to bilateral XGP, we observed the detrimental effects of staghorn calculi on the kidneys. More research on staghorn calculi is needed to improve the high morbidity and mortality associated with this disease.
Figure. Abdominal CT- 10 months prior (left): bilateral staghorn calculi with rounded areas of low-attenuation replacing renal parenchyma representing “bear paw” signs (white arrows). Present (right): interval enlargement of left kidney with larger low-attenuating spaces consistent with worsened XGP; smaller right kidney with less stone burden.