Abstract: SA-PO0372
Milky Urine and Nephrotic-Range Proteinuria: Tricky Complication After Nephroureterectomy
Session Information
- AKI: Case Reports - Drug/Toxin Injury, Crystals, Obstruction, and Unusual Presentations
October 24, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 102 AKI: Clinical, Outcomes, and Trials
Authors
- Dweik, Loai, Cleveland Clinic, Cleveland, Ohio, United States
- Subahi, Ahmed E., Cleveland Clinic, Cleveland, Ohio, United States
- Taliercio, Jonathan J., Cleveland Clinic, Cleveland, Ohio, United States
- Mohmand, Mohammad G., Cleveland Clinic, Cleveland, Ohio, United States
- Mehdi, Ali, Cleveland Clinic, Cleveland, Ohio, United States
Introduction
Nephrectomy in horseshoe kidney (HSK) is challenging due to aberrant lymphatic anatomy. Disruption of retroperitoneal (RP) lymphatics can cause chylous leaks, manifesting as chyluria or chylous ascites. We report a case of chyluria following nephroureterectomy presenting clinically as nephrotic syndrome (NS).
Case Description
A 79-year-old woman with HSK underwent left nephroureterectomy for high-grade papillary urothelial carcinoma. Three weeks postoperatively, she developed edema, dyspnea, acute kidney injury on chronic kidney disease stage 3a (baseline creatinine 1.1, peak 2.58 mg/dL), nephrotic-range proteinuria (UPCR 12 g, >5.5 g albuminuria), hypoalbuminemia (2.8 g/dL), and new ascites. Serologic workup (ANA, C3, C4, hepatitis, HIV, syphilis, serum monoclonals, PLA2R) was negative. Kidney biopsy showed age-related chronic changes with minimal foot process effacement. Urine was noted to be milky with markedly elevated triglycerides (TG) (633 mg/dL; serum TG 109 mg/dL), ascitic fluid TG were similarly elevated, confirming postoperative chylous leak with chyluria and chylous ascites secondary to lymphatic disruption. A low-fat diet was started with complete resolution of proteinuria (0.08 g/24h) within 2 weeks.
Discussion
This case illustrates how postoperative chylous complications can produce a nephrotic clinical phenotype without glomerular disease, representing a diagnostic pitfall. Elevated urine TG with normal serum TG is the key diagnostic clue, indicating a chyloureteral fistula from intraoperative lymphatic injury. Standard urine protein assays cannot differentiate glomerular-derived albumin from lymphatic-derived albumin and lipoproteins; thus, chyluria may cause substantial proteinuria, even in the nephrotic range. Concurrent chylous ascites contributed to hypoalbuminemia through extrarenal protein losses.
Spontaneous resolution supported a transient lymphatic etiology. In non-endemic regions, surgical lymphatic disruption is the leading cause of chyluria, with chylous complications occurring in up to 5% of RP surgeries and typically resolving conservatively.
Clinicians should consider chyluria when nephrotic-range proteinuria follows RP surgery, especially with milky appearing urine and negative glomerular workup. Targeted testing, including urine TG, can prevent misdiagnosis and avoid unnecessary immunosuppression or invasive procedures.