Abstract: SA-PO0354
When Contrast Isn't to Blame: Severe AKI with Mild Hydroureteronephrosis in Metastatic Malignancy
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
- Khater, Abdarrhman, Stony Brook Medicine, Stony Brook, New York, United States
- Ali, Muhammad, Stony Brook Medicine, Stony Brook, New York, United States
- Santos, James Urbano, Stony Brook Medicine, Stony Brook, New York, United States
- Kaur, Navdeep, Stony Brook Medicine, Stony Brook, New York, United States
Introduction
Acute kidney injury (AKI) in advanced malignancy is frequently multifactorial. Malignant ureteral obstruction from extrinsic compression may present with only minimal hydronephrosis yet cause severe post-renal AKI, creating diagnostic uncertainty and risk of anchoring bias.
Case Description
A 59-year-old man with metastatic perianal squamous cell carcinoma receiving retifanlimab was hospitalized for severe thrombocytopenia. Baseline serum creatinine was 0.6–0.7 mg/dL and progressively increased to 3.18 mg/dL during hospitalization. Urinalysis was bland, and the patient had undergone multiple recent contrast-enhanced CT scans. Initial imaging demonstrated only mild bilateral proximal hydroureteronephrosis. Given the temporal association with contrast exposure and systemic therapy, the initial working diagnosis favored contrast-associated AKI with possible medication-related nephrotoxicity.
Despite supportive care, kidney function continued to deteriorate rapidly. Repeat imaging three days later again demonstrated mild bilateral hydroureteronephrosis without a discrete obstructing lesion. Foley catheter placement failed to improve renal function. Due to progressive AKI despite only mild radiographic findings, bilateral nephroureteral tubes were placed. This resulted in brisk post-obstructive diuresis and rapid recovery of kidney function, with serum creatinine returning to baseline within days, confirming severe post-renal AKI from malignant obstruction.
Discussion
This case highlights how malignant ureteral obstruction may cause severe AKI despite minimal hydronephrosis on imaging. In patients with advanced malignancy, rapidly progressive AKI should prompt continued evaluation for evolving obstruction even when alternative etiologies appear plausible. Avoiding diagnostic anchoring is critical, as timely decompression may rapidly restore kidney function and prevent irreversible kidney injury.