Abstract: SA-PO0361
Subcapsular Hematoma in the Setting of Escherichia coli Pyelonephritis and Bilateral Renal Cysts
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
- Saka, Fatimatou, Charles R. Drew University of Medicine and Science, Los Angeles, California, United States
- Stoll, Seaverson D., Dignity Health St Mary Medical Center, Long Beach, California, United States
- Zaidi, Navid S., Dignity Health St Mary Medical Center, Long Beach, California, United States
Introduction
Spontaneous renal subcapsular hematoma (Wunderlich syndrome) is an uncommon condition most often associated with renal neoplasms or anticoagulation. Non-neoplastic causes, including infection, are rare and may present a diagnostic challenge, particularly in patients with renal cysts where hemorrhagic complications can mimic malignancy. While prior reports describe pyelonephritis-associated Wunderlich syndrome without underlying cystic disease, this case uniquely demonstrates infection-associated hemorrhage from pre-existing renal cysts, increasing the risk of misdiagnosis.
Case Description
A 69-year-old man with hypertension, coronary artery disease, and prior prostate and bladder cancer presented with fever, chills, right flank pain, and dark urine. Laboratory evaluation revealed leukocytosis (17,000/µL). Urinalysis demonstrated pyuria, hematuria, and positive nitrites, and urine culture grew Escherichia coli. Serum creatinine was elevated at 1.6 mg/dL and improved with treatment; hemoglobin remained stable. Computed tomography demonstrated a right subcapsular hematoma (~2.5 cm) with pararenal stranding and multiple bilateral renal cysts. The patient denied trauma and was not receiving anticoagulation, and coagulation studies were normal. Magnetic resonance imaging confirmed the hematoma without an enhancing mass, with several cysts demonstrating hemorrhagic features. Given clinical stability and absence of imaging features suggestive of malignancy, a multidisciplinary approach favored conservative management. The patient was treated with intravenous fluids and antibiotics, resulting in symptom resolution. Recognition of infection-associated hemorrhage from benign cysts allowed renal-sparing management and avoided unnecessary invasive intervention.
Discussion
In the absence of trauma, anticoagulation, or malignancy, infection-associated subcapsular hematoma remains rare. Most cases of Wunderlich syndrome are due to neoplasms or vascular lesions, underscoring the atypical nature of this presentation. This case highlights an underrecognized mechanism: inflammation-induced rupture of hemorrhagic renal cysts. The coexistence of infection and cystic disease creates diagnostic overlap with malignancy, increasing the likelihood of unnecessary intervention. Careful integration of clinical context and imaging can support conservative, renal-sparing management and help preserve renal function.