E2098. IgG4-Related Disease of the Urinary Tract: Multi-Modality Imaging Findings, Mimics, and Pitfalls
  1. Ayman Gaballah; University of Missouri
  2. Nanda Thimmappa; University of Missouri
  3. khaled Elsayes; MD Anderson Cancer Center
  4. Akram Shaaban; University of Utah
  5. Kumar Sandrasegaran; Mayo Clinic
  6. Azfar Siddiqui; University of Missouri
IgG4-related disease (IgG4-RD) is an immune-mediated condition characterized by lymphoplasmacytic infiltration of the affected organs by IgG4-positive plasma cells with associated variable degrees of fibrosis. The disease can involve almost any organ, including the urinary tract. The upper urinary tract is more commonly involved than the lower tract. The disease has different manifestations and imaging features including tumor-like masses of involved organs.

Educational Goals / Teaching Points
Understand the spectrum and clinical presentation of IgG4-related disease (IgG4-RD) of the urinary tract Recognize typical and atypical imaging features and mimics of IgG4-RD of the urinary tract Review the impact of imaging findings on management options

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Multi-imaging modalities assessment including (Ultrasound, contrast-enhanced ultrasound, CT, MRI and PET/CT) Typical and atypical imaging features of IgG4-related disease of the urinary tract and retroperitoneum Different patterns of renal involvement including parenchymal and extra-parenchymal lesions Differential considerations and mimics of IgG4-RD of the urinary tract such as pyelonephritis, vascular insult, lymphoma, metastases, granulomatosis with polyangiitis and renal cell cancer

IgG4-RD of the urinary tract is not very common. However, its presentation and imaging features can mimic several inflammatory, infectious, vascular, or neoplastic disorders. Diagnosis is typically made with a tissue biopsy, imaging, and serum IgG4 levels. Cross-sectional imaging modalities play a crucial role in diagnosis, treatment planning, and follow-up. Early diagnosis of IgG4-RD can prevent irreversible organ fibrosis by initiating appropriate therapy early. Radiologists should be familiar with the imaging clues that could help them overcome the challenges associated with the diagnosis of these conditions. Proper diagnosis of IgG4-RD can prevent unnecessary invasive procedures and treatment.