IGG4-RELATED RENAL PSEUDOTUMOR: CASE REPORT
DOI:
https://doi.org/10.56238/levv16n53-056Keywords:
IgG4-related Disease, Renal Pseudotumor, Tubulointerstitial Nephritis, Immunohistochemistry, Differential DiagnosisAbstract
Immunoglobulin G4-related disease (IgG4-RD) is a systemic inflammatory condition characterized by dense lymphoplasmacytic infiltrate, fibrosis and obliterative phlebitis. Renal involvement is uncommon and may mimic neoplasms, leading to diagnostic confusion and unnecessary invasive treatments. This report describes a female patient with a left renal tumor identified during routine imaging examinations. Radiological findings suggested angiomyolipoma, and the patient underwent radical nephrectomy. Histopathological analysis revealed collagenous fibrosis, areas of myxoid degeneration and dense lymphoplasmacytic infiltrate with prominent lymphoid aggregates. Immunohistochemistry demonstrated more than 30 IgG4-positive plasma cells per high-power field and an IgG4/IgG ratio of approximately 80%, confirming the diagnosis of IgG4-related tubulointerstitial nephritis with pseudotumor formation. This case highlights the diagnostic challenges of renal IgG4-RD, particularly when it presents as a solitary pseudotumor, since nonspecific radiological findings may simulate malignant tumors and subject patients to avoidable radical surgical therapy.
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