A Rare Case of Ureteral IgG4 Disease Masquerading as Urothelial Carcinoma.

The present paper described a rare case of ureteral IgG4-related disease (IgG4-RD) that mimicked urothelial carcinoma. An otherwise healthy patient presented with computed tomography, ureteroscopic, and biopsy findings that were suspicious of urothelial carcinoma. The patient received a right nephroureterectomy. Histopathology showed ureteral IgG4-RD, without evidence of urothelial carcinoma. Accurate diagnosis of this rare entity should be based on clinical, biochemical, and histopathological findings.