Immunoglobulin G4-Related Disease Arising from the Bladder Wall.

Immunoglobulin G4-related disease (IgG4-RD) is a recently described inflammatory disease with multiorgan involvement. Although there were reports of IgG4-related kidney disease or prostatitis, this disease rarely presents in the bladder. In this report, we describe a case of IgG4-RD arising from bladder wall. This patient had a past history of autoimmune pancreatitis and presented with incidental bladder tumor. Magnetic resonance imaging showed low signal intensity tumor on T2-weighted image, and no invasion to the muscular layer. We performed transurethral resection. Pathological findings showed that there were chronic inflammatory changes infiltrates under the epithelium, and IgG4-positive plasma cells were scattered throughout the lesion. They met the pathological diagnostic criteria for IgG4-RD. We think this is the first case of IgG4-RD arising from and confined to the inside of the bladder wall.