IgG4-related retroperitoneal fibrosis and sclerosing cholangitis independent of autoimmune pancreatitis. A recurrent case after a 5-year history of spontaneous remission.

CONTEXT A new clinicopathological concept of IgG4-related sclerosing disease affecting various organs has recently been proposed in relation to autoimmune pancreatitis. This report describes the case of IgG4-related retroperitoneal fibrosis and sclerosing cholangitis independent of autoimmune pancreatitis, which recurred after a long period of spontaneous remission. CASE REPORT An 80-year-old Japanese man presented with obstructive jaundice owing to a hepatic hilum bile duct stricture. Coincidentally, a soft tissue mass surrounding the abdominal aorta, suggesting retroperitoneal fibrosis, was identified. Unexpectedly, spontaneous regression of obstructive jaundice together with retroperitoneal fibrosis occurred. The presence of high serum IgG4 concentrations measured later led us to consider a possible association with autoimmune pancreatitis; however, there were no clinical features confirming autoimmune pancreatitis. After a 5-year history of spontaneous clinical remission, there was an elevation of serum IgG4 levels and renal dysfunction owing to bilateral hydronephrosis caused by a reemergence of the retroperitoneal mass. Evaluation by endoscopic retrograde cholangiopancreatography revealed a biliary stricture, suggesting sclerosing cholangitis which was observed without the presence of any pancreatic duct abnormality. The subsequent excellent results obtained using steroid therapy, namely the decrease in serum IgG4 levels and the regression of the retroperitoneal mass, strongly suggested that the present case was an IgG4-related sclerosing disease. Aside from high serum IgG4 concentrations, markedly elevated levels of serum IgE was found retrospectively, although the clinical significance remains unknown. CONCLUSION When we encounter fibrotic diseases of unknown etiology, we should measure serum IgG4 concentrations and monitor the disease activity over long periods even after achieving clinical remission.