| Theme |
Autoimmune Pancreatitis -- Present Status & Future Perspectives |
| Title |
Differential Diagnosis between IgG4—related Sclerosing Cholangitis and Primary Sclerosing Cholangitis |
| Author |
Itaru Naitoh |
Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences |
| Author |
Hirotaka Ohara |
Department of Community‒based Medical Education, Nagoya City University Graduate School of Medical Sciences |
| Author |
Takahiro Nakazawa |
Department of Gastroenterology, Nagoya Daini Red Cross Hospital |
| Author |
Shuya Shimizu |
Department of Gastroenterology, Nagoya Daini Red Cross Hospital |
| Author |
Kazuki Hayashi |
Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences |
| Author |
Takashi Joh |
Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences |
| [ Summary ] |
IgG4‒related sclerosing cholangitis (IgG4‒SC) shows increased serum IgG4 level, dense infiltration of IgG4‒positive plasma cells with extensive fibrosis in the bile duct wall, and a good response to steroid therapy. On the contrary, primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown cause that is characterized by diffuse biliary stenosis throughout the intra‒ and extra‒hepatic biliary trees, and liver transplantation is the only potentially curative treatment. IgG4‒SC and PSC should be differentiated appropriately because treatment and prognosis are different. High serum IgG4 level and coexistence with AIP and other IgG4‒related diseases are characteristic findings for IgG4‒SC. The associated inflammatory bowel disease is suggestive for PSC. Band‒like stricture, beaded appearance and pruned tree appearance are characteristic cholangiogram for PSC. Isolated or multiple long strictures without characteristic findings of PSC are suggestive of IgG4‒SC. The intraductal ultrasonography (IDUS) findings differ between PSC and IgG4‒SC. Irregular inner margin, diverticulum‒like outpouching, and disappearance of three layers are specific IDUS findings for PSC. Liver biopsy using IgG4 immunostaining is also useful to distinguish PSC and especially type 2 IgG4‒SC. These two diseases can be differentiated according to the abovementioned characteristic findings. However, isolated IgG4‒SC is difficult to distinguish from PSC. |