Published online May 14, 2006. doi: 10.3748/wjg.v12.i18.2955
Revised: February 28, 2006
Accepted: February 28, 2006
Published online: May 14, 2006
Retroperitoneal fibrosis is an uncommon disorder characterized by the formation of a dense plaque of fibrous tissue in the retroperitoneum, and its etiology remains unknown. Autoimmune pancreatitis is a rare type of chronic pancreatitis characterized by fibrosis with abundant infiltration of IgG4-positive plasma cells and lymphocytes and obliterative phlebitis in the pancreas. We present a case of autoimmune pancreatitis that developed 10 mo after the occurrence of retroperitoneal fibrosis. Histological findings of the resected retroperitoneal mass were marked periureteral fibrosis with abundant infiltration of IgG4-positive plasma cells and lymphocytes and obliterative phlebitis. These findings suggest a common pathophysiological mechanism for retroperitoneal fibrosis and autoimmune pancreatitis in this case. Some cases of retroperitoneal fibrosis might be a retroperitoneal lesion of IgG4-related sclerosing disease.