Major and minor duodenal papillae in autoimmune pancreatitis.

Objective: The objective of this study was to evaluate picture of the major and minor duodenal papillae in patients with autoimmune pancreatitis (AIP). Methods: Endoscopic features of the major and minor papillae were examined in 59 and 13 patients with AIP. After steroid therapy, changes of the major and minor papillae were observed in 5 and 6 patients. The major and minor papillae were observed with narrow band imaging in 24 and 6 patients. Biopsy specimens from the major (n = 50) and minor (n = 13) papillae were immunostained using an anti-IgG4 antibody. Results: Endoscopic features of the major and minor papillae were abnormal in 26 patients (44%; swelling [n = 20] and redness [n = 14]) and 5 patients (38%; swelling [n = 5]). Swelling of the pancreatic head, irregular narrowing of the main pancreatic duct of the pancreatic head, stenosis of the lower bile duct, and abundant infiltration of IgG4-positive plasma cells were more frequent in the patients with an abnormal major papilla compared with those with a normal major papilla. On narrow band imaging, dilated vessels were observed in abnormal papillae. After therapy, swelling of the major and minor papillae improved in all 4 and 2 patients. Conclusions: Endoscopic features of the major and minor papillae were abnormal in 44% and 38% of the patients with AIP.