TY - JOUR
T1 - Autoimmune pancreatitis (AIP) type 1 and type 2
T2 - An international consensus study on histopathologic diagnostic criteria
AU - Zhang, Lizhi
AU - Chari, Suresh
AU - Smyrk, Thomas C.
AU - Deshpande, Vikram
AU - Klöppel, Günter
AU - Kojima, Motohiro
AU - Liu, Xiuli
AU - Longnecker, Daniel S.
AU - Mino-Kenudson, Mari
AU - Notohara, Kenji
AU - Rodriguez-Justo, Manuel
AU - Srivastava, Amitabh
AU - Zamboni, Giuseppe
AU - Zen, Yoh
PY - 2011/11
Y1 - 2011/11
N2 - Objectives: To develop and validate histologic diagnostic criteria for autoimmune pancreatitis (AIP) and its types. Methods: Thirteen pathologists participated in this 2-phase study to develop diagnostic criteria for AIP types 1 and 2 (phase 1) and validate them (phase 2). A virtual library of 40 resected pancreata with AIP and other forms of chronic pancreatitis (CP) was constructed. Readers reviewed the slides online and filled out a questionnaire for histopathologic findings and diagnosis. Results: Diagnostic criteria for AIP and its types were proposed according to the results from the top 5 reviewers in phase 1. The interobserver agreement was significantly improved in phase 2 by applying the proposed diagnostic criteria. Features distinguishing AIP from alcoholic and obstructive forms of CP were periductal lymphoplasmacytic infiltrate, inflamed cellular stroma with storiform fibrosis, obliterative phlebitis, and granulocytic epithelial lesions. Although there was overlap, 2 types of AIP were recognized. Type 1 had dense lymphoplasmacytic infiltrate with storiform fibrosis and obliterative phlebitis, whereas type 2 was distinguished from type 1 by the presence of granulocytic epithelial lesions. Conclusions: Autoimmune pancreatitis can be distinguished from other forms of CP with substantial interobserver agreement. The 2 types of AIP can be distinguished by the proposed consensus histopathologic diagnostic criteria.
AB - Objectives: To develop and validate histologic diagnostic criteria for autoimmune pancreatitis (AIP) and its types. Methods: Thirteen pathologists participated in this 2-phase study to develop diagnostic criteria for AIP types 1 and 2 (phase 1) and validate them (phase 2). A virtual library of 40 resected pancreata with AIP and other forms of chronic pancreatitis (CP) was constructed. Readers reviewed the slides online and filled out a questionnaire for histopathologic findings and diagnosis. Results: Diagnostic criteria for AIP and its types were proposed according to the results from the top 5 reviewers in phase 1. The interobserver agreement was significantly improved in phase 2 by applying the proposed diagnostic criteria. Features distinguishing AIP from alcoholic and obstructive forms of CP were periductal lymphoplasmacytic infiltrate, inflamed cellular stroma with storiform fibrosis, obliterative phlebitis, and granulocytic epithelial lesions. Although there was overlap, 2 types of AIP were recognized. Type 1 had dense lymphoplasmacytic infiltrate with storiform fibrosis and obliterative phlebitis, whereas type 2 was distinguished from type 1 by the presence of granulocytic epithelial lesions. Conclusions: Autoimmune pancreatitis can be distinguished from other forms of CP with substantial interobserver agreement. The 2 types of AIP can be distinguished by the proposed consensus histopathologic diagnostic criteria.
KW - IgG4
KW - autoimmune pancreatitis
KW - chronic pancreatitis
KW - granulocytic epithelial lesion
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U2 - 10.1097/MPA.0b013e318233bec5
DO - 10.1097/MPA.0b013e318233bec5
M3 - Article
C2 - 21975436
AN - SCOPUS:80054864375
SN - 0885-3177
VL - 40
SP - 1172
EP - 1179
JO - Pancreas
JF - Pancreas
IS - 8
ER -