Tissue Acquisition for Histologic Diagnosis

Abstract

Autoimmune pancreatitis (AIP) is recognized as a distinct clinical entity, and it is also identified as a chronic inflammatory process of the pancreas in which the autoimmune mechanism is involved. The diagnosis of AIP is clinically challenging because it is a rare disease, which closely mimics more common pancreaticobiliary malignancies in its presentation such as obstructive jaundice and pancreatic mass. Type 1 AIP has dense periductal lymphoplasmacytic infiltrate with storiform fibrosis and obliterative phlebitis, whereas type 2 is distinguished from type 1 by granulocyte epithelial lesion, less prominent lymphoplasmacytic infiltrate, and less prominent storiform fibrosis [1]. The international consensus diagnostic criteria (ICDC) for AIP were developed based on the agreement of an international panel of experts and ICDC include both type 1 and 2 AIP [2].