| [ Summary ] |
Two different histological groups, lymphoplasmacytic sclerosing pancreatitis (LPSP) and idiopathic duct-centric chronic pancreatitis (IDCP), are recognized in the definition of autoimmune pancreatitis. The former represents the pancreatic manifestation of IgG4-related disease. In addition to obliterative phlebitis and ductal inflammation, there are various histological features which characterize LPSP. One is storiform fibrosis, characterized by swirling patterns, which may be highly cellular in nature with capillary vessels, small spindle-shaped cells, lymphocytes and plasma cells, or may be fibrotic rather than cellular in nature. Lobular inflammation observed in LPSP is also characteristic. IDCP is characterized by the inflammation observed in interlobular ducts with infiltrating neutrophils in the epithelium and/or lumens (granulocytic epithelial lesions). LPSP and IDCP are different clinicopathological entities, and as a result, individual pathological reports should establish the presence ofeither LPSP or IDCP. |