Table 2.
(Statement 2.1): Diagnostic microscopic features of type 1 and type 2 autoimmune pancreatitis (adapted from Zhang et al.226).
| AIP Type 1 | AIP Type 2 | |
|---|---|---|
| Periductal lymphoplasmacytic infiltrate | Present | Present |
| Inflammation of lobules | Present | Patchy,less marked, commonly admixed with neutrophils |
| Storiform fibrosis | Prominent | Occasional |
| Obliterative phlebitis | Yes | Rare |
| Lymphoid follicles | Prominent | Occasional |
| IgG4+ plasma cell infiltration | Marked | Scant or absent |
| GEL | Absent | Present |
| Inflammation of peripancreatic fat | Possible | Rare |
AIP: autoimmune pancreatitis; GEL: granulocytic epithelial lesion