The HISORt criteria for the diagnosis of autoimmune pancreatitis2
| 1. | Histopathology—one or both criteria required | Characteristic appearances within biopsy or resection material* |
| At least 10 IgG4-positive plasma cells per high power field within areas of lymphoplasmacytic infiltrate | ||
| 2. | Imaging and serology—all three criteria required | Diffusely enlarged pancreas with delayed and ‘rim’ enhancement |
| Irregular attenuated pancreatic duct | ||
| Increased serum IgG4 concentration | ||
| Unexplained pancreatic disease after a full clinical workup—including exclusion of cancer | ||
| Raised serum IgG4 concentration and/or extrapancreatic organ involvement with increased numbers of tissue IgG4-positive plasma cells | ||
| 3. | Response to steroid therapy—all three criteria required | Resolution or marked improvement in disease with steroid therapy |
*This includes a lymphoplasmacytic infiltrate, ‘storiform’ fibrosis and obliterative phlebitis; the inflammatory cell infiltrate alone is not sufficient to meet this criterion.