From: Immunoglobulin G4-related sclerosing cholecystitis presenting as gallbladder cancer: a case report
The three major histopathological features associated with IgG4-related disease |
 ①Dense lymphoplasmacytic infiltrate |
 ②Fibrosis, arranged at least focally in a storiform pattern |
 ③Obliterative phlebitis |
Other histopathological features associated with IgG4-related disease are as follows: |
 ①Phlebitis without obliteration of the lumen |
 ②Eosinophilia |
Minimal criteria for IgG4-related disease in a new organ/site |
 ①Characteristic histopathological findings with an elevated IgG4 plasma cells and IgG4/IgG ratio |
 ②High serum IgG4 concentrations |
 ③Effective response to glucocorticoid therapy |
 ④Reports of other organ involvement that is consistent with IgG4-related disease |