Histopathology of the resected mass. (A) Hematoxylin and eosin staining showing thickened bile duct. (B) Hematoxylin and eosin staining revealing lymphoplasmacytic infiltrate, arrow pointing to plasma cell. (C) IgG4 antibody staining revealing more than 55 IgG4 positive cells per high power field.
Shingina et al. Journal of Medical Case Reports 2011 5:485 doi:10.1186/1752-1947-5-485