Reprint of: Pathologic manifestations of Immunoglobulin(Ig)G4-related lung disease

Immunoglobulin(Ig)G4-related disease (IgG4-RD) is a fibroinflammatory condition that can affect virtually any organ and usually presents as tumefactive lesions involving multiple sites. Characteristic histopathology of IgG4-RD consists of dense lymphoplasmacytic infiltrate, fibrosis (often in storiform pattern), and obliterative phlebitis, accompanied by tissue infiltration of IgG4-positive plasma cells with or without elevation of serum IgG4...