Bronchoscopic Evaluation of Central Airway Involvement in IgG4-related Disease

To the Editor: Immunoglobulin G4-related disease (IgG4-RD) is an increasingly recognized systemic fibroinflammatory condition characterized by tumefactive lesions, a dense lymphoplasmacytic infiltrate rich in immunoglobulin G4 (IgG4)-positive plasma cells, a variable degree of fibrosis that has a characteristic storiform pattern, and elevated serum IgG4 levels in the majority of patients. IgG4-RD affects virtually any organ system including the...