IgG4-related airway involvement which developed in a patient receiving corticosteroid therapy for autoimmune pancreatitis

A 66-year-old man was diagnosed with autoimmune pancreatitis in February 2009 and started 40 mg of oral prednisolone followed by a maintenance dose of 5 mg daily. The patient developed a cough in October 2010 and visited our division. He had a high serum concentration of immunoglobulin (Ig) G4 and his chest computed tomography showed airway stenosis without bilateral hilar lymphadenopathy (BHL). The bronchial biopsy specimens revealed lymphoplasmacytic infiltrations with IgG4-positive/IgG-positive plasma cells of more than 50%. Thus, we diagnosed the airway lesion with IgG4-related airway involvement. This is the first report of a patient with IgG4-related airway involvement without BHL.