Immunoglobulin G4-related lung disease accompanied by organizing pneumonia.

The full picture of immunoglobulin G4-related lung disease (IgG4-RLD) has not yet been elucidated. A 69-year-old man was referred to us with a more than 2-week history of productive cough and fatigue. Chest CT showed an airspace consolidation along the bronchovascular bundles. The pathological findings that were obtained from an open-lung biopsy showed both organizing pneumonia and interstitial pneumonia. Based on the established, comprehensive diagnostic criteria for IgG4-related disease (RD) as of 2011, this patient was given a definitive diagnosis of IgG4-RD. A further accumulation and analysis of those cases that concomitantly present with both IgG4-RLD and organizing pneumonia, like our patient, may contribute to the elucidation of the pathology of IgG4-RLD and the establishment of the disease spectrum.