IgG4-related lung disease (IgG4-RLD) may present with a variety of radiological findings, but large lung mass lesion are rare. Although steroid therapy is strongly recommended for IgG4-RLD with or without symptoms, respirologists should be aware that some patients may not need steroid therapy.
Keywords: IgG4 related disease; IgG4‐related lung disease; large lung mass lesion; lung cancer; spontaneous regression.
© 2022 The Authors. Respirology Case Reports published by John Wiley & Sons Australia, Ltd on behalf of The Asian Pacific Society of Respirology.