Arthritis Rheumatol 67 (7): 1688 - 99, 2015. doi: 10.1002 / art.39132 Key Points IgG4-related disease (IgG4-RD) is a chronic, immune-mediated disorder that often manifests with multiorgan involvement and tumor-like masses most often affecting the pancreas, bile ducts, lacrimal glands, orbital tissues, salivary glands, lungs, kidneys, retroperitoneal tissues, aorta, meninges, and the thyroid gland.