IgG4-Related Lung Disease - Three Untreated Cases with a Benign Outcome.

IgG4-related disease is a fibroinflammatory disease in which the organs involved share similar pathological findings. Chest disease has been recently clinically and radiologically characterized. Most reports advocate prompt immunosuppressive therapy and describe a fast and good response. We report 3 cases of untreated IgG4-related lung disease that on follow-up have been clinically asymptomatic and radiologically stable or improved. In some cases of IgG4-related lung disease immunosuppressive therapy may not be warranted.