Two Pathological Patterns in Different Stages of the Same Disease

This paper reports a case of a patient with IgG4-related lung disease who presented with two distinct pathological manifestations during the disease course. The first biopsy indicated an early inflammatory stage with mainly inflammatory exudation, while the second biopsy two years later showed a fibrotic stage with more fibrocyte foci and organizing pneumonia-like changes. By integrating relevant research, this study explores the reasons for the differences in the two pathological results, their impacts on prognosis, and their guiding significance for clinical treatment. It emphasizes that IgG4-related diseases may exhibit different pathological changes at different disease stages, and pathology is more likely to detect the trend of pulmonary fibrosis compared to imaging. Further research on its mechanism is needed.