[IgG4-related disease of the breast].

IgG4-related disease is an immune-mediated disorder with tumor-like multiorgan involvement, elevated serum IgG4 level and specific histopathological appearance (lymphoplasmacytic infiltrate rich in IgG4+ plasma cells and storiform fibrosis). The article presents rare clinical and morphological observations of IgG4-related mastopathy in women with suspected tumor process. A strategy for the treatment of IgG4-related disease should be based on the results of pre-surgery histopathological examination, which may help to avoid unreasonable surgical intervention and choose glucocorticoids or rituximab as the first-line treatment.