Diagnosis of IgG4-related systemic disease by cytology of large pericardial effusion with fine needle aspiration

IgG4-related disease has characteristic features as follows; Serum IgG4 is prominently elevated, IgG4-positive plasma cells infiltrate in involved tissues and various mass-forming lesions with fibrosis, such as the autoimmune pancreatitis, salivary gland and retroperitoneum. As this disease comes to attention, the reports of IgG4-related disease have been increasing, but the pathogenesis and exact frequency of the disease remain unknown. We...