Immunoglobulin G4-related constrictive pericarditis identified by cytological examination of pericardial effusion: a case report

Background Immunoglobulin G4-related disease is increasingly recognized as a systemic autoimmune disorder characterized by immunoglobulin G4-positive lymphocyte infiltration. Organ biopsy and histopathology are the most important diagnostic methods; however, the significance of a cytological examination in immunoglobulin G4-related disease cases is still unclear.