IgG4-Related Pericarditis Diagnosed by Accumulated Pericardial Effusion.

IgG4-related pericarditis has rarely been reported. Here, we report a case of IgG4-related disease that presented with pericardial effusion. A 67-year-old female who presented with palpitations and chest pain was admitted because of a large amount of pericardial effusion that required drainage. The patient underwent pericardial drainage, and the symptoms were gradually alleviated. IgG4 levels were elevated in the serum and pericardial effusions. A biopsy specimen of 18 F-FDG accumulated in the submandibular gland showed lymphocyte infiltration with IgG4-positive cells. The patient was diagnosed with IgG4-related pericarditis. Glucocorticoids resolved serological and imaging abnormalities. Prompt treatment improves the disease status.