Constrictive pericarditis as an emerging manifestation of hyper-IgG4 disease.

A 68-year-old Japanese man was admitted for evaluation of right pleural effusion and bilateral leg edema that had progressively worsened over 6 months. As chest computed tomography revealed marked pericardial thickening, we performed a pericardiectomy, resulting in the remarkable improvement of his clinical manifestations. However, pleural fibrosis associated with fever of unknown origin soon developed. An elevated serum level of serum IgG4 and infiltration of IgG4-positive plasma cell in the resected pericardium were identified; thus, our patient might have hyper-IgG4 disease. Our case is the first report describing constrictive pericarditis as an initial manifestation of hyper-IgG4 disease.