Hydropericardium prevented diagnosis of constrictive pericarditis: an unusual case of Rosai-Dorfman disease.

The present report concerns an unusual case of extranodal Rosai-Dorfman disease involving the epicardium, mesenterium, pleural cavity and lung. All involved lesions showed characteristics of S100-positive histiocytes exhibiting emperipolesis. The patient was a 51-year-old woman with a 2-year evolution of chest distress, dyspnoea and oedema. Pathological examination indicated that heart failure, which resulted from constrictive pericarditis, led to the fatal outcome of this case. Interference from severe hydropericardium prevented timely diagnosis and appropriate treatment. Therefore it is recommend that, despite being a rare condition, pericardium-involved Rosai-Dorfman disease should be taken into consideration in differential diagnoses, especially in cases of severe hydropericardium.