Pericardial effusion as a crucial presentation of Erdheim-Chester disease in a hemodialysis patient: an overlooked diagnosis.

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis whose hallmark is tissue infiltration by CD68-positive, CD1a-negative and usually S-100 protein-positive foamy non-Langerhans histiocytes and mononuclear cells. Here, we report a hemodialysis (HD) patient who presented with fever and pericardial effusion. We performed pericardiocentesis with pericardial biopsy and the histological findings indicated ECD. We administered intravenous methylprednisolone pulse therapy (250 mg/d) followed by oral prednisolone (50 mg/d). The patient's fever gradually subsided and there was no recurrence of pericardial effusion. This is the first report of an HD patient with ECD. We suggest that ECD be considered in the differential diagnosis of new HD patients who present with pericardial effusion, especially when this did not improve following increased dose of HD.