A 29-month-old girl had idiopathic massive pericardial effusion for over 6 months. Lymphangiography was performed for chronic and recurrent pericardial effusion and pulmonary lymphangiectasia, suspected based on CT findings. Magnetic resonance lymphangiography revealed chylolymphatic reflux from a tortuously dilated thoracic duct in the mediastinum to the pericardial space, suggesting primary chylopericardium with lymphangiectasia. Pericardial effusion resolved immediately after thoracic duct embolisation at the lower thoracic level. However, pericardial effusion recurred after 5 months, which resolved after additional embolisation of the abnormal lymphatic collateral vessels from the remnant upper thoracic duct. Here, we report an unusual case with chylous massive pericardial effusion diagnosed by magnetic resonance lymphangiography and treated with percutaneous embolisation.
