Primary idiopathic chylopericardium.

Primary idiopathic chylopericardium is rare and represents a fraction of all pericardial effusions in the pediatric population. Most cases of chylopericardium occur as a complication of cardiac surgery or after trauma. They may also be caused by tuberculosis, neoplasm, or congenital lymphangiomatosis. Primary idiopathic chylopericardium is a rare disease with unknown etiology. In assessing pediatric patients with an enlarged cardiac silhouette one should be aware of this entity and its presentation. We report two cases of primary idiopathic chylopericardium, one of which at 6 weeks of age is the youngest case to our knowledge so far reported.