Primary chylopericardium associated with allergic alveolitis

A 42-year-old woman with extrinsic allergic alveolitis and worsening dyspnea was found to have an enlarged cardiac silhouette. Primary chylopericardium was diagnosed when pericardiocentesis yielded the characteristic milky-white fluid containing microscopic fat droplets. The pericardial effusion resolved with prednisone therapy.