A unique association of giant lymph node hyperplasia (Castleman's dise
ase) and cardiac tamponade is presented. Although pleural effusions ha
ve been previously described with Castleman's disease, the authors bel
ieve this to be the first report of pericardial effusion and tamponade
with this entity. The development of effusions may be due to an infla
mmatory syndrome sometimes seen with the plasma cell variant of this d
isease.