Echinococcosis complicated by purulent pericarditis.

Three patients are described in whom purulent pericarditis arose as a complication of hydatid disease. In one patient a myocardial cyst ruptured into the pericardial cavity and subsequently became superinfected, probably from a coexisting bronchopneumonia. This patient also had widespread intravascular dissemination of germinal membrane. Two patients had echinococcal cysts of the liver, which became infected following surgery. This led to formation of a fistula between the hepatic hydatid and the pericardium, resulting in purulent pericarditis. The cases illustrate the protean nature of echinococcosis, especially the cardiac form, and emphasize the difficulty of recognizing purulent pericarditis as a complication of other conditions.