[Serous fibrinous pleurisy disclosing hydatid cyst of the liver fistulizing into the pleura].

Hydatic cyst of the liver remains a serious public health problem in Morocco and several other Mediterranean countries. This benign affection can cause serious sometimes fatal complications such as cyst rupture into the biliary ducts or the thorax. We present the case of a patient with serofibrous pleurisy and recall the often late diagnosis of hydatic cyst. Biliary pleural fistulization is a rare but serious complication.