Hydatid cyst presenting as an eosinophilic pleural effusion.

A 61-year-old woman presented with an eosinophilic pleural effusion, secondary to transdiaphragmatic intrapleural spread of an hepatic hydatid cyst. Right posterolateral thoracotomy and frenotomy revealed a loculated pleural effusion associated with a 10 x 8 cm hydatid cyst in the posterior segment of the liver. Hydatid disease should be included in the differential diagnosis of eosinophilic pleural effusions in endemic regions.