When Hydatidosis Mimics Empyema: Case Report of a Ruptured Intrapleural Pulmonary CYST

Pulmonary hydatid disease, caused by the larval stage of Echinococcus granulosus, is an uncommon condition, even in endemic areas. Humans become accidental intermediate hosts by ingesting food or soil contaminated with eggs excreted by canines, the definitive hosts. In primary echinococcosis, larval cysts can develop in almost any organ, most commonly the liver, followed by the lungs. Pulmonary hydatid cysts often remain asymptomatic until they rupture, at which point patients may present with symptoms such as productive cough, hemoptysis, fever, or pleural effusion. While parenchymal cysts are rare, extra parenchymal intrapleural hydatid cysts are even more unusual. We report the case of a 42-year-old male who developed a massive unilateral pleural effusion following the rupture of an intrapleural hydatid cyst. This case underscores a rare but important differential diagnosis for pleural effusion. The objective of this report is to highlight this unusual presentation of hydatidosis, explore its potential complications, and discuss the available treatment options, including surgical intervention and medical management.