Perforated lung hydatid cyst presenting with tension pneumothorax and cardiac arrest

Hydatidosis caused by the larval stage of Echinococcus granulosus is the most frequently encountered type of hydatid disease in humans [1, 2]. Due to the close association that exists among sheep and dogs and humans, it is endemic to many parts of the world, particularly the Mediterranean countries including Turkey, the Middle East, South America, Africa, New Zealand, the Russian Federation, Central Asia, and Australia [2, 3]. Of all the body organs, lungs are second only to liver in terms of the disease involvement in adults and, due to their compressible nature and the presence of negative pressure, are the most common site of involvement in children [1, 4]. The most frequently involved organ is the liver (65%) because most of the embryos are trapped within it. Other involved sites are the lungs (25%), and less frequently, the spleen, kidneys, heart, bone, and central nervous system [5]. Structurally, the hydatid cyst of the lung has three layers: pericyst, ectocyst, and endocyst [2, 6]. Multiple protoscolices develop on the inner surface of the germinal layer, differentiate into secondary cysts when cyst ruptures, and form free floating daughter cysts within the mother cyst. Clinically, a small hydatid cyst in the lung often causes no symptoms and they usually remain asymptomatic, while a large one may cause compressive symptoms such as chest pain, coughing, dyspnea, and hemoptysis as well as allergic reactions including anaphylaxis [7]. Importantly, a ruptured pulmonary hydatid cyst into the neighboring or remote cavity spontaneously or iatrogenically is called as “complicated cyst” and it is associated with higher postoperative morbidity and mortality [8]. Interestingly, pulmonary cysts do not calcify, and daughter cyst formation is rare, unlike hydatid cysts located in other surrounding structures such as the pleural cavity, mediastinum and pericardium [2]. The local complications of pulmonary hydatidosis can be classified as rupture (perforation), secondary infection, reactions of the adjacent tissue, and complications associated with space occupation. Rupture, with a reported incidence of 49%, is the most frequent complication of pulmonary hydatid disease [2, 4, 6, 9]. Rupture into the pleural cavity may occur if a live scolex seeds into the pleural cavity as a result of rupture of an intrapulmonary cyst [7]. Pleural manifestations may develop as a complication of pulmonary hydatid disease, which do not involve a parasitic infestation [10, 11]....


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