A rare recurrence of hydatid cyst with chest wall invasion: a case report

Background Hydatid cyst is a zoonotic infection caused by the larval stage of Echinococcus granulosus . While the lungs are frequently affected, rib involvement and chest wall invasion are extremely rare, occurring in less than 2.5% of cases. We report a rare case of recurrent hydatid disease exhibiting infiltrative growth into the costal trabeculae and lung parenchyma. Case presentation A 50-year-old man presented with weight loss. He had a history of splenectomy for hydatid disease 14 years prior. Physical examination and blood tests were unremarkable; however, chest computed tomography (CT) revealed a 56 × 52 mm multilocular cystic lesion in the apico-posterior segment of the left lung, causing destruction of the second, third, and fourth ribs. Immunoglobulin hemagglutination was positive (1/256). During left posterolateral thoracotomy, an 8 × 6 cm lesion was found prolapsing through the intercostal space. Due to the lack of a clear cleavage plane in the parenchyma and extensive rib destruction, an en bloc resection was performed, including a pulmonary wedge resection and partial resection of the three affected ribs. Histopathology confirmed the diagnosis of a hydatid cyst with daughter cysts and bone trabeculae involvement. The patient was discharged on the 10 th postoperative day without complications and started on albendazole (800 mg/day). Conclusion This case demonstrates that hydatid cysts can recur many years after the initial surgery and may exhibit an atypical, infiltrative progression into neighboring tissues, including bone. While parenchyma-preserving surgery is the standard, radical en bloc resection may be necessary for curative treatment in cases of chest wall invasion. Long-term postoperative antihelmintic therapy is essential to prevent further recurrence.