Giant pulmonary hydatid cyst complicated by refractory shock and fulminant acute respiratory distress syndrome: a case report.

INTRODUCTION: Giant pulmonary hydatid cysts are uncommon and may cause profound cardiopulmonary compromise through chronic lung compression and mediastinal displacement. Their surgical removal can be complicated by abrupt hemodynamic and respiratory deterioration. CASE PRESENTATION: A 19-year-old woman from a rural livestock-raising region presented with progressive dyspnea, cough, and right-sided chest pain. Imaging demonstrated a solitary giant pulmonary cyst measuring approximately 40 × 25 × 25 cm, occupying almost the entire right hemithorax and markedly displacing the mediastinum. Serology for Echinococcus granulosus was positive. Through a right posterolateral thoracotomy, approximately 4 L of clear cyst fluid was aspirated, the endocyst was removed, bronchial openings were closed, and capitonnage was performed. Immediately after decompression, severe hypotension developed and was treated for suspected anaphylaxis with epinephrine and norepinephrine. Postoperatively, the patient remained intubated and developed early bilateral pulmonary infiltrates, severe hypoxemic respiratory failure, metabolic acidosis, and refractory shock. Echocardiography showed preserved biventricular function. Despite intensive care support, she died on the third postoperative day. The deterioration was considered multifactorial, with possible contributions from hypersensitivity, systemic inflammatory response, rapid decompression, re-expansion lung injury, and occult airway trauma. CONCLUSION: Giant pulmonary hydatid cysts should be regarded as high-risk physiological lesions even when surgical excision is technically successful. Controlled decompression, gradual lung re-expansion, multidisciplinary perioperative planning, and immediate access to advanced critical care are essential.