Giant thoracic cyst caused by amniotic fluid aspiration during delivery

Abstract In infants born after term, it is not unusual to find aspirated amniotic fluid (AF), but the long term effect on lung morphology and thoracic cavity is still rarely reported. Here, we report a case of a giant fibrocystic thoracic cavity with pulmonary dysplasia in adulthood, possibly due to aspiration of meconium-contaminated amniotic fluid during delivery. The patient was a 20-year-old girl presenting with chest tightness and recurrent cough for 4 months (until the time of arriving our hospital). When she was born, she had a lung infection due to aspiration of amniotic fluid contaminated with meconium, so she was admitted to the neonatal intensive care unit for rescue. Image examinations confirmed a giant thoracic cavity cyst with pulmonary dysplasia in the left thoracic cavity. The patient underwent a thoracoscopic exploratory operation in the Nantong First People's Hospital on February 26, 2021, but the thoracic cyst still existed after the operation, and the patient's symptoms did not improve. She arrived to our hospital on April 21, 2021. On April 28, 2021, she underwent the urgent left thoracic giant cyst resection surgery for intrathoracic hemorrhage. The patient's symptoms improved significantly after the operation, and the patient recovered and was discharged from the hospital smoothly. Four months later, due to the left pneumothorax attack, she returned to our hospital and underwent the left lung repair operation under thoracoscopic. The re-examination result showed that the current left lung recruitment was satisfactory, and the follow-up result showed that everything in daily life is normal. The perinatal inhalation of meconium-and/or blood-stained amniotic liquid is a life-threatening event requiring intensive care. Aspiration of meconium-contaminated amniotic fluid can induce exudative alveolitis, coupled with airway obstruction and degradation of alveolar surfactant, resulting in atelectasis. In addition, amniotic fluid and meconium could disperse from the terminal bronchioles into the alveolar acini and pleural tissue causing pleural thickening. Amniotic fluid contains a variety of mesenchymal stem cells as well as growth factors, especially basic fibroblast growth factor (bFGF), which, in the context of inflammation, ultimately lead to the formation of giant thoracic cyst. In the Discussion section, we conducted an in-depth analysis of the relationship between the amniotic fluid aspiration at birth and its eventual pathological changes in this patient through a literature review.