Chylothorax complicating pulmonary resection caused by lymphatic duct injury outside the conventional regional lymph node dissection area: a case report.

Postoperative chylothorax directly resulting from thoracic duct injury is rare following pulmonary surgery. We describe a patient with suspected lung cancer undergoing thoracoscopic right upper lobe posterior segmentectomy with lobe-specific mediastinal lymph node dissection who presented with persistent chylothorax. Despite sequential conservative measures, including chylous drainage and a low-fat diet, her clinical symptoms recurred persistently. Secondary surgery confirmed a thoracic duct injury, presumably caused by improper stapler application during parenchymal transection, where the staple line over-extended and injured the adjacent duct. This unreported mechanism underscores the need for clinical vigilance against chylothorax resulting from iatrogenic stapler overextension injury.