Chylothorax Following Endoscopic Ultrasound-Guided Fine-Needle Aspiration: A Rare Complication and Its Anatomical Risk Factors.

Chylothorax is an exceptionally rare complication of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), with only a limited number of cases reported in the literature. We present the case of a 66-year-old man who presented with dyspnoea 3 days after EUS-FNA of a paraoesophageal left upper lobe lung mass. Chest radiography and CT demonstrated a left-sided pleural effusion, and image-guided pleural drainage yielded milky fluid whose analysis confirmed chylothorax. He was managed conservatively with a 14-French intercostal chest drain (ICD), dietary modification and octreotide therapy, achieving complete clinical recovery. This case underscores the delayed and potentially under-recognised presentation of post-EUS-FNA chylothorax and raises the possibility that anatomical relationships between thoracic lesions and the thoracic duct may represent a potential risk factor for this uncommon complication.