2.1. Endoscopic Ultrasound (EUS) is the diagnostic method of choice when a pancreatic lesion is found incidentally on cross-sectional imaging. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is a procedure where a target tissue in proximity to the GI tract is biopsied using a fine needle guided in real time by an ultrasound probe fixed at the tip of an endoscope. It may therefore be applied to pancreatic lesions, or lymph nodes examination.