Endoscopic Ultrasound-guided fine needle aspiration (EUS-FNA) can be performed using the 25, 22 or 19 gauge (G) needles. Randomized trials have shown that all three needles are safe and perform equally well. However, in a retrospective study, the diagnostic sensitivity of EUS-FNA for pancreatic masses that measured more than 35mm was less compared to smaller size masses. This is because larger size tumors have more necrosis and it is difficult to identify cancer cells in them to make a diagnosis. Therefore, more biopsies must be performed in larger size tumors to establish a diagnosis. In previous studies it has been shown that the larger 19G needles procure larger and better quality tissue. Therefore, our hypothesis is that, when a larger 19G needle is used to FNA tumors more than 35mm, a diagnosis can be achieved with fewer passes.
