Background and aim: For reduction in cost, time and risk of complications, the number of endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) passes should be minimized. Previous studies have shown that tumor differentiation and site of aspiration will affect the number of passes in patients with pancreatic cancer. There have been no reports that EUS features of pancreatic malignancies per se will influence the number of passes. Our aim was to prospectively assess various factors that would affect the number of passes in patients with pancreatic cancer.
Methods: Between May 2003 and December 2004, 41 patients with presumed pancreatic cancer were studied. EUS-guided FNA was performed with an Olympus GF-UC2000P echoendoscope and a 22-gauge needle. On-site assessment of the specimen by a cytopathologist was available during the procedure.
Results: Adenocarcinomas were confirmed in 25 patients. Pancreatic adenocarcinomas with intratumoral anechoic foci required a higher number of diagnostic passes than those without anechoic change (3.40 vs 2.27, P < 0.05). An average of 4.00 FNA passes for diagnosing a well-differentiated adenocarcinoma was also significantly higher than the 2.40 diagnostic passes for a moderately differentiated adenocarcinoma and the 2.00 passes for a poorly differentiated one (P < 0.05).
Conclusions: The existence of intratumoral anechoic foci was not a rare finding under detailed EUS investigation of pancreatic cancer. Both the existence of intratumoral anechoic foci and the differentiation of the cancer are significant predictive factors for the number of diagnostic EUS-FNA passes.