Histologic diagnosis of pancreatic masses using 25-gauge endoscopic ultrasound needles with and without a core trap: a multicenter randomized trial

Background and study aims: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) with 25-gauge needles yields small volume samples that are mainly processed for cytology. Using 25-gauge needles with a core trap may overcome this limitation. This trial compared 25-gauge needles with and without a core trap in terms of their ability to obtain histologic samples from solid pancreatic masses. Patients and methods: Consecutive patients with solid pancreatic masses who presented to eight Japanese referral centers for EUS-FNA in April – September 2013 were randomized to undergo sampling with a 25-gauge needle with a core trap (ProCore) or a standard 25-gauge needle. Tissue samples were fixed in formalin and processed for histologic evaluation. For the purpose of this study only samples obtained with the first needle pass were used for comparison of: (i) accuracy for the diagnosis of malignancy, (ii) rate of samples with preserved tissue architecture adequate for histologic evaluation, and (iii) sample cellularity. Results: A total of 214 patients were enrolled. Compared to the first pass with a standard needle (n = 108), the first pass with the ProCore needle (n = 106) provided samples that were more often adequate for histologic evaluation (81.1 % vs. 69.4 %; P  = 0.048) and had superior cellularity (rich/moderate/poor, 36 %/27 %/37 % vs. 19 %/26 %/55 %; P  = 0.003). There were no significant differences between the two needles in sensitivity (75.6 % vs. 69.0 %, P  = 0.337) and accuracy (79.2 % vs. 75.9 %, P  = 0.561) for the diagnosis of malignancy. Conclusions: In patients with solid pancreatic masses, a 25-gauge EUS-FNA needle with a core trap provides histologic samples of better quality than a standard 25-gauge needle. There was no difference in accuracy for the diagnosis of malignancy between the needles. Clinical trial number: UMIN000010021.