Core needle versus standard needle for endoscopic ultrasound-guided biopsy of solid pancreatic masses: a randomized crossover study

Background and study aims: A new core biopsy needle for endoscopic ultrasound (EUS)-guided sampling has recently been developed. The aim of this prospective multicenter study was to compare this needle with a standard needle in patients with solid pancreatic masses. Patients and methods: Consecutive patients with solid pancreatic masses referred to 17 centers for EUS-guided sampling were included. Each patient had two passes with a standard 22G needle and a single pass with a 22G core needle performed in a randomized order. Samples from both needles were separately processed for liquid-based cytology and cell-block preparation and were assessed independently by two blinded expert pathologists. The primary endpoint was the accuracy of the detection of malignancy. The reference standard was based on further cytohistological analysis obtained under ultrasound or computed tomography scanning, endoscopic or surgical guidance, and/or by clinical follow-up with repeated imaging examinations for at least 12 months. The secondary endpoints were the rate of technical failure and the quality of the cytohistological samples obtained. Results: Of the 80 patients included (49 men; mean age 67.1 +/- 11.1), 87.5% had final malignant diagnoses (adenocarcinoma n=62, 77.5 %). There was no difference between the needles in diagnostic accuracy (standard needle 92.5% vs. core needle 90%; P=0.68) or technical failure. Both pathologists found the overall sample quality significantly better for the standard needle (expert 1, P=0.009; expert 2, P=0.002). Conclusions: The diagnostic accuracy of EUS sampling for solid pancreatic masses using standard and core needles seems comparable but with a better overall histological sample quality for the former.