This is a single-blind, randomized, controlled trial. One thousand two hundred and twenty four patients with solid pancreatic lesions referred for EUS guided fine needle biopsy will be randomly assigned to 4 arms. For arm A1 which will be used with 22G EUS Procore fine needle biopsy device, the pass sequence is slow pull(SP)-modified wet suction technique(MWST)-slow pull(SP)-modified wet suction technique(MWST). For arm A2 with 22G EUS Procore fine needle biopsy device, the pass sequence is MWST-SP-MWST-SP. For arm B1 with 20G EUS Procore fine needle biopsy device, the pass sequence is SP-MWST-SP-MWST. For arm B2 with 20G EUS Procore fine needle biopsy device, the pass sequence is MWST-SP-MWST-SP. All procedures will be performed by experienced echoendoscopists, and the patients and assessors (cytologists and pathologists) will be blinded during the entire study. The primary outcome measure is the diagnosis yield. Secondary outcome measures are specimen quality.
