Fine-needle Biopsy Combined With Macroscopic On-site Evaluation for Diagnosis of Solid Pancreatic Lesions

The goal of this clinical trial is to compare the diagnostic efficacy, core tissue acquisition ability, number of punctures and puncture time of macroscopic on-site evaluation (MOSE) and two punctures alone in Endoscopic ultrasound guided fine-needle biopsy (EUS-FNB) for solid pancreatic lesions. The main questions it aims to answer is: whether the diagnostic accuracy of EUS-FNB performed with two needle passes is not inferior to that of MOSE. Participants with solid pancreatic lesions who needs histological diagnosis will receive EUS-FNB using 22G Franseen. In Group 1, the macroscopically visible core (MVC) of the specimen was assessed. If the MVC of the sample obtained from the first needle was ≥10mm, the tissue strip was placed in Bottle A and fixed with formalin. A second needle was then used to obtain another tissue strip, which was directly placed into Bottle B containing formalin. However, if the MVC of the first needle sample was \< 10mm, the puncture procedure was continued until the cumulative length of sample's MVC was ≥10mm, and all the sample collected during this process were placed into Bottle A and fixed with formalin. In Group 2, two needles were used to obtain tissue strips, and all the tissue strips were placed into Bottle A formalin. Researchers will compare the diagnostic efficacy, core tissue acquisition ability, number of punctures and puncture time between the MOSE technique and two-needle puncture method.