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.

Inclusion Criteria:

• (Before the trial, subjects must meet all of the requirements listed below in order to be enrolled)

  1. 18-80 years old (inclusive), male and female;
  2. patients with pancreatic solid mass > 1cm detected by CT/MRI/PET-CT or EUS and requiring EUS-FNB diagnosis.
  3. written informed consent was obtained;

Exclusion Criteria:

• (Before the trial, participants could not be enrolled if they met any of the following requirements)

  1. contraindications to endoscopy, such as severe cardiovascular and cerebrovascular diseases;
  2. bleeding coagulation dysfunction (prothrombin international normalized ratio ≥1.5, platelet count ≤ 50 000) or use of antiplatelet drugs;
  3. confirmed pregnancy or possible pregnancy;
  4. pathological diagnosis has been obtained by other methods;
  5. refuse to participate in the study, are participating in another observational clinical trial, or have participated in another clinical trial within 60 days.
  6. other situations where EUS-FNB could not be performed.