The objective of this randomized controlled trial is to evaluate whether wet suction technique (WST), compared with dry suction technique (DST), shall present a better outcome with regard to the diagnostic yield and specimen quality of patients with solid lesions in the pancreatics.

Endoscopic ultrasound guided fine-needle aspiration (EUS-FNA) has become an inevitable indispensable method for acquiring a pathological diagnosis in a variety of clinical conditions. It has been widely used due to the high sensitivity, specificity and safety. In order to improve the puncture efficiency of FNA, many domestic and oversea scholars have conducted several clinical trials. Among them, there are many studies on the type of needle, needle pattern, slow pull or vacuum suction, and there are only two related reports on wet suction (saline) and dry suction technique. There still have many controversies in the researchers about which technique is more dominant in the wet or dry suction. The wet suction technique is relying on pre-flushing the needle with saline to replace the column of air with fluid followed by aspiration at the proximal end, using a prefilled suction syringe with saline. It has been suggested that the presence of a saline-solution column might keep the needle from getting clogged while avoiding the inherent inconvenience of a metal stylet, so that it can improve the quality of specimens, diminish the contamination of blood, and increase the diagnostic yield and accuracy. Wet suction may become the development trend of EUS-FNA in the future because the application of wet suction is expected to improve the diagnostic efficiency and the quality of samples in FNA.

Inclusion Criteria:

1. Age > 18 years, < 80 years
2. female or male
3. Patients are required to undergo EUS-FNA after undergoing imaging examination (MRI, CT, or ultrasonography) which identify that the pancreatic lesions are existing and solid.
4. Agree to attend this study and signed informed consent letter

Exclusion Criteria:

1. bad physical condition, including hemoglobin ≤ 8.0 g/dl, severe cardiorespiratory dysfunction, and so on
2. Coagulopathy (platelet count < 50,000/mm3, international normalized ratio > 1.5) or having taken oral anticoagulation agents such as aspirin or warfarin in the previous week
3. Be rejected by anesthesia
4. Acute pancreatitis in the previous 2 weeks
5. Pregnant or lactation period
6. Psychiatric disease, drug addiction, or other reason for unreliable follow-up or questionnaires
7. Don't agree to attend this study and absence of informed consent