Patients with a diagnosis of solid pancreatic lesions evidenced by imaging studies (CT, MRI) and who undergo endoscopic ultrasound-guided biopsy will be selected. Biopsies will be taken using modified tip needles (FNB) three different methods (capillary by suction, capillary without suction and wet suction).

From the results obtained from the pathology service, 3 variables will be assessed; Cellularity, blood contamination and suitability for a diagnosis.

EUS-BAAF procedure The procedure will be performed with a linear echoendoscope (PENTAX 3.8 EG-3870 UTK) and a HITACHI HI VISION Avius ultrasound processor, after deep sedation by the anesthesiology service. BAF Acquire # 22 needles (Boston Scientific, Malborough, MA) will be used. 3 passes will be made to the tumor, each pass will consist of 10-15 movements of the needle back and forth in a fan within the solid lesion, under complete ultrasound control (ESGE 2017- Gastrointest Endoscopy Clin N Am 22 (2012) 155 -167). Doppler will be used to avoid any vascular structure in the path of the needle.

The passes will be in three different ways to compare.

1. Capillary with suction (puncture with gradual withdrawal of the stylet, applying dry suction with a 10 ml air vacuum syringe after removing the stylet)
2. Capillary without suction (puncture with removal of the stylet gradually, without suction after removing the stylet)
3. Moist suction (Before the puncture, the stylet is removed from the needle and irrigated with 1-2 ml saline solution to replace the air column with liquid, then the solid lesion is punctured and suction is placed with a vacuum syringe of 10 ml of air)

The quality of the biopsy will be evaluated by the pathologist independently and without knowing how the sample was obtained.

Inclusion Criteria:

• Over 18 years old
• Any gender.
• Patients with solid pancreatic lesions evidenced by CT or MRI who do not have a histopathological diagnosis.

Exclusion Criteria:

• That no lesion in the pancreas is identified by EUS.
• Pancreatic lesions with a cystic component.
• Alteration of coagulation parameters (INR> 1.5, Platelets <50,000 / mm3) or having taken antiplatelet agents or oral anticoagulants one week prior to the biopsy.
• History of acute pancreatitis in the last 4 weeks.
• Pregnant
• Refusal or inability to sign informed consent

No individual data sharing plan

The samples will be analyzed independently by the pathology service, not knowing the order and the technique in which the samples were obtained. The histopathological result will be immediately available for patient care, however, the score obtained regarding the quality of the sample will correlate with the technique and the number of passes until the n of the study is completed.