Aspiration of Duodenopancreatic Juice After Secretin Stimulation vs Endoscopic Aspiration for Molecular Analysis of Intraductal Papillary Mucinous Intraductal Neoplasia.

Study to evaluate aspiration of duodenopancreatic juice after secretin stimulation (ADPJ-secr)versus endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for molecular analysis of intraductal papillary mucinous intraductal neoplasia.

Drug: Secretin. Secretin will be administered intravenous during 1 minute at a dose of 0,2 μg/Kg previous to the endoscopic procedure.

Procedure: Endoscopic aspiration. Endoscopic aspiration of duodenopancreatic juice after secretin stimulation

Procedure: Endoscopic ultrasound-guided fine needle aspiration. Endoscopic ultrasound-guided fine needle aspiration of intraductal papillary mucinous intraductal neoplasia (IPMN).

Duodenopancreatic aspiration after secretin stimulation + EUS-FNA (experimental): Duodenopancreatic aspiration after secretin stimulation will be performed followed by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA)

EUS-FNA + duodenopancreatic aspiration after secretin stimulation (experimental): Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) will be performed followed by duodenopancreatic aspiration after secretin stimulation

Proportion of patients with IPMN with GNAS and KRAS mutations in intracystic fluid obtained by EUS-FNA versus pancreatic juice obtained by ADPJ-secr after both techniques.. In intracystic fluid obtained by EUS-FNA versus pancreatic juice obtained by ADPJ-secr after both techniques. Time frame: Through study completion, an average of 30 months.

Proportion of patients with IPMN with Tp53 mutations.. Time frame: Through study completion, an average of 30 months.

DNA concentration expressed in ng/µl. Time frame: Through study completion, an average of 30 months.

Proportion of suitable samples obtained by the two techniques under study (ADPJ-secr and EUS-FNA) for molecular analysis.. Time frame: Through study completion, an average of 30 months.

Proportion of patients undergoing pancreatic resection with a pathological diagnosis of IPMN who have mutations in GNAS and/or KRAS. Time frame: Through study completion, an average of 30 months.

Proportion of patients undergoing pancreatic resection without a pathological diagnosis of IPMN who do not have GNAS and/or KRAS mutations. Time frame: Through study completion, an average of 30 months.

Proportion of patients undergoing pancreatic resection with Tp53 mutations. Time frame: Through study completion, an average of 30 months.

Inclusion Criteria: 1. Be a man or woman over 18 years of age. 2. Willing to comply with the study procedures described in the protocol. 3. Willing and able to give written informed consent. 4. Meet at least one of the following three criteria in relation to the diagnosis or prognosis of IPMN: 4.1 Diagnosis of IMPN based on evidence of major criteria or existence of at least 2 minor criteria. Major criterion: Typical findings on MRI and/or EUS (single or multiple cysts with clear ductal communication and/or focal or diffuse dilatation # 5 mm in diameter of the main pancreatic duct without apparent obstructive cause). Minor criteria: a) Mucosecretory cells and/or extracellular mucin on cytological examination of intracystic fluid. b) Clear mucoid or filmy appearance of the intracystic fluid. c) Intracystic fluid CEA concentration \>192 ng/mL or intracystic glucose \< 50 mg/dL. 4.2 IPMN with cysts with a diameter # 10 mm and/or focal or diffuse dilatation of the main pancreatic duct with a diameter # 7 mm requiring EUS-FNA for diagnostic purposes or to assess risk or existence of malignancy following the main clinical practice guidelines. 4.3 IPMN with indication for surgical resection of the lesion. 5. In case of a woman of childbearing age\*, willing to use highly effective contraception or practice sexual abstinence from the screening visit until one week after undergoing the procedure under study. Highly effective contraceptive methods will include: combined oral, intravaginal or transdermal hormonal contraceptives (containing oestrogens and progestogens) associated with ovulation inhibition; oral, injectable or implantable progestogen-only hormonal contraception associated with ovulation inhibition; intrauterine device; intrauterine hormone-releasing system; bilateral tubal occlusion; vasectomised partner; and sexual abstinence. 6. If you are a woman of childbearing age, be willing to undergo a urine pregnancy test prior to inclusion in the study. Exclusion Criteria: 1. History of surgery that prevents endoscopic access to the major duodenal papilla in the case of ADPJ-secr, or to the area of the stomach or intestine from which to perform FNA. 2. History of acute pancreatitis during the 30 days prior to inclusion. 3. Pregnant women, women who may become pregnant during the month prior to inclusion or women who are breastfeeding. 4. Coagulopathy (PT \< 25%, INR \> 1.5, platelets \< 50,000/mL) preventing FNA. 5. Renal failure with GFR \< 30 mL/min or …

Enrollment: 140 participants (estimated).