A multicentre phase II study to determine the safety and efficacy of EUS-guided nCLE in patients with suspected cystic tumours of the pancreas in whom endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is clinically indicated. Patients will be recruited sequentially to undergo nCLE as part of their routine diagnostic evaluation, followed by standard surveillance. This part of the study will recruit 60 patients.

A multicentre phase II study to determine the safety and efficacy of EUS-guided nCLE in patients with suspected cystic tumours of the pancreas in whom endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is clinically indicated. Patients will be recruited sequentially to undergo nCLE as part of their routine diagnostic evaluation, followed by standard surveillance. This part of the study will recruit 60 patients. The study also includes a feasibility study to evaluate the role of intraoperative nCLE in the diagnosis and staging of pancreatic tumours. This part of the study will recruit a further 20 patients.

Primary endpoint:

Assess the diagnostic performance of the Cellvizio nCLE system in the characterization of pancreatic cysts, compared to standard diagnostic modalities.

Secondary endpoints:

• Assess the safety and efficacy of EUS-nCLE.
• Assess the impact of the Cellvizio nCLE system on the management of patients with pancreatic cysts.
• Develop and validate interpretation criteria for nCLE in the pancreas.
• Assess the diagnostic performance of nCLE in characterising and staging pancreatic tumours intraoperatively.

Inclusion Criteria:

1. A diagnosis of a pancreatic cystic tumour based on multidisciplinary review of imaging for which EUS-FNA is indicated.
2. Pancreatic cystic tumour >1cm in size.
3. ECOG performance status 0, 1 or 2.
4. Estimated life expectancy of at least 12 weeks.
5. Age >18 years.
6. Capable of giving written informed consent.
7. Has not has pancreatitis within the previous 3 months.
8. Women of child-bearing potential must have a negative pregnancy test in the week before nCLE, AND be using an adequate contraception method, which must be continued for at least 1 week after nCLE.

Exclusion Criteria:

1. Acute pancreatitis in the last 3 months.
2. Subject with multiple cysts
3. Subjects for whom EUS-FNA or surgery are contraindicated
4. Known allergy to fluorescein dye
5. Any evidence of severe or uncontrolled systemic diseases or laboratory finding that in the view of the investigator makes it undesirable for the patient to participate in the trial.
6. Any psychiatric disorder making reliable informed consent impossible.
7. Pregnancy or breast-feeding.
8. ECOG performance status 3 or 4