Endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) is a valid and recommended technique for tissue diagnosis of pancreatic masses. However, the diagnostic yield is with a sensitivity of 64%-95% and an accuracy of 78%-94% still very low. The EUS-FNB of pancreatic masses is usually performed with a 22-gauge biopsy needle. The small diameter of the needle is usually responsible for the low yield of tissue samples for histopathological examination. The 19-gauge needles help to overcome the limitations of a 22-gauge needle by acquiring a larger amount of cellular material. Thus, performing EUS-FNB with a 19-gauge needle can maximize tissue acquisition and sample adequacy, which is important for appropriate diagnosis. Contrariwise, the technical success rate for sample retrieval in patients with pancreatic head lesions is significantly lower using the 19-gauge compared to the 22-gauge needle. This is attributable to the technical difficulty to push the needle out of the endoscope in the duodenum. Since about 60% of pancreatic cancers are located in the head region, it is therefore particularly important to improve technical success in these cases. The new 19-gauge biopsy needle "Olympus EZ Shot3 Plus" is more flexible than common biopsy needles such as "EZ Shot2" and should therefore provide improved access to regions like pancreatic head. The aim of this multicenter prospective randomized crossover study is to compare those two needles during EUS-FNB of solid pancreatic masses.

Therefore this study will enroll 40 patients in five German centers with solid pancreatic masses and consecutive indication for EUS-FNB. Both needles will be used in each patient following a predetermined random order.

Primary endpoint is the correct histological diagnosis of the mass assessed by each needle. Technical failure is regarded as a negative histological diagnosis.

Secondary endpoints include a comparison of technical failure using each needle, histological quality, duration of procedure and rate of adverse events.

Inclusion Criteria:

• solid pancreatic mass and consecutive indication for EUS-FNB

Exclusion Criteria:

• incapacity to give informed consent
• Haemorrhagic disease, disorder of hemostasis and coagulation (PT <60%, PTT> 42 sec. and platelets <60000/µL)
• oral anticoagulants
• dual antiplatelet therapy with thienopyridines (e.g. clopidogrel)
• Pregnant or lactating