The primary aim of REuBio study is to evaluate the diagnostic accuracy of repeated endoscopic ultrasound-guided fine needle biopsy after a previous non-diagnostic or inconclusive EUS-guided sampling of solid pancreatic lesions.

Endoscopic ultrasound-guided fine needles biopsy (EUS-FNB) represents the gold standard method for the diagnosis of solid pancreatic lesions (SPLs), even if a non-negligible risk of false-negative or inconclusive results still exists.

In such cases, major guidelines recommend repeating EUS-guided tissue sampling. Nevertheless, this recommendation is not based on high-quality evidence and little is known about the performance of repeated EUS-FNB (rEUS-FNB).

The primary aim of this study is to evaluate the diagnostic accuracy of rEUS-FNB after a previous non-diagnostic or inconclusive EUS-guided sampling of SPLs.

The secondary aims of this study are to evaluate rEUS-FNB sensitivity, specificity, positive predictive value, negative predictive value, specimen adequacy, Bethesda classification, adverse events incidence and factors that influenced rEUS-FNB performance.

Inclusion Criteria:

• Age >18 years old
• Solid pancreatic mass
• Previous non diagnostic or inconclusive EUS-tissue aquisition

Exclusion Criteria:

• age < 18 years old
• pancreatic mass with a predominantly cystic component
• previous pancreatic tissue acquisition was not performed under EUS-guidance (e.g. percutaneous sampling under abdominal ultrasound-guidance)
• repetition of pancreatic tissue sampling, after an inconclusive or non-diagnostic result, obtained by other methods than EUS-FNB, such as EUS-FNA or surgery or percutaneous sampling.
• patients with anatomic alterations or hematologic instability (including presence of severe blood clotting disorders) were excluded.
• rEUS-FNB of an extra-pancreatic mass

A multicenter retrospective observational study enrolling all the consecutive patients who underwent a repeated EUS-guided tissue sampling for solid pancreatic masses with an EUS-FNB needle, after previous non-diagnostic or inconclusive result.