Endoscopic ultrasound core needle for diagnosing of solid pancreatic lesions: is rapid on-site evaluation really necessary?

INTRODUCTION: Endoscopic ultrasound (EUS) guided fine needle aspiration (FNA) has a crucial role in the diagnosis of solid pancreatic lesions and rapid on-site evaluation (ROSE) can increase its diagnostic yield. Rapid on-site evaluation is not always available and after EUS-FNA provides a cytology specimen with scant cellularity. Fine needle biopsy (FNB) specimens containing core tissue may theoretically overcome the limitations of EUS-FNA sampling. It could be hypothesized that EUS-FNB without ROSE could achieve the same adequacy and accuracy of EUS-FNB with ROSE. The aim of this review is to evaluate the evidence on the role of ROSE in the setting of EUS-guided tissue acquisition with core needles in patients with solid pancreatic lesions.