Background: Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is a well-established diagnostic tool to obtain tissue from solid pancreatic masses, gastrointestinal subepithelial lesions, lymph nodes, liver as well as other neighboring organs. EUS-TA has proven to have a major clinical impact in diagnosis and staging, decreasing the need for invasive diagnostic procedures, such as thoracoscopy, mediastinoscopy, laparoscopy and open surgery. EUS-TA includes endoscopic ultrasound guided fine needle aspiration (EUS-FNA) and endoscopic ultrasound guided fine-needle biopsy (EUS-FNB). Both procedures are safe and yield high diagnostic value. Despite its high diagnostic yield, EUS-FNA limitations include the inability to determine histologic architecture, and a small quantitative sample which may be inadequate for further immunohistochemical staining or molecular testing. EUS-FNB, with its larger core biopsy needle, was designed to overcome these potential limitations. It remains unclear if EUS-FNB has truly overcome these obstacles, and the optimal selection of FNA or FNB in different clinical contexts for different lesions is yet to be determined. We present a review on studies examining EUS-FNA vs EUS-FNB.

Conclusion: For solid pancreatic masses, there is no difference in diagnostic accuracy or tissue cores rates when accompanied by rapid on-site evaluation (ROSE). The diagnostic yield is higher in FNB compared to FNA in cases where ROSE is not accessible. In addition, one study indicated that the combined approach of EUS-FNA + FNB resulted in a higher diagnostic yield than EUS-FNA alone, accompanied by a reduced number of needle passes required.
In solid gastrointestinal lesions, FNB is associated with a relatively better diagnostic adequacy and tissue cores rates, with less number of needle passes.
Regarding lymph node biopsy, the availability of prospective trials is limited. Based on the current literature, we would like to propose EUS-FNB as the recommended approach for lymph nodes.