How good is fine needle aspiration? What results should you expect?

Tissue acquisition plays a key role before treatment decision in most of oncological pathologies but also in several benign diseases. By offering tissue sampling, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has become an essential tool in the diagnostic processes. One of the reasons for the success of the technique is related to its excellent diagnostic performance. The diagnostic accuracy of EUS-FNA is above 80% for most of the usual indications. These performances are however dependent on some factors related to both the disease and patient's medical history but also related to medical staff expertise. Endoscopist needs to know how to reach a lesion but also how to efficiently acquire good tissue samples. This review aims to report general recommendations available in the literature for high quality EUS-FNA. Sample processing and sample interpretation also influence diagnostic accuracy of FNA. This paper includes a discussion on sample processing and benefits of the on-site pathology examination. It also provides the results reported in the literature of sample adequacy and diagnostic performance of EUS-FNA for most common indications: Pancreatic diseases, sub-mucosal lesion, mucosal thickenings, lymph nodes, cystic lesion and free fluids.