Techniques for Endoscopic Ultrasound-Guided Fine-Needle Biopsy

Although endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the method of choice to obtain samples to reach definitive diagnosis of lesions of the gastrointestinal tract and of adjacent organs, it cannot fully characterize certain neoplasms. The lack of cytology expertise has hindered the dissemination of EUS, limiting its widespread use. The obtainment of a tissue specimen through EUS fine-needle biopsy (EUS-FNB) may overcome the limitations of EUS-FNA. EUS-FNB is expected to move the practice of EUS from cytology to histology, expanding the use of EUS and facilitating targeted therapies and monitoring of treatment response in a more biologically driven manner.

Key points

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Although endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is accurate, it cannot fully characterize certain neoplasms, and lack of cytology expertise may result in a limited perceived usefulness of EUS.
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EUS Tru-Cut biopsy does not offer any clear advantage compared with EUS-FNA and is technically demanding, with a low transduodenal yield.
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Standard 19-G and 22-G FNA needles with or without high negative pressure have proved to be reliable in obtaining high-quality histologic samples in various indications.
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The novel 19-G and 22-G ProCore needles (Cook Medical, Bloomington, IN, US) have shown a high yield in obtaining histologic samples, whereas 25-G ProCore seems unsuitable for histology.
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EUS-FNB is expected to refine differential diagnostic capabilities, favor widespread EUS use, and pave the road to targeted therapies and monitoring of treatment response.