Endoscopic ultrasound-guided fine needle aspiration or fine needle biopsy: the beauty is in the eye of the beholder

The impact of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) on pancreatic tissue acquisition has been so profound that the technique is regarded as a disruptive innovation [1]. However, EUS-FNA has two major limitations: the diagnostic performance is dependent on the availability of a cytopathologist to render rapid onsite evaluation and it doesn’t provide histology, which may be required to establish a conclusive diagnosis when FNA cytology alone is insufficient. The ProCore biopsy needle was developed to overcome these limitations. In this issue of the journal, two randomized trials compare the diagnostic performance of the ProCore and standard FNA needles for tissue acquisition in solid pancreatic mass lesions [2] [3].

In the French multicenter study by Vanbiervliet et al., 80 patients with solid pancreatic masses underwent fine needle biopsy (FNB) using a single pass of the 22G ProCore needle and FNA with two passes of a standard 22G FNA needle, with the two investigations being performed in a randomized order [2]. The specimens were processed offsite for cytology and histology. There was no difference in diagnostic accuracy (> 90 % for both needles), and the overall histological quality was superior with the FNA needle.

In the second study from South Korea by Lee et al., 116 patients with solid pancreatic masses were randomized to undergo either FNA or FNB using the ProCore or standard FNA needle, with 22G and 25G needles used in the stomach and duodenum respectively [3]. In addition to rapid onsite evaluation, each pass was analyzed for cytology and histology. Similar to the French multicenter study, there was no significant difference between the cohorts in overall diagnostic accuracy (FNB 98.3 % vs. FNA 94.8 %; P = 0.67) or histological accuracy (FNB 82.8 % vs. FNA 77.6 %; P = 0.64).

Both randomized trials deliver the same message: the diagnostic performance of the ProCore and standard FNA needles are comparable. More importantly, the histological yield of the ProCore needle is not superior to a standard FNA needle. A recent meta-analysis comparing the technical performance of the ProCore and standard FNA needles in 641 patients with pancreatic masses found no significant difference in the diagnostic accuracy between the ProCore and standard FNA needles (88.4 % [95 %CI 82.4 % – 93.3 %] vs. 79.9 % [95 %CI 73.6 % – 85.5 %], respectively; P = 0.067), or in terms of histological core tissue procurement (75.4 % [95 %CI 60.2 % – 87.8 %] vs. 75.2 % [95 %CI 63.2 % – 85.5 %], respectively; P = 0.075) [4]. These findings accord with the results of the two randomized trials published in this issue of the journal [2] [3].

In what context do we evaluate these findings and how do we move the discipline of EUS-guided tissue acquisition forward? The answers lie in a critical analysis of historical perspectives and lessons learnt from clinical experience, and reassessment of the technological refinements required to improve procedural outcomes.

• References

• 1 Eltoum IA, Alston EA, Roberson J. Trends in pancreatic pathology practice before and after implementation of endoscopic ultrasound-guided fine-needle aspiration. Arch Pathol Lab Med 2012; 136: 447-453
• 2 Vanbiervliet G, Napoléon B, Paul MCS et al. Core needle versus standard needle for endoscopic ultrasound-guided biopsy of solid pancreatic masses: a randomized crossover study. Endoscopy 2014; 1063-1070
• 3 Lee YN, Moon JH, Kim HK et al. Core biopsy needle versus standard aspiration needle for endoscopic ultrasound-guided sampling of solid pancreatic masses: a randomized parallel-group study. Endoscopy 2014; 1056-1062
• 4 Bang JY, Hasan M, Hawes R et al. EUS-guided tissue acquisition: meta-analysis comparing the procore and standard FNA needles. Gastrointest Endosc 2014; 79: AB427
• 5 Panic N, Larghi A. Techniques for endoscopic ultrasound-guided fine-needle biopsy. Gastrointest Endosc Clin N Am 2014; 24: 83-107
• 6 Bang JY, Hebert-Magee S, Trevino J et al. Randomized trial comparing the 22-gauge aspiration and 22-gauge biopsy needles for EUS-guided sampling of solid pancreatic mass lesions. Gastrointest Endosc 2012; 76: 321-327
• 7 Larghi A, Capurso G, Carnuccio A et al. Ki-67 grading of nonfunctioning pancreatic neuroendocrine tumors on histologic samples obtained by EUS-guided fine-needle tissue acquisition: a prospective study. Gastrointest Endosc 2012; 76: 570-577
• 8 Varadarajulu S, Bang JY, Hebert-Magee S. Assessment of the technical performance of the flexible 19-gauge EUS-FNA needle. Gastrointest Endosc 2012; 76: 336-343
• 9 Roy A, Kim M, Hawes RH et al. Changing trends in tissue acquisition in pancreatic diseases. Gastrointest Endosc 2013; 77: AB134