Endoscopic ultrasound-guided sampling of solid pancreatic masses: the fine needle aspiration or fine needle biopsy dilemma. Is the best needle yet to come?

Abstract

Fine needle aspiration (FNA) is currently the standard of care for sampling pancreatic solid masses by using endoscopic ultrasound (EUS). The accuracy of the technique is reported to be high, especially if coupled with the rapid on site evaluation (ROSE), and it has a high safety profile. However, FNA presents some limitations, such as the small amount of tissue that can be collected and the inability of obtaining a core tissue with intact histological architecture, which is relevant to perform immunohistochemical analysis, molecular profiling and, therefore, targeted therapies. Moreover, the presence of the ROSE by an expert cytopathologist is very important to maximize the diagnostic yield of FNA technique; however, it is not widely available, especially in small centers. Hence, the introduction of EUS fine needle biopsy (FNB) with a new generation of needles, which show a high safety profile too and a satisfying diagnostic accuracy even in the absence of ROSE, could be the key to overcome the limitations of FNA. However, FNB has not yet shown diagnostic superiority over FNA. Considering all the technical aspects of FNA and FNB, the different types of needle currently available, comparisons in term of diagnostic yield, and the different techniques of sampling, a tailored approach should be used in order to determine the needle that is most appropriate for the different specific scenarios.

Effectiveness of introducing a 20-gauge core biopsy needle with a core trap in EUS-FNA/B for diagnosing pancreatic cancer

“…In this retrospective study, we examined the diagnostic efficacy of three puncture needles (PC20, PC22, and AC22) for the first EUS-FNA/B in patients with pancreatic cancer. The PC20 and PC22 employ a core trap system, which contributes to increased tissue acquisition and preservation of the histological structure [ 23 ]. A core trap can reportedly ensure effective cellularity for diagnosis [ 21 , 24 ].…”

“…In EUS-FNA/B, transduodenal puncture is challenging in some cases because of the steep up-angle of the scope [ 23 , 39 ]. A thicker needle with less flexibility has a disadvantage in this procedure, and endoscopists need to use additional needles in some cases.…”

Focal Autoimmune Pancreatitis: A Simple Flow Chart for a Challenging Diagnosis

“…AIP may mimic malignancy presenting the following cytological features: occasional atypical cells, large nuclei, degenerative vacuoles, sparse mitosis. Conversely, cells in AIP tend to lack hyperchromasia, display only minimal architectural disorders, and have only modestly increased nuclear-to-cytoplasmic ratios 40 . Therefore, cytology can be inconclusive.…”

“…EUS-guided sampling should always be performed in the case of pancreatic solid lesions. FNA has a diagnostic accuracy ranging from 77–95% 37 38 , especially if coupled with on-site pathological evaluation (ROSE) 39 40 . It is a safe technique, with morbidity and mortality rates <1%.…”

“…In the absence of ROSE, the 20 G FNB needle outperforms the 25 G FNA needle in terms of histological yield (77 vs 44%; P <0.001) and diagnostic accuracy (87 vs. 78%; P =0.002), with a 99% technical success rate for the FNB needle. 40 . Again, it was reported that using EUS trucut biopsy for acquiring core specimens and preserving tissue architecture could enhance the diagnostic accuracy for f-AIP 41 .…”