|Year : 2020 | Volume
| Issue : 1 | Page : 62-67
Endoscopic ultrasound sampling: From cells to tissue
Suresh Vasan Venkatachalapathy, Guruprasad P Aithal
NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham NG2 7UH, England
|Date of Submission||27-Feb-2020|
|Date of Decision||01-Mar-2020|
|Date of Acceptance||04-Mar-2020|
|Date of Web Publication||20-Jun-2020|
Prof. Guruprasad P Aithal
NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham NG2 7UH
Source of Support: None, Conflict of Interest: None
Extraluminal gastrointestinal (GI) tracts were often difficult to diagnose before the introduction of endoscopic ultrasound (EUS). Surgical procedure or computer tomographic-guided approach was needed to obtain tissue which was either invasive or lacked sensitivity and specificity. EUS-guided tissue acquisition has revolutionized tissue acquisition for upper extraluminal GI lesions. This is because EUS is minimally invasive compared to either surgery or percutaneous approach, close proximity to upper GI extraluminal GI lesions, and tissue acquisition under direct real-time sonographic guidance. Hence, it has become the first-line investigation for tissue acquisition. In the past decade, there have been significant improvements in tissue acquisition through EUS-guided approach. In this article, we have reviewed the key factors that improve tissue acquisition through EUS-guided approach.
Keywords: EUS, EUS guided sampling, FNA, FNB
|How to cite this article:|
Venkatachalapathy SV, Aithal GP. Endoscopic ultrasound sampling: From cells to tissue. Arch Med Health Sci 2020;8:62-7
| Introduction|| |
Early diagnosis of cancers in the gastrointestinal (GI) tract is very important as they alter the prognosis of the disease. A population-based cohort study on 2212 patients reported a median system delay of 55 days (range 33–93 days) from the time of presentation to secondary care and diagnosis of cancer. A recent prospective study reported that the median time diagnostic interval (i.e., onset of the first symptom to first health-care consultation) is 108 days (interquartile range [IQR] 47–222) and 136 days (IQR 86–323) for pancreatic cancer and metastatic pancreatic cancer, respectively. The median health system interval (time to investigation and initiation of treatment from the first consultation) is 76 days (IQR: 28–161). A retrospective study on 80 patients with esophageal cancer reported that a few months' delay before final treatment may have an impact on the stage of cancer and the overall prognosis. This may hold true for other cancers such as pancreatic cancers and bile duct cancers.
One of the important rate-limiting steps in the diagnosis of cancer involving the upper abdomen is the acquisition of tissue to confirm the diagnosis of cancer, especially if the tumor is not involving the lumen of the GI tract. Historical data show that it is often difficult to access retroperitoneal organs such as the pancreas through percutaneous biopsy. In a study investigating computer tomographic (CT)-guided core-needle biopsy, diagnosis of adenocarcinoma was achieved in only 50% of patients undergoing the procedure.
Endoscopic ultrasound (EUS)-guided approach brought about a step change in our ability to sample submucosal, extraluminal, and retroperitoneal structures. EUS has the advantage of providing safe GI access and close access to retroperitoneal structures, liver and biliary tract, which enables the endo-sonographer to acquire tissue under direct sonographic guidance. A randomized comparison study with cross over design reported a sensitivity of 62% and 84% for CT/ultrasound fine-needle aspiration (FNA) and EUS-FNA, respectively, for the diagnosis of pancreatic mass lesions. Steady improvements in the needle design and techniques have improved the diagnostic yield from the EUS-guided sampling with a recent study reporting a diagnostic yield as high as 90%. This could reduce the time to diagnosis and potentially improve the quality of care to patients with a suspected diagnosis of cancer. There is still significant operator dependency and variability in practice among endosonographers. This may affect the tissue yield, and in this article, we will review different factors that may improve the diagnostic yield of the EUS-guided sampling for extraluminal GI cancers.
| Location of the Lesion|| |
The location of the lesion is important for getting adequate tissues. A sampling of peri-esophageal lesions such mediastinal lymph nodes is relatively easy as they are closer to the scope and the endosonographer can maintain a straight, stable scope position while acquiring tissue. This may hold true for submucosal lesions of the GI tract. A retrospective study assessing the diagnostic yield for submucosal lesions reported a diagnostic yield of 89% for EUS-guided sampling. In contrast, sampling of lesions in the uncinate process and head of the pancreas are relatively difficult because the lesion is away from the tip of the scope and the tip of the scope is relatively unstable when it is in the first part of the duodenum. A retrospective study analyzing EUS-guided trucut biopsy (TCB) from 247 patients reported that the site of the biopsy was an independent predictor of diagnostic yield. A retrospective study assessing the diagnostic yield for submucosal lesions reported a diagnostic yield of 89% for EUS-guided sampling.
| Size of the Lesion|| |
The size of the lesion has a significant influence on the tissue acquisition through either fine needle aspiration (FNA) or fine-needle biopsy (FNB). A retrospective study on 583 patients assessing solid pancreatic lesions reported a strong correlation between diagnostic yield and the size of the lesion (r2 = 0.75, P < 0.001). The accuracy of EUS-FNA increased as the lesion size increased, ranging from 47% for lesions <1 cm to 88% for those >4 cm (P < 0.05)., A retrospective study involving 141 patients assessing the diagnostic yield of EUS-FNA for submucosal lesions reported that the diagnostic accuracy of EUS FNA increased to 95% for lesions >5 cm. Another study involving 271 solid lesions reported that the size of the lesion was an independent factor associated with increased tissue acquisition using EUS-FNA.
| Needle Size|| |
The size of the needle does not seem to affect the diagnostic yield for solid lesions. Two small retrospective studies comparing 22G and 25G FNA needle for solid pancreatic lesions did not report significant differences in tissue adequacy;, this held true for FNB needles. A prospective study on 66 patients comparing 22G and 25FNB needle did not report significant between the two needles. The literature is scarce comparing 19G and either 22 or 25G needle, as the choice of the needle is naturally influenced by the site of sampling (e.g., 19G needle is used in 15% or fewer cases when transduodenal approach is taken to sample uncinate process of the pancreas). Hence, in the absence of conclusive evidence, the needle choice should be determined by an endoscopist's preference, location of the lesion, size of the lesion, and the flexibility of the needle.
| Suction|| |
The negative pressure created by either a 10 ml or 20 ml syringe connected to the end of the needle plays an important role in tissue acquisition. One can apply dry suction, wet suction, and slow stylet pull technique. Two prospective randomized control trials, one on FNA of solid pancreatic lesions and another on lymph nodes, comparing dry suction versus no suction; reported increased cellularity with suction samples., Wet suction involves pre-filling the needle with saline as it is less compressible; hence, the negative pressure is transmitted to the needle tip which may enhance the tissue acquisition. A prospective single-blinded randomized control trial comparing wet suction and conventional FNA reported a significantly higher cellularity with wet suction technique (mean cellularity score 1.82 ± 0.76 vs. 1.45 ± 0.76, P < 0.0003). The specimen adequacy for cell block was significantly better in wet suction group (85.5% vs. 75.5%, P= 0.03). Slow stylet pull technique may generate negative pressure when it is pulled slowly after a puncture into the lesion. However, the negative pressure generated by technique is difficult to measure and cannot be reproduced as the speed with which the stylet is pulled out varies with each puncture. This may affect the tissue acquisition. A multicenter randomized control trial comparing the above technique and conventional suction technique reported comparable diagnostic sensitivity.
| Fine-Needle Biopsy Versus Fine-Needle Aspiration Needle|| |
There is a high degree of variability with the diagnostic yield of FNA needles [Figure 1], especially for pancreatic lesions. The diagnostic accuracy ranges from 78% to 95%. The diagnostic yield is even lower when it is used for mediastinal masses and gastrointestinal stromal tumors., A retrospective study on 37 patients reported a sensitivity of 78.4% for the FNA needle. FNA needles do not provide core tissue for immunohistochemical staining and for histology. EUS-FNB needle was developed over a decade ago to overcome this limitation. Different principles have been used to design different types of FNB needles.
|Figure 1: Fine-needle aspiration needle images Courtesy of Boston Scientific|
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Trucut needle was introduced to overcome the limitations of the FNA needle (EUS – TCB). It was possible to get tissue for immunohistochemistry but had its technical limitations. It was difficult to perform TCB unless the lesion is accessible in a straight scope position. This made transduodenal tissue acquisition difficult. A retrospective study on 40 patients reported that the sample was adequate for immunohistochemistry in 91% of EUS-TCB samples compared to 74% of FNA samples (P = 0.025). However, the failure rate with EUS-TCB was 15%. A prospective study on 167 patients comparing dual sampling (EUS-TCB and FNA) versus sequential sampling (EUS-TCB first and FNA only if there was a technical difficulty with EUS-TCB) showed a failure rate of 11% with 50% through transduodenal sampling. The diagnostic accuracy of EUS-TCB was comparable to the FNA (89% vs. 82%, P= 0.21) but dual sampling group higher diagnostic accuracy (93% vs. 82%, P= 0.04).
Due to technical limitations of trucut needle, other flexible FNB needles were developed. A randomized controlled trial comparing 22G EUS FNA needles versus 22G EUS FNB needle, for pancreatic lesions; showed that the diagnostic yield was comparable between the two needles. Another randomized control trial on 80 patients which used one pass with FNB needle and another pass with an FNA needle in a randomized fashion reported similar diagnostic accuracy. A prospective study on 144 patients reported comparable diagnostic yield, but the mean number of passes required was significantly lower for the FNB needle than the FNA needle. A meta-analysis of 9 studies involving 576 patients comparing reverse bevel FNB needle [ProCore-Cook Endoscopy, [Figure 2] and standard FNA needle reported no statistical difference between the two needles for sample adequacy, diagnostic accuracy, or acquisition of core specimen. Another meta-analysis of 15 studies involving 1024 patients reported that the diagnostic yield was relatively better with the FNB needle when there was no rapid on-site evaluation.
The novel fork-tip FNB needle (SharkCore) and the Franseen needle (Acquire needle (Boston scientific)) may have better diagnostic yield compared to the standard FNA needle. A retrospective case–control study reported that 95% of the specimens obtained from the EUS-FNB-SC group had sufficient tissue for histological evaluation, compared with 59% from the EUS-FNA group (P = 0.01). A small retrospective study on 29 patients reported that in 96.5% of patients, the sample was deemed adequate for histological analysis. A retrospective study comparing fork-tip needle against reverse bevel needle (ProCore) reported that the tissue adequacy for histological analysis was 87 and 99% for reverse bevel versus fork tip needle, respectively (P = 0.0009).
The Franseen needle [Figure 3] has a three-plane symmetry with Franseen geometry. It has a large crown tip with three cutting edges which may aid tissue acquisition for histological analysis. A randomized control trial comparing 22G Franseen needle and 22G standard FNA needle reported that the Franseen needle's performance was significantly better for median area of total tissue (6.1 mm 2 [IQR 2.2–9.9] vs. 0.28 mm 2 [IQR 0.045–0.93], P < 0.0001), tumor (0.68 mm 2 [IQR 0.23–2.8] vs. 0.099 mm 2 [IQR 0.004–0.30], P < 0.0001), desmoplastic fibrosis (3.9 mm 2 [IQR 0.5–8.2] vs. 0 [IQR 0–0.11], P < 0.0001), retained tissue architecture (93.5% vs. 19.6%, P < 0.0001), and cell block diagnostic yield (97.8% vs. 82.6% P= 0.03). The sample adequacy for the novel cutting needles is described in [Table 1].
A randomized control trial on 50 patients comparing Franseen needle and fork-tip needle reported no significant difference in the area of total tissue tumor, desmoplastic fibrosis. The sample adequacy for diagnostic cell block was 96% versus 92%, P= 0.32 and for rapid onsite cytological evaluation (ROSE) (94% vs. 98%, P= 0.32). The diagnostic yield and the tissue adequacy for histological assessment have significantly improved in the past 10 years with the introduction of novel FNB needles. It may reduce the need for a rapid onsite evaluation of the sample. It may also help us to do tests including immunohistochemical analysis and DNA sequencing which, in turn, may help tailor the treatment to patients.
| Number of Passes|| |
There is good evidence to suggest that the cytological yield improves with the number of needles passes with the FNA needle.,, If the median number of passes is above or equal to 3, then the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy value are 84.3%, 97%, 99%, 64%, and 84% respectively. However with FNB needles, one may be able to achieve this with a smaller number of passes. A randomized crossover study on 80 patients reported that the overall sample quality was better with the FNB needle. A prospective comparison study on 144 patients reported that the mean number of passes to obtain sufficient tissue was 1.2 ± 0.5 with the core needle versus 2.5 ± 0.9 with the standard needle (P < 0.001).
| Rapid Onsite Cytological Evaluation|| |
The presence of ROSE may reduce the number of passes required for diagnosis and may increase the diagnostic yield. After each FNA pass, the first drop of the sample will be extracted onto a glass slide. This is usually done with an air-filled syringe. The rest of the sample will be sent for the cell block. The glass slides will be air-dried and stained with modified Giemsa for an immediate on-site evaluation. A comprehensive pathology evaluation will later be performed on the pooled tissue obtained during the entire procedure. A prospective study on 182 patients comparing ROSE against standard care reported a significantly higher number of passes (3.5 ± 1.0 vs. 2.0 ± 0.7; P < 0.001), higher diagnostic sensitivity (96.2% vs. 78.2%; P= 0.002), overall accuracy (96.8% vs. 86.2%; P= 0.013), and lower number of inadequate samples (1.0% vs. 12.6%, P= 0.002). Another study on 108 patients examining thoracoabdominal nodes and pancreas reported similar results. A meta-analysis of 34 studies involving 3644 patients reported that ROSE (P = 0.001) remained a significant determinant of EUS-FNA accuracy after correcting for the study population number and reference standard, using meta-regression model.
Two randomized control trials assessed the effects of ROSE on FNA. ROSE significantly reduced the number of passes needed to establish the diagnosis. However, there was no statistically significant difference in the diagnostic accuracy, sample adequacy, and quality. There was no statistically significant difference in procedure time or adverse events., Post hoc analysis of the trial did not show a significant difference in sensitivity for malignancy after four passes. ROSE did not alter the sensitivity for detecting malignancy. ROSE did not reduce the cost of EUS guided sampling but, in fact, increased.,
The novel fork tip and Franseen needles have >90% diagnostic yield and may reduce the need for ROSE. A randomized control trial comparing fork tip and Franseen needle reported retained architecture (100% vs. 83%, P= 0.25), diagnostic cell block (96.0% vs. 92.0%, P= 0.32), and diagnostic adequacy at ROSE (94.0% vs. 98.0%, P= 0.32) between Franseen and fork-tip needles. Other retrospective studies reported similar results with regard to tissue adequacy.,, A randomized control trial comparing Franseen needle against FNA needle reported a cellblock diagnostic yield of 97.8% for Franssen needle. The cost of establishing ROSE into practice is significant (pathology staff costing and additional procedure time). A recent global survey reported ROSE was available only in 48% of the responders in Europe. With the new generation needles, the average cellblock diagnostic yield is >95% and hence may obviate the need for ROSE in future.
| Conclusion|| |
Although significant variability exists among endosonolographers with regard to the technique of EUS-based sampling, we have reviewed the evidence base behind different aspects of the procedure. In parallel with the technique, developments in the design of needles have further enhanced the quality of samples. A combination of techniques and technology has contributed to the quality of care provided to patients with GI tract cancers.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Hansen RP, Vedsted P, Sokolowski I, Søndergaard J, Olesen F. Time intervals from first symptom to treatment of cancer: A cohort study of 2,212 newly diagnosed cancer patients. BMC Health Serv Res 2011;11:284.
Walter FM, Mills K, Mendonça SC, Abel GA, Basu B, Carroll N, et al
. Symptoms and patient factors associated with diagnostic intervals for pancreatic cancer (SYMPTOM pancreatic study): A prospective cohort study. Lancet Gastroenterol Hepatol 2016;1:298-306.
Wang J, Liu F, Gao H, Wei W, Zhang X, Liang Y, et al
. The symptom-to-treatment delay and stage at the time of treatment in cancer of esophagus. Jpn J Clin Oncol 2008;38:87-91.
Rodriguez J, Kasberg C, Nipper M, Schoolar J, Riggs MW, Dyck WP. CT-guided needle biopsy of the pancreas: A retrospective analysis of diagnostic accuracy. Am J Gastroenterol 1992;87:1610-3.
Li L, Liu LZ, Wu QL, Mo YX, Liu XW, Cui CY, et al
. CT-guided core needle biopsy in the diagnosis of pancreatic diseases with an automated biopsy gun. J Vasc Interv Radiol 2008;19:89-94.
Horwhat JD, Paulson EK, McGrath K, Branch MS, Baillie J, Tyler D, et al
. A randomized comparison of EUS-guided FNA versus CT or US-guided FNA for the evaluation of pancreatic mass lesions. Gastrointest Endosc 2006;63:966-75.
Kasi M, Fernandez-Sordo JO, Kaye P, Ragunath K, James M, Aithal GP, et al
. PTH-028 a preliminary report on the feasibility and efficacy of the novel eus guided shark core fine needle biopsy. Gut 2017;66 Suppl 2:A219.
Hunt GC, Smith PP, Faigel DO. Yield of tissue sampling for submucosal lesions evaluated by EUS. Gastrointest Endosc 2003;57:68-72.
Thomas T, Kaye PV, Ragunath K, Aithal G. Efficacy, safety, and predictive factors for a positive yield of EUS-guided Trucut biopsy: A large tertiary referral center experience. Am J Gastroenterol 2009;104:584-91.
Siddiqui AA, Brown LJ, Hong SK, Draganova-Tacheva RA, Korenblit J, Loren DE, et al
. Relationship of pancreatic mass size and diagnostic yield of endoscopic ultrasound-guided fine needle aspiration. Dig Dis Sci 2011;56:3370-5.
Wu L, Guo W, Li Y, Cheng T, Yao Y, Zhang Y, et al
. Value of endoscopic ultrasound-guided fine needle aspiration in pretest prediction and diagnosis of pancreatic ductal adenocarcinoma. Nan Fang Yi Ke Da Xue Xue Bao 2018;38:1171-8.
Mekky MA, Yamao K, Sawaki A, Mizuno N, Hara K, Nafeh MA, et al
. Diagnostic utility of EUS-guided FNA in patients with gastric submucosal tumors. Gastrointest Endosc 2010;71:913-9.
Cooray M, Nistor I, Pham J, Bair D, Arya N. Accuracy of endoscopic ultrasound-fine needle aspiration of solid lesions over time: Experience from a new endoscopic ultrasound program at a Canadian community hospital. Endosc Ultrasound 2017;6:187-94.
] [Full text]
Mavrogenis G, Weynand B, Sibille A, Hassaini H, Deprez P, Gillain C, et al
. 25-gauge histology needle versus 22-gauge cytology needle in endoscopic ultrasonography-guided sampling of pancreatic lesions and lymphadenopathy. Endosc Int Open 2015;3:E63-8.
Berzosa M, Villa N, El-Serag HB, Sejpal DV, Patel KK. Comparison of endoscopic ultrasound guided 22-gauge core needle with standard 25-gauge fine-needle aspiration for diagnosing solid pancreatic lesions. Endosc Ultrasound 2015;4:28-33.
] [Full text]
Park SW, Chung MJ, Lee SH, Lee HS, Lee HJ, Park JY, et al
. Prospective study for comparison of endoscopic ultrasound-guided tissue acquisition using 25-and 22-gauge core biopsy needles in solid pancreatic masses. PLoS One 2016;11:e0154401.
Aithal GP, Anagnostopoulos GK, Tam W, Dean J, Zaitoun A, Kocjan G, et al
. EUS-guided tissue sampling: Comparison of “dual sampling” (Trucut biopsy plus FNA) with “sequential sampling” (Trucut biopsy and then FNA as required). Endoscopy 2007;39:725-30.
Wallace MB, Kennedy T, Durkalski V, Eloubeidi MA, Etamad R, Matsuda K, et al
. Randomized controlled trial of EUS-guided fine needle aspiration techniques for the detection of malignant lymphadenopathy. Gastrointest Endosc 2001;54:441-7.
Lee JK, Choi JH, Lee KH, Kim KM, Shin JU, Lee JK, et al
. A prospective, comparative trial to optimize sampling techniques in EUS-guided FNA of solid pancreatic masses. Gastrointest Endosc 2013;77:745-51.
Polkowski M, Jenssen C, Kaye P, Carrara S, Deprez P, Gines A, et al
. Technical aspects of endoscopic ultrasound (EUS)-guided sampling in gastroenterology: European Society of Gastrointestinal Endoscopy (ESGE) Technical Guideline – March 2017. Endoscopy 2017;49:989-1006.
Attam R, Arain MA, Bloechl SJ, Trikudanathan G, Munigala S, Bakman Y, et al
. “Wet suction technique (WEST)”: A novel way to enhance the quality of EUS-FNA aspirate. Results of a prospective, single-blind, randomized, controlled trial using a 22-gauge needle for EUS-FNA of solid lesions. Gastrointest Endosc 2015;81:1401-7.
Itoi T, Sofuni A, Itokawa F, Irisawa A, Khor CJ, Rerknimitr R. Current status of diagnostic endoscopic ultrasonography in the evaluation of pancreatic mass lesions. Dig Endosc 2011;23 Suppl 1:17-21.
Sepe PS, Moparty B, Pitman MB, Saltzman JR, Brugge WR. EUS-guided FNA for the diagnosis of GI stromal cell tumors: Sensitivity and cytologic yield. Gastrointest Endosc 2009;70:254-61.
Dumonceau JM, Polkowski M, Larghi A, Vilmann P, Giovannini M, Frossard JL, et al
. Indications, results, and clinical impact of endoscopic ultrasound (EUS)-guided sampling in gastroenterology: European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline. Endoscopy 2011;43:897-912.
Fernández-Esparrach G, Sendino O, Solé M, Pellisé M, Colomo L, Pardo A, et al
. Endoscopic ultrasound-guided fine-needle aspiration and trucut biopsy in the diagnosis of gastric stromal tumors: A randomized crossover study. Endoscopy 2010;42:292-9.
Bang JY, Hebert-Magee S, Trevino J, Ramesh J, Varadarajulu S. Randomized trial comparing the 22-gauge aspiration and 22-gauge biopsy needles for EUS-guided sampling of solid pancreatic mass lesions. Gastrointest Endosc 2012;76:321-7.
Vanbiervliet G, Napoléon B, Saint Paul MC, Sakarovitch C, Wangermez M, Bichard P, et al
. Core needle versus standard needle for endoscopic ultrasound-guided biopsy of solid pancreatic masses: A randomized crossover study. Endoscopy 2014;46:1063-70.
Hucl T, Wee E, Anuradha S, Gupta R, Ramchandani M, Rakesh K, et al
. Feasibility and efficiency of a new 22G core needle: A prospective comparison study. Endoscopy 2013;45:792-8.
Bang JY, Hawes R, Varadarajulu S. A meta-analysis comparing ProCore and standard fine-needle aspiration needles for endoscopic ultrasound-guided tissue acquisition. Endoscopy 2016;48:339-49.
Khan MA, Grimm IS, Ali B, Nollan R, Tombazzi C, Ismail MK, et al
. A meta-analysis of endoscopic ultrasound-fine-needle aspiration compared to endoscopic ultrasound-fine-needle biopsy: Diagnostic yield and the value of onsite cytopathological assessment. Endosc Int Open 2017;5:E363-75.
Kandel P, Tranesh G, Nassar A, Bingham R, Raimondo M, Woodward TA, et al
. EUS-guided fine needle biopsy sampling using a novel fork-tip needle: A case-control study. Gastrointest Endosc 2016;84:1034-9.
Paranandi B, Oppong KW, Dawwas M, Leeds JS, Darne A, Haugk B, et al
. PTU-007 comparison of diagnostic performance between two core biopsy needles for endoscopic ultrasound-guided tissue acquisition of solid pancreatic lesions. Gut 2016;65 Suppl 1:A55.
Bang JY, Hebert-Magee S, Navaneethan U, Hasan MK, Hawes R, Varadarajulu S. EUS-guided fine needle biopsy of pancreatic masses can yield true histology. Gut 2018;67:2081-4.
Bang JY, Hebert-Magee S, Navaneethan U, Hasan MK, Hawes R, Varadarajulu S. Randomized trial comparing the Franseen and Fork-tip needles for EUS-guided fine-needle biopsy sampling of solid pancreatic mass lesions. Gastrointest Endosc 2018;87:1432-8.
Chen VK, Eloubeidi MA. Endoscopic ultrasound-guided fine-needle aspiration of intramural and extraintestinal mass lesions: Diagnostic accuracy, complication assessment, and impact on management. Endoscopy 2005;37:984-9.
Mounzer R, Yen R, Marshall C, Sams S, Mehrotra S, Said MS, et al
. Interobserver agreement among cytopathologists in the evaluation of pancreatic endoscopic ultrasound-guided fine needle aspiration cytology specimens. Endosc Int Open 2016;4:E812-9.
Eloubeidi MA, Chen VK, Eltoum IA, Jhala D, Chhieng DC, Jhala N, et al
. Endoscopic ultrasound-guided fine needle aspiration biopsy of patients with suspected pancreatic cancer: Diagnostic accuracy and acute and 30-day complications. Am J Gastroenterol 2003;98:2663-8.
Iglesias-Garcia J, Dominguez-Munoz JE, Abdulkader I, Larino-Noia J, Eugenyeva E, Lozano-Leon A, et al
. Influence of on-site cytopathology evaluation on the diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of solid pancreatic masses. Am J Gastroenterol 2011;106:1705-10.
Klapman JB, Logrono R, Dye CE, Waxman I. Clinical impact of on-site cytopathology interpretation on endoscopic ultrasound-guided fine needle aspiration. Am J Gastroenterol 2003;98:1289-94.
Hébert-Magee S, Bae S, Varadarajulu S, Ramesh J, Frost AR, Eloubeidi MA, et al
. The presence of a cytopathologist increases the diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration cytology for pancreatic adenocarcinoma: A meta-analysis. Cytopathology 2013;24:159-71.
Wani S, Mullady D, Early DS, Rastogi A, Collins B, Wang JF, et al
. The clinical impact of immediate on-site cytopathology evaluation during endoscopic ultrasound-guided fine needle aspiration of pancreatic masses: A prospective multicenter randomized controlled trial. Am J Gastroenterol 2015;110:1429-39.
Lee LS, Nieto J, Watson RR, Hwang AL, Muthusamy VR, Walter L, et al
. Randomized noninferiority trial comparing diagnostic yield of cytopathologist-guided versus 7 passes for EUS-FNA of pancreatic masses. Dig Endosc 2016;28:469-75.
Mohamadnejad M, Mullady D, Early DS, Collins B, Marshall C, Sams S, et al
. Increasing number of passes beyond 4 does not increase sensitivity of detection of pancreatic malignancy by endoscopic ultrasound-guided fine-needle aspiration. Clin Gastroenterol Hepatol 2017;15:1071-800.
van Riet PA, Cahen DL, Poley JW, Bruno MJ. Mapping international practice patterns in EUS-guided tissue sampling: Outcome of a global survey. Endosc Int Open 2016;4:E360-70.
[Figure 1], [Figure 2], [Figure 3]