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World J Gastroenterol. Oct 21, 2014; 20(39): 14292-14300
Published online Oct 21, 2014. doi: 10.3748/wjg.v20.i39.14292
Endoscopic ultrasound guided fine needle aspiration and useful ancillary methods
Mario Tadic, Tajana Stoos-Veic, Rajko Kusec
Mario Tadic, Department of Gastroenterology, Dubrava University Hospital Zagreb, University of Zagreb, Faculty of Pharmacy and Biochemistry, 10040 Zagreb, Croatia
Tajana Stoos-Veic, Department of Pathology and Cytology, Dubrava University Hospital Zagreb, 10040 Zagreb, Croatia
Rajko Kusec, Division of molecular diagnostics and genetics, Dubrava University Hospital Zagreb, University of Zagreb, School of Medicine, 10040 Zagreb, Croatia
Author contributions: Tadic M, Stoos-Veic T and Kusec R contributed equally to the concept and design, drafting and revising of the article and have approved the final version of the manuscript.
Correspondence to: Mario Tadic, MD, PhD, Assistant Professor, Department of Gastroenterology, Dubrava University Hospital Zagreb, University of Zagreb, Faculty of Pharmacy and Biochemistry, Av. Gojka Suska 6, 10040 Zagreb, Croatia.
Telephone: +385-1-2902550 Fax: +385-1-2902550
Received: November 28, 2013
Revised: June 25, 2014
Accepted: July 11, 2014
Published online: October 21, 2014


The role of endoscopic ultrasound (EUS) in evaluating pancreatic pathology has been well documented from the beginning of its clinical use. High spatial resolution and the close proximity to the evaluated organs within the mediastinum and abdominal cavity allow detection of small focal lesions and precise tissue acquisition from suspected lesions within the reach of this method. Fine needle aspiration (FNA) is considered of additional value to EUS and is performed to obtain tissue diagnosis. Tissue acquisition from suspected lesions for cytological or histological analysis allows, not only the differentiation between malignant and non-malignant lesions, but, in most cases, also the accurate distinction between the various types of malignant lesions. It is well documented that the best results are achieved only if an adequate sample is obtained for further analysis, if the material is processed in an appropriate way, and if adequate ancillary methods are performed. This is a multi-step process and could be quite a challenge in some cases. In this article, we discuss the technical aspects of tissue acquisition by EUS-guided-FNA (EUS-FNA), as well as the role of an on-site cytopathologist, various means of specimen processing, and the selection of the appropriate ancillary method for providing an accurate tissue diagnosis and maximizing the yield of this method. The main goal of this review is to alert endosonographers, not only to the different possibilities of tissue acquisition, namely EUS-FNA, but also to bring to their attention the importance of proper sample processing in the evaluation of various lesions in the gastrointestinal tract and other accessible organs. All aspects of tissue acquisition (needles, suction, use of stylet, complications, etc.) have been well discussed lately. Adequate tissue samples enable comprehensive diagnoses, which answer the main clinical questions, thus enabling targeted therapy.

Key Words: Endoscopic ultrasound, Endoscopic ultrasound-guided fine needle aspiration, Endoscopic ultrasound-guided tissue acquisition, Fine needle aspiration cytology, Ancillary studies, Molecular testing, Flow cytometry immunophenotyping

Core tip: All aspects of endoscopic ultrasound tissue acquisition have been well discussed in recent studies. In addition to discussions about important factors that impact tissue acquisition, in this article we have highlighted the methods of ancillary testing needed to satisfy the growing demands of precision medicine standards. Adequate tissue samples and appropriate ancillary testing enable comprehensive diagnosis, and answer the main clinical questions, thus enabling targeted therapy.


Endoscopic ultrasound guided fine needle aspiration (EUS-FNA) is an effective and widespread method for the procurement of pancreatic tissue and, as such, is capable of providing an accurate preoperative diagnosis. EUS-FNA is also the method of choice for the evaluation of mural lesions of the gastrointestinal tract and deep seated structures, such as mediastinal lesions, lymph nodes, liver, spleen and suprarenal glands. It has become very important to accurately determine the type of tumor, to precisely differentiate between primary tumors and metastases, and to identify potentially actionable genetic mutations in order to tailor an adequate therapeutic approach. The novel treatment protocols and application of chemotherapeutic agents are often based on the molecular markers present in the tumor tissue, where classic cytological or histological analyses fail to provide necessary information for further treatment decisions, especially important for neo-adjuvant chemotherapy. Therefore, there is a growing demand to obtain sufficient amounts of tissue samples from suspected lesions for further analyses, or for the procurement of core tissue for histological analysis, if necessary.


Several types of needles for EUS-FNA are present on the market, and there is an abundance of recently published high quality references addressing this important issue. EUS-FNA can be performed using 25-gauge (G), 22-G or 19-G needles. Similar diagnostic yields are reported for all types of needles[1-6]. The most widely used needle for EUS-FNA is the 22-G needle. Thinner and more flexible, the 25-G needle should have better performance for targeting the uncinate process and for the transduodenal approach to the pancreatic head. Still, no significant difference in the diagnostic accuracy has been described[6-8]. The flexibility of the needle is especially important in locations where the scope needs to be bent to target the lesion. However, only one study of 24 patients documented a better technical success rate of the 25-G needle but the study evaluated only lesions located in the uncinate process[3].

On the other hand, a randomized controlled study of 131 patients did not show a significant difference between the 22-G and the 25-G needle in the diagnostic yield, the ease of targeting the lesion, malfunction of the needle, and the complication rate[2]. A larger 19-G needle was developed to obtain larger amounts of material from the lesions, but compared to the 22-G needle, the 19-G needle is stiffer and has a higher rate of technical failure. This is seen in particular in pancreatic head lesions[3]. There is one study showing that the 19-G needle has a higher diagnostic accuracy than the 22-G needle, but technical failures were excluded from the calculations[3]. In a multicenter study with the novel 19-G flexible needle made of nitinol (Expect 19 G Flex, Boston Scientific, Natick, MA, United States), there was no significant difference in diagnostic accuracy between the 22-G and the 19-G needle, but histological core tissue was obtained in a larger number of patients using the 19-G flexible needle[9]. A needle especially designed to obtain core tissue for histological analysis was the Trucut (Cook Endoscopy, Winston Salem, NC, United States) biopsy needle. The idea about the needle was good, but the needles had weak performance due to technical design problems[10-12]. The ProCore (ProCore, Cook Endoscopy) needle overcame some obvious limitations of the Trucut needle, enabling easier acquisition of the core tissue for histological analysis due to the special design. However, transduodenal passage still remained a challenge[13-15]. In the ProCore gamma, there are also 22-G and the 25-G needles with the same design available. Two groups of authors recently studied the utility of the standard 19-G needle[16] and the 19-G flexible needle[17] for obtaining core tissue for histological analysis. The standard 19-G needle experienced problems with the transduodenal approach, while the 19-G flexible needle had no technical difficulties in the acquisition of the specimens for histological analysis[17].


The role of stylets should be to prevent sample contamination by cells that do not originate from the targeted lesion. However, three different studies have not found any advantage or disadvantage of using stylets for EUS-FNA[18-20]. The procedures in which a stylet is used may be clumsy and time-consuming. Although some authors advocate no stylet FNAs, we find it very useful for contamination prevention in routine practice. Furthermore, the stylet can be very useful for pushing out the sample from the needle to the slides or into the liquid transport medium.


Suction applied during EUS-FNA will result in acquisition of more material for further analysis, but it will also make the specimen bloodier[21,22], thus potentially hindering the morphological tissue analysis. EUS-FNA without suction provides specimens with less blood. Applying suction during EUS-FNA of solid lesions was associated with a significantly higher sensitivity (86% vs 67%; P = 0.005) in one study only[21]. Another study reported establishing diagnoses in over 90% of patients without applying suction[22]. For lymph node sampling, applying suction can result in significantly bloodier samples which can affect the diagnostic yield of EUS-FNA[23].

Tissue acquisition

Obtaining “diagnostic” tissue by EUS-FNA may be hindered by necrosis of the suspected lesion. Obtaining the tissue from the peripheral area of the lesion or from multiple areas in the “fanning” way may improve diagnostic yield. A sufficient number of passes must be performed to provide enough material for analysis, and in the case of failure, the procedure needs to be repeated[24]. One study described the advantages of the “fanning” technique in primary tumors, although these advantages were not described regarding lymph node sampling[25].


Tissue acquisition by endoscopic ultrasound is a safe procedure. The reported overall complication rate ranges from 0.3% to 2.2%. The most worrisome complication of an FNA is tumor cell seeding. However, only three cases of needle tract seeding following EUS-FNA have been reported to date[26]. The major complications of EUS tissue acquisition are infections of cystic lesions, bleeding and acute pancreatitis[27,28]. In order to prevent infection, prophylactic antibiotics must be considered for EUS-FNA of cystic lesions. Intracystic bleeding is rarely significant. A change in echogenicity of the cystic fluid indicates intracystic bleeding. The bleeding usually resolves spontaneously, but some medications that affect the process of coagulation may pose problems. In order to avoid bleeding, clopidogrel must be discontinued 7 d prior to the procedure, low molecular-weight heparin 12-24 h prior, and unfractionated heparin 6 h prior to EUS-FNA. Aspirin does not have to be discontinued. It is recommended to discontinue warfarin 5 d prior to the procedure and bridge it with heparin to avoid thrombotic events in high risk patients[29]. Coagulation parameters should be checked before the procedure.


Rapid on-site evaluation (ROSE) by attending cytopathologists undoubtedly improves the diagnostic yield of EUS-FNA, reduces costs and decrease the number of repeated procedures[30]. Macroscopic specimen analysis is of limited value when performed by an endosonographer, but it may be useful for the rough assessment of specimen adequacy. When performed by an experienced cytopathologist[24,31], it can save time and reduce the number of passes necessary to acquire additional tissue after the initial ROSE. The ROSE findings and clinical suspicions should be considered as the starting point for the selection of further ancillary methods.


Individualized medicine and various options of targeted therapy in modern health care increase the demands for molecular and other ancillary testing on small tissue specimens. Requests for minimally invasive procedures for tissue acquisition are especially emphasized in patients with unresectable malignant diseases, and for patients requiring neoadjuvant chemotherapy. EUS-FNA is an efficient, cost-effective and minimally invasive method for tissue acquisition with diagnostic accuracy comparable to excisional biopsy[32].

A number of ancillary laboratory tests are routinely employed in establishing diagnostic and prognostic factors in tissue specimens from various lesions of the gastrointestinal tract, pancreatic masses and other accessible organs. These include microbiology, immunocyto(histo)chemistry, flow cytometry, biochemical analyses, conventional cytogenetics and various molecular methods.

The correct choice of ancillary method often depends on the type of aspirated sample, the quality of the specimen and the preliminary cytological diagnosis (ROSE). It is also institution- and resource-dependent, hence, in-house protocols and algorithms defining sample processing should be developed. The on-site cytopathologist can serve to liaise between the laboratory and the clinician, triage the samples and ensure optimal sample collection and processing[33]. This approach is gaining in importance as we witness the expanding role of cytological samples in providing data for targeted therapy[34].

Except in the formalin-fixed, paraffin-embedded (FFPE) histological tissue, a number of ancillary tests are also easily performed on the EUS-guided FNA samples[27]. Specimens can be processed in different ways depending on the laboratory set-up and the pathologist’s preference.

Most laboratories prefer at least two direct cytological smears for ROSE, one air-dried and one ethanol-fixed, then rinsing of the needle for the preparation of cell blocks (FFPE tissue). Another method of cell block preparation is simply letting the aspirated sample clot on the glass and then fixing it in formalin as described by Bellizzi and Stelow[35]. Different practices, with more direct slides made on the spot are not unusual in institutions where a cytopathologist is present on-site to make the decision regarding specimen processing. The advantages and disadvantages of cell block preparation, and its use, are discussed elsewhere[33,36].

Core tissue for histological diagnosis is not easily obtained from the pancreas and other deep-seated sites, as adequate tissue sampling requires special types of needles. Reported sensitivities and specificities are similar for FNA and core biopsy for malignant diagnoses[13]. In addition, formalin, as a fixative, can damage DNA for molecular testing. Thus, EUS-FNA remains the primary means of establishing a tissue diagnosis preoperatively, and it ensures samples for ancillary testing.

A major complaint regarding EUS-FNA is that it does not yield enough tissue to meet the increasing demands for ancillary (molecular) testing[33]. This drawback can be overcome by implementing ROSE, which determines the number of passes necessary to ensure adequate sample collection, processing and storage[37]. EUS-FNA has some additional advantages, including sampling of the wider area of the lesion. Aspirates also usually yield more tumor and less stromal cells than core biopsy[33]. The inability to assess tissue architecture, and to determine some valuable prognostic factors, such as the number of mitoses or angioinvasion, remains a major disadvantage. The assessment of such prognostic factors can be a problem with small core biopsy specimens as well.

Based on the type of specimen, some tests are more likely to be employed then others. Liquid samples from cystic pancreatic lesions need to be evaluated macroscopically for viscosity, which can provide valuable information about the nature of the cyst. The cyst fluid is then submitted for routine cytology, biochemical analysis, microbiology if necessary, and possibly for molecular analysis[38]. If the fluid is thick, direct smears, instead of cytospins, can be made for cytomorphologic evaluation.

For solid lesions, immunocytochemistry (ICC) or immunohistochemistry (IHC) are methods of choice for the diagnosis and tumor subclassification. Cell blocks or smears can also be submitted for molecular tests if needed. Lymphoid tissue and liquid specimens are highly suitable for the flow cytometry immunophenotyping.

There are several possible means of processing aspirated samples obtained by EUS-FNA for molecular and other ancillary tests (Table 1).

Table 1 Possible methods of sample processing.
Sample typesAncillary methods
Direct cytological smearsCytomorphological diagnostic evaluation
ICC staining
Molecular testing (FISH)
Excellent source for isolation of good quality DNA[39,40]
Cell blocks (formalin-fixed, paraffin-embedded tissue)IHC
Various molecular tests
Tissue storage
Touch imprint slides (tumor cell rich slides made by imprinting the tumor)IHC
Molecular testing (FISH)
Fresh aspirated specimens (especially of lymph nodes)Flow cytometry - immunophenotyping
RNA based gene expression studies
DNA based studies[41]
Fresh frozen (cryopreserved) FNA specimensRNA based gene expression studies
DNA based studies[42]
FTA cards (filter paper)Effective RNA and DNA preservation
Not suitable for morphology[43]
Formalin fixed paraffin embedded core tissueHistological morphologic evaluation
IHC and molecular studies

The most useful addition to cytology in routine preoperative evaluation of pancreatic cystic lesions is the biochemical measurement of enzyme levels, especially carcinoembryonic antigen (CEA) and amylase levels[44].

The cytological analysis of cystic lesions is accurate in diagnosing cystic pancreatic neoplasms and is currently the only method that can accurately differentiate between malignant and benign cysts, as well as between various types of benign cysts. The diagnostic yield of cytology alone is limited because, despite a high specificity, it has low sensitivity for detecting malignancy due to the low cellularity of cystic lesions[45]. The measurements of CEA and amylase levels in the cystic fluid help differentiate serous from mucinous cysts[46]. Mucinous cysts are considered, at least, premalignant or low-grade non-invasive neoplasms, but the distinction of mucinous cystic neoplasms (MCN) from non-mucinous cysts is not sufficient to determine the need for operative treatment, as it was a few years ago[47]. Cysts with a low risk of progression are suitable for surveillance. The threshold value of 192 ng/mL is usually found to be distinctive between mucinous and non-mucinous cysts. CEA levels have limited value in the subclassification of mucinous cysts[48,49], and contrary to early studies[50], subsequent studies[51,52] have shown that CEA levels do not discriminate between malignant and benign mucinous cysts.

Amylase levels are usually higher in post-pancreatitis lesions, e.g., pseudocysts, but can be elevated in mucinous cystic neoplasm as well. Al- Rushdan[49] reports that the measurements of amylase levels do not discriminate between the various types of MCN and intraductal papillary mucinous neoplasms. Nevertheless, cytology, coupled with biochemical measurements of CEA and amylase levels in cystic fluid, is currently the best way of assessing pancreatic cysts preoperatively. The addition of molecular studies seems promising[53,54].


A wide application of ICC and IHC on small tissue samples enables better characterization and subclassification of tumors, which have become increasingly important with regard to targeted therapy for malignant diseases. The main principle of these methods is detecting and visualizing antigens on the cell surface, cytoplasm or nucleus. The method is suitable for FFPE samples, including excisional or small core biopsies or cell blocks obtained during EUS-FNA. It is also routinely performed on air-dried, previously unstained direct cytological smears, cytospins or liquid based cytology preparations. ICC can also be performed on previously stained (Papanicolaou) and archived cytological smears.

Presently, IHC (ICC) is routinely used for the diagnosis and subtyping of various tumors, and is increasingly used for the evaluation of prognostic factors[55,56].

While the diagnosis of pancreatic ductal adenocarcinoma does not require IHC confirmation, other solid neoplasms, including lymphoma, neuroendocrine tumors (NET), solid pseudo-papillary neoplasms or acinic cell carcinoma, need IHC or ICC for the final diagnosis. The biological behavior of pancreatic NETs cannot be predicted by morphology alone, so proliferative markers, such as Ki-67, have become an essential tool for grading pancreatic NETs, which is necessary for adequate patient management. Spindle cell submucosal gastric tumors are another example of neoplasms which require IHC or ICC for definitive diagnosis and grading.

Most laboratories use direct smears for ROSE, and cell blocks for IHC and other ancillary methods. Major disadvantages of cell blocks include low cellularity, pooled nature of the specimen, uneven distribution of tumor cells in the block, and the lack of ROSE. Because of these drawbacks, we should bear in mind that direct smears and cytospins are also suitable for ICC.


Flow cytometry is a technology that simultaneously measures and then analyses multiple physical characteristics of single particles, usually cells, as they flow in a fluid stream through a laser-beam. The measured properties include particle relative size, relative granularity or internal complexity, and relative fluorescence intensity.

Immunophenotyping has become a fundamental step in the diagnosis and subclassification of hematologic malignancies, especially nodal and extra nodal lymphoproliferative disorders. The main advantage of the method is the possibility of detecting a specific surface or cytoplasmatic antigen on targeted cells by applying a complete panel of antibodies to small samples. Other applications include DNA/RNA analysis and functional analysis (oxygenation, enzyme activity, phagocytosis, etc.).

EUS-FNA coupled with flow cytometry has become widely used in evaluating the deep-seated lesions, especially mediastinal and retroperitoneal lymph nodes[57], and there are several described cases of a primary lymphoma of the pancreas diagnosed by EUS- FNA and flow cytometry[58-60]. Flow cytometry has broadened the usefulness of EUS-FNA and increased its diagnostic yield[55].


Conventional cytogenetics for detecting structural chromosomal abnormalities studying the whole karyotype is not routinely used on EUS-FNA samples of pancreatic lesions, but is used in the diagnostic algorithms of some deep-seated soft tissue lesions and hematological malignancies. EUS-FNA can be a good tissue source for cell cultures when needed[61].


With emerging targeted therapies for various types of malignant diseases, there is an increased demand for molecular testing as part of the routine diagnostic and prognostic workup, as well as for research purposes. The main goal is to identify any actionable genetic mutations. EUS-FNA is a minimally invasive, highly suitable method of tissue acquisition for molecular studies. The integrity of DNA and RNA available from FFPE tissue is often compromised because of the methods for tissue fixation and storage. Although genomic studies of large archival FFPE cohorts are critical for molecular studies, the best material for molecular studies remains fresh tissue[62]. With improved isolation techniques, DNA isolation is possible from paraffin-embedded tissue. Cytological material obtained by EUS-FNA provides good quality DNA regardless of the differences in sample preparation[63]. This is partly due to the use of nucleic acid-friendly fixatives other than formalin[34]. FNA samples for molecular studies can be processed in different ways[33], depending on the type of the sampled tissue (ROSE diagnosis), the laboratory resources, and the type of test needed. The choice of ancillary method should be focused on answering the dominant clinical questions.

Various methods of molecular analysis are employed in the evaluation of pancreatic cysts and solid masses. The ones most frequently used in diagnostic and prognostic workups are the polymerase chain reaction (PCR) based techniques and fluorescence in situ hybridization (FISH).

PCR-based DNA studies usually evaluate the kras mutational status and the loss of heterozygosity of several markers situated on different chromosomes, particularly in the cystic pancreatic lesions, in an attempt to increase the diagnostic sensitivity[64,65]. After the initial enthusiasm, recent studies have reported low sensitivity for the kras mutational analysis in cystic fluid[66]. The value of the kras analysis in solid pancreatic masses is not as well documented, as there are only a limited number of studies addressing the issue, and they have reported variable results[67-69]. Salek et al[70] Studied the kras mutation, p53 and allelic loses at 9p and 18q, and have concluded that they are not suitable prognostic markers for pancreatic cancer. Nevertheless, the meta-analysis by Fuccio et al[71] concluded that kras mutation analysis can be helpful in the diagnostic workup of pancreatic lesions when there is a limited tissue sample obtained and the diagnosis is inconclusive. A study by Pellisé et al[72] showed increased sensitivity to the detection of lymph node micrometastases using hypermethylation analysis performed by methylation-specific PCR using EUS-FNA samples from the lymph nodes of patients with various types of gastric, intestinal and lung cancer.

RNA studies of gene expressions are presently limited to research purposes, but there are several reports analyzing RNA expression of various genes for diagnostic expression analysis[73,74], and a report studying the preservation of the sensitive RNA molecules for future use[42]. FISH is a molecular method performed on the intact cell nuclei and has the advantage of visualization of the cells with the detected abnormality. There have been several attempts to use FISH in the diagnostic workup of pancreatic lesions using probes for different markers (chromosomal polysomy, deletions, etc.). Cohorts of included patients were usually small, so a comparison of the data is of limited value. The main conclusion is, that in the setting of inconclusive cytology, FISH can aid in the diagnosis of pancreatic malignancy[64,75,76]. On the other hand, FISH is crucial for the diagnosis and prognosis of some tumors with well-defined chromosomal abnormalities and gene rearrangements, such as lung cancers (including metastases), lymphomas and other tumors. As there are no specific molecular markers identified as yet for the specific diagnosis of solid or cystic pancreatic masses, the research area remains wide. High-throughput techniques look promising in finding adequate biomarkers for pancreatic neoplasms. Methods using DNA microarrays, comparative genomic hybridization and DNA sequencing can be performed on samples obtained by EUS-FNA, as high quality DNA can be harvested and adequately processed[77].


The main issue with tissue acquisition is obtaining a large enough sample that will be able to provide a comprehensive diagnosis to satisfy the growing demands for individualized patient management and targeted therapy for the malignant disease. EUS-FNA remains a minimally invasive, easy to perform, and altogether more effective method of sampling tissue from deep-seated lesions than any other available method. Numerous factors influence the yield of the EUS-FNA. At present, the best results are achieved by collaboration between a skilled endosonographer performing the EUS-FNA (tissue acquisition) and an on-site cytopathologist. The choice of the needle and sampling technique should be up to the performing endosonographer. The preliminary cytological diagnosis directs further action. The ROSE findings and clinical suspicions should be taken as the starting point for the selection of further ancillary methods. The choice of specimen processing should be in accordance with institutional protocols and available resources in the best interest of optimal patient care.


P- Reviewer: Gornals JB, La Tijera MFH, Luks FI, Maluf-Filho F, Zhang Q S- Editor: Wen LL L- Editor: Cant MR E- Editor: Liu XM

1.  Williams DB, Sahai AV, Aabakken L, Penman ID, van Velse A, Webb J, Wilson M, Hoffman BJ, Hawes RH. Endoscopic ultrasound guided fine needle aspiration biopsy: a large single centre experience. Gut. 1999;44:720-726.  [PubMed]  [DOI]
2.  Siddiqui UD, Rossi F, Rosenthal LS, Padda MS, Murali-Dharan V, Aslanian HR. EUS-guided FNA of solid pancreatic masses: a prospective, randomized trial comparing 22-gauge and 25-gauge needles. Gastrointest Endosc. 2009;70:1093-1097.  [PubMed]  [DOI]
3.  Song TJ, Kim JH, Lee SS, Eum JB, Moon SH, Park do H, Seo DW, Lee SK, Jang SJ, Yun SC. The prospective randomized, controlled trial of endoscopic ultrasound-guided fine-needle aspiration using 22G and 19G aspiration needles for solid pancreatic or peripancreatic masses. Am J Gastroenterol. 2010;105:1739-1745.  [PubMed]  [DOI]
4.  Sakamoto H, Kitano M, Komaki T, Noda K, Chikugo T, Dote K, Takeyama Y, Das K, Yamao K, Kudo M. Prospective comparative study of the EUS guided 25-gauge FNA needle with the 19-gauge Trucut needle and 22-gauge FNA needle in patients with solid pancreatic masses. J Gastroenterol Hepatol. 2009;24:384-390.  [PubMed]  [DOI]
5.  Itoi T, Itokawa F, Kurihara T, Sofuni A, Tsuchiya T, Ishii K, Tsuji S, Ikeuchi N, Kawai T, Moriyasu F. Experimental endoscopy: objective evaluation of EUS needles. Gastrointest Endosc. 2009;69:509-516.  [PubMed]  [DOI]
6.  Madhoun MF, Wani SB, Rastogi A, Early D, Gaddam S, Tierney WM, Maple JT. The diagnostic accuracy of 22-gauge and 25-gauge needles in endoscopic ultrasound-guided fine needle aspiration of solid pancreatic lesions: a meta-analysis. Endoscopy. 2013;45:86-92.  [PubMed]  [DOI]
7.  Camellini L, Carlinfante G, Azzolini F, Iori V, Cavina M, Sereni G, Decembrino F, Gallo C, Tamagnini I, Valli R. A randomized clinical trial comparing 22G and 25G needles in endoscopic ultrasound-guided fine-needle aspiration of solid lesions. Endoscopy. 2011;43:709-715.  [PubMed]  [DOI]
8.  Fabbri C, Polifemo AM, Luigiano C, Cennamo V, Baccarini P, Collina G, Fornelli A, Macchia S, Zanini N, Jovine E. Endoscopic ultrasound-guided fine needle aspiration with 22- and 25-gauge needles in solid pancreatic masses: a prospective comparative study with randomisation of needle sequence. Dig Liver Dis. 2011;43:647-652.  [PubMed]  [DOI]
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;76:321-327.  [PubMed]  [DOI]
10.  Levy MJ. Endoscopic ultrasound-guided trucut biopsy of the pancreas: prospects and problems. Pancreatology. 2007;7:163-166.  [PubMed]  [DOI]
11.  Larghi A, Verna EC, Stavropoulos SN, Rotterdam H, Lightdale CJ, Stevens PD. EUS-guided trucut needle biopsies in patients with solid pancreatic masses: a prospective study. Gastrointest Endosc. 2004;59:185-190.  [PubMed]  [DOI]
12.  Möller K, Papanikolaou IS, Toermer T, Delicha EM, Sarbia M, Schenck U, Koch M, Al-Abadi H, Meining A, Schmidt H. EUS-guided FNA of solid pancreatic masses: high yield of 2 passes with combined histologic-cytologic analysis. Gastrointest Endosc. 2009;70:60-69.  [PubMed]  [DOI]
13.  Iglesias-Garcia J, Poley JW, Larghi A, Giovannini M, Petrone MC, Abdulkader I, Monges G, Costamagna G, Arcidiacono P, Biermann K. Feasibility and yield of a new EUS histology needle: results from a multicenter, pooled, cohort study. Gastrointest Endosc. 2011;73:1189-1196.  [PubMed]  [DOI]
14.  Larghi A, Iglesias-Garcia J, Poley JW, Monges G, Petrone MC, Rindi G, Abdulkader I, Arcidiacono PG, Costamagna G, Biermann K. Feasibility and yield of a novel 22-gauge histology EUS needle in patients with pancreatic masses: a multicenter prospective cohort study. Surg Endosc. 2013;27:3733-3738.  [PubMed]  [DOI]
15.  Iwashita T, Nakai Y, Samarasena JB, Park do H, Zhang Z, Gu M, Lee JG, Chang KJ. High single-pass diagnostic yield of a new 25-gauge core biopsy needle for EUS-guided FNA biopsy in solid pancreatic lesions. Gastrointest Endosc. 2013;77:909-915.  [PubMed]  [DOI]
16.  Larghi A, Verna EC, Ricci R, Seerden TC, Galasso D, Carnuccio A, Uchida N, Rindi G, Costamagna G. EUS-guided fine-needle tissue acquisition by using a 19-gauge needle in a selected patient population: a prospective study. Gastrointest Endosc. 2011;74:504-510.  [PubMed]  [DOI]
17.  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.  [PubMed]  [DOI]
18.  Wani S, Gupta N, Gaddam S, Singh V, Ulusarac O, Romanas M, Bansal A, Sharma P, Olyaee MS, Rastogi A. A comparative study of endoscopic ultrasound guided fine needle aspiration with and without a stylet. Dig Dis Sci. 2011;56:2409-2414.  [PubMed]  [DOI]
19.  Rastogi A, Wani S, Gupta N, Singh V, Gaddam S, Reddymasu S, Ulusarac O, Fan F, Romanas M, Dennis KL. A prospective, single-blind, randomized, controlled trial of EUS-guided FNA with and without a stylet. Gastrointest Endosc. 2011;74:58-64.  [PubMed]  [DOI]
20.  Sahai AV, Paquin SC, Gariépy G. A prospective comparison of endoscopic ultrasound-guided fine needle aspiration results obtained in the same lesion, with and without the needle stylet. Endoscopy. 2010;42:900-903.  [PubMed]  [DOI]
21.  Puri R, Vilmann P, Săftoiu A, Skov BG, Linnemann D, Hassan H, Garcia ES, Gorunescu F. Randomized controlled trial of endoscopic ultrasound-guided fine-needle sampling with or without suction for better cytological diagnosis. Scand J Gastroenterol. 2009;44:499-504.  [PubMed]  [DOI]
22.  Bang JY, Ramesh J, Trevino J, Eloubeidi MA, Varadarajulu S. Objective assessment of an algorithmic approach to EUS-guided FNA and interventions. Gastrointest Endosc. 2013;77:739-744.  [PubMed]  [DOI]
23.  Wallace MB, Kennedy T, Durkalski V, Eloubeidi MA, Etamad R, Matsuda K, Lewin D, Van Velse A, Hennesey W, Hawes RH. Randomized controlled trial of EUS-guided fine needle aspiration techniques for the detection of malignant lymphadenopathy. Gastrointest Endosc. 2001;54:441-447.  [PubMed]  [DOI]
24.  Tadic M, Kujundzic M, Stoos-Veic T, Kaic G, Vukelic-Markovic M. Role of repeated endoscopic ultrasound-guided fine needle aspiration in small solid pancreatic masses with previous indeterminate and negative cytological findings. Dig Dis. 2008;26:377-382.  [PubMed]  [DOI]
25.  Bang JY, Magee SH, Ramesh J, Trevino JM, Varadarajulu S. Randomized trial comparing fanning with standard technique for endoscopic ultrasound-guided fine-needle aspiration of solid pancreatic mass lesions. Endoscopy. 2013;45:445-450.  [PubMed]  [DOI]
26.  Dumonceau JM, Polkowski M, Larghi A, Vilmann P, Giovannini M, Frossard JL, Heresbach D, Pujol B, Fernández-Esparrach G, Vazquez-Sequeiros E. 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.  [PubMed]  [DOI]
27.  Jenssen C, Dietrich CF. Endoscopic ultrasound-guided fine-needle aspiration biopsy and trucut biopsy in gastroenterology - An overview. Best Pract Res Clin Gastroenterol. 2009;23:743-759.  [PubMed]  [DOI]
28.  Tarantino I, Fabbri C, Di Mitri R, Pagano N, Barresi L, Mocciaro F, Maimone A, Curcio G, Repici A, Traina M. Complications of endoscopic ultrasound fine needle aspiration on pancreatic cystic lesions: final results from a large prospective multicenter study. Dig Liver Dis. 2014;46:41-44.  [PubMed]  [DOI]
29.  Anderson MA, Ben-Menachem T, Gan SI, Appalaneni V, Banerjee S, Cash BD, Fisher L, Harrison ME, Fanelli RD, Fukami N. Management of antithrombotic agents for endoscopic procedures. Gastrointest Endosc. 2009;70:1060-1070.  [PubMed]  [DOI]
30.  Erickson RA, Sayage-Rabie L, Beissner RS. Factors predicting the number of EUS-guided fine-needle passes for diagnosis of pancreatic malignancies. Gastrointest Endosc. 2000;51:184-190.  [PubMed]  [DOI]
31.  Vilmann P, Săftoiu A. Endoscopic ultrasound-guided fine needle aspiration biopsy: equipment and technique. J Gastroenterol Hepatol. 2006;21:1646-1655.  [PubMed]  [DOI]
32.  Kocjan G. Fine needle aspiration cytology of the pancreas: a guide to the diagnostic approach. Coll Antropol. 2010;34:749-756.  [PubMed]  [DOI]
33.  Knoepp SM, Roh MH. Ancillary techniques on direct-smear aspirate slides: a significant evolution for cytopathology techniques. Cancer Cytopathol. 2013;121:120-128.  [PubMed]  [DOI]
34.  da Cunha Santos GStandardizing preanalytical variables for molecular cytopathology. Cancer Cytopathol. 2013;121:341-343.  [PubMed]  [DOI]
35.  Bellizzi AM, Stelow EB. Pancreatic cytopathology: a practical approach and review. Arch Pathol Lab Med. 2009;133:388-404.  [PubMed]  [DOI]
36.  Noda Y, Fujita N, Kobayashi G, Itoh K, Horaguchi J, Takasawa O, Obana T, Koshita S, Kanno Y, Suzuki T. Diagnostic efficacy of the cell block method in comparison with smear cytology of tissue samples obtained by endoscopic ultrasound-guided fine-needle aspiration. J Gastroenterol. 2010;45:868-875.  [PubMed]  [DOI]
37.  da Cunha Santos GROSEs (Rapid on-site evaluations) to our patients: The impact on laboratory resources and patient care. Cancer Cytopathol. 2013;121:537-539.  [PubMed]  [DOI]
38.  Garud SS, Willingham FF. Molecular analysis of cyst fluid aspiration in the diagnosis and risk assessment of cystic lesions of the pancreas. Clin Transl Sci. 2012;5:102-107.  [PubMed]  [DOI]
39.  Stoos-Veić T, Livun A, Ajduković R, Pejsa V, Jaksić O, Kusec R. Detection of t(14; 18) by PCR of IgH/BCL2 fusion gene in follicular lymphoma from archived cytological smears. Coll Antropol. 2010;34:425-429.  [PubMed]  [DOI]
40.  Killian JK, Walker RL, Bilke S, Chen Y, Davis S, Cornelison R, Smith WI, Meltzer PS. Genome-wide methylation profiling in archival formalin-fixed paraffin-embedded tissue samples. Methods Mol Biol. 2012;823:107-118.  [PubMed]  [DOI]
41.  Khode R, Larsen DA, Culbreath BC, Parrish S, Walker KL, Sayage-Rabie L, Beissner RS, Rao A. Comparative study of epidermal growth factor receptor mutation analysis on cytology smears and surgical pathology specimens from primary and metastatic lung carcinomas. Cancer Cytopathol. 2013;121:361-369.  [PubMed]  [DOI]
42.  Ladd AC, O’Sullivan-Mejia E, Lea T, Perry J, Dumur CI, Dragoescu E, Garrett CT, Powers CN. Preservation of fine-needle aspiration specimens for future use in RNA-based molecular testing. Cancer Cytopathol. 2011;119:102-110.  [PubMed]  [DOI]
43.  Saieg MA, Geddie WR, Boerner SL, Bailey D, Crump M, da Cunha Santos G. EZH2 and CD79B mutational status over time in B-cell non-Hodgkin lymphomas detected by high-throughput sequencing using minimal samples. Cancer Cytopathol. 2013;121:377-386.  [PubMed]  [DOI]
44.  van der Waaij LA, van Dullemen HM, Porte RJ. Cyst fluid analysis in the differential diagnosis of pancreatic cystic lesions: a pooled analysis. Gastrointest Endosc. 2005;62:383-389.  [PubMed]  [DOI]
45.  Pitman MB, Brugge WR, Warshaw AL. The value of cyst fluid analysis in the pre-operative evaluation of pancreatic cysts. J Gastrointest Oncol. 2011;2:195-198.  [PubMed]  [DOI]
46.  Nagula S, Kennedy T, Schattner MA, Brennan MF, Gerdes H, Markowitz AJ, Tang L, Allen PJ. Evaluation of cyst fluid CEA analysis in the diagnosis of mucinous cysts of the pancreas. J Gastrointest Surg. 2010;14:1997-2003.  [PubMed]  [DOI]
47.  Crippa S, Salvia R, Warshaw AL, Domínguez I, Bassi C, Falconi M, Thayer SP, Zamboni G, Lauwers GY, Mino-Kenudson M. Mucinous cystic neoplasm of the pancreas is not an aggressive entity: lessons from 163 resected patients. Ann Surg. 2008;247:571-579.  [PubMed]  [DOI]
48.  Pitman MB, Michaels PJ, Deshpande V, Brugge WR, Bounds BC. Cytological and cyst fluid analysis of small (& lt; or =3 cm) branch duct intraductal papillary mucinous neoplasms adds value to patient management decisions. Pancreatology. 2008;8:277-284.  [PubMed]  [DOI]
49.  Al-Rashdan A, Schmidt CM, Al-Haddad M, McHenry L, Leblanc JK, Sherman S, Dewitt J. Fluid analysis prior to surgical resection of suspected mucinous pancreatic cysts. A single centre experience. J Gastrointest Oncol. 2011;2:208-214.  [PubMed]  [DOI]
50.  Brugge WR, Lewandrowski K, Lee-Lewandrowski E, Centeno BA, Szydlo T, Regan S, del Castillo CF, Warshaw AL. Diagnosis of pancreatic cystic neoplasms: a report of the cooperative pancreatic cyst study. Gastroenterology. 2004;126:1330-1336.  [PubMed]  [DOI]
51.  Cizginer S, Turner BG, Bilge AR, Karaca C, Pitman MB, Brugge WR. Cyst fluid carcinoembryonic antigen is an accurate diagnostic marker of pancreatic mucinous cysts. Pancreas. 2011;40:1024-1028.  [PubMed]  [DOI]
52.  Park WG, Mascarenhas R, Palaez-Luna M, Smyrk TC, O’Kane D, Clain JE, Levy MJ, Pearson RK, Petersen BT, Topazian MD. Diagnostic performance of cyst fluid carcinoembryonic antigen and amylase in histologically confirmed pancreatic cysts. Pancreas. 2011;40:42-45.  [PubMed]  [DOI]
53.  Khalid A, Zahid M, Finkelstein SD, LeBlanc JK, Kaushik N, Ahmad N, Brugge WR, Edmundowicz SA, Hawes RH, McGrath KM. Pancreatic cyst fluid DNA analysis in evaluating pancreatic cysts: a report of the PANDA study. Gastrointest Endosc. 2009;69:1095-1102.  [PubMed]  [DOI]
54.  Al-Haddad M, DeWitt J, Sherman S, Schmidt CM, LeBlanc JK, McHenry L, Coté G, El Chafic AH, Luz L, Stuart JS. Performance characteristics of molecular (DNA) analysis for the diagnosis of mucinous pancreatic cysts. Gastrointest Endosc. 2014;79:79-87.  [PubMed]  [DOI]
55.  Sodikoff JB, Johnson HL, Lewis MM, Garud SS, Bharmal SJ, Keilin SA, Siddiqui MT, Cai Q, Willingham FF. Increased diagnostic yield of endoscopic ultrasound-guided fine needle aspirates with flow cytometry and immunohistochemistry. Diagn Cytopathol. 2013;41:1043-1051.  [PubMed]  [DOI]
56.  Eloubeidi MA, Khan AS, Luz LP, Linder A, Moreira DM, Crowe DR, Eltoum IA. Combined use of EUS-guided FNA and immunocytochemical stains discloses metastatic and unusual diseases in the evaluation of mediastinal lymphadenopathy of unknown etiology. Ann Thorac Med. 2012;7:84-91.  [PubMed]  [DOI]
57.  Nunez AL, Jhala NC, Carroll AJ, Mikhail FM, Reddy VV, Xian RR, Jhala DN. Endoscopic ultrasound and endobronchial ultrasound-guided fine-needle aspiration of deep-seated lymphadenopathy: Analysis of 1338 cases. Cytojournal. 2012;9:14.  [PubMed]  [DOI]
58.  Stacchini A, Carucci P, Pacchioni D, Accinelli G, Demurtas A, Aliberti S, Bosco M, Bruno M, Balbo Mussetto A, Rizzetto M. Diagnosis of deep-seated lymphomas by endoscopic ultrasound-guided fine needle aspiration combined with flow cytometry. Cytopathology. 2012;23:50-56.  [PubMed]  [DOI]
59.  Miletić Z, Gizdić B, Stoos-Veić T, Kaić G, Novak NP, Tadić M, Jaksić O, Ostović KT. Flow cytometric analysis of deep-seated lymph nodes. Coll Antropol. 2010;34:377-380.  [PubMed]  [DOI]
60.  Khashab M, Mokadem M, DeWitt J, Emerson R, Sherman S, LeBlanc J, McHenry L, Al-Rashdan A, Al-Haddad M. Endoscopic ultrasound-guided fine-needle aspiration with or without flow cytometry for the diagnosis of primary pancreatic lymphoma - a case series. Endoscopy. 2010;42:228-231.  [PubMed]  [DOI]
61.  Yasuda I, Goto N, Tsurumi H, Nakashima M, Doi S, Iwashita T, Kanemura N, Kasahara S, Adachi S, Hara T. Endoscopic ultrasound-guided fine needle aspiration biopsy for diagnosis of lymphoproliferative disorders: feasibility of immunohistological, flow cytometric, and cytogenetic assessments. Am J Gastroenterol. 2012;107:397-404.  [PubMed]  [DOI]
62.  Hosein AN, Song S, McCart Reed AE, Jayanthan J, Reid LE, Kutasovic JR, Cummings MC, Waddell N, Lakhani SR, Chenevix-Trench G. Evaluating the repair of DNA derived from formalin-fixed paraffin-embedded tissues prior to genomic profiling by SNP-CGH analysis. Lab Invest. 2013;93:701-710.  [PubMed]  [DOI]
63.  Dejmek A, Zendehrokh N, Tomaszewska M, Edsjö A. Preparation of DNA from cytological material: effects of fixation, staining, and mounting medium on DNA yield and quality. Cancer Cytopathol. 2013;121:344-353.  [PubMed]  [DOI]
64.  Reicher S, Boyar FZ, Albitar M, Sulcova V, Agersborg S, Nga V, Zhou Y, Li G, Venegas R, French SW. Fluorescence in situ hybridization and K-ras analyses improve diagnostic yield of endoscopic ultrasound-guided fine-needle aspiration of solid pancreatic masses. Pancreas. 2011;40:1057-1062.  [PubMed]  [DOI]
65.  Shen J, Brugge WR, Dimaio CJ, Pitman MB. Molecular analysis of pancreatic cyst fluid: a comparative analysis with current practice of diagnosis. Cancer. 2009;117:217-227.  [PubMed]  [DOI]
66.  Sawhney MS, Devarajan S, O’Farrel P, Cury MS, Kundu R, Vollmer CM, Brown A, Chuttani R, Pleskow DK. Comparison of carcinoembryonic antigen and molecular analysis in pancreatic cyst fluid. Gastrointest Endosc. 2009;69:1106-1110.  [PubMed]  [DOI]
67.  Khalid A, Nodit L, Zahid M, Bauer K, Brody D, Finkelstein SD, McGrath KM. Endoscopic ultrasound fine needle aspirate DNA analysis to differentiate malignant and benign pancreatic masses. Am J Gastroenterol. 2006;101:2493-2500.  [PubMed]  [DOI]
68.  Ogura T, Yamao K, Hara K, Mizuno N, Hijioka S, Imaoka H, Sawaki A, Niwa Y, Tajika M, Kondo S. Prognostic value of K-ras mutation status and subtypes in endoscopic ultrasound-guided fine-needle aspiration specimens from patients with unresectable pancreatic cancer. J Gastroenterol. 2013;48:640-646.  [PubMed]  [DOI]
69.  Liu SL, Chen G, Zhao YP, Wu WM, Zhang TP. Diagnostic accuracy of K-ras mutation for pancreatic carcinoma: a meta-analysis. Hepatobiliary Pancreat Dis Int. 2013;12:458-464.  [PubMed]  [DOI]
70.  Salek C, Minarikova P, Benesova L, Nosek V, Strnad R, Zavoral M, Minarik M. Mutation status of K-ras, p53 and allelic losses at 9p and 18q are not prognostic markers in patients with pancreatic cancer. Anticancer Res. 2009;29:1803-1810.  [PubMed]  [DOI]
71.  Fuccio L, Hassan C, Laterza L, Correale L, Pagano N, Bocus P, Fabbri C, Maimone A, Cennamo V, Repici A. The role of K-ras gene mutation analysis in EUS-guided FNA cytology specimens for the differential diagnosis of pancreatic solid masses: a meta-analysis of prospective studies. Gastrointest Endosc. 2013;78:596-608.  [PubMed]  [DOI]
72.  Pellisé M, Castells A, Ginès A, Agrelo R, Solé M, Castellví-Bel S, Fernández-Esparrach G, Llach J, Esteller M, Bordas JM. Detection of lymph node micrometastases by gene promoter hypermethylation in samples obtained by endosonography- guided fine-needle aspiration biopsy. Clin Cancer Res. 2004;10:4444-4449.  [PubMed]  [DOI]
73.  Carrara S, Cangi MG, Arcidiacono PG, Perri F, Petrone MC, Mezzi G, Boemo C, Talarico A, Cin ED, Grassini G. Mucin expression pattern in pancreatic diseases: findings from EUS-guided fine-needle aspiration biopsies. Am J Gastroenterol. 2011;106:1359-1363.  [PubMed]  [DOI]
74.  Zihao G, Jie Z, Yan L, Jing Z, Jing C, Xue L, Jing Z, Heng LW, Ru G, Jianyu H. Analyzing S100A6 expression in endoscopic ultrasonography-guided fine-needle aspiration specimens: a promising diagnostic method of pancreatic cancer. J Clin Gastroenterol. 2013;47:69-75.  [PubMed]  [DOI]
75.  Kubiliun N, Ribeiro A, Fan YS, Rocha-Lima CM, Sleeman D, Merchan J, Barkin J, Levi J. EUS-FNA with rescue fluorescence in situ hybridization for the diagnosis of pancreatic carcinoma in patients with inconclusive on-site cytopathology results. Gastrointest Endosc. 2011;74:541-547.  [PubMed]  [DOI]
76.  Henkes DN, Patel SN, Rosenkranz LA, Escobedo JL. The utility of UroVysion fluorescence in situ hybridization in pancreatic fine-needle aspiration samples directed and obtained by endoscopic ultrasonography. Arch Pathol Lab Med. 2013;137:64-71.  [PubMed]  [DOI]
77.  Nonogaki K, Itoh A, Kawashima H, Ohno E, Ishikawa T, Matsubara H, Itoh Y, Nakamura Y, Nakamura M, Miyahara R. A preliminary result of three-dimensional microarray technology to gene analysis with endoscopic ultrasound-guided fine-needle aspiration specimens and pancreatic juices. J Exp Clin Cancer Res. 2010;29:36.  [PubMed]  [DOI]