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

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.

Diagnostic utility of endoscopic ultrasound-guided fineneedle aspiration biopsy for glomus tumor of the stomach

A 52-year-old man was referred for further investigation of a gastric submucosal tumor on the greater curvature of the antrum. Endoscopic ultrasonography demonstrated a hypoechoic solid mass, which was primarily connected to the muscular layer of the stomach. We performed endoscopic ultrasoundguided fine-needle aspiration biopsy. The pathological examination showed proliferation of oval-shaped cells with nest formation, which stained strongly positive for muscle actin, and negative for c-kit, CD34, CD56,desmin, S-100, chromogranin, and neuron-specific enolase. Therefore, we performed laparoscopy and endoscopy cooperative surgery based on the preoperative diagnosis of glomus tumor of the stomach. The final histological diagnosis confirmed the preoperative diagnosis. Although preoperative diagnosis of glomus tumor of the stomach is difficult with conventional images and endoscopic biopsy, endoscopic ultrasoundguided fine-needle aspiration biopsy is an essential tool to gain histological evidence of glomus tumor of the stomach for early diagnosis.

Concise review on the comparative efficacy of endoscopic ultrasound-guided fine-needle aspiration vs core biopsy in pancreatic masses, upper and lower gastrointestinal submucosal tumors

Endoscopic ultrasound(EUS)-guided fine needle aspiration with or without biopsy(FNA/FNB) are the primary diagnostic tools for gastrointestinal submucosal tumors. EUS-guided fine needle aspiration(EUS-FNA) is considered a first line diagnostic method for the characterization of pancreatic and upper gastrointestinal lesions, since it allows for the direct visualization of the collection of specimens for cytopathologic analysis. EUSFNA is most effective and accurate when immediate cytologic assessment is permitted by the presence of a cytopathologist on site. Unfortunately, the accuracy and thus the diagnostic yield of collected specimens suffer without this immediate analysis. Recently, a EUS-FNB needle capable of obtaining core samples(fine needle biopsy, FNB) has been developed and has shown promising results. This new tool adds a new dimension to the diagnostic and therapeutic utility of this technique. The aim of the present review is to compare the efficacy of EUS-FNA to that afforded by EUS-FNB in the characterization of pancreatic masses and of upper and lower gastrointestinal submucosal tumors.

Endoscopic ultrasound-guided fine-needle aspiration biopsy-Recent topics and technical tips

Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) is a useful procedure that enables reliable pathological diagnoses of pancreatobiliary diseases, subepithelial lesions, and swollen lymph nodes. In recent years, a pathological diagnosis based on EUS-FNA has made it possible to provide accurate treatment methods not only in these fields, but also in respiratory organs and otorhinolaryngology. This review discusses the latest topics pertaining to EUS-FNA as well as procedural tips.

Preoperative diagnosis of gastrointestinal stromal tumor by endoscopic ultrasound-guided fine needle aspiration

AIM： to evaluate the role of endoscopic ultrasonographyguided fine needle aspiration （EUS-FNA） in the preoperative diagnosis of gastrointestinal stromal tumor （GIST）.METHODS： From September 2002 to June 2006, Fiftythree consecutive EUS-FNAs of GI tract subepithelial hypoechoic tumors with continuity to proper muscle layer suspected as GIST by standard EUS were evaluated prospectively. The reference standards for the final diagnosis were surgery （n = 31）, or clinical follow-up （n = 22）. Additionally, immunophenotyping of specimens obtained by EUS-FNA and surgical resection specimens were compared.RESULTS： In 2 cases puncture was not performed because of anatomical problems. The collection rate of adequate specimens from the GI tract subepithelial hypoechoic tumor with continuity to proper muscle layer was 82% （42/51）. The diagnostic rate for the tumor less than 2 cm, 2 to 4 cm, and 4 cm or more were 71% （15/21）, 86% （18/21）, and 100% （9/9）,respectively. In 29 surgically resected cases, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of EUS-FNA using immunohistochemical analysis of GIST were 100%（24/24）, 80% （4/5）, 96% （24/25）, 100% （4/4）, and 97% （28/29）, respectively. No major complications were encountered.CONCLUSION： EUS-FNA with immunohistochemical analysis is a safe and accurate method in the pretherapeutic diagnosis of GIST. It should be taken into consideration in decision making, especially in early diagnosis following minimal invasive surgery for GIST.

Ultrasound-guided vs endoscopic ultrasound-guided fine-needle aspiration for pancreatic cancer diagnosis

AIM: To clarify the effectiveness and safety of endo- scopic ultrasound-guided fine-needle aspiration (EUS-FNA) for the diagnosis of pancreatic cancer (PC). METHODS: Patients who were diagnosed with unresectable, locally advanced or metastatic PC between February 2006 and September 2011 were selected for this retrospective study. FNA biopsy for pancreatic tumors had been performed percutaneously under extracorporeal ultrasound guidance until October 2009; then, beginning in November 2009, EUS-FNA has been performed. We reviewed the complete medical records of all patients who met the selection criteria for the following data: sex, age, location and size of the targeted tumor, histological and/or cytological findings, details of puncture procedures, time from day of puncture until day of definitive diagnosis, and details of severe adverse events. RESULTS: Of the 121 patients who met the selection criteria, 46 had a percutaneous biopsy (Group A) and 75 had an EUS-FNA biopsy (Group B). Adequate cytological specimens were obtained in 42 Group A patients (91.3%) and all 75 Group B patients (P=0.0192), and histological specimens were obtained in 41 Group A patients (89.1%) and 65 Group B patients (86.7%). Diagnosis of malignancy by cytology was positive in 33 Group A patients (78.6%) and 72 Group B patients (94.6%) (P=0.0079). Malignancy by both cytology and pathology was found in 43 Group A (93.5%) and 73 Group B (97.3%) patients. The mean period from the puncture until the cytological diagnosis in Group B was 1.7 d, which was significantly shorter than that in Group A (4.1 d) (P < 0.0001). Severe adverse events were experienced in two Group A patients (4.3%) and in one Group B patient (1.3%). CONCLUSION: EUS-FNA, as well as percutaneous needle aspiration, is an effective modality to obtain cytopathological confirmation in patients with advanced PC.

Diagnostic value of liquid-based cytology and smear cytology in pancreatic endoscopic ultrasound-guided fine needle aspiration: A meta-analysis

BACKGROUND Smear cytology(SC)using endoscopic ultrasound-guided fine needle aspiration(EUS-FNA)is the established and traditional choice for diagnosing pancreatic lesions.Liquid-based cytology(LBC)is a novel alternative cytological method,however,the comparative diagnostic efficacy of LBC remains inconclusive.AIM To examine the diagnostic efficacy of LBC and SC for pancreatic specimens obtained through EUS-FNA via a systematic review and meta-analysis.METHODS A systematic literature search was performed using PubMed,EMBASE,the Cochrane Library,and Web of Science.The numbers of true positives,false positives,true negatives,and false negatives for each cytological test(LBC and CS)were extracted from the included studies.The pooled sensitivity and specificity and the area under the summary receiver operating characteristic curve(AUC)were calculated,and the AUC was compared by Tukey's multiple comparisons test.The quality of the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies II tool.RESULTS A total of 1656 patients in eight studies were included.The pooled sensitivity and specificity and the AUC for LBC were 0.76(95%CI:0.72-0.79),1.00(95%CI:0.98-1.00),and 0.9174,respectively,for diagnosing pancreatic lesions.The pooled estimates for SC were as follows:Sensitivity,0.68(95%CI:0.64-0.71);specificity,0.99(95%CI:0.96-100.00);and AUC,0.9714.Similarly,the corresponding values for LBC combined with SC were 0.87(95%CI:0.84-0.90),0.99(95%CI:0.96-1.00),and 0.9894.Tukey’s multiple comparisons test was used to compare the sensitivities and AUCs of the three diagnostic methods;statistically significant differences were found between the three methods,and LBC combined with SC was superior to both LBC(P<0.05)and SC(P<0.05).The pooled sensitivity and AUC did not change significantly in the sensitivity analysis.CONCLUSION LBC may be sensitive than SC in the cytological diagnosis of pancreatic lesions,however,the superior diagnostic performance of their combination emphasizes their integrated usage in the clinical evaluation of pancreatic lesions.

Endoscopic ultrasound-guided fine needle aspiration in the differentiation of type 1 and type 2 autoimmune pancreatitis

AIM:To investigate the usefulness of endoscopic ultrasound-guided fine needle aspiration(EUS-FNA) in the differentiation of autoimmune pancreatitis(AIP).METHODS:We retrospectively reviewed 47 of 56 AIP patients who underwent EUS-FNA and met the Asian diagnostic criteria.On 47 EUS-FNA specimens,we evaluated the presence of adequate material and characteristic features of lymphoplasmacytic sclerosing pancreatitis(LPSP) and idiopathic duct-centric pancreatitis(IDCP) mentioned in the International Consensus Diagnostic Criteria and examined if these findings make a contribution to the differential diagnosis of type 1 and type 2 AIP.A disposable 22-gauge needle was used for EUS-FNA.RESULTS:Adequate specimens including pancreatic tissue for differentiating AIP from cancer were obtained from 43 of 47 patients who underwent EUSFNA.EUS-FNA was performed from the pancreatic head in 21 cases,which is known to be technically difficult when performed by core biopsy;there was no significant difference in the results compared with pancreatic body-tail.Nine of 47 patients met level 1 findings of LPSP and 5 patients met level 2 findings of LPSP.No one met level 1 findings of IDCP,but 3 patients met level 2 findings of IDCP.Of 10 seronegative cases,2 cases were diagnosed with "definitive type 1 AIP",and 3 cases were diagnosed with "probable type 2 AIP" when considering both the level 2 histological findings and response to steroids.CONCLUSION:EUS-FNA is useful in the differentiation of type 1 and type 2 AIP,particularly in seronegative cases.

Peritoneal dissemination of pancreatic cancer caused by endoscopic ultrasound-guided fine needle aspiration:A case report and literature review

BACKGROUND Endoscopic ultrasound-guided fine needle aspiration(EUS-FNA)is a biopsy technique widely used to diagnose pancreatic tumors because of its high sensitivity and specificity.Although needle-tract seeding caused by EUS-FNA has been recently reported,dissemination of pancreatic cancer cells is generally considered to be a rare complication that does not affect patient prognosis.However,the frequency of dissemination and needle-tract seeding appears to have been underestimated.We present a case of peritoneal dissemination of pancreatic cancer due to preoperative EUS-FNA.CASE SUMMARY An 81-year-old man was referred to the Department of Surgery of our hospital in Japan owing to the detection of a pancreatic mass on computed tomography during medical screening.Trans-gastric EUS-FNA revealed that the mass was an adenocarcinoma;hence laparoscopic distal pancreatectomy with lymphadenectomy was performed.No intraoperative peritoneal dissemination and liver metastasis were visually detected,and pelvic lavage cytology was negative for carcinoma cells.The postoperative surgical specimen was negative for carcinoma cells at the dissected margin and the cut end margin;however,pathological findings revealed adenocarcinoma cells on the peritoneal surface proximal to the needle puncture site,and the cells were suspected to be disseminated via EUSFNA.Hence,the patient received adjuvant therapy with S-1(tegafur,gimeracil,and oteracil potassium);however,computed tomography performed 5 mo after surgery revealed liver metastasis and cancerous peritonitis.The patient received palliative therapy and died 8 mo after the operation.CONCLUSION The indications of EUS-FNA should be carefully considered to avoid iatrogenic dissemination,especially for cancers in the pancreatic body or tail.

Can the wet suction technique change the efficacy of endoscopic ultrasound-guided fine-needle aspiration for diagnosing autoimmune pancreatitis type 1? A prospective single-arm study

BACKGROUND Other than surgery,endoscopic ultrasound-guided fine-needle aspiration(EUSFNA)is the only procedure for histologically diagnosing autoimmune pancreatitis(AIP).However,adequate specimens are difficult to obtain.Recently,more adequate specimens were reported to be obtained with EUS-FNA with a wet suction technique(WEST)than with conventional EUS-FNA.AIM To histologically diagnose AIP by EUS-FNA with a WEST.METHODS Eleven patients with possible type 1 AIP between February 2016 and August 2018 underwent EUS-FNA with a WEST(WEST group),with four punctures by 19 or 22 G needles.As a historical control,23 type 1 AIP patients who underwent no fewer than four punctures with 19 or 22 G needles were enrolled(DRY group).Patient characteristics and histological findings were compared between the two groups.RESULTS Three histopathological factors according to the International Consensus Diagnostic Criteria were significantly greater in the WEST group than the DRY group[lymphoplasmacytic infiltrate without granulocytic infiltration:9(81.8%)vs 6(26.1%),P=0.003,storiform fibrosis:5(45.5%)vs 1(4.3%),P=0.008,abundant(>10 cells/HPF)IgG4-positive cells:7(63.6%)vs 5(21.7%),P=0.026].Level 1 or level 2 histopathological findings were observed more often in the WEST group than in the DRY group[8(72.7%)vs 3(13.0%),P=0.001].CONCLUSION EUS-FNA with a WEST was more successful than standard EUS-FNA in histologically diagnosing AIP.

Push vs pull method for endoscopic ultrasound-guided fine needle aspiration of pancreatic head lesions: Propensity score matching analysis

AIM To evaluate the efficacy of endoscopic ultrasoundguided fine needle aspiration(EUS-FNA) of pancreatic head cancer when pushing(push method) or pulling the echoendoscope(pull method).METHODS Overall, 566 pancreatic cancer patients had their first EUS-FNA between February 2001 and December 2017. Among them, 201 who underwent EUS-FNA for pancreatic head lesions were included in this study. EUS-FNA was performed by the push method in 85 patients, the pull method in 101 patients and both the push and pull methods in 15 patients. After propensity score matching(age, sex, tumor diameter, and FNA needle), 85 patients each were stratified into the push and pull groups. Patient characteristics and EUSFNA-related factors were compared between the two groups.RESULTS Patient characteristics were not significantly different between the two groups. The distance to lesion was significantly longer in the push group than in the pull group(13.9 ± 4.9 mm vs 7.0 ± 4.9 mm, P < 0.01). The push method was a significant factor influencing the distance to lesion(≥ median 10 mm)(P < 0.01). Additionally, tumor diameter ≥ 25 mm(OR = 1.91, 95%CI: 1.02-3.58, P = 0.043) and the push method(OR = 1.91, 95%CI: 1.03-3.55, P = 0.04) were significant factors contributing to the histological diagnosis of malignancy.CONCLUSION The pull method shortened the distance between the endoscope and the lesion and facilitated EUS-FNA of pancreatic head cancer. The push method contributed to the histological diagnosis of pancreatic head cancer using EUS-FNA specimens.

Endoscopic Ultrasound-Guided Fine Needle Aspiration Cytology of Gastrointestinal Tract Tumors and Related Organs: Predictive Factors for Accurate Cytopathological Diagnosis

Background: Endoscopic ultrasonography (EUS) is well-established, highly accurate clinical diagnostic test for detection and staging of gastrointestinal tract lesions and related organs. The addition of endoscopic guided fine needle aspiration cytology (EUS-FNAC) has improved the performance characteristics of EUS. Aim: Evaluate the validity of EUS-FNAC in diagnosis of gastrointestinal tract lesions and related organs and assess predictive factors for an accurate EUS-FNAC diagnosis. Methods: Our study included cytological sampling from one hundred sixty-six lesions obtained from gastrointestinal tract and related organs. Factors affecting EUS-FNA accuracy were analyzed. The histopathological results or clinical follow-up were used as the gold standard method. Results: Samples were obtained from: pancreatic masses (n = 80), gastric masses (n = 34), lymph nodes (n = 22), hepatobiliary masses (n = 18) and rectal masses (n = 2). Statistical analysis of sensitivity, specificity, Positive Predictive Value, Negative Predictive Value, and diagnostic accuracy of EUS alone was 80.4%, 51.6%, 75.8%, 76.2% and 75.9% respectively. The sensitivity, specificity, positive predictive value and negative predictive value of EUS-FNAC are 78.8%, 96.8%, 97.6% and 73.2% respectively. Addition of FNAC to EUS improved diagnostic accuracy to 85.5%. Positive statistical association was present between cytological adequacy and adequate cell block preparations, larger lesion size, presence of rapid on site evaluation (ROSE) and obtaining at least two passes from target lesion. Conclusions: EUS is valuable diagnostic and cost effective tool for gastrointestinal tract lesions and related organs when combined with FNAC.

Impact of endoscopic ultrasound-guided fine needle biopsy for diagnosis of pancreatic masses

AIM： To evaluate the diagnostic accuracy of histological evaluation of pancreatic tissue samples obtained by a modified method for recovering and processing the endoscopic ultrasound （EUS）-guided fine needle aspiration （FNA） material in the differential diagnosis of pancreatic solid masses. METHODS： Sixty-two consecutive patients with pancreatic masses were prospectively studied. EUS was performed by the linear scanning Pentax FG-38UX echoendoscope. Three FNAs （22G needle） were carried out during each procedure. The materials obtained with first and second punctures were processed for cytological study. Haterials of the third puncture were recovered into 10% formol solution by careful injection of saline solution through the needle, and processed for histological study. RESULTS： Length of the core specimen obtained for histological analysis was 6.5±5.3 mm （range 1-22 mm）. Cytological and histological samples were considered as adequate in 51 （82.3%） and 52 cases （83.9%）, respectively. Overall sensitivity of both pancreatic cytology and histology for diagnosis of malignancy was 68.4%. Conbary to cytology, histology was able to diagnose tumours other than adenocarcinomas, and all cases of inflammatory masses. Combination of cytology and histology allowed obtaining an adequate sample in 56 cases （90.3%）, with a global sensitivity of 84.21%, specificity of 100% and an overall accuracy of 90.32%. The complication rate was 1.6%.CONCLUSION： Adequate pancreatic core specimens for histological examination can be obtained by EUS-guided FNA. This technique is mainly useful for the diagnosis of different types of pancreatic tumours and evaluation of benign diseases.

22-gauge core vs 22-gauge aspiration needle for endoscopic ultrasound-guided sampling of abdominal masses

AIM To compare the aspiration needle(AN) and core biopsy needle(PC) in endoscopic ultrasound-guided fine needle aspiration(EUS-FNA) of abdominal masses.METHODS Consecutive patients referred for EUS-FNA were included in this prospective single-center trial. Each patient underwent a puncture of the lesion with both standard 22-gauge(G) AN(Echo Tip Ultra; Cook Medical, Bloomington, Indiana, United States) and the novel 22 G PC(Echo Tip Pro Core; Cook Medical, Bloomington, Indiana, United States) in a randomized fashion; histology was attempted in the PC group only. The main study endpoint was the overall diagnostic accuracy, including the contribution of histology to the final diagnosis. Secondary outcome measures included material adequacy, number of needle passes, and complications.RESULTS Fifty six consecutive patients(29 men; mean age 68 years) with pancreatic lesions(n = 38), lymphadenopathy(n = 13), submucosal tumors(n = 4), or others lesions(n = 1) underwent EUS-FNA using both of the needles in a randomized order. AN and PC reached similar overall results for diagnostic accuracy(AN: 88.9 vs PC: 96.1, P = 0.25), specimen adequacy(AN: 96.4% vs PC: 91.1%, P = 0.38), mean number of passes(AN: 1.5 vs PC: 1.7, P = 0.14), mean cellularity score(AN: 1.7 vs PC: 1.1, P = 0.058), and complications(none). A diagnosis on the basis of histology was achieved in the PC group in 36(64.3%) patients, and in 2 of those as the sole modality. In patients with available histology the mean cellularity score was higher for AN(AN: 1.7 vs PC: 1.0, P = 0.034); no other differences were of statistical significance.CONCLUSION Both needles achieved high overall diagnostic yields and similar performance characteristics for cytological diagnosis; histological analysis was only possible in 2/3 of cases with the new needle.

Endoscopic ultrasound fine needle aspiration vs fine needle biopsy in solid lesions:A multi-center analysis

BACKGROUND While endoscopic ultrasound(EUS)-guided fine needle aspiration(FNA)is considered a preferred technique for tissue sampling for solid lesions,fine needle biopsy(FNB)has recently been developed.AIM To compare the accuracy of FNB vs FNA in determining the diagnosis of solid lesions.METHODS A retrospective,multi-center study of EUS-guided tissue sampling using FNA vs FNB needles.Measured outcomes included diagnostic test characteristics(i.e.,sensitivity,specificity,accuracy),use of rapid on-site evaluation(ROSE),and adverse events.Subgroup analyses were performed by type of lesion and diagnostic yield with or without ROSE.A multivariable logistic regression was also performed.RESULTS A total of 1168 patients with solid lesions(n=468 FNA;n=700 FNB)underwent EUS-guided sampling.Mean age was 65.02±12.13 years.Overall,sensitivity,specificity and accuracy were superior for FNB vs FNA(84.70%vs 74.53%;99.29%vs 96.62%;and 87.62%vs 81.55%,respectively;P<0.001).On subgroup analyses,sensitivity,specificity,and accuracy of FNB alone were similar to FNA+ROSE[(81.66%vs 86.45%;P=0.142),(100%vs 100%;P=1.00)and(88.40%vs 85.43%;P=0.320].There were no difference in diagnostic yield of FNB alone vs FNB+ROSE(P>0.05).Multivariate analysis showed no significant predictor for better accuracy.On subgroup analyses,FNB was superior to FNA for non-pancreatic lesions;however,there was no difference between the techniques among pancreatic lesions.One adverse event was reported in each group.CONCLUSION FNB is superior to FNA with equivalent diagnostic test characteristics compared to FNA+ROSE in the diagnosis of non-pancreatic solid lesions.Our results suggest that EUS-FNB may eliminate the need of ROSE and should be employed as a first-line method in the diagnosis of solid lesions.

Endoscopic ultrasound fine needle aspiration vs fine needle biopsy for pancreatic masses,subepithelial lesions,and lymph nodes

Endoscopic ultrasound tissue acquisition,in the form of both fine needle aspiration(EUS-FNA)and fine needle biopsy(EUS-FNB),is utilized for pancreatic mass lesions,subepithelial lesions,and lymph node biopsy.Both procedures are safe and yield high diagnostic value.Despite its high diagnostic yield,EUS-FNA has potential limitations associated with cytological aspirations,including inability to determine histologic architecture,and a small quantitative sample for further immunohistochemical staining.EUS-FNB,with its larger core biopsy needle,was designed to overcome these potential limitations.However,it remains unclear which technique should be used and for which lesions.Comparative trials are plagued by heterogeneity at every stage of comparison;including variable needles used,and different definitions of endpoints,which therefore limit generalizability.Thus,we present a review of prospective trials,systematic reviews,and meta-analyses on studies examining EUS-FNA vs EUSFNB.Prospective comparative trials of EUS-FNA vs EUS-FNB primarily focus on pancreatic mass lesions,and yield conflicting results in terms of demonstrating the superiority of one method.However,consistent among trials is the potential for diagnosis with fewer passes,and a larger quantity of sample achieved for next generation sequencing.With regard to subepithelial lesions and lymph node biopsy,fewer prospective trials exist,and larger prospective studies are necessary.Based on the available literature,we would recommend EUS-FNB for peri-hepatic lymph nodes.

Endoscopic ultrasound guided fine needle aspiration and useful ancillary methods

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.

Pancreatic paraganglioma diagnosed by endoscopic ultrasoundguided fine needle aspiration: A case report and review of literature

BACKGROUND Pancreatic paragangliomas(PPGL)are rare benign neuroendocrine neoplasms but malignancy can occur.PPGL are often misdiagnosed as pancreatic neuroendocrine tumor or pancreatic adenocarcinoma.CASE SUMMARY We reviewed 47 case reports of PPGL published in PubMed to date.Fifteen patients(15/47)with PPGL underwent endoscopic ultrasound-guided fine needle aspiration(EUS-FNA).Only six(6/15)were correctly diagnosed as PPGL.All patients with PPGL underwent surgical resection except three(one patient surgery was aborted because of hypertensive crisis,two patients had metastasis or involvement of major vessels).Our patient remained on close surveillance as she was asymptomatic.CONCLUSION Accurate preoperative diagnosis of PPGL can be safely achieved by EUS-FNA with immunohistochemistry.Multidisciplinary team approach should be considered to bring the optimal results in the management of PPGL.

Endoscopic ultrasound fine needle aspiration:Technique and applications in clinical practice

Since its initial report in 1992,endoscopic ultrasoundguided fine needle aspiration(EUS-FNA) has now been incorporated into the diagnostic and staging algorithm for the evaluation of benign and malignant diseases of the gastrointestinal tract and of adjacent organs.Its introduction constitutes a major breakthrough in the endoscopic field and has gradually transformed EUS from a pure imaging modality into a more interventional procedure.In addition,the possibility of collecting samples,providing a definitive cytological and/or histological evidence of the presence of malignancy,has strongly contributed to changing EUS from a subjective,highly operator dependant procedure into a more objective one.This article will review the instrumentation,technique and the most important clinical applications of EUS-FNA.

Comparison of cytological and histological preparations in the diagnosis of pancreatic malignancies using endoscopic ultrasoundguided fine needle aspiration

BACKGROUND:Endoscopic ultrasound-guided fine needle aspiration(EUS-FNA) has become a crucial diagnostic technique for pancreatic malignancies.The specimen obtained by EUS-FNA can be prepared for either cytological or histological examinations.This study was to compare diagnostic performance of cytological and histological preparations using EUSFNA in the same lesions when pancreatic malignancies were suspected.METHODS:One hundred and eighteen patients who underwent EUS-FNA for suspected pancreatic malignancies were consecutively enrolled.All procedures were conducted by a single echoendoscopist under the same conditions.Four adequate preparations were obtained by 22-gauge needles with 20 to-and-fro movements for each pass.The 4 preparations included 2 cytological and 2 histological specimens.The pathologic reviews of all specimens were conducted independently by a single experienced cytopathologist.Sensitivity,specificity,and accuracy of the 2 preparations were compared.RESULTS:The enrolled patients consisted of 62 males(52.5%),with the mean age of 64.6±10.5 years.Surgery was performed in 23(19.5%) patients.One hundred and sixteen(98.3%) lesions were classified as malignant,while 2(1.7%) were benign.Sensitivity of cytology and histology were 87.9% and 81.9%,respectively,with no significant difference(P=0.190).Accuracy was also not significantly different.Cytological preparation was more sensitive when the size of lesion was <3 cm(86.7% vs 68.9%,P=0.033).CONCLUSIONS:Our results suggested that the diagnostic performances of cytological and histological preparations are not significantly different for the diagnosis of pancreatic malignancies.However,cytological preparation might be more sensitive for pancreatic lesions <3 cm.