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.

Endoscopic ultrasound-guided fine-needle aspiration pancreatic adenocarcinoma samples yield adequate DNA for next-generation sequencing:A cohort analysis

BACKGROUND Genetic tests are increasingly performed for the management of unresectable pancreatic cancer.For genotyping aimed samples current guidelines recommend using core specimens,although based on moderate quality evidence.However,in clinical practice among the endoscopic ultrasound(EUS) guided tissue acquisition methods,fine needle aspiration(FNA) is the most widely performed.AIM To assess the adequacy for next generation sequencing(NGS) of the DNA yielded from EUS-FNA pancreatic adenocarcinoma(PDAC) samples.METHODS Between November 2018 and December 2021,105 patients with PDAC confirmed by EUS-FNA were included in the study at our tertiary gastroenterology center.Either 22 gauge(G) or 19G FNA needles were used.One pass was dedicated to DNA extraction.DNA concentration and purity(A260/280,A260/230) were assessed by spectrophotometry.We assessed the differences in DNA parameters according to needle size and tumor characteristics(size,location) and the adequacy of the extracted DNA for NGS(defined as A260/280 ≥ 1.7,and DNA yield:≥ 10 ng for amplicon based NGS,≥ 50 ng for whole exome sequencing [WES],≥ 100 ng for whole genome sequencing [WGS]) by analysis of variance and ttest respectively.Moreover,we compared DNA purity parameters across the different DNA yield categories.RESULTS Our cohort included 49% male patients,aged 67.02 ± 8.38 years.The 22G needle was used in 71%of the cases.The DNA parameters across our samples varied as follows:DNA yield:1289 ng(inter quartile range:534.75-3101),A260/280 = 1.85(1.79-1.86),A260/230 = 2.2(1.72-2.36).DNA yield was > 10 ng in all samples and > 100 ng in 93% of them(one sample < 50 ng).There were no significant differences in the concentration and A260/280 between samples by needle size.Needle size was the only independent predictor of A260/230 which was higher in the 22G samples(P =0.038).NGS adequacy rate was 90% for 19G samples regardless of NGS type,and for 22G samples it reached 89% for WGS adequacy and 91% for WES and amplicon based NGS.Samples with DNA yield > 100 ng had significantly higher A260/280(1.89 ± 0.32 vs 1.34 ± 0.42,P = 0.013).Tumor characteristics were not corelated with the DNA parameters.CONCLUSION EUS-FNA PDAC samples yield DNA adequate for subsequent NGS.DNA amount was similar between 22G and 19G FNA needles.DNA purity parameters may vary indirectly with needle size.

Contrast-enhanced guided endoscopic ultrasound procedures

Contrast-enhanced endoscopic ultrasound(CH-EUS)can overcome the limi-tations of endoscopic ultrasound-guided acquisition by identifying microvessels inside inhomogeneous tumours and improving the characterization of these tumours.Despite the initial enthusiasm that oriented needle sampling under CH-EUS guidance could provide better diagnostic yield in pancreatic solid lesions,further studies did not confirm the supplementary values in cases of tissue acquisition guided by CH-EUS.This review details the knowledge based on the available data on contrast-guided procedures.The indications for CH-EUS tissue acquisition include isoechoic EUS lesions with poor visible delineation where CH-EUS can differentiate the lesion vascularisation from the surrounding parenchyma and also the mural nodules within biliopancreatic cystic lesions,which occur in select cases.Additionally,the roles of CH-EUS-guided therapy in patients whose pancreatic fluid collections or bile ducts that have an echogenic content have indications for drainage,and patients who have nonvisualized vessels that need to be highlighted via Doppler EUS are presented.Another indication is represented if there is a need for an immediate assessment of the post-radiofrequency ablation of pancreatic neuroendocrine tumours,in which case CH-EUS can be used to reveal the incomplete tumour destruction.

Usefulness of endoscopic ultrasound-guided fine needle aspiration in the diagnosis of hepatic, gallbladder and biliary tract Lesions

Endoscopic ultrasound(EUS)-guided fine needle aspira-tion(FNA) of the liver is a safe procedure in the diag-nosis and staging of hepatobiliary malignancies with a minimal major complication rate. EUS-FNA is useful for liver lesions poorly accessible to other imaging modali-ties of the liver. EUS-guided FNA of biliary neoplasia and malignant biliary stricture is superior to the con-ventional endoscopic brushing and biopsy.

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.

Identification of biomarkers of human pancreatic adenocarcinomas by expression profiling and validation with gene expression analysis in endoscopic ultrasound-guided fine needle aspiration samples

AIM： To compare gene expression profiles of pancreatic adenocarcinoma tissue specimens, human pancreatic and colon adenocarcinoma and leukemia cell lines and normal pancreas samples in order to distinguish differentially expressed genes and to validate the differential expression of a subset of genes by quantitative real-time RT-PCR （RT-QPCR） in endoscopic ultrasound-guided fine needle aspiration （EUS-guided FNA） specimens.METHODS： Commercially dedicated cancer cDNA macroarrays （Atlas Human Cancer 1.2） containing 1176 genes were used. Different statistical approaches （hierarchical clustering, principal component analysis （PCA） and SAM） were used to analyze the expression data. RT-QPCR and immunohistochemical studies were used for validation of results.RESULTS： RT-QPCR validated the increased expression of LCN2 （lipocalin 2） and for the first time PLAT （tissue-type plasminogen activator or tPA） in malignant pancreas as compared with normal pancreas. Immunohistochemical analysis confirmed the increased expression of LCN2 protein localized in epithelial cells of ducts invaded by carcinoma. The analysis of PLAT and LCN2 transcripts in 12 samples obtained through EUS-guided FNA from patients with pancreatic adenocarcinoma showed significantly increased expression levels in comparison with those found in normal tissues, indicating that a sufficient amount of high quality RNA can be obtained with this technique.CONCLUSION： Expression profiling is a useful method to identify biomarkers and potential target genes. Molecular analysis of EUS-guided FNA samples in pancreatic cancer appears as a valuable strategy for the diagnosis of pancreatic adenocarcinomas.

Rapid on-site evaluation of endoscopic-ultrasound-guided fine-needle aspiration diagnosis of pancreatic masses

Endoscopic ultrasound (EUS) has become an essential tool for the study of pancreatic diseases. Specifically, EUS plays a pivotal role evaluating patients with a known or suspected pancreatic mass. In this setting, differential diagnosis remains a clinical challenge. EUS-guided fine-needle aspiration (FNA) and fine-needle biopsy (FNB) have been proven to be safe and useful tools in this setting. EUS-guided FNA and FNB, by obtaining cytological and/or histological samples, are able to diagnose pancreatic lesions with high sensitivity and specificity. In this context, several methodological features, trying to increase the diagnostic yield of EUS-guided FNA and FNB, have been evaluated. In this review, we focus on the role of rapid on-site evaluation (ROSE). From data reported in the literature, ROSE may increase diagnostic yield of EUS-FNA specimens by 10%-30%, and thus, diagnostic accuracy. However, we should point out that many recent studies have reported adequacy rates of &#x0003e; 90% without ROSE, indicating that, perhaps, at high-volume centers, ROSE may not be indispensable to achieve excellent results. The use of ROSE can be considered important during the learning curve of EUS-FNA, and also in hospital with diagnostic accuracy rates &#x0003c; 90%.

Endoscopic ultrasound-guided fine-needle aspiration for the diagnosis of pancreatic cysts by combined cytopathology and cystic content analysis

Recent advances in imaging technology have resulted in an increase in incidental discoveries of pancreatic cystic lesions. Pancreatic cysts comprise a wide variety of lesions and include non-neoplastic cysts and neoplastic cysts. Because some pancreatic cysts have more of a malignant potential than others, it is absolutely essential that an accurate diagnosis is rendered so that effective care can be given to each patient. In many centers, endoscopic ultrasound(EUS)-guided fine-needle aspiration(FNA) has emerged as the modality of choice that enables one to distinguish between mucinous and non-mucinous lesion, diagnose malignancy and collect cyst fluid for further diagnostic studies, such as pancreatic enzyme levels, molecular analysis and other tumor biomarkers. The current review will focus on EUSguided FNA and the cytological diagnosis for pancreatic cysts.

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.

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.

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.

Endoscopic ultrasound-guided fine-needle aspiration cytology in pancreaticobiliary carcinomas:diagnostic efficacy of cell-block immunocyto-chemistry

BACKGROUND： Endoscopic ultrasound-guided fine-needle aspiration cytology was demonstrated to be a useful tool for the diagnosis and staging of pancreaticobiliary neoplastic le- sions. Nonetheless, the diagnostic value of this procedure may be limited by low cellularity of the specimen, contamination of intestinal cells and unfeasibility of ancillary immunocy- tochemical procedures. The present study was to evaluate its usefulness in the diagnosis of neoplastic lesions.

Randomized controlled study of the safety and efficacy of nitrous oxide-sedated endoscopic ultrasound-guided fine needle aspiration for digestive tract diseases

AIM To evaluate the efficacy and safety of nitrous oxidesedated endoscopic ultrasound-guided fine needle aspiration. METHODS Enrolled patients were divided randomly into an experimental group(inhalation of nitrous oxide) and a control group(inhalation of pure oxygen) and heart rate, blood oxygen saturation, blood pressure, electrocardiogram(ECG) changes, and the occurrence of complications were monitored and recorded. All patients and physicians completed satisfaction questionnaires about the examination and scored the process using a visual analog scale. RESULTS There was no significant difference in heart rate, blood oxygen saturation, blood pressure, ECG changes, or complication rate between the two groups of patients(P > 0.05). However, patient and physician satisfaction were both significantly higher in the nitrous oxide compared with the control group(P < 0.05).CONCLUSION Nitrous oxide-sedation is a safe and effective option for patients undergoing endoscopic ultrasound-guided fine needle aspiration.

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.

Cell-block procedure in endoscopic ultrasound-guided-fine-needle-aspiration of gastrointestinal solid neoplastic lesions

In the present review we have analyzed the clinical applications of endoscopic ultrasound-guided-fineneedle-aspiration(EUS-FNA) and the methodological aspects obtained by cell-block procedure(CBP) in the diagnostic approach to the gastrointestinal neoplastic pathology. CBP showed numerous advantages in comparison to the cytologic routine smears; in particular, better preservation of cell architecture, achievement of routine haematoxylin-eosin staining equivalent to histological slides and possibility to perform immunohistochemistry or molecular analyses represented the most evident reasons to choose this method. Moreover, by this approach, the differential diagnosis of solid gastrointestinal neoplasias may be more easily achieved and the background of contaminant nonneoplastic gastrointestinal avoided. Finally, biological samples collected by EUS-FNA CBP-assisted should be investigated in order to identify and quantify further potential molecular markers.

Endoscopic ultrasound-guided fine-needle aspiration for suspected malignancies adjacent to the gastrointestinal tract

AIM: To investigate the impact of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in association with a multidisciplinary team evaluation for the detection of gastrointestinal malignancies.

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.

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.