Diagnostic efficacy of cell block immunohistochemistry, smear cytology, and liquid-based cytology in endoscopic ultrasound-guided fine-needle aspiration of pancreatic lesions: a single-institution experience

Diagnostic Efficacy of Cell Block and Liquid-Based Cytology for Endoscopic Ultrasound-Guided Fine Needle Aspiration in Pancreatic Tumors

This study aimed to evaluate the diagnostic efficacy of cell block (CB) and liquid-based cytology (LBC) for endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in pancreatic tumors. The study included patients who underwent EUS-FNA for pancreatic tumors between January 2015 and February 2021 and whose cytology samples were both processed for LBC and CB. Data of 390 patients (220 men, mean age: 64.2 ± 11.4 years) were retrospectively analyzed. Of the detected lesions (size: 17-120 mm; mean: 39.9 ± 13.9 mm), 220 (56.4%) were located in the head and uncinate process of the pancreas. Lesions in 339 (86.9%) patients were diagnosed as malignant using CB and/or LBC and suspicious for malignancy in 44 (11.3%) patients. In 7 patients with non-diagnostic (6 cases) or negative for malignancy (1 case) EUS-FNA results using both methods, the diagnosis of malignancy was established via ultrasound-guided percutaneous biopsy. Malignancy was detected in 324 (92.4%), 313 (87.9%), and 298 (87.9%) patients using CB, LBC, and both CB and LBC, respectively. Final diagnosis was obtained in 339 (98%) patients by using CB and/or LBC. The combined use of the both methods exhibited significantly superior diagnostic accuracy compared with CB and LBC alone (P < .001). Liquid-based cytology and CB exhibit high diagnostic accuracy for the detection of pancreatic tumors in patients undergoing EUS-FNA. The combined use of both methods showed a significantly higher diagnostic accuracy than LBC and CB alone.

Rapid on-site evaluation and cell blocks: getting the most from the least invasive method in cytopathology

INTRODUCTION

Fine needle aspiration cytology (FNAC) sampling is a minimally invasive procedure done to identify the pathology behind superficial and deep-seated lesions. Rapid on-site evaluation (ROSE) can be an adjunct to the FNACs. Our study aimed to identify the role of ROSE in diagnostic adequacy and to check the benefit of cell block (CB)/cell buttons prepared from the ROSE samples.

MATERIAL AND METHODS

A prospective study was conducted where all patients referred for FNAC were included. ROSE using 1% aqueous toluidine blue stain and CB/cell button preparations were done for the identification of various cytological lesions.

RESULTS

Among 600 cases included in the study most common age group was third and fourth decades with a mean age of 41.6 years and M: F ratio of 1:1.7. Ultrasound-guided procedures were done in 20% of cases. CB preparation was available in 14% of cases. Most CBs were from the cases wherein ROSE was performed 81% (77 out of 86), with CB helping in making an accurate diagnosis in 17% of cases. Lymph nodes 26%, and thyroid 23% were the most common sites for sampling with the highest number of repeat procedures from non-ROSE cases (14%). The non-diagnostic rate for non-ROSE cases was 7.7% (23/300) even after the repeat procedures as compared to 1.3% (4/300) for ROSE. Three slides on average were consumed in ROSE-performed procedures, as compared to an average of 5 slides in non-ROSE. The average turnaround time was 1.7 days for non-ROSE cases and 1.05 for ROSE cases respectively. Cyto-histopathological correlation was available in 40% of cases with a sensitivity of 98.1%, specificity of 96.7%, positive predictive value of 90%, negative predictive value of 99.4%, and diagnostic accuracy of 97%. The correlation of CB, number of slides consumed, and turnaround time among the 2 groups were statistically significant (P value < 0.001).

CONCLUSIONS

ROSE is a method used to assess material aspirated at the time of FNAC procedures to determine the adequacy and to an extent to identify whether the lesion is neoplastic or non-neoplastic. CBs have helped in increasing diagnostic accuracy apart from the fact that the paraffin-embedded tissue material can be used for further studies.

Advances in diagnostic liquid-based cytology

Liquid-based cytology (LBC) has changed the landscape of gynaecological cytology. A growing demand exists for LBC in diagnostic cytology, particularly for ancillary testing, such as immunocytochemistry and molecular testing. Ancillary testing solely based on conventional preparation (CP) methods remains challenging. Recently, the increased demand for specialist testing and minimally invasive techniques, such as endoscopic ultrasonography fine-needle aspiration, to obtain cellular samples has led to an increasing demand for ancillary testing on cytology LBC supernatant, slides and cell block (CB). This facilitates the diagnosis and prognosis in cytology samples enabling personalized treatment. An understanding of the history and future prospects of LBC is crucial for its application in routine diagnostics by cytopathologists and cytotechnologists. In this review, we initiated an internet search using the keyword 'liquid-based cytology', and we conducted a literature review to discuss the usefulness of combined diagnosis of LBC and CP, immunocytochemistry and molecular testing and assessed the quality of nucleic acids in diagnostic LBC. High-quality and cell-rich diagnostic LBC surpassed the CP method alone in terms of reliability and versatility of ancillary testing in cytological diagnosis. Conclusively, diagnostic LBC lends itself to various new technologies and is expected to continue evolving with innovations in the future.

K-ras mutation detected by peptide nucleic acid-clamping polymerase chain reaction, Ki-67, S100P, and SMAD4 expression can improve the diagnostic accuracy of inconclusive pancreatic EUS-FNB specimens

OBJECTIVES

We aimed to assess the diagnostic utility of an immunohistochemical panel including calcium-binding protein P, p53, Ki-67, and SMAD family member 4 and K-ras mutation for diagnosing pancreatic solid lesion specimens obtained by endoscopic ultrasound-guided fine-needle biopsy and to confirm their usefulness in histologically inconclusive cases.

METHODS

Immunohistochemistry and peptide nucleic acid-clamping polymerase chain reaction for K-ras mutation were performed on 96 endoscopic ultrasound-guided fine-needle biopsy specimens. The diagnostic efficacy of each marker and the combination of markers was calculated. The diagnostic performances of these markers were evaluated in 27 endoscopic ultrasound-guided fine-needle biopsy specimens with histologically inconclusive diagnoses. A classification tree was constructed.

RESULTS

K-ras mutation showed the highest accuracy and consistency. Positivity in more than two or three of the five markers showed high diagnostic accuracy (94.6 % and 93.6 %, respectively), and positivity for more than three markers showed the highest accuracy for inconclusive cases (92.0 %). A classification tree using K-ras mutation, Ki-67, S100P, and SMAD4 showed high diagnostic performance, with only two misclassifications in inconclusive cases.

CONCLUSIONS

K-ras mutation detection via peptide nucleic acid-clamping polymerase chain reaction is a stable and accurate method for distinguishing between pancreatic ductal adenocarcinoma and non-pancreatic ductal adenocarcinoma lesions. A classification tree using K-ras mutation, Ki-67, S100P, and SMAD4 helps increase the diagnostic accuracy of cases that are histologically difficult to diagnose.

Tissue processing of endoscopic ultrasound-guided fine-needle aspiration specimens from solid pancreatic lesions

Now that tissue cores can be obtained using fine-needle biopsy (FNB) needles, the ways tissues are handled for endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) are changing. Direct smear, touch smear of core tissues, and centrifugation have been used for cytological examinations, and liquid-based cytology (LBC), which allows immunostaining and genetic tests that use residual samples, is emerging as an alternative. We emphasize that liquid cytology (Cytospin™ cytology and LBC) is still important, because it enables the diagnosis of pancreatic ductal adenocarcinoma (PDAC) when cancerous cells are scarce in specimens. Cell blocks are being replaced by core tissues obtained via FNB needles. Recent reports indicate that rapid on-site evaluation (ROSE) is not necessary when FNB needles are used, and macroscopic on-site evaluation is used to evaluate specimen adequacy. Macroscopic findings of specimens are helpful in the diagnostic workup and for clarifying specimen-handling methods. In addition to the red strings and white cores observed in PDAC, mixed red and white strings, gray tissues, and gelatinous tissues are observed. Gray (necrotic) tissues and gelatinous (mucus) tissues are more suitable than histology for cell block or cytological processing. Tumor cells in neuroendocrine tumors (NETs) are numerous in red strings but cannot be observed macroscopically. ROSE might thus be necessary for lesions that may be NETs. Core tissues can be used for genetic tests, such as those used for KRAS mutations and comprehensive genomic profiling. Cytological materials, including slides and LBC specimens, can also be genetic test materials.

Real-Time Evaluation of Thyroid Cytology Using New Digital Microscopy Allows for Sample Adequacy Assessment, Morphological Classification, and Supports Molecular Analysis

Thyroid cytological examination, a key tool in preoperative thyroid nodule evaluation, is specific and accurate; some drawbacks are due to inadequate or indeterminate cytological reports and there is a need for an innovative approach overcoming the limits of traditional cytological diagnostics. Fluorescence laser confocal microscopes (FCM) is a new optical technique for allowing immediate digital imaging of fresh unfixed tissues and real-time assessment of sample adequacy and diagnostic evaluation for small biopsies and cytological samples. Currently, there are no data about the use of FCMs in the field of thyroid nodular pathology. The aims of this study were to test FCM technology for evaluating the adequacy of FNA samples at the time of the procedure and to assess the level of concordance between FCM cytological evaluations, paired conventional cytology, and final surgical histology. The secondary aim was to define the integrity of nucleic acids after FCM evaluation through NGS molecular analysis. Sample adequacy was correctly stated. Comparing FCM evaluation with the final histology, all cases resulting in malignant or suspicious for malignancy at FCM, were confirmed to be carcinomas (PPV 100%). In conclusion, we describe a successful application of FCM in thyroid preoperative cytological evaluation, with advantages in immediate adequacy assessment and diagnostic information, while preserving cellular specimens for permanent morphology and molecular analysis, thus improving timely and accurate patient management.

A prospective randomized noninferiority trial comparing conventional smears and SurePathTM liquid-based cytology in endoscopic ultrasound-guided sampling of esophageal, gastric, and duodenal lesions

BACKGROUND

Several liquid-based cytology (LBC) methods are currently used, but the diagnostic accuracy of each method is not well known. We aimed to compare the diagnostic performance of SurePathTM LBC and conventional smear (CS) cytology in endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) samples of esophageal, gastric, and duodenal lesions.

METHODS

As a prospective randomized noninferiority study, patients who needed EUS-FNA due to subepithelial mass in the upper gastrointestinal tract were randomly assigned 1:1 to the LBC and CS groups. Cytologic preparation was carried out using a crossover design where 1 method was used for the first needle-pass sample and another method was used for the second needle-pass sample. The primary outcome was to compare the diagnostic performance between LBC and CS using the final diagnosis as the gold standard.

RESULTS

A total of 87 patients were randomized and 60 patients were analyzed. There were no differences between LBC and CS in diagnostic accuracy (91.7% vs 86.7%, P = .380), sensitivity (97.7% vs 90.7%, P = .169), specificity (76.5% vs 76.5%, P > .99), negative predictive value (92.9% vs 76.5%, P = .225), or positive predictive value (91.3% vs 90.7%, P = .921). The background of LBC was less bloody than that of CSs (5.0% vs 53.3%, P < .001) and the sample preparation time of LBC was shorter than that of CSs (29 ± 7 seconds vs 90 ± 17 seconds, P < .001).

CONCLUSION

In the EUS-FNA of a subepithelial mass in the upper gastrointestinal tract, the diagnostic performance of LBC was not inferior to that of CS. The field of view was better in LBC, because the background was less bloody and necrotic. As LBC is more convenient to perform and takes shorter time, it is expected that it can replace the CS method for EUS-FNA samples.

Fine-needle aspiration cytology for the diagnosis of plasma cell neoplasms in the head and neck region: A systematic analysis of the literature

BACKGROUND

Cytopathologic analysis is feasible and provides detailed morphological characterisation of head and neck lesions.

AIMS

To integrate the available data published on fine-needle aspiration cytology (FNAC) used for the diagnosis of plasma cell neoplasms (PCN) of the head and neck region.

MATERIALS AND METHODS

Searches on PubMed, Web of Science, Embase, and Scopus were performed to compile data from case reports/case series published in English. The Joanna Briggs Institute tool was used for the critical appraisal of studies.

RESULTS

A total of 82 studies comprising 102 patients were included in this review. There was a predilection for men (68.6%) (male/female ratio: 2.1:1). Individuals in their 50s (29.4%), 60s (22.5%), and 70s (22.5%) were more often affected. The thyroid gland (26.2%) was the main anatomical location, followed by scalp (15.5%), neck/cervical region (15.5%), jaws (13.6%), and major salivary glands (13.6%). For FNAC analysis, a smear was employed in 41 (40.6%) cases and a cell block was used in four (3.9%). In 56 (55.4%) reports, no cytological methods were available. Morphologically, 34 (56.7%) cases had a diagnosis of PCN with agreement between cytopathology and histopathology. The rate of wrong diagnoses when using cytology was 27.5%. Immunophenotyping was performed in 49 (48%) of the cases. The 69-month disease-free survival rate was 60.2%, while the 27-month overall survival rate was 64.1%.

CONCLUSION

This study reinforces that FNAC can be an ancillary tool in the first step towards the diagnosis of PCN of the head and neck region, especially when applying a cell block for cytological analysis.

The usefulness of liquid-based cytology for endoscopic ultrasound-guided tissue acquisition of solid pancreatic masses

Liquid-based cytology (LBC) is used primarily for cervical cytology, although it is also used for analyzing liquid samples such as urine and ascites specimens, as well as fine needle aspiration material, such as those obtained from breast and thyroid. The usefulness of the LBC method for endoscopic ultrasound-guided tissue acquisition (EUS-TA) of solid pancreatic masses was recently reported. The LBC method can produce multiple pathological slides and can be applied to immunocytochemistry and genetic analyses. In this article, we review the usefulness of LBC for EUS-TA of solid pancreatic masses.

Oral brush biopsy using liquid-based cytology is a reliable tool for oral cancer screening: A cost-utility analysis: Oral brush biopsy for oral cancer screening

Background

This study aimed to assess the diagnostic utility and associated cost of oral liquid‐based brush cytology (OLBC) in the diagnosis of oral cancer and oral potentially malignant disorders (OPMDs).

Methods

A total of 284 patients with oral mucosal lesions were included. OLBC samples were collected from all patients immediately before undergoing surgical biopsies. A liquid‐based cytology slide was prepared from each OLBC sample for cytological evaluation using the modified 2014 Bethesda cytology system. The results and the cost were compared with the histopathological outcomes.

Results

The level of agreement between the two approaches was very good (weighted kappa = 0.824). The accuracy of OLBC in differentiating between the different diagnostic groups was 91.69%, whereas the associated sensitivity and specificity were 79.23% and 94.81%, respectively. The estimated cost of each OLBC sample was at least 26% less than the cost of a single biopsy and more than 42% less in cases of multiple biopsied lesions.

Conclusions

The proposed modifications of the Bethesda system can be adopted as a standardized system for oral cytological assessment. Our findings support OLBC as a reliable adjunct to surgical biopsy in the diagnosis of OPMDs. This tool has potential for oral cancer–finding and surveillance programs.

Oral brush liquid‐based cytology is a reliable adjunct to surgical biopsy in the diagnosis of oral potentially malignant disorders. It has potential for oral cancer‐finding and surveillance programs.

Immunoexpression of oral brush biopsy enhances the accuracy of diagnosis for oral lichen planus and lichenoid lesions

Background

This study assessed the efficacy of using oral liquid‐based brush cytology (OLBC) coupled with immunostained cytology‐derived cell‐blocks, quantified using machine‐learning, in the diagnosis of oral lichen planus (OLP).

Methods

Eighty‐two patients diagnosed clinically with either OLP or oral lichenoid lesion (OLL) were included. OLBC samples were obtained from all patients before undergoing surgical biopsy. Liquid‐based cytology slides and cell‐blocks were prepared and assessed by cytomorphology and immunocytochemistry for four antibodies (Ki‐67, BAX, NF‐κB‐p65, and AMACR). For comparison purposes, a sub‐group of 31 matched surgical biopsy samples were selected randomly and assessed by immunohistochemistry. Patients were categorized according to their definitive diagnoses into OLP, OLL, and clinically lichenoid, but histopathologically dysplastic lesions (OEDL). Machine‐learning was utilized to provide automated quantification of positively stained protein expression.

Results

Cytomorphological assessment was associated with an accuracy of 77.27% in the distinction between OLP/OLL and OEDL. A strong concordance of 92.5% (κ = 0.84) of immunostaining patterns was evident between cell‐blocks and tissue sections using machine‐learning. A diagnostic index using a Ki‐67‐based model was 100% accurate in detecting lichenoid cases with epithelial dysplasia. A BAX‐based model demonstrated an accuracy of 92.16%. The accuracy of cytomorphological assessment was greatly improved when it was combined with BAX immunoreactivity (95%).

Conclusions

Cell‐blocks prepared from OLBC are reliable and minimally‐invasive alternatives to surgical biopsies to diagnose OLLs with epithelial dysplasia when combined with Ki‐67 immunostaining. Machine‐learning has a promising role in the automated quantification of immunostained protein expression.

The diagnostic performance of combined conventional cytology with smears and cell block preparation obtained from endoscopic ultrasound-guided fine needle aspiration for intra-abdominal mass lesions

BACKGROUND/AIM

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is the primary method for tissue acquisition of intra-abdominal masses. However, the main limitation of cytology alone is the lack of tissue architecture and inadequate samples. This study aimed to evaluate the diagnostic performance of combined conventional cytology and cell block preparation obtained from EUS-FNA of intra-abdominal masses without Rapid On-site Evaluation (ROSE).

METHODS

Cytologic smears and cell block slides of 166 patients undergoing EUS-FNA during 2010-2015 were reviewed by an experienced cytopathologist blinded to clinical data.

RESULTS

125 patients had neoplastic lesions. Pancreatic adenocarcinoma was the most common etiology (35.5%), followed by lymph node metastasis (27.7%). The mean mass size was 2.5±1.3 cm. The mean number of passes was 1.9±1.28. Tissue adequacy for conventional cytology and cell block preparation was 78.9% and 78.1%, respectively. Factors associated with tissue adequacy were assessed. For cytology, lesions of > 2.1 cm, masses in the pancreatic body or tail, malignancy, and pancreatic cancer were positively associated with adequate cellularity. For cell block preparation, lesions of > 3 cm and malignancy were associated with increased tissue adequacy. The conventional cytology alone had a sensitivity of 68.5%, a specificity of 95.7%, and an area under the receiver operating characteristics (AUROC) of 0.821. The cell block preparation alone had a sensitivity of 65.4%, a specificity of 96%, and an AUROC of 0.807. The combined conventional cytology and cell block preparation performed significantly better than either method alone (p<0.05), as demonstrated by an increased AUROC of 0.853. Furthermore, cell block detected malignancy in 9.3% of cases where the cytologic smears failed to identify malignant cells.

CONCLUSIONS

The combined conventional cytology and cell block preparation increased the diagnostic accuracy of EUS-FNA compared to either method alone. This approach should be implemented in routine practice, especially where ROSE is unavailable.

Evaluation and diagnostic value of next-generation sequencing analysis of residual liquid-based cytology specimens of pancreatic masses

BACKGROUND

Liquid-based cytology (LBC) is a widely used method for processing specimens obtained by endoscopic biopsy. This study evaluated next-generation sequencing (NGS) analysis of LBC specimens to improve the diagnostic accuracy of pancreatic lesions.

METHODS

Upon the diagnosis of a suspected pancreatic mass, LBC residues were used retrospectively. The quantity and quality of DNA extracted from residual LBC samples were evaluated, and an NGS analysis targeting 6 genes (KRAS, GNAS, TP53, CDKN2A, SMAD4, and PIK3CA) was performed.

RESULTS

The library was prepared from LBC specimens taken from 52 cases: 44 were successful, and 8 preparations failed. An analysis of DNA quantity and quality suggested that the success or failure of NGS implementation depended on both properties. The final diagnosis was achieved by a combination of the pathological analysis of the surgical excision or biopsy material with clinical information. Among the 33 cases of pancreatic ductal adenocarcinoma (PDAC), KRAS, TP53, CDKN2A, and SMAD4 mutations were identified in 31 (94%), 16 (48%), 3 (9%), and 2 (6%), respectively. Among the 11 benign cases, only a KRAS mutation was identified in 1 case. On the basis of NGS results, 18 of 33 PDACs (55%) were classified as highly dysplastic or more, and 10 of 11 benign lesions were evaluated as nonmalignant, which was consistent with the final diagnosis.

CONCLUSIONS

NGS analysis using LBC specimens from which DNA of appropriate quantity and quality has been extracted could contribute to improving the assessment of pancreatic tumor malignancies and the application of molecular-targeted drugs.

[Clinical and Technical Guideline for Endoscopic Ultrasound-guided Tissue Acquisition of Pancreatic Solid Tumor: Korean Society of Gastrointestinal Endoscopy]

Endoscopic ultrasound (EUS)-guided tissue acquisition of pancreatic solid tumor requires a strict recommendation for its proper use in clinical practice because of its technical difficulty and invasiveness. The Korean Society of Gastrointestinal Endoscopy appointed a Task Force to draft clinical practice guidelines for EUS-guided tissue acquisition of pancreatic solid tumor. The strength of recommendation and the level of evidence for each statement were graded according to the Minds Handbook for Clinical Practice Guideline Development 2014. The committee, comprising a development panel of 16 endosonographers and an expert on guideline development methodology, developed 12 evidence-based recommendations in eight categories intended to help physicians make evidence- based clinical judgments with regard to the diagnosis of pancreatic solid tumor. This clinical practice guideline discusses EUS-guided sampling in pancreatic solid tumor and makes recommendations on circumstances that warrant its use, technical issues related to maximizing the diagnostic yield (e.g., needle type, needle diameter, adequate number of needle passes, sample obtaining techniques, and methods of specimen processing), adverse events of EUS-guided tissue acquisition, and learning-related issues. This guideline was reviewed by external experts and suggests best practices recommended based on the evidence available at the time of preparation. This guideline may not be applicable for all clinical situations and should be interpreted in light of specific situations and the availability of resources. It will be revised as necessary to cover progress and changes in technology and evidence from clinical practice.

Comparison of smear cytology with liquid-based cytology in pancreatic lesions: A systematic review and meta-analysis

BACKGROUND

Endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) is a safe and accurate technique to confirm the diagnosis of pancreatic cancers. Recently, numerous studies comparing the diagnostic efficacy of smear cytology (SC) and liquid-based cytology (LBC) for pancreatic lesions yielded mixed results.

AIM

To compare and identify the better cytology method for EUS-FNA in pancreatic lesions.

METHODS

A comprehensive search of PubMed, Embase, and Cochrane was undertaken through July 18, 2020. The primary endpoint was diagnostic accuracy (sensitivity and specificity). Secondary outcomes included sample adequacy and post procedure complications. In addition, factors affecting diagnostic efficacy were discussed.

RESULTS

Data on a total of 1121 comparisons from 10 studies met the inclusion criteria. Pooled rates of sensitivity for SC and LBC were 78% (67%-87%) vs 75% (67%-81%), respectively. In any case, both SC and LBC exhibited a high specificity close to 100%. Inadequate samples more often appeared in LBC compared with SC. However, the LBC samples exhibited a better visual field than SC. Very few post procedure complications were observed.

CONCLUSION

Our data suggested that for EUS-FNA in pancreatic lesions (particularly solid lesions), SC with Rapid On-Site Evaluation represents a superior diagnostic technique. If Rapid On-Site Evaluation is unavailable, LBC may replace smears. The diagnostic accuracy of LBC depends on different LBC techniques.

Clinical and Technical Guideline for Endoscopic Ultrasound (EUS)-Guided Tissue Acquisition of Pancreatic Solid Tumor: Korean Society of Gastrointestinal Endoscopy (KSGE)

Endoscopic ultrasound (EUS)-guided tissue acquisition of pancreatic solid tumor requires a strict recommendation for its proper use in clinical practice because of its technical difficulty and invasiveness. The Korean Society of Gastrointestinal Endoscopy (KSGE) appointed a task force to draft clinical practice guidelines for EUS-guided tissue acquisition of pancreatic solid tumor. The strength of recommendation and the level of evidence for each statement were graded according to the Minds Handbook for Clinical Practice Guideline Development 2014. The committee, comprising a development panel of 16 endosonographers and an expert on guideline development methodology, developed 12 evidence-based recommendations in eight categories intended to help physicians make evidence-based clinical judgments with regard to the diagnosis of pancreatic solid tumor. This clinical practice guideline discusses EUS-guided sampling in pancreatic solid tumor and makes recommendations on circumstances that warrant its use, technical issues related to maximizing the diagnostic yield (e.g., needle type, needle diameter, adequate number of needle passes, sample obtaining techniques, and methods of specimen processing), adverse events of EUS-guided tissue acquisition, and learning-related issues. This guideline was reviewed by external experts and suggests best practices recommended based on the evidence available at the time of preparation. This guideline may not be applicable for all clinical situations and should be interpreted in light of specific situations and the availability of resources. It will be revised as necessary to cover progress and changes in technology and evidence from clinical practice. (Gut Liver 2021;15:-374)

Clinical and Technical Guideline for Endoscopic Ultrasound (EUS)-Guided Tissue Acquisition of Pancreatic Solid Tumor: Korean Society of Gastrointestinal Endoscopy (KSGE)

Endoscopic ultrasound (EUS)-guided tissue acquisition of pancreatic solid tumor requires a strict recommendation for its proper use in clinical practice because of its technical difficulty and invasiveness. The Korean Society of Gastrointestinal Endoscopy (KSGE) appointed a Task Force to draft clinical practice guidelines for EUS-guided tissue acquisition of pancreatic solid tumor. The strength of recommendation and the level of evidence for each statement were graded according to the Minds Handbook for Clinical Practice Guideline Development 2014. The committee, comprising a development panel of 16 endosonographers and an expert on guideline development methodology, developed 12 evidence-based recommendations in 8 categories intended to help physicians make evidence-based clinical judgments with regard to the diagnosis of pancreatic solid tumor. This clinical practice guideline discusses EUS-guided sampling in pancreatic solid tumor and makes recommendations on circumstances that warrant its use, technical issues related to maximizing the diagnostic yield (e.g., needle type, needle diameter, adequate number of needle passes, sample obtaining techniques, and methods of specimen processing), adverse events of EUS-guided tissue acquisition, and learning-related issues. This guideline was reviewed by external experts and suggests best practices recommended based on the evidence available at the time of preparation. This guideline may not be applicable for all clinical situations and should be interpreted in light of specific situations and the availability of resources. It will be revised as necessary to cover progress and changes in technology and evidence from clinical practice.

Efficacy of oral brush cytology cell block immunocytochemistry in the diagnosis of oral leukoplakia and oral squamous cell carcinoma

OBJECTIVES

This study assessed the efficacy of using oral liquid-based brush cytology and cell block immunocytochemistry in the diagnosis of oral leukoplakia as minimally invasive diagnostic adjuncts.

METHODS

Seventy-two patients diagnosed clinically with either oral leukoplakia (OLK) or oral squamous cell carcinoma were included. Oral brush samples using Orcellex^® brushes were obtained from all participants directly before undergoing surgical biopsy. Cell blocks were prepared for all samples and assessed for cytomorphology and immunocytochemistry of DNA mismatch repair proteins (MSH-6, MSH-2, MLH-1 and PMS-2). A combined index score of immunocytochemistry expression and cytology grading was compared against the gold standard (histopathological diagnosis).

RESULTS

A significant association was observed between the cytological assessments of oral liquid-based brush cytology samples and the histopathological diagnosis (P < .005). In addition, there was a significant inverse correlation between the grade of oral epithelial dysplasia and the cumulative score of the studied DNA mismatch repair proteins (P < .005). Grading criteria for both oral liquid-based brush cytology and immunocytochemistry cumulative index scores are proposed based on the analysis of receiver operating characteristic curve coordinates. The diagnostic accuracy of this approach was outstanding in terms of discrimination between the presence or absence of oral epithelial dysplasia (0.961) and squamous cell carcinoma (0.977) separately.

CONCLUSION

Oral liquid-based brush cytology cell block immunocytochemistry provides a reliable strategy to investigate oral mucosal epithelial disorders. This approach presents a minimally invasive, highly accurate and non-technically demanding method for the surveillance of oral potentially malignant disorders and squamous cell carcinoma.

Diagnostic efficacy of different pathologic methods for assessing tissue obtained by endoscopic ultrasound-guided fine needle aspiration: a prospective study

AIMS

The best method for processing specimens by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has not been standardized and varies considerably between medical centers. The purpose of this study is to explore whether a combination of histologic and cytologic methods can increase the diagnostic efficacy of EUS-FNA in solid lesions around the digestive tract.

METHODS

We recruited 52 patients (65 cases total) with solid lesions around the digestive tract who underwent EUS-FNA as performed by the same endoscopic physician from December 2016 to January 2018. All the EUS-FNA specimens were processed by conventional smear cytology (CS), liquid-based cytology (LBC), cell block (CB), and histopathology. All the pathologic results were tracked to investigate the diagnostic value of the methods.

RESULTS

Fifty-three malignant lesions and 12 benign lesions were analyzed. The diagnostic accuracy levels of the CS, LBC, CB, and histopathology were 96.9%, 89.2%, 91.9%, and 48.1%, respectively. CS had a higher diagnostic accuracy than CB (P < 0.05) and LBC (P < 0.05). The cytologic methods had a significantly higher diagnostic accuracy than histopathology (P < 0.05). The combined diagnostic accuracy of all the methods was 100%. The diagnostic sensitivities of the CS, LBC, CB and histopathology were 96.2%, 86.8%, 90.4%, and 37.2%, respectively, and the diagnostic specificity of each of the four methods was 100%.

CONCLUSIONS

Different pathological methods can compensate for one another, substantially improving the overall positive detection rate of EUS-FNA. Combining cytology and histology can contribute additional diagnostic efficacy to EUS-FNA in solid lesions around the digestive tract.

Comparison of EUS-guided conventional smear and liquid-based cytology in pancreatic lesions: A systematic review and meta-analysis

Background and study aims  Endoscopic ultrasound (EUS)-guided fine-needle aspiration (EUS-FNA) has limitations of inadequate sampling and false-negative results for malignancy. It has been performed using conventional smear (CS) cytology with rapid on-site evaluation (ROSE) with reasonable diagnostic accuracy. An alternative to ROSE is liquid-based cytology (LBC). Commonly used LBC techniques include precipitation-based (SurePath™) and filtration-based (ThinPrep ^® , CellPrep ^® ). Data regarding the diagnostic efficacy of LBC compared with CS are limited. Methods  Multiple databases were searched through March 2020 to identify studies reporting diagnostic yield of EUS-guided CS and LBC in pancreatic lesions. Pooled diagnostic odds and rates of performance for the cytologic diagnoses of benign, suspicious, and malignant lesions were calculated. Diagnostic efficacy was evaluated by pooled rates of accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Results  Nine studies with a total of 1308 patients were included in our final analysis. Pooled diagnostic odds of CS cytology were 1.69 (CI 1.02-2.79) and 0.39 (CI 0.19-0.8) for malignant lesions when compared to filtration-based and precipitation-based LBC techniques, respectively. For CS, precipitation-based and filtration-based LBC, pooled diagnostic accuracy was 79.7 %, 85.2 %, 77.3 %, sensitivity was 79.2 %, 83.6 %, 68.3 %, and specificity was 99.4 %, 99.5 %, 99.5 %, respectively. Conclusions  The precipitation-based LBC technique (SurePath™) had superior diagnostic odds for malignant pancreatic lesions compared with CS cytology in the absence of ROSE. It showed superior accuracy and sensitivity, but comparable specificity and PPV. Diagnostic odds of CS cytology in the absence of ROSE were superior to the filtration-based LBC technique (ThinPrep ^® , Cellprep ^® ) for diagnosing malignant pancreatic lesions.

Optimizing cytological specimens of EUS-FNA of solid pancreatic lesions: A pilot study to the effect of a smear preparation training for endoscopy personnel on sample quality and accuracy

BACKGROUND

In the absence of rapid on-side pathological evaluation, endoscopy staff generally "smears" endoscopic ultrasound guided fine needle aspiration (EUS-FNA) specimens on a glass slide. As this technique is vulnerable to preparation artifacts, we assessed if its quality could be improved through a smear-preparation-training for endoscopy staff.

METHODS

In this prospective pilot study, 10 endosonographers and 12 endoscopy nurses from seven regional EUS-centers in the Netherlands were invited to participate in a EUS-FNA smear-preparation-training. Subsequently, post training slides derived from solid pancreatic lesions were compared to pre-training "control" slides. Primary outcome was to assess if the training positively affects smear quality and, consequently, diagnostic accuracy of EUS-FNA of solid pancreatic lesions.

RESULTS

Participants collected and prepared 71 cases, mostly pancreatic head lesions (48%). Sixty-eight controls were selected from the pretraining period. The presence of artifacts was comparable for smears performed before and after training (76% vs 82%, P = .36). Likewise, smear cellularity (≥50% target cells) before and after training did not differ (44% (30/68) vs 49% (35/71), P = .48). Similar, no difference in diagnostic accuracy for malignancy was detected (P = .10).

CONCLUSION

In this pilot EUS-FNA smear-preparation-training for endoscopy personnel, smear quality and diagnostic accuracy were not improved after the training. Based on these results, we plan to further study other training programs and possibilities.

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.

Comparison between Conventional Smear and Liquid-Based Preparation in Endoscopic Ultrasonography-Fine Needle Aspiration Cytology of Pancreatic Lesions

The present study aimed to compare the diagnostic accuracy between conventional smear (CS) and liquid-based preparation (LBP) in endoscopic ultrasonography-fine needle aspiration cytology (EUS-FNAC) of pancreatic lesions. Using 31 eligible studies, the diagnostic accuracy of cytologic examination in CS and LBP was evaluated through a conventional meta-analysis and diagnostic test accuracy review. Overall concordance rates were 82.8% (95% confidence interval [CI], 79.8–85.5%) and 94.0% (95% CI, 84.4–97.8%) in CS and LBP, respectively. CS with rapid on-site evaluation (ROSE) showed a higher concordance rate than CS without ROSE. In CS, the pooled sensitivity and specificity were 89.8% (95% CI, 85.2–93.1%) and 95.0% (95% CI, 90.0–97.6%), respectively. The diagnostic odds ratio (OR) and area under curve (AUC) of the summary receiver operating characteristic (SROC) curve were 90.32 (95% CI, 43.85–147.11) and 0.945, respectively. In LBP, the pooled sensitivity and specificity were 80.9% (95% CI, 69.7–88.7%) and 99.9% (95% CI, 1.5–100.0%), respectively. The diagnostic OR and AUC of the SROC curve were 57.21 (95% CI, 23.61–138.64) and 0.939, respectively. Higher concordance rates were found in CS with ROSE and LBP in EUS-FNAC of pancreatic lesions. Regardless of the cytologic preparation method, EUS-FNAC is a useful and accurate diagnostic tool for pancreatic lesions.

Comparison of liquid-based cytology with conventional smear cytology for EUS-guided FNA of solid pancreatic masses: a prospective randomized noninferiority study

BACKGROUND AND AIMS

There are limited data on the efficacy of liquid-based cytology (LBC) for EUS-guided FNA specimens. We aimed to evaluate the diagnostic efficacy of LBC for solid pancreatic neoplasms compared with conventional smears (CSs).

METHODS

In this randomized, crossover, noninferiority trial, we randomly assigned (1:1) patients with suspected pancreatic cancer to the LBC group or the CS group. Aspirates from the first needle pass were processed by one method, aspirates from the second pass by the other method, and specimens from the last pass were processed as core biopsy samples. The primary endpoint was the diagnostic efficacy of each method, with the final diagnosis as the gold standard. A noninferiority margin of -10% was assumed.

RESULTS

Of 170 randomized patients, 165 were classified as malignant and 5 as benign. Unsatisfactory samples were less frequent in the LBC group (1.78%) compared with the CS group (5.33%). The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of LBC versus CS were 88.0% versus 83.8% (P = .276), 87.7% versus 83.2% (P = .256), 100% versus 100% (P = .999), 100% versus 100% (P = .999), and 16.7% versus 16.1% (P = .953), respectively. A bloody background was significantly more frequent in the CS group (CS, 85.2%; LBC, 1.8%; P < .001), whereas the nuclear features were similar for both groups.

CONCLUSIONS

The diagnostic usefulness of LBC was comparable with that of CS. The cytomorphologic features did not differ significantly between the 2 methods, and the reduced bloody backgrounds allowed better visibility in the LBC method. (Clinical trial registration number: NCT03606148.).

Comparison of smear cytology and liquid-based cytology in EUS-guided FNA of pancreatic lesions: experience from a large tertiary center

BACKGROUND AND AIMS

Studies comparing the diagnostic efficacy of liquid-based cytology (LBC) and smear cytology (SC) of pancreatic tissue sampling obtained via EUS-guided FNA (EUS-FNA) are still insufficient, mainly because results were controversial. We compared the diagnostic efficiency of LBC and SC of EUS-FNA of pancreatic lesions in one of the largest tertiary hospitals in China.

METHODS

A retrospective database search (January 2015 to January 2019) was performed for patients who underwent EUS-FNA with both LBC and SC. Demographic, cytologic, and endosonographic data were collected from 819 patients; 514 cases met the inclusion criteria. Diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were compared. Rapid on-site evaluation was not available in all cases.

RESULTS

Three hundred eighty-five cases (74.90%) had confirmed malignancy, and 40 cases (7.78%) confirmed benign neoplasm. Adequate tissue sampling rates showed no significant difference between the 2 groups. The sensitivity, accuracy, and negative predictive value (NPV) of LBC were higher than those of SC with statistical significance (71.4% vs 55.1%, 76.1% vs 61.6%, and 40.6% vs 27.7%, respectively). The sensitivity, accuracy, and NPV of combined SC and LBC were higher than those of LBC alone with statistical significance (83.9% vs 71.4%, 86.5% vs 76.1%, and 56.8% vs 40.6%, respectively). Multivariate analysis revealed that pancreatic neck/body/tail lesions (P = .003), solid lesions (P < .001), 22-gauge needle size (P < .001), and number of needle passage >3 (P = .041) were associated with higher diagnostic sensitivity in all participants using LBC, whereas number of needle passage >3 (P = .017) was associated with higher diagnostic sensitivity using SC.

CONCLUSIONS

LBC was more accurate and sensitive than SC in EUS-FNA of pancreatic lesions with higher NPV when rapid on-site evaluation is unavailable. Pancreatic neck/body/tail lesions, solid lesions, 22-gauge needle, and more than 3 passes were associated with higher sensitivity when using LBC. Performing more than 3 passes is associated with higher sensitivity when using SC.

Diagnostic yield and agreement on fine-needle specimens from solid pancreatic lesions : comparing the smear technique to liquid-based cytology

Background and study aims  The traditional "smear technique" for processing and assessing endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is sensitive to artifacts. Processing and evaluation of specimens collected in a liquid medium, liquid-based cytology (LBC) may be a solution. We compared the diagnostic value of EUS-FNA smears to LBC in pancreatic solid lesions in the absence of rapid on-site evaluation (ROSE). Patients and methods  Consecutive patients who required EUS-FNA of a solid pancreatic lesion were included in seven hospitals in the Netherlands and followed for at least 12 months. Specimens from the first pass were split into two smears and a vial for LBC (using ThinPrep and/or Cell block). Smear and LBC were compared in terms of diagnostic accuracy for malignancy, sample quality, and diagnostic agreement between three cytopathologists. Results  Diagnostic accuracy for malignancy was higher for LBC (82 % (58/71)) than for smear (66 % (47/71), P  = 0.04), but did not differ when smears were compared to ThinPrep (71 % (30/42), P  = 0.56) or Cell block (62 % (39/63), P  = 0.61) individually. Artifacts were less often present in ThinPrep (57 % (24/42), P  = 0.02) or Cell block samples (40 % (25/63), P  < 0.001) than smears (76 % (54/71)). Agreement on malignancy was equally good for smears and LBC (ĸ = 0.71 versus ĸ = 0.70, P  = 0.98), but lower for ThinPrep (ĸ = 0.26, P  = 0.01) than smears. Conclusion  After a single pass, LBC provides higher diagnostic accuracy than the conventional smear technique for EUS-FNA of solid pancreatic lesions in the absence of ROSE. Therefore, LBC, may be an alternative to the conventional smear technique, especially in centers lacking ROSE.

EUS tissue acquisition: From A to B

EUS-guided tissue acquisition (EUS-TA) has made rapid development since its introduction in the early 1990s. The technique is widely accepted and invaluable for staging and diagnosis of a variety of upper gastrointestinal and mediastinal lesions. Fine-needle aspiration (FNA) has long been the gold standard, but due to its limitations such as the inability to retain stroma and associated cellular architecture, novel biopsy needles (FNB) were designed. Overall, FNA and FNB needles perform seemingly equally in terms of diagnostic accuracy, however, the second-generation FNB needles require less passes. The third-generation FNB needles (crown-cut needle types) seem to be preferable to FNA needles as well as to the second-generation FNB needles, when larger histological specimens and preserved tissue architecture are required. EUS-TA is constantly under development, and new applications of this technique include tumor risk stratification according to its genetic profile as well as minimally invasive creation of patient-derived organoids, hallmarks of personized medicine. It remains yet to be shown, whether these applications will lead to a decisive shift from aspiration to biopsy, i.e., from A to B.

Design of an immunohistochemistry biomarker panel for diagnosis of pancreatic adenocarcinoma

BACKGROUND

Challenges still exist in differentiating pancreatic adenocarcinoma from benign disease. The use of adjuvant testing of tissue biopsies has demonstrated potential diagnostic value. We designed a proof of concept study to first validate four individual immunohistochemistry biomarkers and then combine them into a panel to boost overall diagnostic sensitivity.

METHODS

Malignant and benign pancreas from 27 pancreaticoduodenectomy specimens underwent immunohistochemistry staining with VHL, IMP3, S100A4, S100P. Using ROC curve analysis, threshold criteria for number of cells staining were chosen for each biomarker. Biomarkers were then evaluated as a panel for their ability to discriminate malignant from benign specimens.

RESULTS

Diagnostic sensitivity of VHL, IMP3, S100A4, and S100P were 75.0%, 79.2%, 45.8%, and 0%. When VHL, IMP3, and S100A4 were grouped into a panel, they were able to distinguish cancer from normal tissue with a sensitivity of 100% and a specificity of 96%.

CONCLUSIONS

The high diagnostic value of an IHC panel consisting of VHL, IMP3, and S100A4 on surgical specimens suggests the need for future prospective studies of these biomarkers on biopsy specimens.

Diagnostic efficacy of smear plus liquid-based cytology for EUS-FNA of solid pancreatic lesions: A propensity-matched study

Liquid-based cytology (LBC) is a thin-layer slide preparation procedure that was developed to overcome the cell crowding and contamination associated with smear cytology (SC). The present study compared diagnostic efficacy between SC alone and SC combined with LBC (SLBC) using endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) samples of pancreatic lesions.We retrospectively analyzed data derived from 311 consecutive patients. Specimens obtained via EUS-FNA from 179 patients between December 2011 and May 2016 were analyzed by SC, and those obtained from 132 patients between June 2016 and October 2017 were analyzed by SLBC. The 2 groups were compared in terms of adequate sample rate, diagnostic accuracy, sensitivity, and specificity using propensity score matching.SC and SLBC were compared using propensity score-matching in 204 patients (n = 102 per group). The adequate sample rate did not differ significantly between SLBC (100%) and SC (99.0%, P = 1). Diagnostic sensitivity, negative predictive value and accuracy were better for SLBC than for SC in terms of cytological (93.2% vs 67.4%, 68.4% vs 23.1%, and 94.1% vs 69.6%, P < .01 each, respectively) and cytohistological (95.5% vs 81.5%, 76.5% vs 34.6%, and 96.1% vs 82.4%, P < .01, P = .02, and P < .01, respectively) analyses.SLBC improves the diagnostic efficacy of EUS-FNA for pancreatic lesions compared to LBC.

It is necessary to exam bottom and top slide smears of EUS-FNA for pancreatic cancer

BACKGROUND

Despite many reports on the diagnostic yield of cytology from endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), inter-slide differences are unknown. This prospective study aimed to compare diagnostic yield and cellular characteristics of bottom slides (BS) and top slides (TS) from EUS-FNA cytology performed without an on-site cytopathologist.

METHODS

In patients with suspected pancreatic cancer on previous imaging explorations, a single endoscopist performed EUS-FNA and obtained 2 sets of cytology slide (8 BS and 8 TS), 1 cellblock slide, and 1 biopsy slide. Both slide sets were randomly assigned. A cytopathologist with more than 10 years of expertise in pancreatic cytopathology blindly inspected and compared two slide sets.

RESULTS

In total, 73 specimens [42 head (57.5%), 16 body (21.9%), and 15 tail (20.5%)] were acquired for final analysis. Seventy-one cases were finally diagnosed with pancreatic cancer. The sensitivity and specificity of BS were 80.3% and 100.0%; and of TS 78.9% and 100.0%, respectively. In analyzing inter-slide difference, 66 cases (90.4%) showed consistent results between BS and TS. However, seven (9.6%) were positive only in one slide sets (4 BS and 3 TS). The proportions of specimens more than moderate and high cellularity were 75.3% and 60.3% in both slide sets (P> 0.99), and the proportion of artifact-free sets were 50.7%, and 52.1% for the BS and TS, respectively (P= 0.869).

CONCLUSIONS

Although BS and TS exhibited highly consistent diagnostic yields in cytologic smears from EUS-FNA, the proportion of inter-slide discordance is clinically considerable. Both slide sets need to be examined if there is no on-site cytopathologist.

Comparison of liquid-based cytology (CellPrepPlus) and conventional smears in pancreaticobiliary disease

BACKGROUND/AIMS

Endoscopic ultrasound-guided fine needle aspiration (EUSFNA) and brushing cytology are used worldwide to diagnose pancreatic and biliary malignant tumors. Liquid-based cytology (LBC) has been developed and it is currently used to overcome the limitations of conventional smears (CS). In this study, the authors aimed to compare the diagnostic value of the CellPrepPlus (CP; Biodyne) LBC method with CS in samples obtained using EUS-FNA and brushing cytology.

METHODS

This study prospectively enrolled 75 patients with pancreatic or biliary lesions from June 2012 to October 2013. For cytological analyses, including inadequate specimens, benign and atypical were further classified into benign, and suspicious and malignant were subcategorized as malignant. Sensitivity, specificity, accuracy, and positive predictive values (PPV) and negative predictive values (NPV) were evaluated.

RESULTS

In the EUS-FNA based cytological analysis of pancreatic specimens, CP had a sensitivity of 60.7%; specificity, 100%; accuracy, 77.1%; PPV, 100%; and NPV, 64.5%. CS had a sensitivity of 85.7%; specificity, 100%; accuracy, 91.7%; PPV, 100%; and NPV, 83.3%. In the brushing cytology based analysis of biliary specimens, CP had sensitivity of 53.1%; specificity, 100%; accuracy, 54.5%; PPV, 100%; and NPV, 6.3%. CS had a sensitivity of 78.1%; specificity, 100%; accuracy, 78.8%; PPV, 100%; and NPV, 12.5%.

CONCLUSION

Our study found that CP had a lower sensitivity because of low cellularity compared with CS. Therefore, CP (LBC) has a lower diagnostic accuracy for pancreatic EUS-FNA based and biliary brush cytology based analyses compared with CS.

K-ras mutation analysis of residual liquid-based cytology specimens from endoscopic ultrasound-guided fine needle aspiration improves cell block diagnosis of pancreatic ductal adenocarcinoma

Background

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) technology is widely used for the diagnosis of pancreatic masses. However, in some cases, inadequate tissue volume or difficulty of morphological diagnosis are constraining factors for adequate cytopathological evaluation. K-ras mutation is the most frequently acquired genetic abnormality, occurring in approximately 90% of all patients with pancreatic ductal adenocarcinoma (PDAC). In the present study, the clinical utility of residual liquid-based cytology (LBC) specimens obtained using EUS-FNA for K-ras mutation analysis was evaluated.

Methods

In this study, 81 patients with pancreatic lesions were examined. The cell block (CB) specimens separated from EUS-FNA samples were morphologically evaluated by hematoxylin–eosin (HE) staining. Final diagnoses were confirmed by CB specimens, surgical resection specimens, diagnostic imaging, and clinical follow-up. Genomic DNA of residual LBC specimens stored at 4°C for several months were extracted and assessed for K-ras mutations using a fluorescence resonance energy transfer-based preferential homoduplex formation assay.

Results

K-ras mutation analysis using residual LBC samples was successful in all cases. The sensitivity, specificity, and accuracy of CB examination alone were 77.4%, 100%, and 81.3%, respectively, and those of the combination of CB examination and K-ras mutation analysis were 90.3%, 92.3%, and 90.7%, respectively. Furthermore, K-ras mutations were detected in 8 (57.1%) of 14 PDAC samples for which the CB results were inconclusive.

Conclusion

These findings suggest that K-ras mutation analysis using residual LBC specimens improves the diagnostic accuracy of EUS-FNA.

Pathological and Molecular Aspects to Improve Endoscopic Ultrasonography-Guided Fine-Needle Aspiration From Solid Pancreatic Lesions

Endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) has been applied to pancreatic lesions since the 1990s, and its use is now widespread. Improvements in endoscopic devices and sampling techniques have resulted in excellent diagnostic ability for solid pancreatic lesions. However, clinical improvements alone are not responsible for it; pathological aspects have also played important roles. Rapid on-site evaluation minimizes endoscopic procedures, although its value at improving the diagnostic ratio is still debated. Diagnostic efficacy differs by sample preparations (direct smear, cytospin, liquid-based cytology, cell block, and biopsy) and by staining methods (Papanicoloau, Diff-Quik, hematoxylin-eosin, and Giemsa). Several immunocytochemistry protocols aid in diagnosing epithelial components with cytological atypia and in differentiating various tumor types. One cytopathology diagnostic system is telecytology, which uses transmitted digital images and enables real-time diagnosis of EUS-FNA samples by expert cytologists at remote locations. However, EUS-FNA samples are useful for more than just diagnoses, as molecular analysis of these samples allows the identification of prognostic markers, such as genetic alterations in K-ras and EGFR. Expression of drug-metabolizing enzymes, human equilibrative nucleoside transporter 1, correlates with the response to gemcitabine-based chemotherapy. These pathology efforts have enhanced the diagnostic efficacy of EUS-FNA, thereby leading to better outcomes for patients with pancreatic diseases.

Pancreatic Cancer Diagnosis and Management: Has the Time Come to Prick the Bubble?

Pancreatic cancer (PC) is associated with poor prognosis and very dismal survival rates. The most effective possibility of cure is tumor resection, which is only possible in about 15% of patients diagnosed at early stages of disease progression. Recent whole-genome sequencing studies pointed genetic alterations in 12 core signaling pathways in PC. These observations hint at the possibility that the initial mutation in PC might appear nearly 20 years before any symptoms occur, suggesting that a large window of opportunity may exist for early detection. Biomarkers with the potential to identify pre-neoplastic disease or very early stages of cancer are of great promise to improve patient survival. The concept of liquid biopsy refers to a minimally invasive sampling and analysis of liquid biomarkers that can be isolated from body fluids, primarily blood, urine and saliva. A myriad of circulating molecules may be useful as tumor markers, including cell-free DNA (cfDNA), cell-free RNA (cfRNA), circulating tumor cells (CTC), circulating tumor proteins, and extracellular vesicles, more specifically exosomes. In this review, we discuss with more detail the potential role of exosomes in several aspects related to PC, from initiation to tumor progression and its applicability in early detection and treatment. Exosomes are small circulating extracellular vesicles of 50-150 nm in diameter released from the plasma membrane by almost all cells and exhibit some advantages over other biomarkers. Exosomes are central players of intercellular communication and they have been implicated in a series of biological process, including tumorigenesis, migration and metastasis. Several exosomal microRNAs and proteins have been observed to distinguish PC from benign pancreatic diseases and healthy controls. Besides their possible role in diagnosis, understanding exosomes functions in cancer has clarified the importance of microenvironment in PC progression as well as its influence in proliferation, metastasis and resistance to chemotherapy. Increasing knowledge on cancer exosomes provides valuable insights on new therapeutic targets and can potentially open new strategies to treat this disease. Continuous research is needed to ascertain the reliability of using exosomes and their content as potential biomarkers, so that, hopefully, in the near future, they will provide the opportunity for early diagnosis, treatment intervention and increase survival of PC patients.

Endoscopic Ultrasound-Guided Fine-Needle Aspiration Cytology Combined With Automated Quantitative DNA Cytometry Can Improve the Value in the Detection of Pancreatic Malignancy

OBJECTIVES

Quantitative DNA-image cytometry (ICM) is used to diagnose malignancy via detecting changes in DNA content. We aimed to estimate the value of cytology, DNA-ICM, and their combination in diagnosing pancreatic malignancy.

METHODS

One hundred twenty-one endoscopic ultrasound-guided fine-needle aspiration samples from 116 patients suspected for pancreatic malignancy were examined by cytology and DNA-ICM. Their results and the final diagnoses (malignancy or not) were collected. Diagnostic values were compared among cytology, DNA-ICM, and their combination.

RESULTS

The DNA-ICM had a lower sensitivity and accuracy than cytology (64.2% vs 81.1%; 71.9% vs 85.1%). The combination of the techniques significantly improved the diagnostic accuracy compared with that of cytology or DNA-ICM alone (0.932 vs 0.905, P = 0.02; 0.932 vs 0.821, P < 0.0001). Using the Youden index, we determined that one cell with DI (DNA index) ≥2.5 is the optimal cutoff value for DNA-ICM to diagnose pancreatic malignancy. After adoption of this criterion, the sensitivity and accuracy were improved to 74.7% and 80.2% with DNA-ICM and 90.5% and 92.6% with the combined method.

CONCLUSIONS

The DNA-ICM is an effective complementary method to cytology in diagnosing pancreatic malignancy. Although the diagnostic value for DNA-ICM is lower than that of cytology, an improved value was obtained after their combination.

Endoscopic ultrasound guided fine-needle aspiration: What variables influence diagnostic yield?

BACKGROUND

Endoscopic ultrasound (EUS) guided fine-needle aspiration (FNA) plays an important role in the diagnosis of various lesions. We sought to determine factors that influence the diagnostic yield of EUS-FNA, specifically, the presence of a cytopathologist, FNA site, and the endoscopist's skill.

METHODS

The data on cytopathologist's availability, duration of procedure, number of passes made, and diagnostic material for cell block (CB) preparation was collected over an 18 months period.

RESULTS

230 specimens (218 patients) were obtained from pancreas (114), lymph node (64), submucosal lesions of the gastrointestinal tract (27), liver (8), and miscellaneous (17) sites. The results were classified as informative (77.8%) and non-informative (NI) (22.2%). The NI rate was significantly high, when a cytopathologist was absent (P = .0008). As the likelihood of cytopathologist's presence increased from 35.8% to 82.9%, the CB quality increased (P < .0001). In the absence of a cytopathologist, the likelihood of NI result increased more than 2-fold (P = .03) and of an inadequate CB increased 3-fold (P < .0001). The more experienced endoscopist "C" (compared to the less experienced "A + B") was less likely to get inadequate material (40.5% vs. 66.3%) (P = .0001).

CONCLUSION

The diagnostic yield of EUS-FNA is significantly related to the presence of an on-site cytopathologist and endoscopist's skill in procuring diagnostic material.

Comparison of cytological and histological preparations in the diagnosis of pancreatic malignancies using endoscopic ultrasound-guided 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 EUS-FNA 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.

Diagnostic efficacy of liquid-based cytology for solid pancreatic lesion samples obtained with endoscopic ultrasound-guided fine-needle aspiration: Propensity score-matched analysis

BACKGROUND AND AIM

There is a paucity of data on the diagnostic efficacy of liquid-based cytology (LBC) for pancreatic samples obtained by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). Using propensity score matching, we retrospectively analyzed the additional diagnostic value of LBC compared to a conventional Papanicolaou smear (CPS) for samples of solid pancreatic lesions obtained by EUS-FNA.

METHODS

This cohort study included 126 matched patients who underwent initial EUS-FNA for solid pancreatic lesions between January 2009 and August 2014. CPS was used for cytology of EUS-FNA samples obtained until May 2012 (63 patients). Subsequently, LBC was used for cytological analysis (63 patients). Diagnostic yields of CPS and LBC for malignancy were compared. Risk factors for cytological misdiagnosis with LBC were investigated.

RESULTS

Overall rate of malignancy was 86% after matching. LBC had higher diagnostic sensitivity and accuracy than CPS (96.6% vs 84.0%, P = 0.03; and 96.8% vs 87.3%, P = 0.05). LBC was significantly more sensitive for diagnosing pancreatic head lesions (96.4% vs 78.1%, P = 0.04). The sensitivity for pancreatic ductal adenocarcinoma (PDAC) with LBC was higher (98.1% vs 83.0%, P = 0.009). Multivariate analysis revealed that malignant tumors other than PDAC (P = 0.004) and lesion size ≤20 mm (P = 0.046) were risk factors for LBC misdiagnosis in all participants.

CONCLUSIONS

For solid pancreatic lesions, LBC of EUS-FNA samples contributes to the diagnosis of malignancy. Malignant tumors other than PDAC and small tumors are difficult to diagnose using EUS-FNA and LBC.

Imaging modalities for characterising focal pancreatic lesions

BACKGROUND

Increasing numbers of incidental pancreatic lesions are being detected each year. Accurate characterisation of pancreatic lesions into benign, precancerous, and cancer masses is crucial in deciding whether to use treatment or surveillance. Distinguishing benign lesions from precancerous and cancerous lesions can prevent patients from undergoing unnecessary major surgery. Despite the importance of accurately classifying pancreatic lesions, there is no clear algorithm for management of focal pancreatic lesions.

OBJECTIVES

To determine and compare the diagnostic accuracy of various imaging modalities in detecting cancerous and precancerous lesions in people with focal pancreatic lesions.

SEARCH METHODS

We searched the CENTRAL, MEDLINE, Embase, and Science Citation Index until 19 July 2016. We searched the references of included studies to identify further studies. We did not restrict studies based on language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We planned to include studies reporting cross-sectional information on the index test (CT (computed tomography), MRI (magnetic resonance imaging), PET (positron emission tomography), EUS (endoscopic ultrasound), EUS elastography, and EUS-guided biopsy or FNA (fine-needle aspiration)) and reference standard (confirmation of the nature of the lesion was obtained by histopathological examination of the entire lesion by surgical excision, or histopathological examination for confirmation of precancer or cancer by biopsy and clinical follow-up of at least six months in people with negative index tests) in people with pancreatic lesions irrespective of language or publication status or whether the data were collected prospectively or retrospectively.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched the references to identify relevant studies and extracted the data. We planned to use the bivariate analysis to calculate the summary sensitivity and specificity with their 95% confidence intervals and the hierarchical summary receiver operating characteristic (HSROC) to compare the tests and assess heterogeneity, but used simpler models (such as univariate random-effects model and univariate fixed-effect model) for combining studies when appropriate because of the sparse data. We were unable to compare the diagnostic performance of the tests using formal statistical methods because of sparse data.

MAIN RESULTS

We included 54 studies involving a total of 3,196 participants evaluating the diagnostic accuracy of various index tests. In these 54 studies, eight different target conditions were identified with different final diagnoses constituting benign, precancerous, and cancerous lesions. None of the studies was of high methodological quality. None of the comparisons in which single studies were included was of sufficiently high methodological quality to warrant highlighting of the results. For differentiation of cancerous lesions from benign or precancerous lesions, we identified only one study per index test. The second analysis, of studies differentiating cancerous versus benign lesions, provided three tests in which meta-analysis could be performed. The sensitivities and specificities for diagnosing cancer were: EUS-FNA: sensitivity 0.79 (95% confidence interval (CI) 0.07 to 1.00), specificity 1.00 (95% CI 0.91 to 1.00); EUS: sensitivity 0.95 (95% CI 0.84 to 0.99), specificity 0.53 (95% CI 0.31 to 0.74); PET: sensitivity 0.92 (95% CI 0.80 to 0.97), specificity 0.65 (95% CI 0.39 to 0.84). The third analysis, of studies differentiating precancerous or cancerous lesions from benign lesions, only provided one test (EUS-FNA) in which meta-analysis was performed. EUS-FNA had moderate sensitivity for diagnosing precancerous or cancerous lesions (sensitivity 0.73 (95% CI 0.01 to 1.00) and high specificity 0.94 (95% CI 0.15 to 1.00), the extremely wide confidence intervals reflecting the heterogeneity between the studies). The fourth analysis, of studies differentiating cancerous (invasive carcinoma) from precancerous (dysplasia) provided three tests in which meta-analysis was performed. The sensitivities and specificities for diagnosing invasive carcinoma were: CT: sensitivity 0.72 (95% CI 0.50 to 0.87), specificity 0.92 (95% CI 0.81 to 0.97); EUS: sensitivity 0.78 (95% CI 0.44 to 0.94), specificity 0.91 (95% CI 0.61 to 0.98); EUS-FNA: sensitivity 0.66 (95% CI 0.03 to 0.99), specificity 0.92 (95% CI 0.73 to 0.98). The fifth analysis, of studies differentiating cancerous (high-grade dysplasia or invasive carcinoma) versus precancerous (low- or intermediate-grade dysplasia) provided six tests in which meta-analysis was performed. The sensitivities and specificities for diagnosing cancer (high-grade dysplasia or invasive carcinoma) were: CT: sensitivity 0.87 (95% CI 0.00 to 1.00), specificity 0.96 (95% CI 0.00 to 1.00); EUS: sensitivity 0.86 (95% CI 0.74 to 0.92), specificity 0.91 (95% CI 0.83 to 0.96); EUS-FNA: sensitivity 0.47 (95% CI 0.24 to 0.70), specificity 0.91 (95% CI 0.32 to 1.00); EUS-FNA carcinoembryonic antigen 200 ng/mL: sensitivity 0.58 (95% CI 0.28 to 0.83), specificity 0.51 (95% CI 0.19 to 0.81); MRI: sensitivity 0.69 (95% CI 0.44 to 0.86), specificity 0.93 (95% CI 0.43 to 1.00); PET: sensitivity 0.90 (95% CI 0.79 to 0.96), specificity 0.94 (95% CI 0.81 to 0.99). The sixth analysis, of studies differentiating cancerous (invasive carcinoma) from precancerous (low-grade dysplasia) provided no tests in which meta-analysis was performed. The seventh analysis, of studies differentiating precancerous or cancerous (intermediate- or high-grade dysplasia or invasive carcinoma) from precancerous (low-grade dysplasia) provided two tests in which meta-analysis was performed. The sensitivity and specificity for diagnosing cancer were: CT: sensitivity 0.83 (95% CI 0.68 to 0.92), specificity 0.83 (95% CI 0.64 to 0.93) and MRI: sensitivity 0.80 (95% CI 0.58 to 0.92), specificity 0.81 (95% CI 0.53 to 0.95), respectively. The eighth analysis, of studies differentiating precancerous or cancerous (intermediate- or high-grade dysplasia or invasive carcinoma) from precancerous (low-grade dysplasia) or benign lesions provided no test in which meta-analysis was performed.There were no major alterations in the subgroup analysis of cystic pancreatic focal lesions (42 studies; 2086 participants). None of the included studies evaluated EUS elastography or sequential testing.

AUTHORS' CONCLUSIONS

We were unable to arrive at any firm conclusions because of the differences in the way that study authors classified focal pancreatic lesions into cancerous, precancerous, and benign lesions; the inclusion of few studies with wide confidence intervals for each comparison; poor methodological quality in the studies; and heterogeneity in the estimates within comparisons.

Pancreatic cancer

Pancreatic cancer is a highly lethal disease, for which mortality closely parallels incidence. Most patients with pancreatic cancer remain asymptomatic until the disease reaches an advanced stage. There is no standard programme for screening patients at high risk of pancreatic cancer (eg, those with a family history of pancreatic cancer and chronic pancreatitis). Most pancreatic cancers arise from microscopic non-invasive epithelial proliferations within the pancreatic ducts, referred to as pancreatic intraepithelial neoplasias. There are four major driver genes for pancreatic cancer: KRAS, CDKN2A, TP53, and SMAD4. KRAS mutation and alterations in CDKN2A are early events in pancreatic tumorigenesis. Endoscopic ultrasonography and endoscopic ultrasonography-guided fine-needle aspiration offer high diagnostic ability for pancreatic cancer. Surgical resection is regarded as the only potentially curative treatment, and adjuvant chemotherapy with gemcitabine or S-1, an oral fluoropyrimidine derivative, is given after surgery. FOLFIRINOX (fluorouracil, folinic acid [leucovorin], irinotecan, and oxaliplatin) and gemcitabine plus nanoparticle albumin-bound paclitaxel (nab-paclitaxel) are the treatments of choice for patients who are not surgical candidates but have good performance status.

Fine-Needle Aspiration with Immunohistochemistry Using a Modified Scrape Cell Block Technique for the Diagnosis of Thyroid and Parathyroid Nodules

OBJECTIVE

To evaluate the diagnostic accuracy of a modified scrape cell block (SCB) technique in a large series of patients. The technique was especially developed and tested for fine-needle aspiration of thyroid and parathyroid nodules.

STUDY DESIGN

Eighty-two ultrasound-guided fine-needle aspiration specimens with the sonographic aspect of a thyroid (n = 33) or a possible parathyroid nodule (n = 49) were studied. Immunohistochemistry (IHC) was used on cell blocks containing plasma, thromboplastin, and selected 3-dimensional cell aggregates scraped off Papanicolaou-stained smears. Antibodies for chromogranin A, thyroglobulin, parathyroid hormone, calcitonin, and carcinoembryonic antibody (CEA) were used. In cases of reduced immunosensitivity or suspected metastases or rare primary tumors, additional IHC markers were employed.

RESULTS

Chromogranin A was expressed in all 28 parathyroid adenomas (PA), in 7 of 8 hyperplastic parathyroid glands, and in 13 of 14 medullary thyroid carcinomas (MTC). When combining positivity for chromogranin A and calcitonin/CEA, the specificity for the detection of MTC was 100%. Parathyroid hormone was expressed in 26 of 36 parathyroid nodules (72.2%). When combining follicular microarchitecture and expression of chromogranin A, the specificity for the detection of parathyroid tissue was 97%.

CONCLUSION

With the modified SCB technique, accurate cytological diagnoses were obtained in 97.6% of 82 patients.

Comparison of cytologic preparation methods in endoscopic ultrasound-guided fine needle aspiration for diagnosis of pancreatic adenocarcinoma

BACKGROUND

There are few studies about the diagnostic yield of cytologic preparation method of pancreatic samples obtained by Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). The aim of this study was to compare the accuracy of ThinPrep(®) and smear method in diagnosis of pancreatic cancer.

METHODS

A total of 125 EUS-FNA procedures were performed between July 2010 and June 2015. Patients in group I (n = 36; July 2010 to June 2014) had cytology slides prepared by consecutive allocation of samples. Patients in group II (n = 12; July 2014 to June 2015) had cytology slides prepared by alternately allocation of samples.

RESULTS

There were 24 men and 24 women (median age: 67 years; range 39-84). The median size of lesions was 3.9 cm (range; 1.4-7.2 cm). The locations of the pancreatic cancer were 10 in head (20.8%), 21 in body (43.8%), and 17 in tail (35.4%). The ThinPrep(®) method confirmed malignancy in 35 of 48 cases (72.9%). On the other hand, the smear method confirmed malignancy in 44 of 48 cases (91.7%). The diagnostic yield of smear method was statistically higher than liquid method (P = 0.012). Also, smear method is superior to liquid method in both consecutive and alternative allocation method. ThinPrep(®) provided a correct diagnosis in one case where the smear method was incorrect.

CONCLUSIONS

Smear method was a superior preparation method to liquid method in diagnosis of pancreatic cancer, even if splitting method was not used and variable allocation method was used.

Endoscopic ultrasonography in interventional diagnosis and treatment of digestive diseases

Since 1980, when endoscopic ultrasonography (EUS) was invented, great progress has been made in the development of EUS devices and technology, and EUS-guided diagnosis and treatment of digestive diseases have been widely adopted. Because of its safety, effectiveness and minimal invasion, EUS-guided interventional diagnosis and treatment of digestive diseases have been widely applied in the clinical work, and more and more new technologies are being developed. In this paper, we review the recent progress of EUS for the interventional diagnosis and treatment of digestive diseases.

Endoscopic ultrasonography for differentiation of malignant and benign common bile duct strictures

AIM: To assess the diagnostic value of endoscopic ultrasonography (EUS) in the differentiation of malignant and benign common bile duct strictures.

METHODS: A retrospective review was undertaken of 39 patients with clinically suspected bile duct stricture who underwent EUS. EUS findings were compared with transabdominal ultrasound and MRI findings. The final diagnosis was based on clinical data, histopathology, cytology and follow-up results ( ≥ 4 mo). The diagnostic value of EUS for malignant or benign common bile duct strictures was analyzed.

RESULTS: Of all the 39 patients, 30 were diagnosed with malignant common bile duct stricture and 9 were diagnosed with benign disease. The accuracy rates of EUS, MRI, and B-ultrasound in the differential diagnosis of bile duct strictures were 92.3%, 76.9% and 61.8%, respectively, which were statistically significant (P < 0.05). The sensitivity, specificity, positive predictive value and negative predictive value of EUS were 96.4%, 81.2%, 93.1%, and 90.0%, respectively. The sensitivity and negative predictive value of these three methods were statistically significant, with EUS having the highest values (P < 0.05). In contrast, the specificity and positive predictive value had no statistically significant differences among different groups (P > 0.05). Four of 39 patients had a pathological or cytological diagnosis by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). The accuracy rate of the EUS-FNA was 100%, which was statistically significant compared with those of EUS, MRI, and B-ultrasound (P < 0.05).

CONCLUSION: EUS has a higher accuracy rate in the differential diagnosis of benign and malignant common bile duct strictures than B-ultrasound and MRI, and EUS-FNA can improve the ability to distinguish benign and malignant common bile duct strictures.