False-positive EUS-guided FNA cytology for solid pancreatic lesions

The World Health Organization Reporting System for Pancreaticobiliary Cytopathology: Review and Comparison to the Papanicolaou Society of Cytopathology System

CONTEXT.—

The World Health Organization (WHO) Reporting System for Pancreaticobiliary Cytopathology (WHO System) is the product of a joint venture between the World Health Organization, the International Academy of Cytology, and the International Agency for Research on Cancer. The WHO System revises the Papanicolaou Society of Cytopathology System for Reporting Pancreaticobiliary Cytology (PSC System) and replaces the 6-tiered system with a 7-tiered system.

OBJECTIVE.—

To explain the WHO System and the differences with the PSC System.

DATA SOURCES.—

The WHO System and the PSC System of Reporting Pancreaticobiliary Cytopathology.

CONCLUSIONS.—

The diagnostic categories of the WHO System are "Insufficient/Inadequate/Nondiagnostic"; "Benign (Negative for Malignancy)"; "Atypical"; "Pancreaticobiliary Neoplasm, Low Risk/Low Grade (PaN-Low)"; "Pancreatic Neoplasm, High Risk/High Grade (PaN-High)"; "Suspicious for Malignancy"; and "Malignant." In the WHO System, the "benign" category includes both nonneoplastic and neoplastic lesions, so the "Neoplastic: Benign" category of the PSC system has been eliminated. Low-grade malignancies, pancreatic neuroendocrine tumors (PanNETs), and solid-pseudopapillary neoplasm (SPN) classified as "Neoplastic: Other" in the PSC System are classified as "Malignant" in the WHO System, leaving in the "Neoplasm" category intraductal lesions, which are divided into 2 new diagnostic categories: "Pancreaticobiliary Neoplasm (PaN)-Low Risk/Grade" and "PaN-High Risk/Grade." As with the PSC System, the WHO System advocates close correlation with imaging and encourages incorporation of ancillary testing into the final diagnosis, such as biochemical (carcinoembryonic antigen [CEA] and amylase) and molecular testing. The WHO System includes risk of malignancy per category, and reporting and diagnostic management options that recognize the variations in resources of low- and middle-income countries.

Risk of malignancy and overall survival associated with the diagnostic categories in the World Health Organization Reporting System for Pancreaticobiliary Cytopathology

BACKGROUND

The World Health Organization (WHO) classification system revised the Papanicolaou Society of Cytopathology (PSC) system for reporting pancreaticobiliary cytopathology. To better stratify intraductal and/or cystic neoplasms by cytologic grade, the neoplastic, other category was replaced by two new categories: pancreaticobiliary neoplasm, low-risk/grade (PaN-Low) and pancreaticobiliary neoplasm, high-risk/grade (PaN-High). Low-grade malignancies were placed in the malignant category, and benign neoplasms were placed in the benign/negative for malignancy category.

METHODS

An institutional pathology database search identified patients who underwent endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for pancreatic lesions from January 2015 to April 2022. The absolute risk of malignancy (ROM) was determined by histologic and/or clinical follow-up of at least 6 months, and overall survival rates were calculated across diagnostic categories, comparing the WHO and PSC systems.

RESULTS

In total, 1012 cases were reviewed and recategorized. The ROM for the WHO system was 8.3% for insufficient/inadequate/nondiagnostic, 3.2% for benign/negative for malignancy, 24.6% for atypical, 9.1% for PaN-Low, 46.7% for PaN-High, 75% for suspicious for malignancy, and 100% for malignant. Comparatively, the ROM for the PSC system was 7.4% for nondiagnostic, 3.0% for negative for malignancy, 23.1% for atypical, 0% for neoplastic, benign, 7.3% for neoplastic, other, 75% for suspicious for malignancy, and 100% for malignant. The WHO system demonstrated superior stratification for overall survival.

CONCLUSIONS

The WHO system significantly improves the stratification of ROM and overall survival across diagnostic categories by introducing the PaN-Low and PaN-High categories and reassigning low-grade malignancies to the malignant category. Analyzing EUS-FNA samples with the WHO system provides critical insights for guiding clinical management.

Liquid-based cytology features of pancreatic acinar cell carcinoma: comparison with other non-ductal neoplasms of the pancreas

BACKGROUND

Acinar cell carcinoma (ACC) is a rare malignant epithelial neoplasm, which shares many cytomorphological features with other non-ductal pancreatic neoplasms such as pancreatic neuroendocrine neoplasm (PanNEN) and solid-pseudopapillary neoplasm (SPN). Due to the relative rarity of these tumors, pathologists are less familiar with the cytological features, especially on liquid-based cytology (LBC) which has been relatively recently introduced for endoscopic ultrasound-guided fine needle aspiration specimens.

METHODS

We evaluated the detailed cytological features of 15 histologically confirmed ACC (7 conventional smears [CS], 8 LBC), and compared them with the LBC features of SPN (n = 9) and PanNEN (n = 9).

RESULTS

Compared with CS, LBCs of ACC demonstrated significantly less bloody background. All ACCs demonstrated prominent nucleoli and macronucleoli on LBC. On comparison with the LBC features of SPN and PanNEN, most ACCs demonstrated a necrotic background with apoptotic debris while PanNEN and SPN did not show these features. Acinar structures were predominantly observed in ACC, while frequent pseudopapillary structures were seen only in SPN. Prominent nucleoli and macronucleoli were only seen in ACC.

CONCLUSIONS

ACC had characteristic cytological features that could be observed on LBC preparations, such as high cellularity, necrotic/apoptotic background, nuclear tangles, acinar arrangement of cells, and macronucleoli. These findings also help distinguish ACC from PanNEN and SPN on LBC. It is important to be familiar with these features, as an accurate diagnosis on endoscopic ultrasound-guided fine needle aspiration cytology would have impact on the management of the patient.

Endoscopic ultrasound-guided tissue acquisition for the diagnosis of focal liver lesion

In patients with liver tumors, the histopathology examination can assist in diagnosis, staging, prognosis, and therapeutic management strategy. Endoscopic ultrasound (EUS)-guided tissue acquisition using fine needle aspiration (FNA) or more newly fine needle biopsy (FNB) is a well-developed technique in order to evaluate and differentiate the liver masses. The goal of the EUS-FNA or EUS-FNB is to provide an accurate sample for a histopathology examination. Therefore, malignant tumors such as hepatocarcinoma, cholangiocarcinoma and liver metastasis or benign tumors such as liver adenoma, focal hyperplastic nodular tumors and cystic lesions can be accurately diagnosed using EUS-guided tissue acquisition. EUS-FNB using 19 or 22 Ga needle provide longer samples and a higher diagnostic accuracy in patients with liver masses when compared with EUS-FNA. Few data are available on the diagnostic accuracy of EUS-FNB when compared with percutaneously, ultrasound, computer tomography or transjugulary-guided liver biopsies. This review will discuss the EUS-guided tissue acquisition options in patients with liver tumors and its efficacy and safety in providing accurate samples. The results of the last studies comparing EUS-guided liver biopsy with other conventional techniques are presented. The EUS-guided tissue acquisition using FNB can be a suitable technique in suspected liver lesions in order to provide an accurate histopathology diagnosis, especially for those who require endoscopy.

The WHO system versus the Papanicolaou society of cytopathology system for reporting pancreaticobiliary cytology for risk stratification-which is better?

BACKGROUND

Recently, the World Health Organization (WHO) has proposed a reporting system for pancreaticobiliary cytopathology. We applied this classification for pancreatic lesion samples by fine needle aspiration (FNA) and compared the results to the previous classification of the Papanicolaou Society of Cytopathology (PSC) system for risk stratification.

METHODS

The computerized database was searched for all pancreatic endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and transabdominal ultrasound-guided FNA (TUS-FNA) samples from 2016 to 2020 and cases were reassigned as per the PSC and the WHO diagnostic categories. Cases with follow-up, clinicoradiological, and/or histopathology were included in the study. The risk of malignancy (ROM) was calculated across all diagnostic categories based on clinical data, imaging data, and histopathology wherever available.

RESULTS

There were a total of 625 pancreatic FNA. In 230 cases, follow-up information was available which included 116 EUS and 114 TUS-FNA samples. The ROM for PSC categories I-VI was 40%, 19.7%, 28.6%, 57.1%, 94.7%, and 97.9% and for the WHO categories (I-VII), it was 60%, 21.3%, and 35.7%, not representative, not applicable, 94.7% and 94.9%. The overall sensitivity and specificity of PSC was 68.2% and 96.2% when categories V and VI were taken as positive and 78.9% and 93.3% for WHO when categories VI and VII were taken as positive.

CONCLUSIONS

Pancreatic FNA samples reported as per the WHO system showed better sensitivity as compared to the PSC system resulting in better risk stratification and consequently better patient management. The overall high specificity and moderate sensitivity reaffirm the utility of FNA in pancreatic lesions.

Focal Type 2 Autoimmune Pancreatitis Mimicking Pancreatic Cancer: Treatment with Neoadjuvant Chemotherapy and Surgery

A 51-year-old man was referred to our hospital for the further examination of main pancreatic duct interruption. Imaging findings showed a 25-mm-diameter mass lesion located in the pancreatic head. Endoscopic ultrasonography (EUS)-guided fine-needle aspiration (FNA) was performed on the mass. Cytology suggested adenocarcinoma, but the histological diagnosis was not confirmed. We made a comprehensive diagnosis of resectable pancreatic cancer. The mass shrank after preoperative adjuvant chemotherapy, and the patient underwent surgery. The final pathological diagnosis was type 2 autoimmune pancreatitis (AIP). Two years after surgery, AIP had not recurred in the remaining pancreas.

A brief review of the WHO reporting system for pancreaticobiliary cytopathology

The World Health Organization (WHO), the International Academy of Cytology, and the International Agency for Research on Cancer have developed an approach to standardized reporting of pancreaticobiliary cytopathology. The WHO Reporting System for Pancreaticobiliary Cytopathology (WHO System) revises the Papanicolaou Society of Cytopathology (PSC) System for Reporting Pancreaticobiliary Cytology published in 2015 and replaces the 6 PSC categories with 7 categories: "Insufficient/Inadequate/Nondiagnostic"; "Benign/Negative for malignancy"; "Atypical"; "Pancreaticobiliary neoplasm, low risk/grade (PaN-low)"; "Pancreatic neoplasm, high risk/grade (PaN-High)"; "Suspicious for malignancy"; and "Malignant". In the PSC system, there is a single category for "Neoplastic" lesions that includes 2 groups, 1 for benign neoplasms and 1 named "Neoplastic-other", dominated by premalignant intraductal neoplasms primarily intraductal papillary mucinous neoplasms and low-grade malignant neoplasms (pancreatic neuroendocrine tumors (PanNET) and solid pseudopapillary neoplasms (SPN). In the WHO System, benign neoplasms with virtually no risk of malignancy are included in the "Benign" category and low-grade malignancies (PanNET and SPN) are included in the "Malignant" category, as per the 5th edition of the WHO Classification of Digestive System Tumors, while the non-invasive pre-malignant lesions of the ducts are divided by the cytomorphological grade of the epithelium into PaN-low and PaN-high with distinctly different risks of malignancy. Within each category, key diagnostic cytopathologic features and the ancillary studies for diagnostic and prognostic evaluation, as well as the implications of diagnosis for patient care and management, are outlined. Reporting and diagnostic management options recognize the variations in the availability of diagnostic and prognostic ancillary testing modalities in low- and middle-income countries.

Using Endoscopy in the Diagnosis of Pancreato-Biliary Cancers

Pancreatic cancer and cholangiocarcinoma are life threatening oncological conditions with poor prognosis and outcome. Pancreatic cystic lesions are considered precursors of pancreatic cancer as some of them have the potential to progress to malignancy. Therefore, accurate identification and classification of these lesions is important to prevent the development of invasive cancer. In the biliary tract, the accurate characterization of biliary strictures is essential for providing appropriate management and avoiding unnecessary surgery. Techniques have been developed to improve the diagnosis, risk stratification, and management of pancreato-biliary lesions. Endoscopic ultrasound (EUS) and associated techniques, such as elastography, contrasted-enhanced EUS, and EUS-guided needle confocal laser endomicroscopy, may improve diagnostic accuracy. In addition, intraductal techniques applied during endoscopic retrograde cholangiopancreatography (ERCP), such as new generation cholangioscopy and in vivo cellular evaluation through probe-based confocal laser endomicroscopy, can increase the diagnostic yield in characterizing indeterminate biliary strictures. Both EUS-guided and intraductal approaches can provide the possibility for tissue sampling with new tools, such as needles, biopsies forceps, and brushes. At the molecular level, novel biomarkers have been explored that provide new insights into diagnosis, risk stratification, and management of these lesions.

Randomized controlled trial comparing the Franseen needle with the Fork-tip needle for EUS-guided fine-needle biopsy

BACKGROUND AND AIMS

EUS-guided FNA primarily provides cytologic samples. EUS-guided fine-needle biopsy (FNB) with needles that provide histologic specimens may enhance diagnostic yield and facilitate accessory tissue staining. Several different needle designs are currently available and design superiority is unknown. We designed a randomized controlled trial to compare 2 commonly used EUS-FNB needles in their ability to provide histologic tissue samples (primary endpoint) and to reach an accurate diagnosis (secondary endpoint).

METHODS

A total of 150 lesions from 134 patients (November 2018 to June 2019) were randomized 1:1 between biopsy with a Franseen needle and a Fork-tip needle. The groups were compared regarding the quality of the tissue samples and diagnostic accuracy.

RESULTS

Of 150 lesions, 75 were pancreatic and 75 were other solid lesions in and around the GI tract. There was no statistically significant difference between the Franseen needle and the Fork-tip needle in the yield of adequate histologic samples, 71 of 75 (94.7%) versus 72 of 75 (96%), (P = 1.00), an absolute difference of -1.3% (95% confidence interval [CI], -8.1% to 5.4%). The 2 groups were similar in the diagnostic accuracy of histologic analysis, 64 of 75 (85.3%) versus 68 of 75 (90.7%) (P = .45), absolute difference -5.4% (95% CI, -15.7% to 5%); and in the diagnostic accuracy of combined cytologic and histologic analysis, 65 of 75 (86.7%) versus 69 of 75 (92%) (P = .43), absolute difference -5.3% (95% CI, -15.2% to 4.5%).

CONCLUSIONS

There was no significant difference in the performance of the Franseen needle versus the Fork-tip needle. Both needles achieved a high yield of histologic tissue samples and high diagnostic accuracy. (Clinical trial registration number: NCT03672032.).

Modified Endoscopic Ultrasound Needle to Obtain Histological Core Tissue Samples: A Retrospective Analysis

Background/Aims

Endoscopic ultrasound (EUS)-guided fine-needle aspiration is very effective for providing specimens for cytological evaluation. However, the ability to provide sufficient tissue for histological evaluation has been challenging due to the technical limitations of dedicated core biopsy needles. Recently, a modified EUS needle has been introduced to obtain tissue core samples for histological analysis. We aimed to determine (1) its ability to obtain specimens for histological assessment and (2) the diagnostic accuracy of EUS-guided fine-needle biopsy (EUS-FNB) using this needle.

Methods

We retrospectively analyzed consecutive cases of FNB using modified EUS needles for 342 lesions in 303 patients. The cytology and histological specimens were analyzed. Diagnostic accuracy was calculated.

Results

Adequate cytological and histological assessment was possible in 293/342 (86%) and 264/342 (77%) lesions, respectively. Diagnostic accuracy of the cytological specimen was 294/342 (86%) versus 254/342 (74%) for the histological specimen (p<0.01). Diagnostic accuracy of the combined cytological and histological assessment was 323/342 (94.4%), which was significantly higher than that of both histology alone (p<0.001) and cytology alone (p=0.001).

Conclusions

EUS-FNB with the modified EUS needle provided histologic tissue cores in the majority of cases and achieved excellent diagnostic accuracy with few needle passes.

Diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration: A single-center analysis

Background: Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) has become an important modality for identification of intra-abdominal masses. This study analyzed the accuracy of EUS-FNAB in a single medical center and explored factors related to positive diagnosis. Materials and methods: In total, 77 patients with EUS-FNAB were retrospectively reviewed from July 2016 to February 2020. "Atypical (tends to be neoplasm/malignancy)," "suspicious (first consider neoplasm/malignancy)," and "malignant" were defined as positive cytology. The final diagnoses were based on histopathologic examination. The positive rate of EUS-FNAB for the diagnosis of neoplasm and its associations with age, sex, target puncture mass size, liver function, tumor markers, albumin, hypertension, and diabetes were examined. Results: Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of EUS-FNAB cytologic diagnoses in all patients were 77.9% (60/77), 76.1% (54/71), 100%, 100%, and 26.1% (6/23), respectively. Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of EUS-FNAB cytologic diagnoses in the pancreas were 80.0% (48/60), 79.3% (46/58), 100%, 100%, and 14.3% (2/14), respectively. The results of EUS-FNAB in pancreatic masses showed that the level of CA19-9 was higher in the true positive group than in the false-negative group (p<0.05). There were no factors associated with the true positive cytologic diagnoses (p>0.05). Conclusions: Our single-medical center study showed that EUS-FNAB is an accurate diagnostic procedure for the evaluation of intra-abdominal masses. Further follow-up is required to explore factors associated with the true positive cytology.

How to measure quality in endoscopic ultrasound

Quality is a key focus for gastrointestinal endoscopy and main international gastroenterology societies instituted specific task forces focused on this issue. Endoscopic ultrasound (EUS) represents one of the most fascinating fields to explore in gastrointestinal endoscopy due to its relatively limited availability out of high-volume centers. This leads to a particular need to define widely accepted quality indicators (QIs) and the ways to measure them. The current manuscript reviews these indicators in light of their impact on common clinical practice.

Endoscopic ultrasonography-guided tissue acquisition: How to achieve excellence

Endoscopic ultrasound (EUS)-guided tissue acquisition is a basic forte of an endosonographer. The multiple skills required to accomplish successful results include not only the puncture itself, but also proper lesion identification, correct puncture sequence, collaboration with the pathologist onsite or remotely, proper handling of the specimens, choosing one or more of cytology, cell-block, and/or tissue core preparation and, last, deciding the immunohistochemistry (IHC) panels and ancillary tests which may be needed for the current case. Error in any of these decisions may lead to incomplete or inconclusive information from the procedure, even if the aspirate is 'adequate.' In the present review, we will describe the technical aspects of EUS-guided tissue acquisition, current needles available and how to choose between them, and how to appropriately handle the specimen. We will also discuss the optimal approach to common targets including lymph nodes, pancreatic masses, pancreatic cysts, and subepithelial lesions.

Role of the preoperative usefulness of the pathological diagnosis of pancreatic diseases

Pancreatic cancer is the fifth leading cause of cancer death and has the lowest survival rate of any solid cancer. Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) is currently capable of providing a cytopathological diagnosis of pancreatic malignancies with a higher diagnostic power, with a sensitivity and specificity of 85%-89% and 98%-99%, compared to pancreatic juice cytology (PJC), whose sensitivity and specificity are only 33.3%-93% and 83.3%-100%. However, EUS-FNA is not effective in the cases of carcinoma in situ and minimally invasive carcinoma because both are undetectable by endoscopic ultrasonography, although PJC is able to detect them. As for the frequency of complications such as post endoscopic retrograde cholangiopancreatography pancreatitis, EUS-FNA is safer than PJC. To diagnose pancreatic cancer appropriately, it is necessary for us to master both procedures so that we can select the best methods of sampling tissues while considering the patient’s safety and condition.

Reliable Detection of Somatic Mutations in Fine Needle Aspirates of Pancreatic Cancer With Next-generation Sequencing: Implications for Surgical Management

OBJECTIVE

To determine the feasibility of genotyping pancreatic tumors via fine needle aspirates (FNAs).

BACKGROUND

FNA is a common method of diagnosis for pancreatic cancer, yet it has traditionally been considered inadequate for molecular studies due to the limited quantity of DNA derived from FNA specimens and tumor heterogeneity.

METHODS

In vitro mixing studies were performed to deduce the minimum cellularity needed for genetic analysis. DNA from both simulated FNAs and clinical FNAs was sequenced. Mutational concordance was determined between simulated FNAs and that of the resected specimen.

RESULTS

Limiting dilution studies indicated that mutations present at allele frequencies as low as 0.12% are detectable. Comparison of simulated FNAs and matched tumor tissue exhibited a concordance frequency of 100% for all driver genes present. In FNAs obtained from 17 patients with unresectable disease, we identified at least 1 driver gene mutation in all patients including actionable somatic mutations in ATM and MTOR. The constellation of mutations identified in these patients was different than that reported for resectable pancreatic cancers, implying a biologic basis for presentation with locally advanced pancreatic cancer.

CONCLUSIONS

FNA sequencing is feasible and subsets of patients may harbor actionable mutations that could potentially impact therapy. Moreover, preoperative FNA sequencing has the potential to influence the timing of surgery relative to systemic therapy. FNA sequencing opens the door to clinical trials in which patients undergo neoadjuvant or a surgery-first approach based on their tumor genetics with the goal of utilizing cancer genomics in the clinical management of pancreatic cancer.

Diagnostic yield of EUS-guided FNA for malignant biliary stricture: a systematic review and meta-analysis

BACKGROUND AND AIMS

EUS-guided FNA (EUS-FNA) is increasingly being used for tissue diagnosis of extrahepatic biliary strictures. The aim of this study was to determine the diagnostic yield of EUS-FNA in malignant biliary strictures.

METHODS

A comprehensive literature review was carried out by 2 reviewers for studies evaluating the accuracy of EUS-FNA in biliary stricture. A meta-analysis was performed to determine the pooled estimates of sensitivity, specificity, likelihood ratios, and diagnostic odds ratio for EUS-FNA of extrahepatic biliary stricture. A Quality Assessment of Diagnostic Accuracy Studies questionnaire was used to assess the quality of the selected studies. Several sensitivity analyses were performed to assess the effect of the quality of the studies on the accuracy of the final results of the meta-analysis.

RESULTS

Twenty studies involving 957 patients met inclusion criteria and were included in the meta-analysis. The pooled sensitivity and specificity of EUS-FNA for diagnosis of malignant biliary stricture were 80% (95% confidence interval [CI], 74%-86%), and 97% (95% CI, 94%-99%), respectively. The pooled positive likelihood ratio was 12.35 (95% CI, 7.37-20.72), and the negative likelihood ratio was 0.26 (95% CI, 0.18-0.38). The pooled diagnostic odds ratio for diagnosing a malignant biliary stricture was 70.53 (95% CI, 38.62-128.82). The area under the receiver-operating characteristic curve was 0.97. Sensitivity analyses showed that the quality of the included studies did not affect the accuracy of the final results of the meta-analysis.

CONCLUSION

This meta-analysis demonstrates that EUS-FNA is sensitive and highly specific for diagnosing malignancy in biliary strictures. Further studies are needed to compare EUS--FNA with emerging methods including cholangioscopy-guided biopsy and laser endomicroscopy.

Endoscopic ultrasound in the diagnosis and management of carcinoma pancreas

Endoscopic ultrasound (EUS) has become an important component in the diagnosis and treatment of carcinoma pancreas. With the advent of advanced imaging techniques and tissue acquisition methods the role of EUS is becoming increasingly important. Small pancreatic tumors can be reliably diagnosed with EUS. EUS guided fine needle aspiration establishes diagnosis in some cases. EUS plays an important role in staging of carcinoma pancreas and in some important therapeutic methods that include celiac plexus neurolysis, EUS guided biliary drainage and drug delivery. In this review we attempt to review the role of EUS in diagnosis and management of carcinoma pancreas.

Endoscopic ultrasound in the diagnosis and management of carcinoma pancreas

Endoscopic ultrasound (EUS) has become an important component in the diagnosis and treatment of carcinoma pancreas. With the advent of advanced imaging techniques and tissue acquisition methods the role of EUS is becoming increasingly important. Small pancreatic tumors can be reliably diagnosed with EUS. EUS guided fine needle aspiration establishes diagnosis in some cases. EUS plays an important role in staging of carcinoma pancreas and in some important therapeutic methods that include celiac plexus neurolysis, EUS guided biliary drainage and drug delivery. In this review we attempt to review the role of EUS in diagnosis and management of carcinoma pancreas.

Ultrasound-guided percutaneous fine-needle aspiration of solid pancreatic neoplasms: 10-year experience with more than 2,000 cases and a review of the literature

OBJECTIVES

To evaluate the diagnostic accuracy and complication rate of percutaneous ultrasound-guided fine-needle aspiration (US-FNA) of solid pancreatic neoplasms through the analysis of 10-year experiences of two centres.

METHODS

Clinical, radiological and pathologic data of 2,024 patients with solid pancreatic masses who underwent US-FNAs were retrospectively evaluated. Indications for aspiration were: unresectable lesions before neo-adjuvant therapy; doubtful imaging findings; and suspicion of uncommon neoplasms with prognostic or therapeutic implications such as metastases or lymphoma. US-FNAs were performed using aspiration needles with a cytopathologist present in centre 1. In centre 2, cytologic samples were collected with Chiba needles and separately evaluated by a cytopathologist.

RESULTS

US-FNA had a diagnostic sample rate of 92.2 % (centre 1: 95.9 %; centre 2: 87.2 %). US-FNA repetition after non-diagnostic samples provided a diagnosis in 86.3 % of cases. Sensitivity, specificity, positive and negative predictive values, and accuracy were 98.7 %, 100 %, 100 %, 75.5 %, and 98.7 %, respectively. The complication rate was 0.8 %.

CONCLUSIONS

Percutaneous US-FNA is a sensitive, accurate and safe method for the invasive diagnosis of solid pancreatic neoplasms. The use of aspiration needles and the on-site presence of a cytopathologist may lead to a high rate of diagnostic samples, thus reducing the need for US-FNA repetition.

KEY POINTS

• Percutaneous ultrasound-guided fine-needle aspiration of pancreatic neoplasms is sensitive and accurate. • The short-term complication rate of percutaneous ultrasound-guided fine-needle aspiration is low. • Technical aspects may influence the rate of diagnostic samples.

Implication of suspicious cytology in endoscopic ultrasound-guided fine-needle aspiration for pancreatic cancer

PURPOSE

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has become a preferred technique to evaluate pancreatic masses. The clinical management of a "suspicious for adenocarcinoma" cytological diagnosis is unclear in unresectable cases. We sought to determine whether a suspicious diagnosis in the setting of a high clinical suspicion of malignancy could be sufficient for initiating non-operative therapy, such as chemotherapy, in unresectable patients.

METHODS

Twenty-nine solid pancreatic mass cytology specimens obtained by EUS-FNA with a diagnosis of suspicious for adenocarcinoma were identified from 2000 to 2012. Pathology, clinical, and radiologic data were analyzed.

RESULTS

Additional procedures were performed in 21 of the 29 patients. Sixteen of the 21 patients had confirmation of malignancy on further tissue sampling and an additional 2 had confirmed unresectable cancers during surgical exploration. Three of the 21 patients had benign diagnoses on subsequent tissue sampling. Of the remaining eight patients who did not undergo additional diagnostic procedures, six were deemed clinically malignant and treated, one died within a year of the EUS-FNA, and one was lost to follow-up.

CONCLUSIONS

Consideration of a suspicious diagnosis on EUS-FNA of solid pancreatic masses as sufficient for initiating non-operative therapy is reasonable in the setting of a high clinical suspicion of malignancy.

Endoscopic ultrasound-guided pancreatic fine-needle aspiration: potential pitfalls in one institution's experience of 1212 procedures

BACKGROUND

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has emerged as the diagnostic modality of choice for mass lesions in the pancreas. The objective of the current study was to determine the accuracy and pitfalls of EUS-FNA in the diagnosis of pancreatic lesions in cases that involved follow-up surgical resection.

METHODS

Cases of EUS-FNA of pancreatic lesions performed from 2007 to mid-2012 for which subsequent surgical resection was performed were retrieved from the department's database. The accuracy of the cytologic diagnosis was assessed using the histological diagnosis as the gold standard. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated. "Neoplastic," "suspicious," and "malignant" were classified as a positive cytologic diagnosis. In one calculation method, "atypical" was also included as a positive cytologic diagnosis whereas in another it was not considered to be a positive cytological result. The cases with a cytologic-histological discrepancy were reviewed to identify sources of errors.

RESULTS

A total of 1212 cases from 1104 patients (518 women and 586 men; age range, 18-94 years [average age, 63.5 years]) were identified. Cytologic diagnoses included 52 unsatisfactory, 224 benign, 129 atypical, 140 neoplasm, 35 suspicious, and 632 malignant diagnoses. Of these cases, 397 patients had histological follow-up information available. The sensitivity, specificity, positive predictive value, and negative predictive value were 83.2%, 85.9%, 95.9%, and 56.1%, respectively, with atypical cases excluded from the analysis. When atypical cases were included as a positive cytologic diagnosis, the sensitivity, specificity, positive predictive value, and negative predictive value were 86.7%, 67.9%, 90.7%, and 58.5%, respectively, and were 73.7%, 87.7%, 95.6%, and 48.0%, respectively, when atypical cases were included as a negative cytologic diagnosis. The major difficulty in EUS-FNA cytology was to differentiate pancreatic mucinous neoplasms from contaminants of gastric mucosa. Other pitfalls included differentiating mucinous neoplasm from extensive pancreatic intraepithelial neoplasia, and endocrine tumor from nesidioblastosis versus acinar cell carcinoma or intrapancreatic spleen.

CONCLUSIONS

EUS-FNA is a valuable tool for the diagnosis of pancreatic lesions, especially solid malignant tumors. Cytologic-radiological correlation is essential in differentiating pancreatic mucinous neoplasms from gastric mucosa, because the former usually are found to have characteristic features on imaging. Pathologists should be aware of the pitfalls in the cytologic diagnosis of pancreatic lesions that may significantly change the clinical management of the patients.

The added value of using mutational profiling in addition to cytology in diagnosing aggressive pancreaticobiliary disease: review of clinical cases at a single center

Background

This study aimed to better understand the supporting role that mutational profiling (MP) of DNA from microdissected cytology slides and supernatant specimens may play in the diagnosis of malignancy in fine-needle aspirates (FNA) and biliary brushing specimens from patients with pancreaticobiliary masses.

Methods

Cytology results were examined in a total of 30 patients with associated surgical (10) or clinical (20) outcomes. MP of DNA from microdissected cytology slides and from discarded supernatant fluid was analyzed in 26 patients with atypical, negative or indeterminate cytology.

Results

Cytology correctly diagnosed aggressive disease in 4 patients. Cytological diagnoses for the remaining 26 were as follows: 16 negative (9 false negative), 9 atypical, 1 indeterminate. MP correctly determined aggressive disease in 1 false negative cytology case and confirmed a negative cytology diagnosis in 7 of 7 cases of non-aggressive disease. Of the 9 atypical cytology cases, MP correctly diagnosed 7 as positive and 1 as negative for aggressive disease. One specimen that was indeterminate by cytology was correctly diagnosed as non-aggressive by MP. When first line malignant (positive) cytology results were combined with positive second line MP results, 12/21 cases of aggressive disease were identified, compared to 4/21 cases identified by positive cytology alone.

Conclusions

When first line cytology results were uncertain (atypical), questionable (negative), or not possible (non-diagnostic/indeterminate), MP provided additional information regarding the presence of aggressive disease. When used in conjunction with first line cytology, MP increased detection of aggressive disease without compromising specificity in patients that were difficult to diagnose by cytology alone.

Applications of endoscopic ultrasound in pancreatic cancer

Since the introduction of endoscopic ultrasound guided fine-needle aspiration (EUS-FNA), EUS has assumed a growing role in the diagnosis and management of pancreatic ductal adenocarcinoma (PDAC). The objective of this review is to discuss the various applications of EUS and EUS-FNA in PDAC. Initially, its use for detection, diagnosis and staging will be described. EUS and EUS-FNA are highly accurate modalities for detection and diagnosis of PDAC, this high accuracy, however, is decreased in specific situations particularly in the presence of chronic pancreatitis. Novel techniques such as contrast-enhanced EUS, elastography and analysis of DNA markers such as k-ras mutation analysis in FNA samples are in progress and might improve the accuracy of EUS in the detection of PDAC in this setting and will be addressed. EUS and EUS-FNA have recently evolved from a diagnostic to a therapeutic technique in the management of PDAC. Significant developments in therapeutic EUS have occurred including advances in celiac plexus interventions with direct injection of ganglia and improved pain control, EUS-guided fiducial and brachytherapy seed placement, fine-needle injection of intra-tumoral agents and advances in EUS-guided biliary drainage. The future role of EUS and EUS in management of PDAC is still emerging.

The value of mutational profiling of the cytocentrifugation supernatant fluid from fine-needle aspiration of pancreatic solid mass lesions

Fine-needle aspiration (FNA) of pancreatic solid masses can be significantly impacted by sampling variation. Molecular analysis of tumor DNA can be an aid for more definitive diagnosis. The aim of this study was to evaluate how molecular analysis of the cell-free cytocentrifugation supernatant DNA can help reduce sampling variability and increase diagnostic yield. Twenty-three FNA smears from pancreatic solid masses were performed. Remaining aspirates were rinsed for preparation of cytocentrifuged slides or cell blocks. DNA was extracted from supernatant fluid and assessed for DNA quantity spectrophotometrically and for amplifiability by quantitative PCR (qPCR). Supernatants with adequate DNA were analyzed for mutations using PCR/capillary electrophoresis for a broad panel of markers (KRAS point mutation by sequencing, microsatellite fragment analysis for loss of heterozygosity (LOH) of 16 markers at 1p, 3p, 5q, 9p, 10q, 17p, 17q, 21q, and 22q). In selected cases, microdissection of stained cytology smears and/or cytocentrifugation cellular slides were analyzed and compared. In all, 5/23 samples cytologically confirmed as adenocarcinoma showed detectable mutations both in the microdissected slide-based cytology cells and in the cytocentrifugation supernatant. While most mutations detected were present in both microdissected slides and supernatant fluid specimens, the latter showed additional mutations supporting greater sensitivity for detecting relevant DNA damage. Clonality for individual marker mutations was higher in the supernatant fluid than in microdissected cells. Cytocentrifugation supernatant fluid contains levels of amplifiable DNA suitable for mutation detection and characterization. The finding of additional detectable mutations at higher clonality indicates that supernatant fluid may be enriched with tumor DNA. Molecular analysis of the supernatant fluid could serve as an adjunct method to reduce sampling variability and increase diagnostic yield, especially in cases with a high clinical suspicion for malignancy and limited number of atypical cells in the smears.

How good is fine needle aspiration? What results should you expect?

Tissue acquisition plays a key role before treatment decision in most of oncological pathologies but also in several benign diseases. By offering tissue sampling, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has become an essential tool in the diagnostic processes. One of the reasons for the success of the technique is related to its excellent diagnostic performance. The diagnostic accuracy of EUS-FNA is above 80% for most of the usual indications. These performances are however dependent on some factors related to both the disease and patient's medical history but also related to medical staff expertise. Endoscopist needs to know how to reach a lesion but also how to efficiently acquire good tissue samples. This review aims to report general recommendations available in the literature for high quality EUS-FNA. Sample processing and sample interpretation also influence diagnostic accuracy of FNA. This paper includes a discussion on sample processing and benefits of the on-site pathology examination. It also provides the results reported in the literature of sample adequacy and diagnostic performance of EUS-FNA for most common indications: Pancreatic diseases, sub-mucosal lesion, mucosal thickenings, lymph nodes, cystic lesion and free fluids.

Mutational analysis of cytocentrifugation supernatant fluid from pancreatic solid mass lesions

Diagnosis of fine-needle aspirations of pancreatic solid masses is complicated by many factors that keep its false-negative rate high. Our novel approach analyzes cell-free cytocentrifugation supernatant, currently a discarded portion of the specimen. Supernatant and cytology slides were collected from 25 patients: 11 cases with confirmed outcome [five positive (adenocarcinoma) and six negative (inflammatory states)], plus 14 without confirmed outcomes. Slides were microdissected, DNA was extracted from microdissections and corresponding supernatants, and all were analyzed for KRAS point mutation and loss of heterozygosity. Notably, higher levels of free DNA were found in supernatants than in corresponding microdissected cells. Supernatants contained sufficient DNA for mutational profiling even when samples contained few to no cells. Mutations were present in 5/5 malignancies and no mutations were present in inflammatory states. In conclusion, these findings support using supernatant for mutational genotyping when diagnostic confirmation is required for pancreatic solid masses. Diagn. Cytopathol. 2014;42:719–725. © 2013 Wiley Periodicals, Inc.

False-negative rate of endoscopic ultrasound-guided fine-needle aspiration for pancreatic solid and cystic lesions with matched surgical resections as the gold standard: one institution's experience

BACKGROUND

The diagnosis of pancreatic tumors is often complicated because of sampling and interpretive challenges. The current study was performed to determine the rates, types, and causes of diagnostic discrepancies.

METHODS

The authors retrospectively reviewed cytology cases from 2004 to 2010 using matched surgical resection cases as the gold standard.

RESULTS

A total of 733 cases were divided into 3 categories: 1) positive or suspicious (290 cases); 2) negative or atypical (403 cases); and 3) unsatisfactory (40 cases). Of these cases, 101 fine-needle aspiration (FNA) cases had matched surgical resections including 58 positive diagnoses, 39 negative diagnoses, and 4 unsatisfactory diagnoses. All 19 discrepant cases represented false-negative diagnoses without any false-positive cases noted, which included 2 cases with interpretive errors (10%) and 17 cases with sampling errors (90%). All matched cytology cases were divided into 5 subgroups based on the type of lesion or type of error and were analyzed for sensitivity and specificity. The sampling error rate in cystic lesions (8 of 24; 33%) was significantly higher than that in solid lesions (9 of 73; 12%). The false-negative rate in the interpretive error group (3%) was significantly lower than that in the sampling error group (23%).

CONCLUSIONS

The results of the current study confirm that pancreatic endoscopic ultrasound-guided FNA diagnosis has a very low false-positive rate but a relatively high false-negative rate using matched surgical resections as the gold standard. The major cause of a false-negative cytology diagnosis is sampling error and the rate of sampling error in cystic lesions is significantly higher than that in solid lesions.

The role of endoscopic ultrasound in biliary obstruction

The role of endoscopic ultrasound (EUS) in the diagnosis of biliary obstruction is well established, and emerging evidence suggests it may also play a therapeutic role. Differentiating between benign and malignant causes of biliary obstruction can be challenging, but EUS is a crucial tool in the armamentarium of the physician. Evolving technologies such as elastography and contrast enhancement may further supplement the diagnostic abilities of EUS. Therapeutic applications of EUS are evolving rapidly, and EUS-guided cholangiography may aid biliary decompression when endoscopic retrograde cholangiopancreatography (ERCP) has failed or is not possible.

Cytomorphologic and immunophenotypical features of acinar cell neoplasms of the pancreas

BACKGROUND

Acinar cell neoplasms of the pancreas are rare but when encountered, the diagnosis is often established based on cytology specimens. Diagnostic accuracy is important because acinar cell carcinomas are aggressive yet may mimic tumors with different outcomes and management.

METHODS

The authors identified all patients with a diagnosis of acinar cell neoplasm in the institutional database; assessed cytomorphology and immunocytochemistry for trypsin, chymotrypsin, synaptophysin, chromogranin A, and MIB-1; and compared all cytology and final histological diagnoses for diagnostic discrepancies.

RESULTS

Cytological features were described for 16 histologically proven malignant acinar cell neoplasms: acinar cell carcinoma (8 cases), mixed acinar-neuroendocrine carcinoma (6 cases), mixed acinar-ductal carcinoma (1 case), and pancreatoblastoma (1 case).The majority of aspirates from acinar cell cystadenomas were nondiagnostic or negative (5 of 6 cases; 83%). Acinar and neuroendocrine differentiation that was detected by immunocytochemistry in >20% of tumor cells was found to be correlated with mixed acinar-neuroendocrine carcinoma histology. Cytohistological correlation included 32 patients with 17 discordant diagnoses (53%). The following preoperative cytology diagnoses proved to be acinar cell neoplasms on resection: neuroendocrine tumor (5 cases), adenocarcinoma (5 cases), atypical ductal cells (2 cases), solid pseudopapillary neoplasm, and hepatocellular carcinoma. Three aspirates diagnosed as acinar cell carcinoma by cytology proved to be chronic pancreatitis (2 cases) and ductal adenocarcinoma (1 case).

CONCLUSIONS

Acinar cell carcinoma has a distinctive cytological appearance but is frequently misdiagnosed on cytology. Immunocytochemistry is useful for identifying acinar differentiation.

Percutaneous fine needle biopsy in pancreatic tumors: a study of 42 cases

The technological progress within the range of methods of pancreas imaging and their more common accessibility selects a group of patients requiring a microscopic diagnosis. Percutaneous fine needle aspiration biopsy under the control of ultrasonography (PCFNA/USG) is the method commonly used in determining the character of a focal pancreatic lesion. Aim of the Work. An assessment of the accessibility of PCFNA biopsy in the assessment of solid and cystic changes in a pancreas and the correlation of the results of imaging examination, cytological smear and concentration of a serous marker CA19-9. Material and Methodology. In our material we analysed 43 cases of tumors of the pancreas among the patients who were at the average age of 59 ± 10.4 (14 women, 28 men) diagnosed by PCFNA biopsy. Results. In a group we are 23 cases of cancer, 12 cases of inflammation and 7 cases of cellular atypia for which 2 cases of IPMN were included. The sensitivity of the method was 92.5% but specificity was 68%. In our opinion PCFNA/USG is a method of the comparable sensitivity and specificity with fine needle aspiration biopsy with EUS control and its efficiency depends to a considerable degree on experience and interdisciplinary collaboration.

Diagnostic endoscopic ultrasonography: Assessment of safety and prevention of complications

Endoscopic ultrasonography (EUS) has gained wide acceptance as an important, minimally invasive diagnostic tool in gastroenterology, pulmonology, visceral surgery and oncology. This review focuses on data regarding risks and complications of non-interventional diagnostic EUS and EUS-guided fine-needle biopsy (EUS-FNB). Measures to improve the safety of EUS und EUS-FNB will be discussed. Due to the specific mechanical properties of echoendoscopes in EUS, there is a low but noteworthy risk of perforation. To minimize this risk, endoscopists should be familiar with the specific features of their equipment and their patients’ specific anatomical situations (e.g., tumor stenosis, diverticula). Most diagnostic EUS complications occur during EUS-FNB. Pain, acute pancreatitis, infection and bleeding are the primary adverse effects, occurring in 1% to 2% of patients. Only a few cases of needle tract seeding and peritoneal dissemination have been reported. The mortality associated with EUS and EUS-FNB is 0.02%. The risks associated with EUS-FNB are affected by endoscopist experience and target lesion. EUS-FNB of cystic lesions is associated with an increased risk of infection and hemorrhage. Peri-interventional antibiotics are recommended to prevent cyst infection. Adequate education and training, as well consideration of contraindications, are essential to minimize the risks of EUS and EUS-FNB. Restricting EUS-FNB only to patients in whom the cytopathological results may be expected to change the course of management is the best way of reducing the number of complications.

Diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration for solid pancreatic lesion: a systematic review

OBJECTIVE

To summarize EUS-FNA test performance in suspected pancreatic malignancy with meta-analysis.

METHOD

Two reviewers searched MEDLINE (PubMed and Ovid from January 2002 to January 2012) database to identify relevant studies. The reference lists of the trials were manually searched. Included studies used histopathology or clinical and morphological (CT and MRI and US) follow-up as the "gold standard" and provided sufficient data to construct a diagnostic 2 × 2 table. A statistical program of Meta-Disc was used to calculate the pooled sensitivity, specificity, positive LR, negative LR, DOR, and the SROC curve. Subgroup analysis and meta-regression were calculated to evaluate potential sources of heterogeneity.

RESULT

A total of 15 studies with 1860 patients were included for the analysis. The pooled sensitivity and specificity of EUS-FNA were 92 % (95 % CI = 91-93 %, p < 0.001, I (2) = 69.6 %) and 96 % (95 % CI = 93-98 %, p = 0.006, I (2) = 54.9 %), respectively. The positive LR and negative LR were 14.24 (95 % CI = 7.78-26.07) and 0.09 (95 % CI = 0.07-0.13), respectively. The area under the curve was 0.974. The subgroup analysis of six studies with rapid on-site evaluation (ROSE) showed a pooled sensitivity of 95 % (95 % CI = 93-96 %), with p value equal 0.622 and I (2) = 0. The sensitivity analysis of ten high-quality studies (a score of ≥4) showed a pooled sensitivity of 94 % (95 % CI = 93-96 %, p = 0.144, I (2) = 33.1 %), and the pooled specificity was 0.95 (95 % CI, 0.91-0.97).

CONCLUSION

EUS-FNA had overall excellent specificity and sensitivity in accurately diagnosing solid pancreatic masses. ROSE could help to improve the accuracy of diagnostic test.

Pancreatico-biliary endoscopic ultrasound: a systematic review of the levels of evidence, performance and outcomes

Our aim was to record pancreaticobiliary endoscopic ultrasound (EUS) literature of the past 3 decades and evaluate its role based on a critical appraisal of published studies according to levels of evidence (LE). Original research articles (randomized controlled trials, prospective and retrospective studies), meta-analyses, reviews and surveys pertinent to gastrointestinal EUS were included. All articles published until September 2011 were retrieved from PubMed and classified according to specific disease entities, anatomical subdivisions and therapeutic applications of EUS. The North of England evidence-based guidelines were used to determine LE. A total of 1089 pertinent articles were reviewed. Published research focused primarily on solid pancreatic neoplasms, followed by disorders of the extrahepatic biliary tree, pancreatic cystic lesions, therapeutic-interventional EUS, chronic and acute pancreatitis. A uniform observation in all six categories of articles was the predominance of LE III studies followed by LE IV, II b, II a, I b and I a, in descending order. EUS remains the most accurate method for detecting small (< 3 cm) pancreatic tumors, ampullary neoplasms and small (< 4 mm) bile duct stones, and the best test to define vascular invasion in pancreatic and peri-ampullary neoplasms. Detailed EUS imaging, along with biochemical and molecular cyst fluid analysis, improve the differentiation of pancreatic cysts and help predict their malignant potential. Early diagnosis of chronic pancreatitis appears feasible and reliable. Novel imaging techniques (contrast-enhanced EUS, elastography) seem promising for the evaluation of pancreatic cancer and autoimmune pancreatitis. Therapeutic applications currently involve pancreaticobiliary drainage and targeted fine needle injection-guided antitumor therapy. Despite the ongoing development of extra-corporeal imaging modalities, such as computed tomography, magnetic resonance imaging, and positron emission tomography, EUS still holds a leading role in the investigation of the pancreaticobiliary area. The major challenge of EUS evolution is its expanding therapeutic potential towards an effective and minimally invasive management of complex pancreaticobiliary disorders.

The role of endoscopic ultrasonography in the diagnosis and management of pancreatic cancer

EUS with FNA is highly sensitive and specific for diagnosing pancreatic cancer. However, in certain situations, such as in patients with chronic pancreatitis, this high sensitivity and specificity can significantly diminish. The use of new technology, such as EUS elastography, CE-EUS, and gene mutations detection in FNA specimens, can help to differentiate chronic pancreatitis from pancreatic cancer. EUS has evolved from a diagnostic procedure to a therapeutic intervention in pancreatic cancer. EUS-guided fiducial insertion and EUS-guided delivery of antitumor agents, in addition to celiac plexus neurolysis, are the main therapeutic applications of EUS in pancreatic cancer.