Significance of the diagnostic categories "atypical" and "suspicious for malignancy" in the cytologic diagnosis of solid pancreatic masses

Reporting Pancreatic FNAC using the Papanicolaou System: Still a Diagnostic Challenge

Introduction

The Papanicolaou Society of Cytopathology System for reporting Pancreaticobiliary Cytology (PSCPC) is a reliable method to classify pancreatic fine needle aspiration cytology (FNAC) smears. However, it is not without practical problems which can diminish the diagnostic accuracy of the cytological diagnosis.

Aims and Objectives

To determine the diagnostic pitfalls while reporting cytomorphology of pancreatic lesions according to PSCPC on correlating FNAC findings with histopathology.

Materials and Methods

Retrospective analysis of pancreatic FNAC smears received in the Department of Pathology of our tertiary care institute over a period of 2 years was done. The cytological diagnoses were classified according to the Papanicolaou Society of Cytopathology system of reporting pancreaticobiliary cytology and correlated with histopathology. The reasons of cyto-histological discordance were analyzed.

Results

Out of 50 cases in which both FNAC and biopsy of pancreatic lesions were done, 34 cases were positive/malignant (Category VI), eight cases were suspicious for malignancy (Category V), three cases were neoplastic (Category IV), two cases were atypical (Category III), two cases were negative for malignancy (Category II), and one case was non-diagnostic (Category I). Out of 50 cases, histopathology was non-diagnostic due to inadequate material in six cases. The cytological diagnoses were compared with histopathology in the remaining 44 cases. Categories III, IV V, and VI were considered as positive for neoplastic pathology. The sensitivity of FNAC to predict neoplastic pathology was 97.5%, while the specificity was 25%. The positive predictive value was 92.9%. Two cases reported as atypical (Category III) turned out to be adenocarcinoma on histopathology. One case reported as neuroendocrine tumor and two cases reported as adenocarcinoma on cytology displayed features of chronic pancreatitis on histology. One case reported as neoplastic mucinous cyst (Category IV) turned out to be adenocarcinoma on histology (limited concordance).

Conclusion

The cytopathologist needs to be wary of the potential pitfalls to improve the diagnostic accuracy of FNACs.

Diagnostic performance of endoscopic tissue acquisition for pancreatic ductal adenocarcinoma in the PREOPANC and PREOPANC-2 trials

BACKGROUND

Neoadjuvant treatment for pancreatic ductal adenocarcinoma (PDAC) has increased, necessitating histopathologic confirmation of cancer. This study evaluates the performance of endoscopic tissue acquisition (TA) procedures for borderline resectable and resectable PDAC.

METHODS

Pathology reports of patients included in two nationwide randomized controlled trials (PREOPANC and PREOPANC-2) were reviewed. The primary outcome was sensitivity for malignancy (SFM), considering both "suspicious for" and "malignant" as positive. Secondary outcomes were rate of adequate sampling (RAS) and diagnoses other than PDAC.

RESULTS

Overall, 892 endoscopic procedures were performed in 617 patients, including endoscopic ultrasonography (EUS)-guided TA in 550 (89.1%), endoscopic retrograde cholangiopancreatography (ERCP)-guided brush cytology in 188 (30.5%), and periampullary biopsies in 61 patients (9.9%). The SFM was 85.2% for EUS, 88.2% for repeat EUS, 52.7% for ERCP, and 37.7% for periampullary biopsies. The RAS ranged 94-100%. Diagnoses other than PDAC were other periampullary cancers in 24 (5.4%), premalignant disease in five (1.1%), and pancreatitis in three patients (0.7%).

CONCLUSIONS

EUS-guided TA of patients with borderline resectable and resectable PDAC included in RCTs had an SFM above 85% for both first and repeat procedures, meeting international standards. Two percent had false positive result for malignancy and 5% had other (non-PDAC) periampullary cancers.

Fluorescence In Situ Hybridization in Primary Diagnosis of Biliary Strictures: A Single-Center Prospective Interventional Study

Background and aims: Diagnosis of the biliary stricture remains a challenge. In view of the low sensitivity of brush cytology (BC), fluorescence in situ hybridization (FISH) has been reported as a useful adjunctive test in patients with biliary strictures. We aimed to determine performance characteristics of BC and FISH individually and in combination (BC + FISH) in the primary diagnosis of biliary strictures. Methods: This single-center prospective study was conducted between April 2019 and January 2021. Consecutive patients with unsampled biliary strictures undergoing first endoscopic retrograde cholangiopancreatography in our institution were included. Tissue specimens from two standardized transpapillary brushings from the strictures were examined by routine cytology and FISH. Histopathological confirmation after surgery or 12-month follow-up was regarded as the reference standard for final diagnosis. Results: Of 109 enrolled patients, six were excluded and one lost from the final analysis. In the remaining 102 patients (60.8% males, mean age 67.4, range 25–92 years), the proportions of benign and malignant strictures were 28 (27.5%) and 74 (72.5%), respectively. The proportions of proximal and distal strictures were 26 (25.5%) and 76 (74.5%), respectively. In comparison to BC alone, FISH increased the sensitivity from 36.1% to 50.7% (p = 0.076) while maintaining similar specificity (p = 0.311). Conclusions: Dual-modality tissue evaluation using BC + FISH showed an improving trend in sensitivity for the primary diagnosis of biliary strictures when compared with BC alone.

Increased accuracy of FNA-based cytological diagnosis of pancreatic lesions by use of an ethanol-based fixative system: A STROBE compliant study

EUS-guided fine needle aspiration cytology (FNA) is the gold standard of evaluation of solid pancreatic lesions. However, accuracy is generally low. The aim of this study was to compare the diagnostic yield of conventional cytology (CC) with liquid-based cytological analysis using an ethanol based fixative system (LBC) without onsite cytopathological assessment. We performed a retrospective evaluation in patients referred to the Department of Interdisciplinary Endoscopy at Jena University Hospital for FNA of pancreatic masses between 2008 and 2015. LBC preservation of specimen was introduced in April 2011. Gold standard was defined as a surgically obtained histology or a patient follow-up of at least 1 year for diagnosis or exclusion of malignancy. 172 patients were included into the final analysis. Mean age was 64.8 years (SD 12.4 years), 105 patients were male. 107 lesions were malignant, while 65 lesions were benign. 89 specimens were evaluated by CC, whereas 83 specimens were processed by LBC. Liquid-based cytology performed significantly better than conventional cytology in terms of sensitivity (87.8% vs 67.2% (P = .021)), specificity (100% vs 87.1% (P = .047)) negative predictive value (NPV) (85% vs 58.7% (P = .009)) and accuracy (92.8% vs 74.2% (P = .001)). We observed no learning curve after implementation of LBC Liquid based cytology is a simple and inexpensive technique that helps improving sensitivity, specificity, NPV and accuracy over conventional cytology in fine needle aspirates from patients with pancreatic lesions. Therefore, this real-world evidence shows, that EUS-FNA specimen processing should be performed using LBC to achieve best possible results.

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.

[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.

Atypical cells in fine needle aspiration biopsies of pancreas: Causes, work-up, and recommendations for management

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is a sensitive and specific method for diagnosing cancer in solid pancreatic masses. However, some cases receive indeterminate atypical diagnoses, which creates management dilemmas. In the 2014 Papanicolaou Society of Cytopathology (PSC) standardized guidelines for pancreatobiliary cytology, specimens in the "Atypical" category show a spectrum of architectural and/or cellular changes beyond normal or reactive, but, quantitatively or qualitatively, insufficient for classification as neoplastic (benign/other), suspicious or positive for malignancy. Implementation of the PSC system decreased atypical diagnoses, particularly for cystic lesions, and redistributed many cases into benign and neoplastic categories. Because no set cytologic criteria exist for the "Atypical" category there is wide variability in its use, and its frequency ranges from 0%-16% (mean 6%). It consists of a heterogeneous mix of cases that occur because of preanalytic, lesion-specific (low cellularity, necrosis, cystic, reactive and premalignant changes), to pathologist-dependent factors (experience, expertise, training and institutional case volume). Outcomes of atypical diagnoses in solid pancreatic masses range from benign to premalignant and malignant and include reactive atypia in pancreatitis, well differentiated adenocarcinoma, and non-ductal malignancies. The associated risk of malignancy (ROM) ranges from 28%-100%, with an overall intermediate ROM in large-scale studies. Cytopathologists and institutions should monitor and keep their personal and/or laboratory's atypical rates low by judiciously using rapid onsite evaluation, ancillary studies, consensus or expert review, as well as correlation with clinical and radiologic findings. Early repeat EUS-FNA is indicated for unresolved cases.

Accuracy of cytopathology evaluation for resected benign and malignant pancreatic disease

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the preferred method for diagnosing pancreatic masses. While the diagnostic success of EUS-FNA is widely accepted, the actual performance of EUS-FNA is not known. This study sought to define the EUS-FNA accuracy compared with the gold standard, surgically resected specimens. The study was a single institution, retrospective, and chart review of patients with surgically resected pancreatic specimens from 2005 to 2015 with a preoperative EUS-FNA or biliary brushing. Cytological reports were organized from least concerning (i.e., low chance of malignancy) to most concerning (high chance of malignancy) into eight cytologic categories. We identified 741 cytologic cases: 530 EUS-FNA and 211 endoscopic brushings. For EUS-FNA samples, 62.5% of "benign" samples proved to be "benign" on surgical pathology. A cytologic diagnosis of "suspicious for malignancy" or "positive for malignancy" were concordant with a cancer diagnosis on surgical pathology 93.3% and 98.0% of cases, respectively. EUS-FNA proved to be highly reliable at diagnosing malignancy for cytologic samples that were "suspicious" or "positive" for malignancy. Paired with supportive clinical data, these interpretations may be used to justify cancer treatment.

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)

Diagnostic value of digital droplet polymerase chain reaction and digital multiplexed detection of single-nucleotide variants in pancreatic cytology specimens collected by EUS-guided FNA

BACKGROUND AND AIMS

EUS-guided FNA is recommended as a first-line procedure for the histopathologic diagnosis of pancreatic cancer. Molecular analysis of EUS-FNA samples might be used as an auxiliary tool to strengthen the diagnosis. The current study aimed to evaluate the diagnostic performances of K-ras testing using droplet digital polymerase chain reaction (ddPCR) and a novel single-nucleotide variant (SNV) assay performed on pancreatic EUS-FNA samples.

METHODS

EUS-FNA specimens from 31 patients with pancreatic masses (22 pancreatic ductal adenocarcinomas, 7 chronic pancreatitis, and 2 pancreatic neuroendocrine tumors) were included in the study. K-ras testing was initially performed by ddPCR. In addition, mutational status was evaluated using an SNV assay by NanoString technology, using digital enumeration of unique barcoded probes to detect 97 SNVs from 24 genes of clinical significance.

RESULTS

The overall specificity and sensitivity of cytologic examination were 100% and 63%, respectively. K-ras mutation testing was performed using ddPCR, and the sensitivity increased to 87% with specificity 90%. The SNV assay detected at least 1 variant in 90% of pancreatic ductal adenocarcinoma samples; the test was able to detect 2 K-ras codon 61 mutations in 2 cases of pancreatic ductal adenocarcinoma, which were missed by ddPCR. The overall diagnostic accuracy of the cytologic examination alone was 74%, and it increased to 91% when the results of both molecular tests were considered for the cases with negative and inconclusive results.

CONCLUSIONS

The current study illustrated that integration of K-ras analysis with cytologic evaluation, especially in inconclusive cases, can enhance the diagnostic accuracy of EUS-FNA for pancreatic lesions.

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.

The "Twist-Needle" - a new concept for endoscopic ultrasound-guided fine needle-biopsy

Background and study aims  Endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) represents a standard method for tissue acquisition of lesions adjacent to the gastrointestinal wall. Needles of 19 gauge acquire more tissue than needles with a smaller diameter, but are often unable to penetrate solid, rigid masses. In this study we evaluated a novel prototype that links forward movement of the needle to rotation of the needle tip. Materials and methods  Two needle-models that generate either a regular axial movement or a combination of axial movement with rotation of the needle tip were compared ex vivo for measurement of pressure needed to penetrate artificial tissue. Furthermore, a standard 19-gauge EUS-FNB needle was compared to a modified model ("Twist Needle") in an ex vivo model to measure the amount of tissue obtained. Results  Pressure measurements using the rotating needle revealed that significantly less pressure is needed for penetration compared to the regular axial movement (mean ± SEM; 3.7 ± 0.3 N vs. 5.5 ± 0.3 N). Using the modified 19-gauge "Twist Needle" did not diminish tissue acquisition measured by surface amount compared to a standard needle (37 ± 5 mm² vs. 35 ± 6 mm²). Conclusion  The method of rotation of an EUS-FNB needle tip upon forward movement requires less pressure for penetration but does not diminish tissue acquisition. Hence, the concept of our "Twist Needle" may potentially reduce some of the current limitations of standard EUS-FNB.

Spatial-domain low-coherence quantitative phase microscopy to improve the cytological diagnosis of pancreatic cancer

Use of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) cytology to detect pancreatic cancer is limited, with a high false negative rate mainly due to the relatively fewer number of completely cancerous cells. To improve the accuracy of EUS-FNA cytological diagnosis, we evaluated a novel optical system—spatial-domain low-coherence quantitative phase microscopy (SL-QPM)—to analyze nanoscale nuclear architecture on original cytology samples, especially those diagnosed as indeterminate for malignancy, with the goal of maintaining high specificity and reducing false positive rate. We performed SL-QPM on original cytology samples obtained by EUS-FNA from 40 patients with suspicious pancreatic solid lesions (27 adenocarcinomas, 5 neuroendocrine tumor, 8 chronic pancreatitis), including 13 cases that were cytologically indeterminate. Each diagnosis had been confirmed by follow-up surgical pathology. The SL-QPM-derived nanoscale nuclear architectural parameters distinguished pancreatic cancer from cytologically indeterminate cells. A logistic regression model using nuclear entropy and SD increased the sensitivity of cytology in identifying pancreatic cancer from 72% to 94% while maintaining 100% specificity. The SL-QPM-derived nanoscale nuclear architecture properties show great promise in improving the cytological diagnosis of EUS-FNA for pancreatic cancer and could be used when traditional cytopathology does not get an accurate diagnosis, and can be easily translated into a traditional clinical device.

Predictors of Malignancies in Patients with Inconclusive or Negative Results of Endoscopic Ultrasound-guided Fine-needle Aspiration for Solid Pancreatic Masses

Background/Aims

This study analyzed the diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for pancreatic solid masses in patients with or without chronic pancreatitis as well as the clinical parameters relevant to a malignancy when EUS-FNA was negative or inconclusive.

Methods

A total of 97 patients, who underwent EUS-FNA for solid pancreatic masses over 2 years at a single institution, were evaluated. All patients underwent EUS-FNA for 3-5 passes with 22 or 25 G needles without an on-site cytopathologist. The final diagnosis was obtained by surgery or compatible clinical outcomes for a more than 12 month follow-up. The diagnostic yields in the patients with or without chronic pancreatitis were compared and the histories and laboratory data relevant to pancreatic ductal adenocarcinoma (PDAC) or pseudo-tumor were analyzed.

Results

The final diagnoses were adenocarcinoma in 88 patients (90.7%) and inflammatory pseudo-tumor in 9 (9.3%). The results of EUS-FNA were adenocarcinoma (74), suspicious (7), atypical (5), negative (10), and inadequate specimen (1). The diagnostic accuracies were 76.9% and 91.6% in patients with or without chronic pancreatitis, respectively. Among the 23 cases with non-diagnostic results of EUS-FNA, PDAC was finally diagnosed in 5 out of 7 suspicious, 3 out of 5 atypical, and 5 out of 10 negative cytology cases. The clinical parameters related to a pseudo-tumor were a history of alcohol consumption and pancreatitis, and normal alkaline phosphatase levels.

Conclusions

The diagnostic accuracy of pancreatic masses in the background of chronic pancreatitis was low. When EUS-FNA produced inconclusive results, the histories of alcohol consumption, pancreatitis, and serum levels of alkaline phosphatase are useful for making a final diagnosis.

Indeterminate diagnoses in EUS-guided FNA of the pancreas: analysis of cytologist and clinician perceptions, cytologic features, and clinical outcomes

INTRODUCTION

Indeterminate "atypical" or "suspicious for malignancy" diagnoses in the evaluation of pancreatic fine-needle aspiration (FNA) specimens can present challenges in the clinical management of patients with pancreatic masses. A main goal of this study was to identify, via survey, potential differences in perception between cytologists and clinicians with regard to the implications of, and factors contributing to, indeterminate diagnoses. We also evaluated clinical practice at our institution as it relates to such diagnoses and identified clinicopathologic features associated with indeterminate diagnoses, which allowed for correlation with survey results.

MATERIALS AND METHODS

Online surveys were sent to cytologists and clinicians to gather information on the respondents' experiences with pancreatic endoscopic ultrasound-guided FNA and their perceptions about the indeterminate diagnostic categories. Cytological specimens and patient medical records were reviewed to collect data on specimen acquisition, cytological features, tumor characteristics, and patient management.

RESULTS

Survey responses revealed that cytologists and clinicians held similar perceptions of the clinical impact of the indeterminate categories but had dissimilar ideas on the factors contributing to these diagnoses. Statistically significant associations were identified between indeterminate diagnoses and the following variables: number of passes performed; adequacy on rapid on-site evaluation; repeat FNA procedures; lesions with cystic changes; and well-differentiated tumor cytomorphology.

CONCLUSIONS

Awareness of the perceptions of cytologists and clinicians about, as well as the clinical features and cytologic variables associated with, "indeterminate" cases has the potential to improve patient care.

Follow-up of indeterminate cytologic diagnoses of solid pancreatic lesions: atypia versus suspicious (one institution's experience)

INTRODUCTION

A comparison of the long-term risk of malignancy between indeterminate cytological diagnoses, namely, atypical versus suspicious for malignancy, from endoscopic ultrasound-guided (EUS) fine-needle aspiration (FNA) of a pancreatic mass has not been well characterized. The primary aim of this study was to compare the risk of malignancy between patients with such indeterminate diagnoses. Secondarily, we investigated whether serologic markers serve as predictors of risk of malignancy in the setting of indeterminate cytological diagnoses.

MATERIALS AND METHODS

We reviewed 484 cases of EUS-FNA on solid pancreatic lesions, performed at a single academic tertiary care center from 2004 to 2017. Patients with solid pancreas mass lesions who had atypical or suspicious final cytology were identified for further clinical outcome analysis.

RESULTS

Of the 484 patients with pancreas mass lesions, 53 (11%) were given an indeterminate final cytologic diagnosis, with 28 atypical and 25 suspicious for malignancy. Follow-up was completed for 22 and 20 patients from atypical and suspicious diagnoses, respectively. Of patients with follow-up, 15 (68%) and 18 (90%) had subsequent diagnoses of malignancy from atypical and suspicious groups, respectively. There was no statistical difference in predicting risk of malignancy between the two groups (P = 0.24). Serologic markers were available in 29 of 42 patients with follow-up. Serologic markers were elevated in 21 of 29 patients and all were subsequently diagnosed with malignancy. Elevated serologic markers correlated with future risk of malignancy (P = 0.0026).

CONCLUSION

The risk of subsequent malignancy is high for both atypical and suspicious pancreatic solid lesions but there exists no statistical difference between the two. Combined serologic markers with indeterminate cytology proved to be a good predictor of malignancy.

Clinical features, onsite evaluation, and follow-up results in patients with suspicious for adenocarcinoma on EUS-guided FNA of pancreas

BACKGROUND

Occasionally, an interpretation of suspicious for adenocarcinoma is made for endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) of pancreas. In this study, we aimed to assess onsite evaluation and follow-up results for FNAs with suspicious for adenocarcinoma (FNA-SUS) in order to identify likely factors that are associated with this interpretation.

DESIGN

A total of 53 pancreatic FNA-SUS cases and 149 pancreatic FNAs with an interpretation of adenocarcinoma (FNA-ADC) were included in current study. Clinical characteristics, onsite evaluation results, and follow-up results were collected and analyzed.

RESULTS

Compared with FNA-ADC category, FNA-SUS category was associated with increased cystic/ill-defined lesions on imaging, increased frequency of inadequate materials (onsite evaluation), increased total smear/slide number, and increased number of cases with limited materials on permanent slides/sections. For follow-up resections, 21% of FNA-SUS cases (7 of 34) showed benign, dysplastic changes or neuroendocrine tumors and 79% (27 of 34) showed adenocarcinoma with increased frequency of well-differentiated type. In contrast, all FNA-ADC cases showed adenocarcinoma. The average age of those 7 FNA-SUS cases with non-adenocarcinoma on follow-up was significantly younger than that of 27 cases with adenocarcinoma. FNA-SUS cases with adenocarcinoma on follow-up showed even greater frequency of inadequate materials during onsite evaluation and more increased total smear slide number than FNA-ADC cases.

CONCLUSION

Our data demonstrated several clinicopathologic factors that are likely associated with a suspicious cytology. In younger patients with suspicious cytology and non-mass forming lesion, surgical management should be taken with caution as a considerable percentage of patients showed only benign or low-grade dysplastic changes.

Variation of cytopathologists' use of the indeterminate diagnostic categories "atypical" and "suspicious for malignancy" in the cytologic diagnosis of solid pancreatic lesions on endoscopic ultrasound-guided fine-needle aspirates

Indeterminate cytologic diagnoses in endoscopic ultrasound guided fine needle aspiration biopsy (EUS-FNA) of solid pancreatic lesions include the diagnostic categories "atypical" (ATY) and "suspicious for malignancy" (SUSP), which are used at variable rates and are associated with variable underlying risk of malignancy. The aim of this study was to determine individual cytopathologists' rates of indeterminate diagnoses in EUS-FNA of solid pancreatic lesions and their relationship to cytopathologists' experience and volume of pancreatic EUS-FNA examined, as well as the potential impact of departmental consensus review on indeterminate diagnoses.

DESIGN

The diagnostic rates of ATY and SUSP and their underlying risk of malignancy were calculated for six cytopathologists who diagnosed 1,114 of 1,225 EUS-FNA of solid pancreatic lesions from 1/1/2001 to 9/15/2014, and were then compared for the periods before and after the implementation of departmental consensus review during 2009.

RESULTS

The six cytopathologists diagnosed 10% of cases as indeterminate; 82 (7.4%) as "atypical" and 29 (2.6%) as "suspicious". The individual cytopathologists' indeterminate diagnosis rates varied twofold (6.67-12.80%) and did not correlate with their experience, total or annual volume of EUS-FNAs. Of the 56/99 (56.57%) cases with follow-up, the underlying rate of malignancy was 47% (35/75; for "atypical" and 87.5% (21/24); for "suspicious"). The underlying rates of malignancy were 33-67% for "atypical" and 80-100% for "suspicious" diagnoses made by individual cytopathologists. The rate of indeterminate diagnoses decreased from 11.55 to 7.88% after the implementation of departmental consensus review.

CONCLUSION

Individual cytopathologists' rates of indeterminate diagnoses and their significance vary; however, consensus review is helpful in reducing these rates. Diagn. Cytopathol. 2017;45:3-13. © 2016 Wiley Periodicals, Inc.

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.

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.

Standardized terminology and nomenclature for pancreatobiliary cytology: The Papanicolaou Society of Cytopathology Guidelines

The Papanicolaou Society of Cytopathology has developed a set of guidelines for pancreatobiliary cytology including indications for endoscopic ultrasound (EUS) guided fine-needle aspiration (FNA) biopsy, techniques of EUS-FNA, terminology and nomenclature of pancreatobiliary disease, ancillary testing and post-biopsy treatment and management. All documents are based on the expertise of the authors, a review of the literature, discussion of the draft document at several national and international meetings over an 18 month period and synthesis of online comments of the draft document on the Papanicolaou Society of Cytopathology web site [www.papsociety.org]. This document selectively presents the results of these discussions and focuses on a proposed standardized terminology scheme for pancreatobiliary specimens that correlate cytological diagnosis with biological behavior and increasingly conservative patient management of surveillance only. The proposed terminology scheme recommends a six-tiered system: Non-diagnostic, negative, atypical, neoplastic [benign or other], suspicious and positive. Unique to this scheme is the “neoplastic” category separated into “benign” (serous cystadenoma) or “other” (premalignant mucinous cysts, neuroendocrine tumors and solid-pseudopapillary neoplasms (SPNs)). The positive or malignant category is reserved for high-grade, aggressive malignancies including ductal adenocarcinoma, acinar cell carcinoma, poorly differentiated neuroendocrine carcinomas, pancreatoblastoma, lymphoma and metastases. Interpretation categories do not have to be used. Some pathology laboratory information systems require an interpretation category, which places the cytological diagnosis into a general category. This proposed scheme provides terminology that standardizes the category of the various diseases of the pancreas, some of which are difficult to diagnose specifically by cytology. In addition, this terminology scheme attempts to provide maximum flexibility for patient management, which has become increasingly conservative for some neoplasms.

Guidelines for pancreaticobiliary cytology from the Papanicolaou Society of Cytopathology: A review

The newest installment on state-of-the-art standards of practice in cytopathology from the Papanicolaou Society of Cytopathology (PSC) focuses on the pancreaticobiliary system. Similar to the National Cancer Institute recommendations for aspiration cytology of the thyroid, the PSC guidelines for pancreaticobiliary cytology addresses indications, techniques, terminology and nomenclature, ancillary studies, and postprocedure management. Each committee was composed of a multidisciplinary group of experts in diagnosing, managing, and treating patients with pancreaticobiliary disease. Draft documents were posted on an interactive Web-based forum hosted by the PSC Web site (www.papsociety.org) and the topics of terminology, ancillary testing, and management were presented at national and international meetings over an 18-month period for discussion and feedback from practicing pathologists around the world. This review provides a synopsis of these guidelines.