Cytologic predictors of malignancy in bile duct brushings: a multi-reviewer analysis of 60 cases

Comprehensive Approach to Cytomorphology in Liquid-Based Bile Duct Brush Cytology: Integrating Cell Blocks and Histology

Bile duct brush cytology is a widely used and essential method for evaluating biliary tract lesions, although it remains challenging for pathologists. Liquid-based preparations provide a better vision of morphology and enable the preparation of cell blocks, thereby enhancing reliability. However, the establishment of reproducible interpretation criteria and utilization of cell blocks remain limited. This study aimed to investigate the morphological features of liquid-based cytology using objective and reproducible criteria, incorporating histological findings to identify diagnostic features. In total, 151 cases were selected and 42 morphologic criteria were evaluated within representative clusters. Notably, 14 features, including conventional cytologic features, significantly differed between the benign and malignant groups. Malignant cell clusters were more likely to be irregularly shaped and have larger nuclear sizes, increased nuclear pleomorphism, a non-euchromatic chromatin pattern, and a higher nucleus-to-cytoplasm (N/C) ratio. Multinucleation and nuclear molding were observed exclusively in malignant cases. The presence of inflammatory cells did not differ significantly between benign and malignant cases. An increased N/C ratio was observed in the cell blocks and the architectural information aided in diagnosis. The application of cell blocks may be beneficial, emphasizing the significance of nuclear pleomorphism. We also categorized features by analyzing the sensitivity, specificity, and importance of various features. In summary, our study reaffirms the importance of conventional cytomorphologic features in liquid-based preparations of bile duct cytology and suggests a diagnostic approach with more objective morphologic criteria, highlighting the utility of cell blocks.

Diagnostic Pearls and Pitfalls in the Evaluation of Small Biopsies From the Bile Duct and Ampulla

CONTEXT.—

Histopathologic evaluation of bile duct and ampullary biopsies can be challenging. Biopsies from these sites are often tiny, scant, and/or fragmented. When assessing these biopsies, there is significant overlap between reactive atypia and malignancy, in situ precursor lesions can be misinterpreted as malignancy, and nonprimary tumors can mimic primary disease.

OBJECTIVE.—

To provide diagnostic pearls and pitfalls in the evaluation of small biopsies from the biliary tract.

DATA SOURCES.—

Literature review of published studies and the author's own observations.

CONCLUSIONS.—

Because the procedures for obtaining specimens from the bile duct and ampulla are invasive, pathologists need to try to make definitive diagnoses. Diagnostic clues/pearls, ancillary studies, and recognition of various pitfalls can assist in providing accurate and confident diagnoses.

The World Health Organization Reporting System for Pancreaticobiliary Cytopathology: Overview and Summary

The recently published WHO Reporting System for Pancreaticobiliary Cytopathology (World Health Organization [WHO] System) is an international approach to the standardized reporting of pancreaticobiliary cytopathology, updating the Papanicolaou Society of Cytopathology System for Reporting Pancreaticobiliary Cytology (PSC System). Significant changes were made to the categorization of benign neoplasms, intraductal neoplasms, mucinous cystic neoplasms, and malignant neoplasms considered low grade. Benign neoplasms, such as serous cystadenoma, categorized as Neoplastic: benign in the PSC system, are categorized as Benign/negative for malignancy in the WHO system. Pancreatic neuroendocrine tumor, solid-pseudopapillary neoplasm, and gastrointestinal stromal tumor, categorized as Neoplastic: other in the PSC system, are categorized as Malignant in the WHO System in accord with their classification in the 5th edition WHO Classification of Digestive System Tumours (2019). The two new categories of Pancreaticobiliary Neoplasm Low-risk/grade and Pancreaticobiliary Neoplasm High-risk/grade are mostly limited to intraductal neoplasms and mucinous cystic neoplasms. Low-risk/grade lesions are mucinous cysts, with or without low-grade epithelial atypia. High-risk/grade lesions contain neoplastic epithelium with high-grade epithelial atypia. Correlation with clinical, imaging, and ancillary studies remains a key tenet. The sections for each entity are written to highlight key cytopathological features and cytopathological differential diagnoses with the pathologist working in low resource setting in mind. Each section also includes the most pertinent ancillary studies useful for the differential diagnosis. Sample reports are provided for each category. Finally, the book provides a separate section with risk of malignancy and management recommendations for each category to facilitate decision-making for clinicians.

Dysplasia and Early Carcinoma of the Gallbladder and Bile Ducts: Terminology, Classification, and Significance

Most precursor lesions and early cancerous changes in the gallbladder and bile ducts present as clinically/grossly inapparent lesions. Low-grade dysplasia is difficult to define and clinically inconsequential by itself; however, extra sampling is required to exclude accompanying significant lesions. For high-grade dysplasia ('carcinoma in situ'), a complete sampling is necessary to rule out invasion. Tumoral intramucosal neoplasms (ie, intracholecystic and intraductal neoplasia) form radiologically/grossly visible masses, and they account for (present in the background of) about 5% to 10% of invasive cancers of the region. These reveal a spectrum of papilla/tubule formation, cell lineages, and dysplastic transformation. Some subtypes such as intracholecystic tubular non-mucinous neoplasm of the gallbladder (almost never invasive) and intraductal oncocytic or intraductal tubulopapillary neoplasms of the bile ducts (may have a protracted clinical course even when invasive) are to be noted separately. Other types of intracholecystic/intraductal neoplasia have a high frequency of invasive carcinoma and progressive behavior, which often culminates in mortality.

Identification of a novel bile marker clusterin and a public online prediction platform based on deep learning for cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CCA) is a highly aggressive malignant tumor, and its diagnosis is still a challenge. This study aimed to identify a novel bile marker for CCA diagnosis based on proteomics and establish a diagnostic model with deep learning.

METHODS

A total of 644 subjects (236 CCA and 408 non-CCA) from two independent centers were divided into discovery, cross-validation, and external validation sets for the study. Candidate bile markers were identified by three proteomics data and validated on 635 clinical humoral specimens and 121 tissue specimens. A diagnostic multi-analyte model containing bile and serum biomarkers was established in cross-validation set by deep learning and validated in an independent external cohort.

RESULTS

The results of proteomics analysis and clinical specimen verification showed that bile clusterin (CLU) was significantly higher in CCA body fluids. Based on 376 subjects in the cross-validation set, ROC analysis indicated that bile CLU had a satisfactory diagnostic power (AUC: 0.852, sensitivity: 73.6%, specificity: 90.1%). Building on bile CLU and 63 serum markers, deep learning established a diagnostic model incorporating seven factors (CLU, CA19-9, IBIL, GGT, LDL-C, TG, and TBA), which showed a high diagnostic utility (AUC: 0.947, sensitivity: 90.3%, specificity: 84.9%). External validation in an independent cohort (n = 259) resulted in a similar accuracy for the detection of CCA. Finally, for the convenience of operation, a user-friendly prediction platform was built online for CCA.

CONCLUSIONS

This is the largest and most comprehensive study combining bile and serum biomarkers to differentiate CCA. This diagnostic model may potentially be used to detect CCA.

Automated analysis of computerized morphological features of cell clusters associated with malignancy on bile duct brushing whole slide images

BACKGROUND

Bile duct brush specimens are difficult to interpret as they often present inflammatory and reactive backgrounds due to the local effects of stricture, atypical reactive changes, or previously installed stents, and often have low to intermediate cellularity. As a result, diagnosis of biliary adenocarcinomas is challenging and often results in large interobserver variability and low sensitivity OBJECTIVE: In this work, we used computational image analysis to evaluate the role of nuclear morphological and texture features of epithelial cell clusters to predict the presence of pancreatic and biliary tract adenocarcinoma on digitized brush cytology specimens.

METHODS

Whole slide images from 124 patients, either diagnosed as benign or malignant based on clinicopathological correlation, were collected and randomly split into training (ST , N = 58) and testing (Sv , N = 66) sets, with the exception of cases diagnosed as atypical on cytology were included in Sv . Nuclear boundaries on cell clusters extracted from each image were segmented via a watershed algorithm. A total of 536 quantitative morphometric features pertaining to nuclear shape, size, and aggregate cluster texture were extracted from within the cell clusters. The most predictive features from patients in ST were selected via rank-sum, t-test, and minimum redundancy maximum relevance (mRMR) schemes. The selected features were then used to train three machine-learning classifiers.

RESULTS

Malignant clusters tended to exhibit lower textural homogeneity within the nucleus, greater textural entropy around the nuclear membrane, and longer minor axis lengths. The sensitivity of cytology alone was 74% (without atypicals) and 46% (with atypicals). With machine diagnosis, the sensitivity improved to 68% from 46% when atypicals were included and treated as nonmalignant false negatives. The specificity of our model was 100% within the atypical category.

CONCLUSION

We achieved an area under the receiver operating characteristic curve (AUC) of 0.79 on Sv , which included atypical cytological diagnosis.

Cytopathology of Inflammatory Lesions of the Pancreatobiliary Tree

CONTEXT.—

A variety of inflammatory processes affect the pancreatobiliary tree. Some form mass lesions in the pancreas, mimicking pancreatic ductal adenocarcinoma, and others cause strictures in the bile ducts, mimicking cholangiocarcinoma. Acute pancreatitis, chronic pancreatitis, autoimmune pancreatitis, and paraduodenal groove pancreatitis have distinct cytopathologic features that, when correlated with clinical and imaging features, may lead to correct classification preoperatively. In biliary strictures sampled by endobiliary brushing, the uniform features are the variable presence of inflammation and reactive ductal atypia. A potential pitfall in the interpretation of pancreatobiliary fine-needle aspiration and duct brushing specimens is ductal atypia induced by the reactive process. Recognizing cytologic criteria that differentiate reactive from malignant epithelium, using ancillary testing, and correlating these features with clinical and imaging findings can lead to the correct preoperative diagnosis.

OBJECTIVE.—

To summarize the cytomorphologic features of inflammatory processes in the pancreas, describe the cytomorphology of atypia in pancreatobiliary specimens, and review ancillary studies applicable for the differential diagnosis of benign from malignant ductal processes for the purpose of best pathology practice.

DATA SOURCES.—

A PubMed review was performed.

CONCLUSIONS.—

Accurate preoperative diagnosis of benign and malignant processes in the pancreatobiliary tract can be achieved with application of diagnostic cytomorphologic criteria and correlation of ancillary studies with clinical and imaging findings.

Pronounced squamous cell contamination in biliary tract cytology: A diagnostic pitfall

Squamous cells are rarely found in biliary tract cytology specimens, and when present are typically scant in quantity. Over an 8-year time period, two cases at our institution reporting abundant squamous cells were identified. Both patients underwent endoscopic retrograde cholangiopancreatography with bile duct brushings and removal of a migrated biliary stent. The migrated stents were retrieved using rat toothed forceps and required removal of the endoscope through the esophagus with the stent exposed to esophageal and oral mucosa outside of the endoscope. Cytologic examination of the accompanying biliary stent material accordingly revealed abundant benign squamous cells. However, bile duct brushings showed benign ductal epithelial cells without squamous cells. Prior and subsequent cytology and bile duct surgical pathology specimens did not show squamous metaplasia. Migrated biliary stents that require endoscopic withdrawal increase the risk of contaminating samples with squamous cells. Recognition of this unique scenario is important, as the differential diagnosis includes squamous metaplasia and squamous neoplasia.

Biliary cytology: A diagnostic tree for adenocarcinoma based on a cohort of 135 patients with endoscopic retrograde cholangiopancreatography for stenosis of the extrahepatic bile duct

BACKGROUND

The diagnosis of well-differentiated adenocarcinoma on bile aspiration is a well-known challenge. This study was aimed at improving the diagnostic performance and providing a biliary cytology learning atlas.

METHODS

This single-center, retrospective study included 135 cases of informative biliary samples collected between 2009 and 2018 that were classified as benign, atypical, or malignant. A double assessment was performed by a novice and a cytopathologist experienced in biliary cytology to establish the specificities, sensitivities, and inter- and intraobserver κ index agreements of 24 cytological criteria, which were illustrated in a learning atlas.

RESULTS

A multivariate logistic regression was used to assess whether the most specific and reproducible criteria were associated with malignancy. A scoring system was statistically determined: 6 points were attributed in the presence of a 3-dimensional (3D) cluster, anisonucleosis, and a nuclear to cytoplasmic (N:C) ratio > 0.5, whereas 4 points were given in the presence of an enhanced nuclear membrane. A score higher than 10 points resulted in a malignancy diagnosis with 96% sensitivity and 97% specificity.

CONCLUSIONS

A diagnostic tree of malignancy based on 4 criteria, together with a multidisciplinary approach, allows the diagnosis of adenocarcinoma with a specificity of 100% and a sensitivity of 88% or 72% depending on the presence of a single malignant cell or the presence of 3 combined criteria (a 3D cluster, anisonucleosis, and an N:C ratio > 0.5). It comes with a learning atlas useful for cytopathologist training and accuracy in this uncommon cytology.

Cytological Scoring for Pancreatic Specimens Obtained by Endoscopic Ultrasound-Guided Fine Needle Aspiration

OBJECTIVE

Cytological diagnosis of pancreatic specimens obtained by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is often challenging because of the small sample size or well-differentiated adenocarcinoma with weak cytological atypia. Therefore, the sensitivity and specificity of cytological diagnosis for pancreatic cancer should be improved. Hence, we aimed to clarify the utility of cytological scoring to distinguish malignant from benign lesions for the cytological diagnosis of pancreatic EUS-FNA specimens.

METHODS

Seven reviewers, including four cytotechnologists and three medical doctors, evaluated 20 morphological indices in pancreatic specimens obtained by EUS-FNA (malignant, n=111, benign, n=31). Statistical analyses were performed using Fisher's exact test, logistic regression analysis, the area under the receiver operating characteristic curve, and Youden index.

RESULTS

Among the 20 indices, there was a high incidence rate (> 40%) of the following 13 indices in malignant cases: irregular structure, hyperchromatic nucleus, irregular cell polarity, unclear cell boundaries, nuclear membrane thickening, anisonucleosis, overlapping, irregular nuclei, high nuclear/cytoplasmic ratio, binding decline, the simultaneous appearance of malignant and benign cells, enlarged nucleoli, and background necrosis. When we diagnosed pancreatic specimens using these 13 cytological indices, the cutoff value of 8/9 showed the highest Youden index (0.950) as well as high sensitivity and specificity in distinguishing malignant from benign specimens (98% and 97%, respectively).

CONCLUSION

Thirteen cytological indices showed high sensitivity and specificity in differentiating malignant and benign lesions using pancreatic EUS-FNA samples. All 13 indices were important for diagnosing malignancy in the pancreatic cytology smear of EUS-FNA. Further validation studies are required.

Biliary Strictures and Cholangiocarcinoma - Untangling a Diagnostic Conundrum

Cholangiocarcinoma is an uncommon and highly aggressive biliary tract malignancy with few manifestations until late disease stages. Diagnosis is currently achieved through a combination of clinical, biochemical, radiological and histological techniques. A number of reported cancer biomarkers have the potential to be incorporated into diagnostic pathways, but all lack sufficient sensitivity and specificity limiting their possible use in screening and early diagnosis. The limitations of standard serum markers such as CA19-9, CA125 and CEA have driven researchers to identify multiple novel biomarkers, yet their clinical translation has been slow with a general requirement for further validation in larger patient cohorts. We review recent advances in the diagnostic pathway for suspected CCA as well as emerging diagnostic biomarkers for early detection, with a particular focus on non-invasive approaches.

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.

Benign biliary neoplasms and biliary tumor precursors

Benign biliary tumor are common lesions that are often an incidental finding in subjects who undergo medical imaging tests for other conditions. Most are true neoplasms while few result from reactive or malformative proliferation. Benign tumors have no clinical consequences, although the premalignant nature or potential for malignant transformation is of concern in some cases. The main practical problem for pathologists is the need to differentiate them from malignant biliary tumours, which is not always straightforward. Premalignant lesions of the bile duct have been described, although their incidence has been poorly characterized. These lesions include biliary mucinous cystic neoplasms, intraductal papillary neoplasms of the bile duct, and biliary intraepithelial neoplasia. In this article, histopathology of benign biliary tumors and biliary tumor precursors is discussed, with a focus on the main diagnostic criteria.

Evaluation and Pathologic Classification of Choledochal Cysts: Clinicopathologic Analysis of 84 Cases From the West

Choledochal cyst (CC) is believed to be a mostly Asian disorder. As a clinically defined entity, its pathologic correlates are poorly characterized. Eighty-four resected CCs from the West were reanalyzed. After applying established Japanese criteria, 9/66 with available imaging were disqualified and 10/39 with preoperative cyst typing had to be recategorized. None had been diagnosed with, or evaluated for, pancreatobiliary maljunction, but on retrospective analysis of radiologic images, 12/66 were found to have pancreatobiliary maljunction. The clinical findings were: F/M=5.7; mean age, 48; most (77%) presented with abdominal pain; mean size, 2.9 cm; choledocholithiasis 11%. Gross/histologic examination revealed 3 distinct pathology-based categories: (I) Cystic dilatation of native ducts (81%). (II) Double bile duct (13%), almost all of which were found in women (10/11); all were diagnosed by pathologic examination, and not preoperative diagnosis. (III) Gastrointestinal (GI) duplication type (6%). Microscopic findings of the entire cohort included mucosal-predominant lymphoplasmacytic inflammation (50%), follicular cholangitis (7%), mucosal hyperplasia (43%; 13% with papillae), intestinal metaplasia (10%), BilIN-like hyperplasia (17%), erosion/ulceration (13%), and severe dysplasia-mimicking atypia including "detachment atypia" and micropapillary degeneration (11%). Carcinomatous changes were seen in 14 cases (17%) (high-grade dysplasia/carcinoma in situ in 7, intraductal papillary neoplasm 1, and invasive carcinoma 6); and 13/14 of these occurred in pathologic category I, all with cyst size >1 cm. In conclusion, diagnostic imaging guidelines used in Asia are not routinely used (but should be adopted) in the West. Pathologically, cases designated as CC are classifiable in 3 groups: category 1 (dilated native duct type), more prone to carcinomatous change; category 2, double-duct phenomenon (all but 1 being female in this study); and category 3, GI-type duplication. Overall, 17% of CCs show carcinomatous change (50% of them invasive). CC specimens should be carefully examined with this classification and submitted entirely for assessment of at-risk mucosa and cancerous transformation.

Cytologic Assessment of Cystic/Intraductal Lesions of the Pancreatobiliary Tract

CONTEXT.—

Because of new and improved imaging techniques, cystic/intraductal pancreatobiliary tract lesions are increasingly being discovered, and brushings or endoscopic ultrasound/computed tomography/magnetic resonance imaging-guided fine-needle aspiration biopsies from these lesions have become an integral part of pathologists' daily practice. Because patient management has become increasingly conservative, accurate preoperative diagnosis is critical. Cytologic distinction of low-risk (pseudocysts, serous cystadenoma, lymphoepithelial cysts, and squamoid cysts of the pancreatic duct) from high-risk pancreatic cysts (intraductal papillary mucinous neoplasm and mucinous cystic neoplasm) requires incorporation of clinical, radiologic, and cytologic findings, in conjunction with chemical and molecular analysis of cyst fluid. Cytopathologists must ensure appropriate specimen triage, along with cytologic interpretation, cyst classification, and even grading of some (mucinous) cysts. Epithelial atypia in mucinous cysts (intraductal papillary mucinous neoplasm and mucinous cystic neoplasm) has transitioned from a 3-tiered to a 2-tiered classification system, and intraductal oncocytic papillary neoplasms and intraductal tubulopapillary neoplasms have been separately reclassified because of their distinctive clinicopathologic characteristics. Because these lesions may be sampled on brushing or fine-needle aspiration biopsy, knowledge of their cytomorphology is critical.

OBJECTIVE.—

To use an integrated, multidisciplinary approach for the evaluation of cystic/intraductal pancreatobiliary tract lesions (incorporating clinical, radiologic, and cytologic findings with [chemical/molecular] cyst fluid analysis and ancillary stains) for definitive diagnosis and classification.

DATA SOURCES.—

Review of current literature on the cytopathology of cystic/intraductal pancreatobiliary tract lesions.

CONCLUSIONS.—

Our knowledge/understanding of recent updates in cystic/intraductal pancreatobiliary lesions can ensure that cytopathologists appropriately triage specimens, judiciously use and interpret ancillary studies, and incorporate the studies into reporting.

Tiny but mighty: use of next generation sequencing on discarded cytocentrifuged bile duct brushing specimens to increase sensitivity of cytological diagnosis

Bile duct brushing (BDB) is used to evaluate pancreatobiliary lesions as it widely samples lesions with a low complication rate. Cytological evaluation of BDB is a specific but insensitive test. There is limited literature on the use of post-cytocentrifuged (PCC) samples, which are usually discarded, for next-generation sequencing (NGS) as an adjunct to cytological diagnosis of BDB. In this study we investigate whether molecular analysis by NGS of PCC specimens improves the sensitivity of diagnosis. PCC samples from 100 consecutive BDB specimens spanning 93 unique patients were retained. DNA was extracted and mutational analysis was performed agnostic of morphologic or clinical findings. Each BDB specimen was characterized as negative, atypical or positive based on morphological analysis by trained cytopathologists. Performance characteristics for mutational profiling and morphological analysis were calculated on the basis of clinicopathologic follow-up. There was sufficient clinicopathologic follow-up to classify 94 of 100 cases as either malignant (n = 43) or benign (n = 51). Based on morphologic analysis of cytology, these 94 cases were classified as either benign (n = 55), atypical (n = 18), or as at least suspicious or positive for malignancy (n = 21). Morphologic analysis of cytology showed a sensitivity of 49% and a specificity of 100% if atypical cases were considered negative. NGS revealed oncogenic alterations in 40/43 (93%) of malignant cases based on clinicopathologic follow-up. The most common alterations were in KRAS and TP53, observed in 77% and 49% of malignant cases respectively. No alterations were observed in the 51 benign cases classified based on clinicopathologic follow-up. Supplementing cytomorphologic analysis with molecular profiling of PCC by targeted NGS analysis increased the sensitivity to 93% and maintained specificity at 100%. This study provides evidence for the utility of NGS molecular profiling of PCC specimens to increase the sensitivity of BDB cytology samples, although studies with larger cohorts are needed to verify these findings.

Effect of single operator cholangioscopy on accuracy of bile duct cytology

INTRODUCTION

This is the first study to evaluate the accuracy of bile duct brushings since the introduction of single operator cholangioscopy SpyGlass DS system in 2015. The primary aim of our study was to compare the accuracy of cytology brushings against biopsies obtained at endoscopic retrograde cholangiopancreatography (ERCP) and cholangioscopy.

METHOD

A retrospective search for bile duct brushing specimens was performed and the charts reviewed. The gold standard for definitive diagnosis of malignancy was surgical tissue or compelling clinical evidence of malignancy. Definite negative diagnosis relied on lack of clinical/imaging features of malignancy on follow-up.

RESULTS

There was no significant difference in diagnostic accuracy of cytology specimens obtained at different procedures. Overall sensitivity for all methods was 59%, specificity 90% and accuracy of 82%. Notably, all four false-positive cases except for one were from patients with primary sclerosing cholangitis or primary biliary sclerosis. There was no significant difference in sensitivity or specificity between biopsies procured by the two methods. The combined biopsy sensitivity for all modalities was 44% with a specificity of 100%. There was 70% concordance between cytology and biopsy cases. The overall specificity and sensitivity of the combined cytology and biopsy result was 85% and 65.3%, respectively. Ranking of factors that predict clinical diagnosis shows cytology results to surpass other parameters including pancreatic mass, age and stenosis length. Similarly, the presence of two cell populations and three-dimensional clusters was not nearly as predictive of malignancy as single malignant cells.

CONCLUSION

Biliary brush cytology specimens performed better than biopsies irrespective of whether they are procured during ERCP or cholangioscopy. The combination of cytology and biopsy had the best accuracy than either one alone.

Pancreatic Cytology

The diagnostic approach to pancreaticobiliary disease requires a multidisciplinary team in which the cytopathologist plays a crucial role. Fine-needle aspiration, obtained by endoscopic ultrasound, is the diagnostic test of choice for pancreatic lesions. Preoperative clinical management depends on many factors, many of which rely on accurate cytologic assessment. Pancreaticobiliary cytology is wrought with diagnostic pitfalls. Clinical history, imaging studies, cytology samples, and ancillary tests, including immunohistochemistry, biochemical analysis, and genetic sequencing, are integral to forming a complete diagnosis and guiding optimal patient management. This article reviews clinical aspects and the diagnostic work-up of commonly encountered diagnostic entities within the field of pancreatic cytology.

Factors Impacting the Performance Characteristics of Bile Duct Brushings: A Clinico-Cytopathologic Analysis of 253 Patients

Context.—

Literature on factors impacting bile duct brushings (BDBs) performance characteristics remain limited.

Objective.—

To capture the current state of daily practice with BDB sign-out.

Design.—

Two hundred fifty-three of 444 BDBs signed out by more than 7 cytopathologists, with histopathologic and/or clinical follow-up of at least 18 months, were examined.

Results.—

One hundred thirty-five of 253 BDBs (53%) had histologically confirmed malignancies, 22 (9%) had cancer-related deaths, and 96 (38%) were benign. Cytologic diagnoses in the 444 BDBs were nondiagnostic (11 [2.5%]), negative (284 [64%]), atypical (62 [13.9%]), suspicious (34 [7.7%]), and malignant (53 [11.9%]). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of malignancy detection were 35%, 100%, 100%, 58%, and 66%, respectively. When atypical, suspicious, and malignant (ASM) categories were combined, sensitivity increased (58%), specificity and PPV dropped (97%), and accuracy increased (73%). Carcinoma type (bile-duct versus pancreatic-ductal) had no effect on accuracy (P = .60) or diagnostic class (P = .84), nor did time of performance (first 7.5 versus latter 7.5 years, P = .13). Interestingly, ThinPrep + cell block (n = 41) had higher sensitivity (61%) and lower specificity (80%) than ThinPrep only (versus 51% and 100%, respectively). Sensitivity and specificity were higher (47% and 100%) in nonstented than stented specimens (59% and 97%). Relative risk of malignancy for “suspicious” (2.30) and “atypical” (2.28) categories was lower but not very different from that of “malignant” category (2.41).

Conclusions.—

Bile duct brushings had fairly low sensitivity but high specificity and PPV with no false positives. Sensitivity almost doubled and specificity dipped minimally when ASM categories were combined, highlighting the need for better classification criteria for atypical/suspicious cases. Higher specificity, PPV, NPV, and accuracy but lower sensitivity in stented BDBs suggest that they be called malignant only when evidence is overwhelmingly convincing.