Utilization of ancillary studies in the cytologic diagnosis of biliary and pancreatic lesions: The Papanicolaou Society of Cytopathology Guidelines

Diagnostic Assessment of Endoscopic Ultrasonography-Fine Needle Aspiration Cytology in the Pancreas: A Comparison between Liquid-Based Preparation and Conventional Smear

Background and Objectives: This study aimed to elucidate the cytologic characteristics and diagnostic usefulness of endoscopic ultrasonography-fine needle aspiration cytology (EUS-FNAC) by comparing it with liquid-based preparation (LBP) and conventional smear (CS) in pancreas. Methods: The diagnostic categories (I through VII) were classified according to the World Health Organization Reporting System for Pancreaticobiliary Cytopathology. Ten cytologic features, including nuclear and additional features, were evaluated in 53 cases subjected to EUS-FNAC. Nuclear features comprised irregular nuclear contours, nuclear enlargement, hypochromatic nuclei with parachromatin clearing, and nucleoli. Additional cellular features included isolated atypical cells, mucinous cytoplasm, drunken honeycomb architecture, mitosis, necrotic background, and cellularity. A decision tree analysis was conducted to assess diagnostic efficacy. Results: The diagnostic concordance rate between LBP and CS was 49.1% (26 out of 53 cases). No significant differences in nuclear features were observed between categories III (atypical), VI (suspicious for malignancy), and VII (malignant). The decision tree analysis of LBP indicated that cases with moderate or high cellularity and mitosis could be considered diagnostic for those exhibiting nuclear atypia. Furthermore, in CS, mitosis, isolated atypical cells, and necrotic background exerted a more significant impact on the diagnosis of EUS-FNAC. Conclusions: Significant parameters for interpreting EUS-FNAC may differ between LBP and CS. While nuclear atypia did not influence the diagnosis of categories III, VI, and VII, other cytopathologic features, such as cellularity, mitosis, and necrotic background, may present challenges in diagnosing EUS-FNAC.

Evaluating Pancreatic and Biliary Neoplasms with Small Biopsy-Based Next Generation Sequencing (NGS): Doing More with Less

Simple Summary

Pancreatic cancer and cholangiocarcinoma are aggressive diseases mostly diagnosed at an advanced and inoperable stage. This review presents the value of next-generation sequencing (NGS) when performed on small biopsies—including fine-needle aspiration/biopsy samples, brushings, pancreatic juice and bile, and also blood—in the field of pancreatobiliary neoplasia. NGS could guide physicians while evaluating pancreatic solid and cystic lesions or suspicious biliary strictures, performing surveillance in high-risk individuals, or monitoring the disease and assessing prognosis in already diagnosed cancer patients. Evidence suggests that NGS performed on small biopsies is a robust tool for the diagnosis and pre-operative risk stratification of pancreatic and biliary lesions, whereas it also carries significant prognostic and therapeutic value. However, effective standardization of the pre-analytical and analytical assay parameters used for each clinical scenario is needed to fully implement NGS into routine practice and provide more personalized management in patients with suspected or established pancreatobiliary neoplasia.

Abstract

Pancreatic cancer and cholangiocarcinoma are lethal diseases mainly diagnosed at an inoperable stage. As pancreatobiliary surgical specimens are often unavailable for further molecular testing, this review aimed to highlight the diagnostic, prognostic, and therapeutic impact of next-generation sequencing (NGS) performed on distinct small biopsies, including endoscopic ultrasound fine-needle aspirations and biopsies of pancreatic solid and cystic lesions, biliary duct brushings, and also “liquid biopsies” such as the pancreatic juice, bile, and blood. NGS could clarify indeterminate pancreatic lesions or biliary strictures, for instance by identifying TP53 or SMAD4 mutations indicating high-grade dysplasia or cancer. It could also stratify pancreatic cystic lesions, by distinguishing mucinous from non-mucinous cysts and identifying high-risk cysts that should be excised in surgically fit patients, whereas the combination of cytology, elevated cystic CEA levels and NGS could improve the overall diagnostic accuracy. When NGS is performed on the pancreatic juice, it could stratify high-risk patients under surveillance. On the plasma, it could dynamically monitor the disease course and response to therapy. Notably, the circulating tumor DNA (ctDNA) levels have been associated with staging, grading, and survival. Lastly, NGS has shown potential in identifying potentially actionable molecular alterations. In conclusion, NGS applied on small biopsies could carry significant diagnostic, prognostic, and therapeutic value.

Comparison of fine-needle aspiration and fine-needle biopsy devices for endoscopic ultrasound-guided sampling of solid lesions: a systemic review and meta-analysis

BACKGROUND

Endoscopic ultrasound (EUS)-guided tissue acquisition is extensively used, but the optimal sampling device is still a matter of debate. We performed meta-analyses on studies comparing fine-needle aspiration (FNA) with fine-needle biopsy (FNB) needles, and studies comparing different FNB needles.

METHODS

Online databases were searched for randomized controlled trials (RCTs) of at least 50 cases with a suspected solid pancreatic or nonpancreatic lesion that compared FNA with FNB needles. Outcome measures included diagnostic accuracy, adequacy, number of passes, presence of tissue cores, and adverse events. We also performed meta-regression analysis on the effect of FNB design on diagnostic accuracy. Quality was assessed using the QUADAS-2 tool.

RESULTS

18 RCTs comparing FNA with FNB needles were included. FNB provided a higher pooled diagnostic accuracy (87 % vs. 80 %; P = 0.02) and tissue core rate (80 % vs. 62 %; P = 0.002), and allowed diagnosis with fewer passes (P = 0.03), in both pancreatic and nonpancreatic lesions. A total of 93 studies were included comparing different FNB devices. Pooled diagnostic accuracy was higher for forward-facing bevel needles than for the reverse bevel needle. In this analysis, study quality was low and heterogeneity was high (I2  = 80 %).

CONCLUSION

FNB outperformed FNA when sampling pancreatic and nonpancreatic lesions. Forward-facing bevel FNB needles seemed to outperform the reverse bevel FNB needle, but the low quality of evidence prevents us from making strong recommendations on the optimal FNB design.

Intraductal papillary mucinous neoplasm of the pancreas: Cytomorphology, imaging, molecular profile, and prognosis

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) constitutes up to 20% of all pancreatic resections, and has been increasing in recent years. Histomorphological findings of IPMN are well established; however, there are not many published papers regarding the cytological findings of IPMN on fine needle aspiration (FNA) specimens. We review the cytomorphological features, molecular profile, imaging findings, and prognosis of IPMN.

METHODS

The English literature was thoroughly searched with key phrases containing IPMN.

OBSERVATIONS

IPMN is a rare entity, affecting men and women equally and is usually diagnosed at the age of 60-70 years. The characteristic imaging features include a cystic lesion with associated dilatation of the main or branch pancreatic duct, and atrophy of surrounding pancreatic parenchyma. Cytomorphological features of IPMN include papillary fragments of mucinous epithelium in a background of abundant thick extracellular mucin, a hallmark feature. IPMNs should be evaluated for high-grade dysplasia, which manifests with nuclear atypia, nuclear moulding, prominent nucleoli, nuclear irregularity, and cellular crowding. Molecular profiling of IPMN along with carcinoembryonic antigen and amylase levels is useful in predicting malignancy or high-grade dysplasia arising in IPMN. Overall, the prognosis of IPMN is excellent except in those cases with high-grade dysplasia and malignant transformation. Postoperative surveillance is required for resected IPMNs.

CONCLUSION

IPMN requires a multidisciplinary approach for management. Cytomorphological findings of IPMN on FNA, in conjunction with tumour markers in pancreatic fluid cytology and imaging findings, are of paramount importance in clinical decision-making for IPMN.

Pathologic interpretation of endoscopic ultrasound-guided fine needle aspiration cytology/biopsy for pancreatic lesions

Pathologic interpretation of endoscopic ultrasound–guided fine needle aspiration (EUS-FNA) cytology/biopsy specimens is one of the most challenging tasks in cytology and surgical pathology practice, as the procedure often yields minimal amounts of diagnostic material and contains contaminants, such as blood cells and normal intestinal mucosa. EUS-FNA cytology/biopsy will nevertheless become a more popular procedure for evaluation of various pancreatic lesions because they are difficult to approach with conventional endoscopic procedures. Pathologists should understand the structural differences and limitations of EUS-FNA that make pathologic diagnosis difficult. Ancillary tests are available for differential diagnosis of EUS-FNA for various pancreatic lesions. Immunostains are the most commonly used ancillary tests, and pathologists should able to choose the necessary panel for differential diagnosis. Pathologists should review clinical history and radiologic and/or EUS findings before selecting an immunostain panel and making a pathologic diagnosis. In addition, one’s threshold of malignancy should be adjusted according to the appropriate clinical setting to avoid under-evaluation of pathologic diagnoses. Clinico-pathologic correlation is essential in pathologic evaluation of EUS-FNA for pancreatic lesions. Pathologists can reduce errors by correlating clinical and radiologic findings when evaluating EUS-FNA. Some molecular tests can be applied in differential diagnosis of pancreatic neoplastic and cystic lesions. Molecular data should be used as supportive evidence of a specific disease entity, rather than direct evidence, and should be correlated with clinico-pathologic findings to avoid errors in pathologic diagnosis.

Agreement on endoscopic ultrasonography-guided tissue specimens: Comparing a 20-G fine-needle biopsy to a 25-G fine-needle aspiration needle among academic and non-academic pathologists

BACKGROUND AND AIM

A recently carried out randomized controlled trial showed the benefit of a novel 20-G fine-needle biopsy (FNB) over a 25-G fine-needle aspiration (FNA) needle. The current study evaluated the reproducibility of these findings among expert academic and non-academic pathologists.

METHODS

This study was a side-study of the ASPRO (ASpiration versus PROcore) study. Five centers retrieved 74 (59%) consecutive FNB and 51 (41%) FNA samples from the ASPRO study according to randomization; 64 (51%) pancreatic and 61 (49%) lymph node specimens. Samples were re-reviewed by five expert academic and five non-academic pathologists and rated in terms of sample quality and diagnosis. Ratings were compared between needles, expert academic and non-academic pathologists, target lesions, and cytology versus histological specimens.

RESULTS

Besides a higher diagnostic accuracy, FNB also provided for a better agreement on diagnosing malignancy (ĸ = 0.59 vs ĸ = 0.76, P < 0.001) and classification according to Bethesda (ĸ = 0.45 vs ĸ = 0.61, P < 0.001). This equally applied for expert academic and non-academic pathologists and for pancreatic and lymph node specimens. Sample quality was also rated higher for FNB, but agreement ranged from poor (ĸ = 0.04) to fair (ĸ = 0.55). Histology provided better agreement than cytology, but only when a core specimen was obtained with FNB (P = 0.004 vs P = 0.432).

CONCLUSION

This study shows that the 20-G FNB outperforms the 25-G FNA needle in terms of diagnostic agreement, independent of the background and experience of the pathologist. This endorses use of the 20-G FNB needle in both expert and lower volume EUS centers.

Somatic molecular analysis augments cytologic evaluation of pancreatic cyst fluids as a diagnostic tool

Objective: Better tools are needed for early diagnosis and classification of pancreatic cystic lesions (PCL) to trigger intervention before neoplastic precursor lesions progress to adenocarcinoma. We evaluated the capacity of molecular analysis to improve the accuracy of cytologic diagnosis for PCL with an emphasis on non-diagnostic/negative specimens. Design: In a span of 7 years, at a tertiary care hospital, 318 PCL endoscopic ultrasound-guided fine needle aspirations (EUS-FNA) were evaluated by cytologic examination and molecular analysis. Mucinous PCL were identified based on a clinical algorithm and 46 surgical resections were used to verify this approach. The mutation allele frequency (MAF) of commonly altered genes (BRAF, CDKN2A, CTNNB1, GNAS, RAS, PIK3CA, PTEN, SMAD4, TP53 and VHL) was evaluated for their ability to identify and grade mucinous PCL. Results: Cytology showed a diagnostic sensitivity of 43.5% for mucinous PCL due in part to the impact of non-diagnostic (28.8%) and negative (50.5%) specimens. Incorporating an algorithmic approach or molecular analysis markedly increased the accuracy of cytologic evaluation. Detection of mucinous PCL by molecular analysis was 93.3% based on the detection of KRAS and/or GNAS gene mutations (p = 0.0001). Additional genes provided a marginal improvement in sensitivity but were associated with cyst type (e.g. VHL) and grade (e.g. SMAD4). In the surgical cohort, molecular analysis and the proposed algorithm showed comparable sensitivity (88.9% vs. 100%). Conclusions: Incorporating somatic molecular analysis in the cytologic evaluation of EUS-FNA increases diagnostic accuracy for detection, classification and grading of PCL. This approach has the potential to improve patient management.

Evaluation of the SharkCore® needle for EUS-guided core biopsy of pancreatic neuroendocrine tumors

BACKGROUND AND OBJECTIVES

EUS guided core biopsy was once rarely performed but is now entering mainstream practice. Neuroendocrine tumors often warrant core biopsy as sufficient tissue must be obtained to allow for special staining to ensure a correct diagnosis. Traditionally these lesions were sampled with FNA needles. We performed a retrospective pilot study to evaluate the clinical value and efficacy of the a new EUS core needle biopsy needle as compared to a standard EUS FNA needle in the evaluation of patients with known or suspected neuroendocrine tumors.

METHODS

A retrospective analysis of the first 10 patients (between January 2015 and April 2016) to undergo EUS-FNA with the SharkCore® needle at the University of Utah School of Medicine/Huntsman Cancer Center with neuroendocrine tumors. Each case was retrospectively reviewed by a board certified cytopathologist (BLW) for the following cytologic parameters on the aspirate smears or touch/squash preparations: overall cellularity [1 (low) to 3 (high)], percentage of obtained cells that were lesional/representative (<25%, 26%-50%, and >50%), relative ease of interpretation [1 (difficult) to 3 (easy)]. Pathologic material and reporting records were also reviewed for each case to confirm the number of needle passes to achieve diagnostic adequacy, the presence or absence diagnostic material on H&E slide (from cell block, if prepared), whether a definitive diagnosis was able to be rendered, and the presence or absence of a true core/core fragments (within the cell block, if prepared).

RESULTS

A total of 20 patients underwent EUS-FNA for suspected neuroendocrine lesions. Ten patients underwent either transgastric or transduodenal EUS-FNA with the 22 gauge SharkCore® needle. The comparison cohort of 10 patients underwent either transgastric or transduodenal EUS-FNA with the standard 22 gauge Echotip® needle. The SharkCore® needle required a fewer mean number of needle passes to obtain diagnostic adequacy than the Echotip® (P=0.0074). For cases with cell blocks, the SharkCore® needle produced diagnostic material in 100% of cases, whereas Echotip® produced diagnostic material in 60% of cases. There was no significant difference between specimen cellularity, percentage of lesional material, or ease of interpretation between the two needle types.

CONCLUSION

Our pilot investigation targeting patients with known or suspected pancreatic NETs indicates that the SharkCore® needle shows promise in obtaining suitable tissue for ancillary testing that can allow for more definitive pathologic interpretations on EUS FNA specimens. Fewer passes were needed with the core needle when compared to a standard needle.

Role of Fluorescent In Situ Hybridization, Cholangioscopic Biopsies, and EUS-FNA in the Evaluation of Biliary Strictures

BACKGROUND AND AIMS

Our goal was to compare the diagnostic accuracy of FISH in the detection of malignancy compared with other standard diagnostic modalities, including brush cytology and biopsy specimens over a 10-year period of prospective data collection.

METHODS

We conducted a review of all consecutive biliary strictures evaluated between 2006 and 2016. Patients with a final pathologic diagnosis or conclusive follow-up were included. We evaluated the performance of FISH polysomy (CEP 3, 7, and 17) and 9p21 deletion as well as cholangioscopic biopsy (CBx) and EUS-FNA. Statistical analysis was performed with the Mann-Whitney U and Fisher's exact tests.

RESULTS

Of 382 patients with indeterminate strictures, 281 met inclusion criteria. Forty-nine percent were malignant. Cytology, FISH polysomy, and FISH polysomy/9p21 showed a specificity of 99.3%. FISH polysomy/9p21 as a single modality was the most sensitive at 56% (p < 0.001). The sensitivity of FISH polysomy/9p21 and cytology was significantly higher than cytology alone at 63 versus 35% (p < 0.05). EUS-FNA for distal strictures and CBx for proximal strictures increased sensitivity from 33 to 93% (p < 0.001) and 48-76% (p = 0.05) in cytology-negative strictures.

CONCLUSIONS

The high specificity of FISH polysomy/9p21 suggests that a positive result is sufficient for diagnosing malignancy in indeterminate strictures. The significantly higher sensitivity of FISH polysomy/9p21 compared to cytology supports the use of FISH in all non-diagnostic cases. Although both EUS-FNA and CBx were complimentary, our results suggest that distal strictures should be evaluated by EUS initially. Proximal strictures may be evaluated by FISH first and then by CBx if inconclusive.

"Clinical" cytology for endoscopists: A practical guide

Clinical cytology was originally used by clinicians to provide rapid diagnosis. However, with advancing medical subspecialization, few clinicians interpret cytology themselves these days, for example, gynecologists, hematologists, urologists, and occasional gastroenterologist (mainly in Asian countries). Cytological assessment enjoyed a renaissance with the development of endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA). Subsequently, pathologists, most of them more experienced in histology, had to take over. Recently, it has been shown that in-room cytology can be easily performed by the endoscopist themselves for initial evaluation of the quality of the EUS-FNA specimen and an initial diagnosis distinguishing benign or malignant cells. Bringing cytology back to the clinician has some advantages but does not substitute the professional cytopathologist. This report has written to lower the threshold for the clinician to find his way back to the microscope, which may improve both their diagnostic yield and assessment of EUS-FNA sample quality.

Pathologic evaluation of a new endoscopic ultrasound needle designed to obtain core tissue samples: A pilot study

BACKGROUND AND OBJECTIVES

Standard endoscopic ultrasound-fine-needle aspiration (EUS-FNA) needles are in widespread use. Meaningful differences between the available needles have been difficult to identify. Recently, a new EUS needle (Shark Core®, Covidien, Dublin, Leinster, Ireland), has been introduced in an attempt to improve diagnostic accuracy, tissue yield, and to potentially obtain a core tissue sample. We performed a pilot study prospectively to evaluate this new needle when compared to a standard EUS-FNA needle.

MATERIALS AND METHODS

Analysis of the first 15 patients undergoing EUS-FNA with the Shark Core needle was performed and it was compared to EUS-FNA in 15 patients who underwent EUS-FNA with a standard needle.

RESULTS

The Shark Core needle required fewer needle passes to obtain diagnostic adequacy than the standard needle [(χ(2)(1) = 11.3, P < 0.001]. The Shark Core needle required 1.5 passes to reach adequacy, whereas the standard needle required three passes. For cases with cell blocks, the Shark Core needle produced diagnostic material in 85% of cases [95% confidence interval (CI): 54-98], whereas the standard needle produced diagnostic material in 38% of the cases (95% CI: 9-76). The Shark Core needle produced actual tissue cores 82% of the time (95% CI: 48-98) and the standard needle produced no tissue cores (95% CI: 0-71) (P = 0.03).

CONCLUSION

This pilot study found that the Shark Core needle had a high rate of producing adequate cytologic material for the diagnosis of pancreatic and peri-pancreatic lesions sampled by EUS with fewer passes required to obtain a definitive diagnosis and with a high rate of tissue cores being obtained when compared to a standard FNA needle.

What is the current role of endoscopy in primary sclerosing cholangitis?

Endoscopy has important roles in the management of primary sclerosing cholangitis (PSC), ranging from narrowing down the differential diagnoses, screening for complications, determining prognosis and therapy. While the need for a diagnostic endoscopic retrograde cholangiopancreatography (ERCP) may be obviated by a positive magnetic resonance cholangiopancreatography (MRCP), a negative MRCP does not exclude PSC and may therefore necessitate an ERCP, which is traditionally regarded as the gold standard. In this editorial we have not covered the endoscopic management of inflammatory bowel disease in the context of PSC nor of endoscopic surveillance and treatment of portal hypertension complicating PSC.