The Use of Integrated Molecular Testing in the Assessment and Management of Pancreatic Cysts.

PURPOSE OF REVIEW: As abdominal imaging becomes more sensitive and regularly used, pancreatic cystic lesions (PCLs) are being diagnosed more frequently. A small but clinically significant minority of these lesions have a predisposition to either harbor malignancy or undergo malignant transformation. This review highlights the current state and performance of cystic fluid biomarkers and how they may be incorporated into management. RECENT FINDINGS: Among the major domains of molecular testing for PCLs, DNA based analyses have demonstrated the highest accuracy in identifying cyst type and have the most data to support their clinical use. However, epigenetic and protein biomarker based molecular assessments have emerged with the potential to complement DNA based approaches. In addition, recent studies have increasingly demonstrated the value associated with combinations of mutations and other biomarkers in identifying higher grade mucinous cystic lesions. We present the performance of individual biomarkers in cyst fluid analysis with an emphasis on an algorithmic approach to improve the accurate identification of both cyst type and risk of malignant transformation.

Pancreatic Cystic Lesions: Next Generation of Radiologic Assessment.

Pancreatic cystic lesions are frequently identified on cross-sectional imaging. As many of these are presumed branch-duct intraductal papillary mucinous neoplasms, these lesions generate much anxiety for the patients and clinicians, often necessitating long-term follow-up imaging and even unnecessary surgical resections. However, the incidence of pancreatic cancer is overall low for patients with incidental pancreatic cystic lesions. Radiomics and deep learning are advanced tools of imaging analysis that have attracted much attention in addressing this unmet need, however, current publications on this topic show limited success and large-scale research is needed.

Molecular assessment of endoscopically collected pancreatic juice and duodenal fluid from patients with pancreatic diseases.

One concern associated with pancreatic diseases is the poor prognosis of pancreatic cancer. Even with advances in diagnostic modalities, risk stratification of premalignant lesions and differentiation of pancreatic cysts are challenging. Pancreatic lesions of concern include intraductal papillary mucinous neoplasms, mucinous cystic neoplasms, serous cystadenomas, pseudocysts, and retention cysts, as well as cystic degeneration of solid tumors such as solid pseudopapillary neoplasms and pancreatic neuroendocrine neoplasms. Pancreatic juice obtained during endoscopic retrograde cholangiopancreatography has previously been used for the detection of KRAS mutation. Recently, duodenal fluid, which can be obtained during the relatively minimally invasive procedures of endoscopic ultrasound (EUS) and esophagogastroduodenoscopy, and cyst fluid collected by EUS-guided fine-needle aspiration (FNA) were used for molecular biological analysis. Furthermore, advanced analytic methods with high sensitivity were used for the detection of single and multiple markers. Early detection of malignant pancreatic tumors and risk stratification of premalignant tumors can be performed using duodenal fluid samples with a single marker with high sensitivity. Technological advances in simultaneous detection of multiple markers allow for the differentiation of cystic pancreatic tumors. One thing to note is that the clinical guidelines do not recommend pancreatic cyst fluid and pancreatic juice (PJ) sampling by EUS-FNA and endoscopic retrograde cholangiopancreatography, respectively, in actual clinical practice, but state that they be performed at experienced facilities, and duodenal fluid sampling is not mentioned in the guidelines. With improved specimen handling and the combination of markers, molecular markers in PJ samples may be used in clinical practice in the near future.

Increased incidence of indeterminate pancreatic cysts and changes of management pattern: Evidence from nationwide data.

BACKGROUND: Pancreatic cysts are common. However, most studies are based on data collected from individual centers. The present study aimed to evaluate the changes of management patterns for pancreatic cystic lesions (PCLs) by analyzing large epidemiologic data. METHODS: Between January 2007 and December 2018, information regarding pancreatic cystic lesions was acquired from the nationwide Health Insurance Review and Assessment Service database in Korea. RESULTS: The final number of patients with pancreatic cysts was 165 277 among the total claims for reimbursement of 855 983 associated with PCLs over 12 years. The total number of claims were increased from 19 453 in 2007 to 155 842 in 2018 and the prevalence increased from 0.04% to 0.23%. For 12 years, 2874 (1.7%) had pancreatic cancer and 8212 (5.0%) underwent surgery, and 36 had surgery for twice (total 8248 pancreatectomy). After ruling out claims from the first 3 years of washout period, the incidence increased from 9891 to 24 651 and the crude incidence rate of PCLs expanded from 19.96 per 100 000 to 47.77 per 100 000. Compared to specific neoplasm codes (D136 or D377), the use of pancreatic cyst code (K862) has been remarkably increased and the most common since 2010. The annual number of pancreatectomies increased from 518 to 861 between 2007 and 2012, and decreased to 596 until 2018. The percentage of pancreatic cancer in patients who received pancreatectomy increased from 5.6% in 2007 to 11.7% in 2018. CONCLUSIONS: The incidence of PCLs is rapidly increasing. Among PCLs, indeterminate cyst is increasing outstandingly. A trend of decreasing in the number of resections and increasing cancer rates among resected cysts may be attributed to the updated international guidelines.

Comparison of Preoperative Imaging Modalities for the Assessment of Malignant Potential of Pancreatic Cystic Lesions: A Network Meta-analysis.

PURPOSE: The aims of this study are to compare the performance of various preoperative imaging modalities for assessing the malignant potential of pancreatic cystic lesions (PCLs) through a network meta-analysis (NMA) and to clarify the role of 18 F-FDG PET in the management of patients with PCL. METHODS: PubMed, EMBASE, and Cochrane Library were searched for the studies evaluating the performance of preoperative imaging modalities for identifying malignant PCLs. The NMA was performed for 4 representative categories of various imaging modalities in terms of diagnostic performance for differentiating malignant from benign PCL and intraductal papillary mucinous neoplasms only as a subgroup analysis. To calculate the probability of each imaging modality being the most effective diagnostic method, the surface under the cumulative ranking curve values were obtained. RESULTS: A total of 1018 patients from 17 direct comparison studies using 2 or more preoperative imaging modalities were included for differentiating malignant from benign PCL. The positive predictive value (PPV) and accuracy of 18 F-FDG PET were significantly higher than that of CT (PPV: odds ratio [OR], 2.66; 95% credible interval [CrI], 1.21-6.17; accuracy: OR, 2.63; 95% CrI, 1.41-5.38) or MRI (PPV: OR, 2.50; 95% CrI, 1.09-6.26; accuracy: OR, 2.50; 95% CrI, 1.28-5.47) in all PCLs, as well as in the subgroup analysis for intraductal papillary mucinous neoplasm only. 18 F-FDG PET showed the highest surface under the cumulative ranking curve values in all diagnostic performance areas of sensitivity, specificity, PPV, negative predictive value, and accuracy, followed by MRI or CT. CONCLUSIONS: The results from this NMA suggest that 18 F-FDG PET is the best preoperative imaging modality for differentiating malignant from benign PCLs and that it can be used for the preoperative evaluation of PCLs.

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.

Pancreatic Cystic Lesions and Malignancy: Assessment, Guidelines, and the Field Defect.

The widespread use of high-spatial-resolution cross-sectional imaging has led to an increase in detection of incidental pancreatic cystic lesions. These lesions are a diverse group, ranging from indolent and premalignant lesions to invasive cancers. The diagnosis of several of these lesions can be suggested on the basis of their imaging appearance, while many other lesions require follow-up imaging and/or aspiration. The smaller cystic lesions, often branch-duct intraductal papillary mucinous neoplasms, have overlapping imaging characteristics that make diagnostic assessment of the natural history and malignancy risk confusing. Expert panels have developed societal guidelines, based on a consensus, for surveillance of these lesions. However, these guidelines are often inconsistent and are constantly evolving as additional scientific data are accumulated. Identification of features associated with increased risk of malignancy is important for proper management. The concept of field defect, whereby pancreatic adenocarcinoma develops at a site different from the site of the pancreatic cyst, adds to the complexity of screening guidelines. As a result of the differences in guidelines, key stakeholders (eg, radiologists, gastroenterologists, and surgeons) must review and come to a consensus regarding which guideline, or combination of guidelines, to follow at their individual institutions. Standardized reporting and macros are helpful for ensuring the uniformity of interpretations. Radiologists play a critical role in the detection and characterization of pancreatic cystic lesions, in the follow-up recommendations for these lesions, and in the detection of associated cancer. An invited commentary by Zaheer is available online. Online supplemental material is available for this article. ©RSNA, 2021.

Molecular analysis of cyst fluids improves the diagnostic accuracy of pre-operative assessment of pancreatic cystic lesions.

Pancreatic cystic lesions (PCL) are increasingly diagnosed. Endoscopic ultrasound fine-needle aspiration (EUS-FNA) cytology is often used for diagnostic confirmation but can be inconclusive. In this study, the role of molecular analyses in the pre-operative diagnostics of PCL is evaluated. Targeted Next Generation Sequencing (NGS) applied on cytology smears was retrospectively evaluated in a cohort of 37 resected PCL. Usefulness of NGS on fresh cyst fluids was tested in a prospective cohort of patients with newly diagnosed PCL (n = 71). In the retrospective cohort, cytology plus NGS displayed higher sensitivity (94.1% vs. 87.1%) and specificity (100% vs. 50%) than cytology alone for the detection of mucinous neoplasms. In the prospective cohort, sensitivity and specificity of conventional cytology alone were 54.2% and 100% for the detection of mucinous neoplasia and 50.0% and 100% for the detection of high-grade dysplasia, respectively. Adding NGS, all lesions which underwent histopathologic verification (12/71, 17%) could be classified without false positive or false negative results regarding the detection of mucinous neoplasm so far. NGS analysis of cfDNA in PCL fluids is feasible and can increase diagnostic accuracy in the detection of mucinous neoplasms compared to cytology alone. However, algorithms for the detection of high-risk lesions need further improvement.

Cost-effectiveness of consensus guideline based management of pancreatic cysts: The sensitivity and specificity required for guidelines to be cost-effective.

BACKGROUND: Detection of cystic lesions of the pancreas has outpaced our ability to stratify low-grade cystic lesions from those at greater risk for pancreatic cancer, raising a concern for overtreatment. METHODS: We developed a Markov decision model to determine the cost-effectiveness of guideline-based management for asymptomatic pancreatic cysts. Incremental costs per quality-adjusted life year gained and survival were calculated for current management guidelines. A sensitivity analysis estimated the effect on cost-effectiveness and mortality if overtreatment of low-grade cysts is avoided, and the sensitivity and specificity thresholds required of methods of cyst stratification to improve costs expended. RESULTS: "Surveillance" using current management guidelines had an incremental cost-effectiveness ratio of $171,143/quality adjusted life year compared with no surveillance or operative treatment ("do nothing"). An incremental cost-effectiveness ratio for surveillance decreases to $80,707/quality adjusted life year if the operative overtreatment of low-grade cysts was avoided. Assuming a societal willingness-to-pay of $100,000/quality adjusted life year, the diagnostic specificity for high-risk cysts must be >67% for surveillance to be preferred over surgery and "do nothing." Changes in sensitivity alone cannot make surveillance cost-effective. Most importantly, survival in surveillance is worse than "do nothing" for 3 years after cyst diagnosis, although long-term survival is improved. The disadvantage is eliminated when overtreatment of low-grade cysts is avoided. CONCLUSION: Current management of pancreatic cystic lesions is not cost-effective and may increase mortality owing to overtreatment of low-grade cysts. The specificity for risk stratification for high-risk cysts must be greater than 67% to make surveillance cost-effective.

Clinical and Economic Outcomes of Patients Undergoing Guideline-Directed Management of Pancreatic Cysts.

INTRODUCTION: Numerous guidelines exist for the management of pancreatic cysts. We sought to compare the guideline-directed management strategies for pancreatic cysts by comparing 2 approaches (2017 International Consensus Guidelines and 2015 American Gastroenterological Association Guidelines) that differ significantly in their thresholds for imaging, surveillance, and surgery. METHODS: We developed a Monte Carlo model to evaluate the outcomes for a cohort of 10,000 patients managed per each guideline. The primary outcome was mortality related to pancreatic cyst management. Secondary outcomes included all-cause mortality, missed cancers, number of surgeries, number of imaging studies, cumulative cost, and quality-adjusted life years. RESULTS: Deaths because of pancreatic cyst management and quality-adjusted life years were similar in both guidelines at a significantly higher cost of $3.6 million per additional cancer detected in the Consensus Guidelines. Deaths from "unrelated" causes (1,422) vastly outnumbered deaths related to pancreatic cysts (125). Secondary outcomes included more missed cancers in the American Gastroenterological Association guideline (71 vs 49), more surgeries and imaging studies in the Consensus guideline (711 vs 163; 116,997 vs 68,912), and higher cost in the Consensus guideline ($168.3 million vs $89.4 million). As the rate of malignant transformation increases, a more-intensive guideline resulted in fewer deaths related to pancreatic cyst management. DISCUSSION: Our study demonstrates trade-offs between more- and less-intensive management strategies for pancreatic cysts. Although deaths related to pancreatic cyst management were similar in each strategy, fewer missed cancers in the more-intensive surveillance strategy is offset by a greater number of surgical deaths and higher cost. In conclusion, our study identifies that if the rate malignant transformation of pancreatic cysts is low (0.12% annually), a less-intensive guideline will result in similar deaths to a more-intensive guideline at a much lower cost.

Long-Term Assessment of Pancreatic Function After Pancreatectomy for Cystic Neoplasms.

BACKGROUND: With advances in cross-sectional imaging, pancreatic cysts are more frequently diagnosed and have become a common indication for pancreatectomy. The impact of pancreatectomy in these patients is important. The purpose of this study was to assess short-term outcomes, long-term nutritional status, quality of life (QOL), and pancreas function after pancreatectomy for cystic neoplasms. MATERIALS AND METHODS: At a single institution, patients at least 3 y post-pancreatectomy for benign cystic neoplasms were identified. Using a validated questionnaire, short-term outcomes, long-term outcomes including endocrine and exocrine insufficiency, long-term nutritional status, and preoperative and postoperative QOL were compared based on operation and indication for resection. RESULTS: Among 102 eligible patients, 70 had valid contact information and 51 (72.9%) agreed to participate. Median follow-up was 6 (4-8) y. Patients undergoing pancreatoduodenectomy for benign cysts had higher morbidity than a similar cohort resected for pancreatic adenocarcinoma (patients with at least 1 ≥ grade 2 complication [49.0% versus 31.6%, P = 0.038]). After long-term follow-up, pancreatectomy did not significantly affect perceived QOL. Half of patients had mild-moderate or severe malnourishment, but pancreatic enzyme replacement was reported by only 4 (7.8%) patients. New-onset diabetes was present in 15 (29.4%) patients with median time-to-diagnosis of 6 (1-12) mo after resection. CONCLUSIONS: Pancreatectomy for benign cysts did not negatively impact patients' perceived QOL. However, after long-term follow-up, malnutrition and pancreatic insufficiency occurred in a significant percentage and may be greater than previously estimated. Consideration of short- and long-term outcomes should factor into preoperative counseling, especially in cysts with minimal risk of progression to malignancy.

African-Americans and Indigenous Peoples Have Increased Burden of Diseases of the Exocrine Pancreas: A Systematic Review and Meta-Analysis.

Ethnic health disparity is a well-acknowledged issue in many disease settings, but not diseases of the exocrine pancreas. A systematic review and meta-analysis was conducted to explore the race- and ethnicity-specific burden of diseases of the exocrine pancreas. Studies that compared health-related endpoints between two or more ethnicities were eligible for inclusion. Proportion meta-analyses were conducted to compare burden between groups. A total of 42 studies (24 on pancreatic cancer, 17 on pancreatitis, and one on pancreatic cyst) were included in the systematic review, of which 19 studies were suitable for meta-analyses. The incidence of pancreatic cancer was 1.4-fold higher among African-Americans, while the incidence of acute pancreatitis was 4.8-fold higher among an indigenous population (New Zealand Maori) compared with Caucasians. The prevalence of post-pancreatitis diabetes mellitus was up to 3.0-fold higher among certain ethnicities, including Asians, Pacific Islanders, and indigenous populations compared with Caucasians. The burden of diseases of the exocrine pancreas differs between ethnicities, with African-Americans and certain indigenous populations being at the greatest risk of developing these diseases. Development of race- and ethnicity-specific screening as well as protocols for lifestyle modifications may need to be considered with a view to reducing the disparities in burden of diseases of the exocrine pancreas.

Downstream Costs Associated With Incidental Pancreatic Cysts Detected at MRI.

OBJECTIVE: The purpose of this study is to assess downstream costs associated with pancreatic cysts incidentally detected at MRI. MATERIALS AND METHODS: Two hundred patients with an incidental pancreatic cyst detected at MRI were identified. Downstream events (imaging, office visits, endoscopic ultrasound-guided fine-needle aspiration, or chemotherapy) were identified from the electronic medical record. Radiologists' recommendations and ordering physician management were classified relative to the American College of Radiology (ACR) incidental findings committee recommendations. Costs for the downstream events were estimated using national Medicare rates and a 3% annual discount rate. Mean costs were computed. RESULTS: Estimated downstream costs averaged $460 per cyst ($872 per cyst with any follow-up testing). Nine patients had a clinically relevant outcome during follow-up (increase in cyst size, development of new cyst, or development of pancreatic cancer). Downstream cost per cyst with a clinically relevant outcome was $1364. Costs were greater when ordering physicians overmanaged ($842) versus when they were adherent ($631) or undermanaged ($252) relative to radiologist recommendation. Although costs were $252 when ordering physicians undermanaged relative to ACR incidental findings committee recommendations, costs were similar when ordering physicians were adherent ($811) or overmanaged ($845) relative to ACR incidental findings committee recommendations. Costs did not vary significantly according to whether radiologists recommended follow-up testing ($317-$491) or whether radiologist recommendations were adherent, undermanaged, or overmanaged relative to ACR incidental findings committee recommendations ($344-$528). CONCLUSION: The findings suggest a role for targeted educational efforts, collaborative partnerships, and other initiatives to foster greater adherence to radiologist recommendations, including critical test results notification systems, automated reminders within electronic health systems, and stronger language within radiology reports when no follow-up testing is recommended.

Comparison of endoscopic ultrasound, computed tomography and magnetic resonance imaging in assessment of detailed structures of pancreatic cystic neoplasms.

AIM: To evaluate the advantages of endoscopic ultrasound (EUS) in the assessment of detailed structures of pancreatic cystic neoplasms (PCNs) compared to computed tomography (CT) and magnetic resonance imaging (MRI). METHODS: All patients with indeterminate PCNs underwent CT, MRI, and EUS. The detailed information, including size, number, the presence of a papilla/nodule, the presence of a septum, and the morphology of the pancreatic duct of PCNs were compared among the three imaging modalities. The size of each PCN was determined using the largest diameter measured. A cyst consisting of several small cysts was referred to as a mother-daughter cyst. Disagreement among the three imaging modalities regarding the total number of mother cysts resulted in the assumption that the correct number was the one in which the majority of imaging modalities indicated. RESULTS: A total of 52 females and 16 males were evaluated. The median size of the cysts was 42.5 mm by EUS, 42.0 mm by CT and 38.0 mm by MRI; there was no significant difference in size as assessed among the three imaging techniques. The diagnostic sensitivity and ability of EUS to classify PCNs were 98.5% (67/68) and 92.6% (63/68), respectively. These percentages were higher than those of CT (73.1%, P < 0.001; 17.1%, P < 0.001) and MRI (81.3%, P = 0.001; 20.3%, P < 0.001). EUS was also able to better assess the number of daughter cysts in mother cysts than CT (P = 0.003); however, there was no significant difference between EUS and MRI in assessing mother-daughter cysts (P = 0.254). The papilla/nodule detection rate by EUS was 35.3% (24/68), much higher than those by CT (5.8%, 3/52) and MRI (6.3%, 4/64). The detection rate of the septum by EUS was 60.3% (41/68), which was higher than those by CT (34.6%, 18/52) and by MRI (46.9%, 30/64); the difference between EUS and CT was significant (P = 0.02). The rate of visualizing the pancreatic duct using EUS was 100%, whereas using CT and MRI it was less than 10%. CONCLUSION: EUS helps visualize the detailed structures of PCNs and has many advantages over CT and MRI. EUS is valuable in the diagnosis and assessment of PCNs.

Assessment of morbidity and mortality associated with endoscopic ultrasound-guided fine-needle aspiration for pancreatic cystic lesions: A systematic review and meta-analysis.

BACKGROUND AND AIM: With increased availability of imaging technology, detection of pancreatic cystic lesions (PCL) is on the rise. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) improves the diagnosis accuracy of PCL. Systematic evaluation of morbidity and mortality associated with EUS-FNA for PCL has not been carried out. We conducted a systematic review and meta-analysis of morbidity and mortality associated with EUS-FNA. METHODS: A literature search for relevant English-language articles was conducted on PubMed and EMBASE databases. Main outcome measures for this analysis were adverse effects of diagnostic EUS-FNA, and the associated morbidity and mortality, in patients with PCL. RESULTS: Forty studies, with a combined subject population of 5124 patients with PCL, satisfied the inclusion criteria. Overall morbidity as a result of adverse events of EUS-FNA was 2.66% (95% confidence interval [CI]: 1.84-3.62%), and the associated mortality was 0.19% (95% CI: 0.09-0.32%). Common post-procedure adverse events included pancreatitis 0.92% (95% CI: 0.63-1.28%), hemorrhage 0.69% (95% CI: 0.42-1.02%), pain 0.49% (95% CI: 0.27-0.79%), infection 0.44% (95% CI: 0.27-0.66%), desaturation 0.23% (95% CI: 0.12-0.38%) and perforation 0.21% (95% CI: 0.11-0.36%). There was no peritoneal seeding in our study. Incidence of adverse events associated with prophylactic periprocedural antibiotic use was 2.77% (95% CI: 1.87-3.85%). CONCLUSIONS: EUS-FNA is a safe procedure for diagnosis of PCL and is associated with a relatively low incidence of adverse events. Most adverse events were mild, self-limiting, and did not require medical intervention.

Impact of EUS-guided fine-needle biopsy sampling with a new core needle on the need for onsite cytopathologic assessment: a preliminary study.

BACKGROUND AND AIMS: FNA is the primary method of EUS tissue acquisition. In an attempt to improve our yield of EUS-guided tissue acquisition, we compared fine-needle biopsy (FNB) sampling without rapid onsite evaluation (ROSE) with FNA with ROSE and assessed the concordance of FNA and FNB sampling. METHODS: This was a retrospective review of prospectively collected data from consecutive patients. Patients underwent FNB sampling and FNA of the same single lesion, with the same needle gauge and number of passes. FNA with ROSE was performed with a standard FNA needle. FNB sampling was performed with a new dedicated core needle. FNA samples were assessed with ROSE, and a final interpretation was provided by cytopathology staff; FNB samples were analyzed by surgical pathologists, each not made aware of the other's opinion. RESULTS: Thirty-three patients underwent 312 passes in 42 different lesions. A diagnosis of malignancy was more likely with FNB sampling than with FNA (72.7% vs 66.7%, P = .727), although statistical significance was not reached. FNA and FNB sampling had similar sensitivities, specificities, and accuracies for cancer (81.5% vs 88.9%, 100% vs 100%, and 84.8% vs 90.9%, respectively). FNB sampling provided qualitative information not reported on FNA, such as degree of differentiation in malignancy, metastatic origin, and rate of proliferation in neuroendocrine tumors. CONCLUSIONS: FNB sampling without ROSE using a dedicated core needle performed as well as FNA with ROSE in this small cohort, suggesting that FNB sampling with this new core needle may eliminate the need for an onsite cytopathologic assessment, without loss of diagnostic accuracy.