Fine-needle aspiration of pancreatic cystic lesions: a randomized study with long-term follow-up comparing standard and flexible needles

BACKGROUND

Pancreatic cystic lesions (PCLs) are increasingly found on cross-sectional imaging, with the majority having a low risk for malignancy. The added value of fine-needle aspiration (FNA) in risk stratification remains unclear. We evaluated the impact of three FNA needles on diagnostic accuracy, clinical management, and the ability to accrue fluid for tumor markers.

METHODS

A multicenter prospective trial randomized 250 patients with PCLs ≥ 13 mm 2:1:1 to 19G Flex, 19G, and 22G needles with crossover for repeated FNA procedures. Diagnostic accuracy was established at 2-year follow-up, with the final diagnosis from surgical histopathology or consensus diagnosis by experts based sequentially on clinical presentation, imaging, and aspirate analysis in blinded review.

RESULTS

Enrolled patients (36 % symptomatic) had PCLs in the head (44 %), body (28 %), and tail (26 %). Percentage of cyst volume aspirated was 78 % (72 % - 84 %) for 19G Flex, 74 % (64 % - 84 %) for 22G, and 73 % (63 % - 83 %) for 19G (P = 0.84). Successful FNA was significantly higher for 19G Flex (89 % [82 % - 94 %]) and 22G (82 % [70 % - 90 %]) compared with 19G (75 % [63 % - 85 %]) (P = 0.02). Repeated FNA was required more frequently in head/uncinate lesions than in body and tail (P < 0.01). Diagnostic accuracy of the cyst aspirate was 84 % (73 % - 91 %) against histopathology at 2-year follow-up (n = 79), and 77 % (70 % - 83 %) against consensus diagnosis among nonsurgical cases (n = 171). Related serious adverse events occurred in 1.2 % (0.2 % - 3.5 %) of patients.

CONCLUSIONS

Our study results demonstrate a statistically significant difference among the three needles in the overall success rate for aspiration, but not in the percentage of cyst volume aspirated. Flexible needles may be particularly valuable in sampling cystic PCLs in the pancreatic head/uncinate process.

Improvement in adenoma detection using a novel artificial intelligence-aided polyp detection device

Background and study aims  Detecting colorectal neoplasia is the goal of high-quality screening and surveillance colonoscopy, as reflected by high adenoma detection rate (ADR) and adenomas per colonoscopy (APC). The aim of our study was to evaluate the performance of a novel artificial intelligence (AI)-aided polyp detection device, Skout, with the primary endpoints of ADR and APC in routine colonoscopy. Patients and methods  We compared ADR and APC in a cohort of outpatients undergoing routine high-resolution colonoscopy with and without the use of a real-time, AI-aided polyp detection device. Patients undergoing colonoscopy with Skout were enrolled in a single-arm, unblinded, prospective trial and the results were compared with a historical cohort. All resected polyps were examined histologically. Results  Eighty-three patients undergoing screening and surveillance colonoscopy at an outpatient endoscopy center were enrolled and outcomes compared with 283 historical control patients. Overall, ADR with and without Skout was 54.2 % and 40.6 % respectively ( P  = 0.028) and 53.6 % and 30.8 %, respectively, in screening exams ( P  = 0.024). Overall, APC rate with and without Skout was 1.46 and 1.01, respectively, ( P  = 0.104) and 1.18 and 0.50, respectively, in screening exams ( P  = 0.002). Overall, true histology rate (THR) with and without Skout was 73.8 % and 78.4 %, respectively, ( P  = 0.463) and 75.0 % and 71.0 %, respectively, in screening exams ( P  = 0.731). Conclusion  We have demonstrated that our novel AI-aided polyp detection device increased the ADR in a cohort of patients undergoing screening and surveillance colonoscopy without a significant concomitant increase in hyperplastic polyp resection. AI-aided colonoscopy has the potential for improving the outcomes of patients undergoing colonoscopy.

A multimodality test to guide the management of patients with a pancreatic cyst

Pancreatic cysts are common and often pose a management dilemma, because some cysts are precancerous, whereas others have little risk of developing into invasive cancers. We used supervised machine learning techniques to develop a comprehensive test, CompCyst, to guide the management of patients with pancreatic cysts. The test is based on selected clinical features, imaging characteristics, and cyst fluid genetic and biochemical markers. Using data from 436 patients with pancreatic cysts, we trained CompCyst to classify patients as those who required surgery, those who should be routinely monitored, and those who did not require further surveillance. We then tested CompCyst in an independent cohort of 426 patients, with histopathology used as the gold standard. We found that clinical management informed by the CompCyst test was more accurate than the management dictated by conventional clinical and imaging criteria alone. Application of the CompCyst test would have spared surgery in more than half of the patients who underwent unnecessary resection of their cysts. CompCyst therefore has the potential to reduce the patient morbidity and economic costs associated with current standard-of-care pancreatic cyst management practices.

Position statement on EUS-guided ablation of pancreatic cystic neoplasms from an international expert panel

Background and aim  Recently, several guidelines with divergent recommendations on management of pancreatic cystic neoplasm have been published but the role of endoscopic ultrasound (EUS)-guided pancreatic cyst ablation has not been thoroughly addressed. The aim of the current paper is to explore the issues surrounding EUS-guided pancreatic cyst ablation by generating a list of clinical questions and providing answers based on best scientific evidence available. Methods  An expert panel in EUS-guided pancreatic cyst ablation was recruited from members of the Asian EUS group and an international expert panel. A list of clinical questions was created and each question allocated to one member to generate a statement in response. The statements were then discussed in three Internet conference meetings between October 2016 and October 2017. The statements were changed until consensus was obtained. Afterwards, the complete set of statements was sent to all the panelist to vote on strength of the statements, classification of the statement sand grading of the evidence. Results  Twenty-three statements on EUS-guided drainage of pancreatic cyst ablation were formulated. The statements addressed indications for the procedures, technical aspects, pre-procedure and post-procedure management, management of complications, and competency and training in the procedures. Conclusion  The current set of statements on EUS-guided pancreatic cyst ablation are the first to be published by any endoscopic society. Clinicians interested in developing the technique should reference these statements and future studies should address the key issues raised in the document.

Diagnostic yield of the SharkCore EUS-guided fine-needle biopsy

INTRODUCTION

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the standard diagnostic procedure for many intrathoracic and intra-abdominal lesions. Next-generation fine-needle biopsies (FNBs) can increase diagnostic yield by procuring tissue suitable for histological processing. We evaluate the diagnostic yield and operating characteristics of the SharkCore (SC; Medtronic Corp., Minneapolis, MN) FNB in a tertiary referral facility.

MATERIALS AND METHODS

We performed a single-center retrospective review of SC-FNB-acquired tissue between January 2014 and March 2018. Patient demographic data, endoscopic features, and pathology data were obtained from the electronic medical record. Diagnostic yield was assessed by the ability to obtain a definitive diagnosis, defined as malignant or benign interpretations. Operating characteristics were also calculated.

RESULTS

A total of 179 lesions were sampled with the SC-FNB in 157 patients (mean age: 63 years, 57% male). Of these, 31 lesions were concomitantly sampled with a conventional FNA needle. Most lesions were pancreatic (49%). Diagnostic yield was 86%, which was independent of lesion location, lesion size and needle gauge. Diagnostic accuracy was highest when both histology and cytology specimens were analyzed concurrently (96.5%). In patients with a history of chronic pancreatitis, accuracy, sensitivity, and negative predictive value were reduced (71.4%, 20.0%, and 69.2%, respectively). Rapid onsite evaluation (ROSE) occurred in 64.8% of cases and was more likely to be diagnostic at the time of rapid evaluation if SC-acquired tissue was utilized versus FNA-acquired tissue (P = 0.03); however, final diagnostic yield did not differ between needles (P = 0.13).

CONCLUSIONS

SC-FNB shows high diagnostic yield and accuracy and provides diagnostic tissue for ROSE. SC-FNB is an effective alternative to conventional FNA.

Cyst Fluid Biosignature to Predict Intraductal Papillary Mucinous Neoplasms of the Pancreas with High Malignant Potential

BACKGROUND

Current standard-of-care technologies, such as imaging and cyst fluid analysis, are unable to consistently distinguish intraductal papillary mucinous neoplasms (IPMNs) of the pancreas at high risk of pancreatic cancer from low-risk IPMNs. The objective was to create a single-platform assay to identify IPMNs that are at high risk for malignant progression.

STUDY DESIGN

Building on the Verona International Consensus Conference branch duct IPMN biomarker review, additional protein, cytokine, mucin, DNA, and microRNA cyst fluid targets were identified for creation of a quantitative polymerase chain reaction-based assay. This included messenger RNA markers: ERBB2, GNAS, interleukin 1β, KRAS, MUCs1, 2, 4, 5AC, 7, prostaglandin E2R, PTGER2, prostaglandin E synthase 2, prostaglandin E synthase 1, TP63; microRNA targets: miRs 101, 106b, 10a, 142, 155, 17, 18a, 21, 217, 24, 30a, 342, 532, 92a, and 99b; and GNAS and KRAS mutational analysis. A multi-institutional international collaborative contributed IPMN cyst fluid samples to validate this platform. Cyst fluid gene expression levels were normalized, z-transformed, and used in classification and regression analysis by a support vector machine training algorithm.

RESULTS

From cyst fluids of 59 IPMN patients, principal component analysis confirmed no institutional bias/clustering. Lasso (least absolute shrinkage and selection operator)-penalized logistic regression with binary classification and 5-fold cross-validation used area under the curve as the evaluation criterion to create the optimal signature to discriminate IPMNs as low risk (low/moderate dysplasia) or high risk (high-grade dysplasia/invasive cancer). The most predictive signature was achieved with interleukin 1β, MUC4, and prostaglandin E synthase 2 to accurately discriminate high-risk cysts from low-risk cysts with an area under the curve of up to 0.86 (p = 0.002).

CONCLUSIONS

We have identified a single-platform polymerase chain reaction-based assay of cyst fluid to accurately predict IPMNs with high malignant potential for additional studies.

Thermal ablation of pancreatic cyst with a prototype endoscopic ultrasound capable radiofrequency needle device: A pilot feasibility study

BACKGROUND AND OBJECTIVES

Pancreatic cysts are evaluated by endoscopic ultrasound and fine needle aspiration (EUS). The only accepted treatment is pancreatectomy, which is associated with morbidity and mortality. This study evaluated the optimal thermal dosimetry of a novel radiofrequency ablation device using a standard electrosurgical unit in ex vivo cyst models.

METHODS

A modified EUS 22-gauge monopolar needle prototype with a tip electrode connected to a standard electrosurgical unit (Erbe USA, Marietta, GA, USA) was used to induce a subboiling point temperature. A cyst model was created using 2-cm sections of porcine small intestine ligated and filled with saline. After ablation, the cyst models were prepared for pathological evaluation. The epithelial layers were measured in at least two different sites with a micrometer and compared with the corresponding control sample.

RESULTS

Thirty-two cyst models were ablated with maximum temperatures of 50°C, 60°C, 90°C, and 97°C in 8, 11, 11, and 2 cysts, respectively. Longer ablation times were required to induce higher temperatures. A trend in the reduction in thickness of the measured layers was observed after exposure to higher temperatures. A temperature over 50°C was required for the ablation of the muscularis, submucosa, and villi, and over 60°C was required to ablate the mucosal crypts.

CONCLUSIONS

In a preclinical model, a novel radiofrequency EUS-capable needle connected to a standard electrosurgical unit using standard low-voltage coagulation provided ablation in a temperature-dependent fashion with a threshold of at least 60°C and a safe cyst margin below 97°C. This potentially will allow low-cost, convenient cyst ablation.

Serous cystic neoplasm of the pancreas: a multinational study of 2622 patients under the auspices of the International Association of Pancreatology and European Pancreatic Club (European Study Group on Cystic Tumors of the Pancreas)

OBJECTIVES

Serous cystic neoplasm (SCN) is a cystic neoplasm of the pancreas whose natural history is poorly known. The purpose of the study was to attempt to describe the natural history of SCN, including the specific mortality.

DESIGN

Retrospective multinational study including SCN diagnosed between 1990 and 2014.

RESULTS

2622 patients were included. Seventy-four per cent were women, and median age at diagnosis was 58 years (16-99). Patients presented with non-specific abdominal pain (27%), pancreaticobiliary symptoms (9%), diabetes mellitus (5%), other symptoms (4%) and/or were asymptomatic (61%). Fifty-two per cent of patients were operated on during the first year after diagnosis (median size: 40 mm (2-200)), 9% had resection beyond 1 year of follow-up (3 years (1-20), size at diagnosis: 25 mm (4-140)) and 39% had no surgery (3.6 years (1-23), 25.5 mm (1-200)). Surgical indications were (not exclusive) uncertain diagnosis (60%), symptoms (23%), size increase (12%), large size (6%) and adjacent organ compression (5%). In patients followed beyond 1 year (n=1271), size increased in 37% (growth rate: 4 mm/year), was stable in 57% and decreased in 6%. Three serous cystadenocarcinomas were recorded. Postoperative mortality was 0.6% (n=10), and SCN's related mortality was 0.1% (n=1).

CONCLUSIONS

After a 3-year follow-up, clinical relevant symptoms occurred in a very small proportion of patients and size slowly increased in less than half. Surgical treatment should be proposed only for diagnosis remaining uncertain after complete workup, significant and related symptoms or exceptionally when exists concern with malignancy. This study supports an initial conservative management in the majority of patients with SCN.

TRIAL REGISTRATION NUMBER

IRB 00006477.

A combination of molecular markers and clinical features improve the classification of pancreatic cysts

BACKGROUND & AIMS

The management of pancreatic cysts poses challenges to both patients and their physicians. We investigated whether a combination of molecular markers and clinical information could improve the classification of pancreatic cysts and management of patients.

METHODS

We performed a multi-center, retrospective study of 130 patients with resected pancreatic cystic neoplasms (12 serous cystadenomas, 10 solid pseudopapillary neoplasms, 12 mucinous cystic neoplasms, and 96 intraductal papillary mucinous neoplasms). Cyst fluid was analyzed to identify subtle mutations in genes known to be mutated in pancreatic cysts (BRAF, CDKN2A, CTNNB1, GNAS, KRAS, NRAS, PIK3CA, RNF43, SMAD4, TP53, and VHL); to identify loss of heterozygozity at CDKN2A, RNF43, SMAD4, TP53, and VHL tumor suppressor loci; and to identify aneuploidy. The analyses were performed using specialized technologies for implementing and interpreting massively parallel sequencing data acquisition. An algorithm was used to select markers that could classify cyst type and grade. The accuracy of the molecular markers was compared with that of clinical markers and a combination of molecular and clinical markers.

RESULTS

We identified molecular markers and clinical features that classified cyst type with 90%-100% sensitivity and 92%-98% specificity. The molecular marker panel correctly identified 67 of the 74 patients who did not require surgery and could, therefore, reduce the number of unnecessary operations by 91%.

CONCLUSIONS

We identified a panel of molecular markers and clinical features that show promise for the accurate classification of cystic neoplasms of the pancreas and identification of cysts that require surgery.

Managing incidental pancreatic cystic neoplasms with integrated molecular pathology is a cost-effective strategy

BACKGROUND AND STUDY AIMS

Current guidelines recommend using endoscopic ultrasound (EUS), carcinoembryonic antigen (CEA) testing and cytology to manage incidental pancreatic cystic neoplasms (PCN); however, studies suggest a strategy including integrated molecular pathology (IMP) of cyst fluid may further aid in predicting risk of malignancy. Here, we evaluate several strategies for diagnosing and managing asymptomatic PCN using healthcare economic modeling.

PATIENTS AND METHODS

A third-party-payer perspective Markov decision model examined four management strategies in a hypothetical cohort of 1000 asymptomatic patients incidentally found to have a 3 cm solitary pancreatic cystic lesion. Strategy I used cross-sectional imaging, recommended surgery only if symptoms or risk factors emerged. Strategy II considered patients for resection without initial EUS. Strategy III (EUS + CEA + Cytology) referred only those with mucinous cysts (CEA > 192 ng/mL) for resection. Strategy IV implemented IMP; a commercially available panel provided a "Benign," "Mucinous," or "Aggressive" classification based on the level of mutational change in cyst fluid. "Benign" and "Mucinous" patients were followed with surveillance; "Aggressive" patients were referred for resection. Quality-adjusted life-years (QALY), relative risk with 95 %CI, Number Needed to Treat (NNT), and incremental cost-effectiveness ratios were calculated.

RESULTS

Strategy IV provided the greatest increase in QALY at nearly identical cost to the cheapest approach, Strategy I. Relative risk of malignancy compared to the current standard of care and nearest competing strategy, Strategy III, was 0.18 (95 %CI 0.06 - 0.53) with an NNT of 56 (95 %CI 34 - 120).

CONCLUSIONS

Use of IMP was the most cost-effective strategy, supporting its routine clinical use.

Endoscopic ultrasound guided radiofrequency ablation, for pancreatic cystic neoplasms and neuroendocrine tumors

AIM

To outline the feasibility, safety, adverse events and early results of endoscopic ultrasound (EUS)-radiofrequency ablation (RFA) in pancreatic neoplasms using a novel probe.

METHODS

This is a multi-center, pilot safety feasibility study. The intervention described was radiofrequency ablation (RF) which was applied with an innovative monopolar RF probe (1.2 mm Habib EUS-RFA catheter) placed through a 19 or 22 gauge fine needle aspiration (FNA) needle once FNA was performed in patients with a tumor in the head of the pancreas. The Habib™ EUS-RFA is a 1 Fr wire (0.33 mm, 0.013") with a working length of 190 cm, which can be inserted through the biopsy channel of an echoendoscope. RF power is applied to the electrode at the end of the wire to coagulate tissue in the liver and pancreas.

RESULTS

Eight patients [median age of 65 (range 27-82) years; 7 female and 1 male] were recruited in a prospective multicenter trial. Six had a pancreatic cystic neoplasm (four a mucinous cyst, one had intraductal papillary mucinous neoplasm and one a microcystic adenoma) and two had a neuroendocrine tumors (NET) in the head of pancreas. The mean size of the cystic neoplasm and NET were 36.5 mm (SD ± 17.9 mm) and 27.5 mm (SD ± 17.7 mm) respectively. The EUS-RFA was successfully completed in all cases. Among the 6 patients with a cystic neoplasm, post procedure imaging in 3-6 mo showed complete resolution of the cysts in 2 cases, whilst in three more there was a 48.4% reduction [mean pre RF 38.8 mm (SD ± 21.7 mm) vs mean post RF 20 mm (SD ± 17.1 mm)] in size. In regards to the NET patients, there was a change in vascularity and central necrosis after EUS-RFA. No major complications were observed within 48 h of the procedure. Two patients had mild abdominal pain that resolved within 3 d.

CONCLUSION

EUS-RFA of pancreatic neoplasms with a novel monopolar RF probe was well tolerated in all cases. Our preliminary data suggest that the procedure is straightforward and safe. The response ranged from complete resolution to a 50% reduction in size.

Targeted screening of individuals at high risk for pancreatic cancer: results of a simulation model

PURPOSE

To identify when, from the standpoint of relative risk, magnetic resonance (MR) imaging-based screening may be effective in patients with a known or suspected genetic predisposition to pancreatic cancer.

MATERIALS AND METHODS

The authors developed a Markov model of pancreatic ductal adenocarcinoma (PDAC). The model was calibrated to National Cancer Institute Surveillance, Epidemiology, and End Results registry data and informed by the literature. A hypothetical screening strategy was evaluated in which all population individuals underwent one-time MR imaging screening at age 50 years. Screening outcomes for individuals with an average risk for PDAC ("base case") were compared with those for individuals at an increased risk to assess for differential benefits in populations with a known or suspected genetic predisposition. Effects of varying key inputs, including MR imaging performance, surgical mortality, and screening age, were evaluated with a sensitivity analysis. RESULTS In the base case, screening resulted in a small number of cancer deaths averted (39 of 100 000 men, 38 of 100 000 women) and a net decrease in life expectancy (-3 days for men, -4 days for women), which was driven by unnecessary pancreatic surgeries associated with false-positive results. Life expectancy gains were achieved if an individual's risk for PDAC exceeded 2.4 (men) or 2.7 (women) times that of the general population. When relative risk increased further, for example to 30 times that of the general population, averted cancer deaths and life expectancy gains increased substantially (1219 of 100 000 men, life expectancy gain: 65 days; 1204 of 100 000 women, life expectancy gain: 71 days). In addition, results were sensitive to MR imaging specificity and the surgical mortality rate.

CONCLUSION

Although PDAC screening with MR imaging for the entire population is not effective, individuals with even modestly increased risk may benefit.

Hand scanning optical coherence tomography imaging using encoder feedback

We present a new method for generating micron-scale OCT images of interstitial tissue with a hand scanning probe and a linear optical encoder that senses probe movement relative to a fixed reference point, i.e., tissue surface. Based on this approach, we demonstrate high resolution optical imaging of biological tissues through a very long biopsy needle. Minor artifacts caused by tissue noncompliance are corrected using a software algorithm which detects the simple repetition of the adjacent A-scans. This hand-scanning OCT imaging approach offers the physician the freedom to access imaging sites of interest repeatedly.

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 postbiopsy treatment and management. All documents are based on the expertise of the authors, a review of the literature, discussions 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: Nondiagnostic, 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). 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.

In vivo endomicroscopy improves detection of Barrett's esophagus-related neoplasia: a multicenter international randomized controlled trial (with video)

BACKGROUND

Confocal laser endomicroscopy (CLE) enables in vivo microscopic imaging of the GI tract mucosa. However, there are limited data on endoscope-based CLE (eCLE) for imaging Barrett's esophagus (BE).

OBJECTIVE

To compare high-definition white-light endoscopy (HDWLE) alone with random biopsy (RB) and HDWLE + eCLE and targeted biopsy (TB) for diagnosis of BE neoplasia.

DESIGN

Multicenter, randomized, controlled trial.

SETTING

Academic medical centers.

PATIENTS

Adult patients with BE undergoing routine surveillance or referred for early neoplasia.

INTERVENTION

Patients were randomized to HDWLE + RB (group 1) or HDWLE + eCLE + TB (group 2). Real-time diagnoses and management plans were recorded after HDWLE in both groups and after eCLE in group 2. Blinded expert pathology diagnosis was the reference standard.

MAIN OUTCOME MEASUREMENTS

Diagnostic yield, performance characteristics, clinical impact.

RESULTS

A total of 192 patients with BE were studied. HDWLE + eCLE + TB led to a lower number of mucosal biopsies and higher diagnostic yield for neoplasia (34% vs 7%; P < .0001), compared with HDWLE + RB but with comparable accuracy. HDWLE + eCLE + TB tripled the diagnostic yield for neoplasia (22% vs 6%; P = .002) and would have obviated the need for any biopsy in 65% of patients. The addition of eCLE to HDWLE increased the sensitivity for neoplasia detection to 96% from 40% (P < .0001) without significant reduction in specificity. In vivo CLE changed the treatment plan in 36% of patients.

LIMITATIONS

Tertiary-care referral centers and expert endoscopists limit generalizability.

CONCLUSION

Real-time eCLE and TB after HDWLE can improve the diagnostic yield and accuracy for neoplasia and significantly impact in vivo decision making by altering the diagnosis and guiding therapy. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01124214.).

Interobserver agreement for the detection of Barrett's esophagus with optical frequency domain imaging

BACKGROUND

Optical frequency domain imaging (OFDI) is a second-generation form of optical coherence tomography (OCT) providing comprehensive cross-sectional views of the distal esophagus at a resolution of ~7 μm.

AIM

Using validated OCT criteria for squamous mucosa, gastric cardia mucosa, and Barrett's esophagus (BE), the objective of this study was to determine the inter- and intra-observer agreements by a large number of OFDI readers for differentiating these tissues.

METHODS

OFDI images were obtained from nine subjects undergoing screening and surveillance for BE. Sixty-four OFDI image regions of interest were randomly selected for review. A training set of 19 images was compiled distinguishing squamous mucosa from gastric cardia and BE using previously validated OCT criteria. The ten readers then interpreted images in a test set of 45 different images of squamous mucosa (n = 15), gastric cardia (n = 15), or BE (n = 15). Interobserver agreement differentiating the three tissue types and BE versus non-BE mucosa was determined using multi-rater Fleiss's κ value. The images were later randomized again and four readers repeated the test 3 weeks later to assess intraobserver reliability.

RESULTS

All ten readers showed excellent agreement for the differentiation of BE versus non-BE mucosa (κ = 0.811 p < 0.0001) and for differentiating BE versus gastric cardia versus squamous mucosa (κ = 0.866, p < 0.0001). For the four readers who repeated the test, the median intraobserver agreement (BE vs. non-BE) was high (κ = 0.975, IQR: 0.94, 1.0).

CONCLUSIONS

Trained readers have a high interobserver agreement for differentiating BE, squamous, and gastric cardia mucosa using OFDI.

Optical coherence tomography imaging for cancer diagnosis and therapy guidance

Optical Coherence Tomography (OCT) is an emerging optical technology that has shown great promise for early cancer detection. Using backreflected light to visualize tissue microstructure, OCT can provide information on nuclear size and shape, nuclear-to-cytoplasmic ratio, and the organization and structure of glands. It can also provide functional information, like blood flow, tissue birefringence, etc. These capabilities could potentially be employed in three ways: as a primary diagnostic test to replace biopsy, as a screening tool to direct biopsy, and as a diagnostic tool to guide therapy and monitor therapy response. In this paper we present an application of OCT for pancreatic cancer diagnosis and therapy guidance.

Accuracy of EUS in the evaluation of small gastric subepithelial lesions

BACKGROUND

EUS combined with endoluminal resection techniques is increasingly used to provide a definitive diagnosis of small gastric subepithelial lesions seen on standard upper endoscopy.

OBJECTIVE

To evaluate the accuracy of EUS in diagnosing small gastric subepithelial lesions by using histology as the criterion standard.

DESIGN

A retrospective study.

SETTING

Academic tertiary care center.

PATIENTS

A total of 22 patients (15 women, mean age 62.2 years) with an endoscopically resected gastric subepithelial lesion were included in this 3-year retrospective study.

MAIN OUTCOME MEASUREMENTS

The size, echogenicity, the layer of origin, and presumptive diagnosis were determined by EUS. The diagnostic accuracy of EUS was determined by using histology as the criterion standard.

RESULTS

The mean size of the 22 lesions was 13.6 mm (range 8-20 mm). An endoscopic cap band mucosectomy device was used to resect 16 (72.7%) lesions, whereas 6 (27.3%) were resected with a saline solution-assisted and snare technique. Using histology as a criterion standard, we found that the accuracy of the EUS diagnosis was 10 of 22 (45.5%). EUS alone had an accuracy rate of 30.8% and 66.7%, respectively, in the diagnosis of neoplastic and non-neoplastic lesions.

LIMITATIONS

A single-center, retrospective analysis.

CONCLUSION

EUS imaging had a low accuracy rate in the diagnosis of gastric subepithelial lesions, and endoscopic submucosal resection should be performed to provide a histologic diagnosis. Resection of small subepithelial lesions of 20 mm or less can be accomplished en bloc with an endoscopic cap band mucosectomy device.

Pseudocyst of the pancreas: the role of cytology and special stains for mucin

BACKGROUND

Currently, the preoperative diagnosis of a pancreatic cyst is based on clinical and imaging findings, frequently in conjunction with chemical analysis of cyst fluid and cytologic evaluation. The purpose of these diagnostic tests is to distinguish benign from malignant cysts of the pancreas. Accordingly, it is imperative to distinguish pancreatic pseudocysts from their mimics. In this study, the authors explored the cytomorphologic features of pseudocyst of the pancreas and evaluated the role of Alcian blue and mucicarmine stains in the cytologic evaluation of pancreatic cysts.

METHODS

Forty-two patients were identified who had an eventual diagnosis of pancreatic pseudocyst and had an endoscopic ultrasound-guided fine-needle aspirate available. Clinical and imaging findings and chemical analyses of cyst fluid were recorded. The cytologic preparations were evaluated for gastrointestinal contamination, inflammatory cells, mucin, and pigmented material. The cytomorphologic features of 110 neoplastic mucinous cysts (intraductal papillary-mucinous neoplasms/mucinous cystic neoplasms of the pancreas) were evaluated and compared with the pseudocysts.

RESULTS

The majority of patients (95%) had a prior episode of pancreatitis. On imaging, the pseudocysts were unilocular (92%). In 69% of cases, the endosonographic diagnosis was that of a pseudocyst. The mean carcinoembryonic antigen level was 41 ng/mL. In contrast, the cytopathologist rendered a definitive diagnosis of pseudocyst in only 10% of cases. The majority of smears (75%) revealed neutrophils and/or histiocytes. Atypical epithelial clusters were identified in 3 cases, 1 of which was diagnosed as suspicious for carcinoma. Yellow pigmented material, which was identified in 13 pseudocysts (31%), was not observed in neoplastic mucinous cysts. Alcian blue- and mucicarmine-positive material was identified in 64% and 40% of pseudocysts, respectively, and in 57% and 38% of neoplastic mucinous cysts, respectively.

CONCLUSIONS

The diagnosis of a pseudocyst depended primarily on clinical and imaging findings and on chemical analysis of cyst fluid. The cytologic features frequently were nonspecific. The presence of yellow pigmented material served as a surrogate marker of a pseudocyst. Special stains for mucin did not distinguish pseudocysts from neoplastic mucinous cysts.

EUS-based criteria for the diagnosis of chronic pancreatitis: the Rosemont classification

BACKGROUND

EUS is increasingly used in the diagnosis of chronic pancreatitis (CP). A number of publications in this field have used different EUS terminology, features, and criteria for CP, making it difficult to reproduce their findings and apply them in clinical practice. Moreover, traditional criteria such as the Cambridge classification for CP are arguably outdated and have lost their relevance.

OBJECTIVE

Our purpose was to establish consensus-based criteria for EUS features of CP.

DESIGN

Consensus study.

MAIN OUTCOME MEASUREMENTS

Thirty-two internationally recognized endosonographers anonymously voted on terminology of EUS features, rank order, and category (major vs minor criteria). Consensus was defined as greater than two thirds agreement among participants.

RESULTS

Major criteria for CP were (1) hyperechoic foci with shadowing and main pancreatic duct (PD) calculi and (2) lobularity with honeycombing. Minor criteria for CP were cysts, dilated ducts > or =3.5 mm, irregular PD contour, dilated side branches > or =1 mm, hyperechoic duct wall, strands, nonshadowing hyperechoic foci, and lobularity with noncontiguous lobules.

LIMITATION

Lack of broadly accepted reference standard.

CONCLUSION

In a complex disease such as CP that has no universally accepted reference standard, an EUS-based criterion for diagnosis can be determined by expert consensus opinion and the existing body of evidence. Here we present the new "Rosemont criteria" for the EUS diagnosis of CP.

Endoscopic ultrasound-guided fine-needle aspiration for diagnosis of solid pseudopapillary tumors of the pancreas: a multicenter experience

BACKGROUND AND STUDY AIMS

Solid pseudopapillary tumors of the pancreas are rare, low-grade, epithelial neoplasms that are usually discovered incidentally in young women. Distinguishing solid pseudopapillary tumors from other pancreatic tumors, especially pancreatic endocrine tumors, can be challenging. The role of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in this context remains unclear. The purpose of this study was to describe the endoscopic ultrasound features of solid pseudopapillary tumors and the role of EUS-FNA in the preoperative diagnosis of these tumors.

PATIENTS AND METHODS

Patients from five tertiary referral centers with surgically confirmed solid pseudopapillary tumors who had undergone preoperative EUS-FNA were included. The endoscopic ultrasound findings, cytologic descriptions, immunostaining results, operative records, surgical pathology, and results of the most recent clinical follow-up were reviewed.

RESULTS

A total of 28 patients were identified (four men [14 %], 24 women [86 %], mean age +/- standard deviation [SD] 35 +/- 10 years). Solid pseudopapillary tumors had been found as incidental findings on cross-sectional imaging in 50 % of cases. The mean tumor size +/- SD was 42 +/- 19.5 mm and the majority were located in the pancreatic body and tail. The endoscopic ultrasound report described a well-defined, echo-poor mass in 86 %; the tumors were solid in 14 patients (50 %), mixed solid and cystic in 11 patients (39 %), and cystic in three patients (11 %). A preoperative diagnosis of solid pseudopapillary tumor was made in 21 patients (75 %) on the basis of EUS-FNA cytology. Surgical resection was performed in all cases. Laparoscopic resection was performed in eight of these patients (29 %).

CONCLUSIONS

A solid pseudopapillary tumor should be included in the differential diagnosis of any well-demarcated, echo-poor, solid or mixed solid/cystic pancreatic lesion seen during endoscopic ultrasound, particularly in young women. The diagnostic accuracy of EUS-FNA for solid pseudopapillary tumors was 75 % in this study. A definitive preoperative diagnosis can guide the surgical approach in selected cases.

ACG practice guidelines for the diagnosis and management of neoplastic pancreatic cysts

The diagnosis and management of pancreatic cystic lesions is a common problem. At least 1% of hospitalized patients at major medical centers will have a pancreatic cystic lesion on cross sectional imaging. Up to a quarter of all pancreata examined in an autopsy series contained a pancreatic cyst, 16% of which were lined by an "atypical" epithelium and 3% of which had progressed to carcinoma-in-situ (high grade dysplasia). in the past, it was thought these cystic lesions were benign, but increasing evidence points to the cystic lesions as being the origin of some pancreatic malignancies. The most important clinical tools in the diagnosis and management of pancreatic cystic lesions are cross sectional imaging, endoscopic ultrasound, and cyst fluid analysis. The most important differential diagnosis is distinguishing mucinous (pre-malignant) and non-mucinous cystic lesions. The findings of a macrocystic lesion containing viscous fluid rich in CEA are supportive of a diagnosis of a mucinous lesion. Serous lesion are the most common non-mucinous cyst and are characterized by a microcystic morphology, non-viscous fluid and a low concentration of CEA in the cyst fluid. The following document includes a description of neoplastic pancreatic cysts, a critical review of relevant diagnostic tests, and a discussion of treatment options. We have proposed a set of guidelines for the diagnosis and management of patients with neoplastic pancreatic cysts. The guidelines are based on published data backed by an analysis of the quality of the data and are designed to address the most frequent and important clinical scenarios. In addition to providing a summary of the diagnostic data, we offer diagnostic and management suggestions based on 13 common clinical problems. Although the field is rapidly evolving, a set of core principles is provided based on a balance between the risk of malignancy and the benefit of pancreatic resection.

Autoimmune pancreatitis: more than just a pancreatic disease? A contemporary review of its pathology

CONTEXT

Autoimmune pancreatitis (AIP) is a chronic inflammatory condition of the pancreas constituting one quarter of Whipple resections performed for benign conditions in North America.

OBJECTIVE

We review the clinical, radiologic, and characteristic histopathologic patterns of this disease and discuss the extrapancreatic manifestations of AIP.

DESIGN

We searched the literature using MEDLINE and OVID, related conference abstracts, and bibliographies of selected studies.

RESULTS

Autoimmune pancreatitis predominantly affects elderly individuals, frequently presenting as obstructive jaundice and occasionally in association with other autoimmune diseases. The histology is characterized by a collar of periductal inflammation, obliterative phlebitis, and the absence of stigmata of alcoholic pancreatitis. A prepancreatectomy diagnosis can be rendered using a combination of clinical findings, radiologic features, elevated immunoglobulin G4 levels, endoscopic ultrasound-guided fine-needle aspiration biopsy, and response to steroids. The disease can involve the bile ducts (sclerosing cholangitis), gallbladder (lymphoplasmacytic sclerosing cholecystitis), and kidney (interstitial nephritis) and can form inflammatory masses in the lungs.

CONCLUSIONS

Despite significant evolution in our understanding of AIP, a prepancreatectomy diagnosis remains a challenge in the North American and European population.

EUS-guided portal vein catheterization and pressure measurement in an animal model: a pilot study of feasibility

BACKGROUND

The extrahepatic portal vein is inaccessible to direct catheterization.

METHODS

Because EUS can readily image the portal vein, the feasibility of EUS-guided portal vein catheterization by using a 22-gauge needle was studied in 7 normal pigs and 14 pigs in which portal hypertension was induced (7/14 anticoagulated).

RESULTS

Catheterization was not possible by EUS or transhepatic methods in, respectively, 3 and 5 animals. One anticoagulated animal had a small amount of periduodenal bleeding as a result of EUS catheterization. The mean normal portal vein pressure (1 standard deviation) as determined by EUS and transhepatic methods was, respectively, 20.3 (4) mm Hg and 20.4 (2) mm Hg. Injection of polyvinyl alcohol particles increased the portal vein pressure by 10.2 (11.59) mm Hg. There was a close correlation under all conditions between the mean portal vein pressures obtained by EUS and transhepatic catheterization (r=0.91).

CONCLUSIONS

EUS-guided portal vein catheterization appears to be feasible in an animal model and provides accurate pressure measurements.