Intraductal papillary mucinous neoplasms of the pancreas: differentiation of malignant and benign tumors by endoscopic ultrasound findings of mural nodules. Ann Surg. 2009;249:628-634. [PMID: 19300203 DOI: 10.1097/sla.0b013e3181a189a8]

Towards a Simplified and Cost-Effective Diagnostic Algorithm for the Surveillance of Intraductal Papillary Mucinous Neoplasms (IPMNs): Can We Save Contrast for Later?

The increased detection of pancreatic cysts in recent years has triggered extensive diagnostic investigations to clarify their potential risk of malignancy, resulting in a large number of patients undergoing numerous imaging follow-up studies for many years. Therefore, there is a growing need for optimization of the current surveillance protocol to reduce both healthcare costs and waiting lists, while still maintaining appropriate sensibility and specificity. Imaging is an essential tool for evaluating patients with intraductal papillary mucinous neoplasms (IPMNs) since it can assess several predictors for malignancy and thus guide further management recommendations. Although contrast-enhanced magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography (MRCP) has been widely recommended by most international guidelines, recent results support the use of unenhanced abbreviated-MRI (A-MRI) protocols as a surveillance tool in patients with IPMN. In fact, A-MRI has shown high diagnostic performance in malignant detection, with high sensitivity and specificity as well as excellent interobserver agreement. The aim of this paper is, therefore, to discuss the current available evidence on whether the implementation of an abbreviated-MRI (A-MRI) protocol for cystic pancreatic lesion surveillance could improve healthcare economics and reduce waiting lists in clinical practice without significantly reducing diagnostic accuracy.

Association of high-risk stigmata and worrisome features with advanced neoplasia in intraductal papillary mucinous neoplasms (IPMN): A systematic review

BACKGROUND

This systematic review aimed to assess the diagnostic accuracy of the International Consensus Fukuoka Guidelines (ICG2017) in identifying high-risk lesions of Intraductal Papillary Mucinous Neoplasms (IPMNs).

METHODS

The ICG2017 revision committee conducted a comprehensive literature review to establish evidence-based statements on IPMNs. The review focused on articles examining the diagnostic value of imaging features (e.g., cyst or main pancreatic duct diameter), clinical symptoms associated with IPMN, and serum biomarkers. Five clinical questions regarding high-risk stigmata (HRS) and worrisome features (WF) in the ICG2017 guidelines were addressed.

RESULTS

A total of 210 articles were reviewed. The findings revealed a significant association between the presence of mural nodules ≥5 mm in diameter or solid components with contrast enhancement and the diagnosis of high-grade dysplasia or invasive carcinoma. Contrast-enhanced diagnostic tools, such as CT, MRI, or EUS, demonstrated the highest prediction rate and were recommended. Positive cytology was identified as an HRS, while symptoms like acute pancreatitis and cyst diameter growth ≥2.5 mm per year were considered WFs. The use of nomograms and multiple diagnostic factors was recommended for optimal IPMN management.

CONCLUSIONS

This systematic review provides evidence supporting the improved diagnostic accuracy of ICG2017 in identifying high-risk lesions of IPMN. The multidisciplinary incorporation of HRS and WF based on imaging findings and clinical symptoms is crucial. These findings should inform the revision of ICG2017, enhancing the evaluation and management of IPMN patients. By implementing these recommendations, clinicians can make more informed decisions, leading to better diagnosis and treatment outcomes for high-risk IPMN cases.

Use of contrast-enhanced harmonic endoscopic ultrasonography for the diagnosis of pancreatic cystic lesions

Endoscopic ultrasonography (EUS) provides high spatial and contrast resolution and is a useful tool for evaluating the pancreato-biliary regions. Recently, contrast-enhanced harmonic EUS (CH-EUS) has been used to evaluate lesion vascularity, especially for the diagnosis of pancreatic tumors. CH-EUS adds two major advantages when diagnosing pancreatic cystic lesions (PCL). First, it can differentiate between mural nodules and mucous clots, thereby improving the accurate classification of PCL. Second, it helps with evaluation of the malignant potential of PCL, especially of intraductal papillary mucinous neoplasms by revealing the vascularity in the mural nodules and solid components. This review discusses the use and limitations of CH-EUS for the diagnosis of PCL.

A comparative study between computed tomography and endoscopic ultrasound in the detection of a mural nodule in intraductal papillary mucinous neoplasm -Multicenter observational study in Japan

BACKGROUND/OBJECTIVES

The detection of malignancy is a major concern in the management of intraductal papillary mucinous neoplasm (IPMN). The height of the mural nodule (MN), estimated using endoscopic ultrasound (EUS) and computed tomography (CT), has been considered crucial for predicting malignant IPMN. Currently, whether surveillance using CT or EUS alone is sufficient for detecting MNs remains unclear. This study aimed to compare the ability of CT and EUS to detect MNs in IPMN.

METHODS

This multicenter, retrospective observational study was conducted in 11 Japanese tertiary institutions. Patients who underwent surgical resection of IPMN with MN after CT and EUS examinations were eligible to participate. The MN detection rates between CT and EUS were examined.

RESULTS

Two-hundred-and-forty patients who underwent preoperative EUS and CT had pathologically confirmed MNs. The MN detection rates of EUS and CT were 83% and 53%, respectively (p < 0.001). Additionally, the MN detection rate of EUS was significantly higher than that of CT regardless of morphological type (76% vs. 47% in branch-duct-type IPMN; 90% vs. 54% in mixed IPMN; 98% vs. 56% in main-duct-type IPMN; p < 0.001). Further, pathologically confirmed MNs ≥5 mm were more frequently observed on EUS than on CT (95% vs. 76%, p < 0.001).

CONCLUSIONS

EUS was superior to CT for the detection of MN in IPMN. EUS surveillance is essential for the detection of MNs.

Ultrasonographic Features of Nonneoplastic Protrusions in Pancreatic Cysts by Contrast-Enhanced Endoscopic Ultrasound

OBJECTIVES

Most of the pancreatic cyst protrusions detected by B-mode endoscopic ultrasound (BM-EUS) are nonneoplastic and are not enhanced by contrast-enhanced EUS (CE-EUS) using ultrasound contrast agent (USCA). This study aimed to identify useful findings for distinguishing between neoplastic and nonneoplastic pancreatic cyst protrusions on BM-EUS to facilitate efficient USCA use.

MATERIALS AND METHODS

A total of 151 pancreatic cyst protrusions in 119 consecutive patients who underwent CE-EUS were analyzed. We focused on the echo level (hyperechoic/isoechoic/hypoechoic/anechoic), base type (sessile without a basal waist/sessile with a basal waist/pedunculated), surface type (smooth/irregular), and the presence/absence of a hyperechoic surface layer. Enhanced and unenhanced protrusions on CE-EUS were interpreted as neoplastic and nonneoplastic, respectively.

RESULTS

Forty-five and 106 protrusions were enhanced and unenhanced, respectively, on CE-EUS performed using USCA. In univariable analysis of predictors of nonneoplastic protrusion on BM-EUS, the following factors were found to be significant: echo level (hypoechoic/anechoic), base type (sessile with a basal waist/pedunculated), a smooth surface, and a hyperechoic surface layer. Of these, only a hyperechoic surface layer remained significant in the multivariable analysis ( P < 0.0001; odds ratio, 40.74; 95% confidence interval, 7.07-387.49).

CONCLUSIONS

Pancreatic cyst protrusions with a hyperechoic surface layer on BM-EUS are suggestive of nonneoplastic disease.

Risk Models for Pancreatic Cyst Diagnosis

The overall prevalence of pancreatic cysts (PCs) is high in the general population. In clinical practice PCs are often incidentally discovered and are classified into benign, premalignant, and malignant lesions according to the World Health Organization. For this reason, in the absence of reliable biomarkers, to date clinical decision-making relies mostly on risk models based on morphological features. The aim of this narrative review is to present the current knowledge regarding PC's morphologic features with related estimated risk of malignancy and discuss available diagnostic tools to minimize clinically relevant diagnostic errors.

Dilatation of the main pancreatic duct of unknown origin: causes and risk factors of pre-malignancy or malignancy

INTRODUCTION

A dilatation of the main pancreatic duct (MPD) is mainly due to obstructive causes (pancreatic tumor, chronic pancreatitis) or intraductal papillary mucinous neoplasm (IPMN). This study aims to assess the risk of pre-malignancy or malignancy in case of MPD dilatation with no visible mass nor obstructive calcification on computed tomography scan (CT-scan) in a population operated for it.

PATIENTS AND METHODS

All patients operated on from November 2015 to December 2019 in our center for a significant dilatation of the MPD without visible obstructive cause on CT-scan were included. Preoperative work-up included at least CT-scan, magnetic resonance imaging (MRI), and endoscopic ultrasonography (EUS). Primary endpoint was the final pathological diagnosis. Secondary endpoints were predictive factors of malignancy.

RESULTS

101 patients were included, mean age 68 years-old. Final pathological data were pancreatic adenocarcinoma (n = 2), IPMN with high-grade dysplasia (n = 37), high-grade Pancreatic Intraepithelial Neoplasia (PanIN) (n = 2) (total of pre-malignant or malignant lesions: n = 41), neuroendocrine tumor (n = 6), IPMN with low-grade dysplasia (n = 45), low-grade PanIN (n = 5), chronic pancreatitis (n = 3), and benign stenosis (n = 1). On preoperative explorations, the median diameter of MPD was 7 mm [3-35]. MRI and/or EUS showed intraductal material, nodule, or cyst in 22, 32, and 52 patients, respectively; 22 patients without nodule visible on MRI or EUS had still a pre-malignant or malignant lesion. In multivariate analysis, predictive factors for pre-malignancy or malignancy were symptoms before surgery (p = 0.01), MPD dilatation without downstream stenosis (p = 0.046), and the presence of nodule (p = 0.009).

CONCLUSION

A dilatation of the MPD without detectable mass or obstructive calcification on CT-scan was associated with a pre-malignant or malignant lesion in 41 patients. Symptoms before surgery, MPD dilatation without duct narrowing, and the presence of nodules on MRI/EUS were associated with the risk of  pre-malignancy or malignancy.

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.

Clinical Utility of the Contrast-Enhanced Endoscopic Ultrasound Guided Fine Needle Aspiration in the Diagnosis of Pancreatic Cyst

Endoscopic ultrasound fine needle aspiration (EUS-FNA) cytology from an intracystic fluid is useful in the differentiation of pancreatic cysts, with low sensitivity, which increases when the solid component is targeted. The clinical utility of contrast-enhanced guided EUS-FNA (CH-EUS-FNA) in the solid component is not known. We aimed to assess the diagnostic value of CH-EUS-FNA in enhanced mural nodules and discrimination between different cysts using contrast-enhanced endoscopic ultrasound (CH-EUS). The prospective study recruited patients with pancreatic cysts with an unclear diagnosis. The CH-EUS was followed by CH-EUS-FNA. The final diagnosis was based on surgery or the correlation between clinical history, cross-sectional imaging, echoendoscopic morphology, cystic fluid analysis, and follow-up. Fifty-eight patients with pancreatic cysts were evaluated. The mucinous cysts had wall arterial enhancement more often than non- mucinous cysts (p < 0.0001), with 90.2% sensitivity and 70.6% specificity. The CH-EUS-FNA from cystic fluid and mural nodules identified mucinous cysts and malignancy with 82.4% and 84.2% sensitivity and 92% and 100% specificity. Twenty-one cysts had solid components, but only 13 were enhanced mural nodules on EUS assessment with conclusive cytology in all cases and malignancy in 76.9%. Contrast-enhanced endoscopic ultrasound should be completed in all PCN with solid components in order to avoid unnecessary EUS-FNA and to guide FNA for the identification of malignant cysts.

Diagnostic Dilemma of Biliopancreatic Contrast-Enhanced Harmonic Endoscopic Ultrasonography

Background: The utility of contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) alone in the biliopancreatic region appears to be limited because it is highly dependent on the experience and skill of the endoscopist. Therefore, the present study aimed to validate the efficacy of CH-EUS in clinical practice. Methods: Between January 2018 and March 2019, 301 consecutive patients who underwent CH-EUS were prospectively enrolled in this study. The diagnostic performance of CH-EUS was compared with that of dynamic computed tomography (CT), magnetic resonance imaging (MRI), and all combinations (i.e., CH-EUS, dynamic CT, and MRI) using a Bonferroni correction. A multiple logistic regression analysis was performed to extract each disease that allowed the CH-EUS diagnosis to be consistent with the final diagnosis. Results: In multiple comparisons of diagnostic performance, no significant differences were observed among dynamic CT, MRI, and CH-EUS (p = 1.00), but the diagnostic performance was significantly higher when all modalities were combined (p < 0.001). Moreover, only intraductal papillary mucinous neoplasm comprising adenoma or carcinoma (IPMN, n = 161) showed significance with respect to the agreement with the final diagnosis (p = 0.006). Conclusions: Our results showed that CH-EUS-based diagnosis of IPMN may be possible in clinical practice. On the contrary, to accurately diagnose biliopancreatic diseases other than IPMN, comprehensive diagnosis using multiple modalities may be necessary, rather than relying on CH-EUS alone.

Preoperative Predictive Features of Invasive Carcinoma Among Intraductal Papillary Mucinous Neoplasm of the Pancreas

OBJECTIVE

Noninvasive intraductal papillary mucinous neoplasms (IPMNs) theoretically do not metastasize. The purpose of this study is to preoperatively distinguish invasive carcinomas associated with IPMN from noninvasive IPMN.

METHODS

A total of 131 patients who underwent surgical resection for IPMN were retrospectively analyzed to identify the predictors of invasive carcinoma, based on the International Association of Pancreatology Consensus Guidelines.

RESULTS

Of the 131 patients, 29 (22%) had invasive carcinomas and 102 (78%) had noninvasive IPMN. An enhancing mural nodule (MN) greater than or equal to 5 mm, obstructive jaundice, an abrupt change in the caliber of the pancreatic duct (PD) with distal pancreatic atrophy, and lymphadenopathy were the significant predictors of invasive carcinoma in univariate analysis. The optimal cutoff value for the size of the enhancing MN to differentiate invasive carcinoma was 13 mm. In multivariate analysis, enhancing MN greater than or equal to 13 mm, obstructive jaundice, and an abrupt change in the PD caliber were the independent predictors. When all these factors were absent, only 17% were invasive carcinomas.

CONCLUSIONS

Enhancing MN greater than or equal to 13 mm, obstructive jaundice, and an abrupt change in the PD caliber were predictive factors for invasive carcinoma. Systematic lymph node dissection may be omitted when a high-risk patient has none of these factors.

Efficacy of Contrast-Enhanced Endoscopic Ultrasonography for the Diagnosis of Pancreatic Tumors

Endoscopic ultrasound can be useful for obtaining detailed diagnostic images for pancreatic disease. Contrast-enhanced harmonic endoscopic ultrasound has allowed to demonstrate not only microvasculature but also real perfusion imaging using second-generation contrast agents. Furthermore, endoscopic ultrasound fine-needle aspiration cytology and histology have become more ubiquitous; however, the risk of dissemination caused by paracentesis has yet to be resolved, and the application of less invasive contrast-enhanced endoscopic ultrasound for the differential diagnosis of pancreatic tumors has been anticipated. Contrast-enhanced harmonic endoscopic ultrasound can contribute to the differential diagnosis of pancreatic tumors.

Malignant potential and specific characteristics of pure main duct type intraductal papillary mucinous neoplasm

BACKGROUND

As the malignant potential of main duct (MD-) type intraductal papillary mucinous neoplasm (IPMN) has been discussed together with Mixed-type in most previous studies, the malignant potential of pure MD-type IPMN remains unclear. This study evaluated the specific characteristics and predictors of high-grade dysplasia (HGD) and invasive intraductal papillary mucinous carcinoma (IPMC) for pure MD-type IPMN.

METHODS

From 1,100 patients with IPMN, this study includes 387 patients that underwent surgery. We evaluated the specific characteristics of pure MD-type IPMN by comparing clinicopathological factors between MD-type (n = 79) and branch duct (BD-) type (n = 146) or Mixed-type IPMN (n = 162), and predictors of HGD/invasive IPMC in pure MD-type IPMN.

RESULTS

The rate of HGD/invasive IPMC was significantly higher in MD-type than in BD-type (70.9 vs. 48.6%, P = 0.001), although there was no difference between MD-type and Mixed-type IPMNs (P = 0.343). Recurrence-free survival (RFS) and disease-specific survival (DSS) of patients with MD-type were better than those of patients with Mixed-type (P = 0.008 and P = 0.009, respectively). There were no significant differences in RFS, overall survival, and DSS between patients with MD-type and patients with BD-type IPMNs. Multivariate analysis showed two independent predictors of HGD/invasive IPMC in MD-type IPMN; mural nodule height ≥5 mm (P = 0.025, odds ratio [OR]; 16.949) and carcinoembryonic antigen (CEA) level in the pancreatic juice obtained by preoperative endoscopic retrograde pancreatography ≥50 ng/ml (P = 0.039, OR; 9.091).

CONCLUSIONS

Measurement of mural nodule height and CEA in the pancreatic juice might be useful in determining surgical indication for pure MD-type IPMN, although further studies for confirmation are essential.

Role of endoscopic ultrasound in anticancer therapy: Current evidence and future perspectives

The digestive system is one of the most common sites of malignancies in humans. Since gastrointestinal tumors represent a massive global health burden both in terms of morbidity and health care expenditures, scientists continuously develop novel diagnostic and therapeutic methods to ameliorate the detrimental effects of this group of diseases. Apart from the well-established role of the endoscopic ultrasound (EUS) in the diagnostic course of gastrointestinal and hepatobiliary malignancies, we have recently become acquainted with a vast array of its therapeutic possibilities. A multitude of previously established, evidence-based methods that might now be guided by the EUS emerged: Radiofrequency ablation, brachytherapy, fine needle injection, celiac plexus neurolysis, and endoscopic submucosal dissection. In this review we endeavored to provide a comprehensive overview of the role of these methods in different malignancies of the digestive system, primarily in the treatment and symptom control in pancreatic cancer, and additionally in the management of hepatic, gastrointestinal tumors, and pancreatic cysts.

Contrast-enhanced EUS for the characterization of mural nodules within pancreatic cystic neoplasms: systematic review and meta-analysis

BACKGROUND AND AIMS

Pancreatic cystic neoplasms (PCNs) carry a considerable malignancy risk. Along with main duct dilation, the presence of enhanced mural nodules represents a significant risk factor for malignancy. Several articles assessed the role of contrast-enhanced EUS (CE-EUS) for the identification of malignant features in mural nodules. We evaluate the pooled diagnostic performance of CE-EUS for the identification of high-grade dysplasia or invasive carcinoma among mural nodules in PCNs.

METHODS

A systematic review (Medline, PubMed, EMBASE) and meta-analysis were conducted. Subgroup analysis was used to assess the usefulness of a dedicated contrast-harmonic (CH-EUS). The primary outcome was pooled sensitivity for identification of high-grade dysplasia or invasive carcinoma.

RESULTS

Ten studies (532 patients) were included. Pooled sensitivity of CE-EUS was 88.2% (95% confidence interval [CI], 82.7%-92.5%), specificity 79.1% (95% CI, 74.5%-83.3%), and diagnostic accuracy 89.6% (95% CI, 83.4%-95.8%). Eight studies (320 patients) were conducted using CH-EUS: pooled sensitivity increased to 97.0% (95% CI, 92.5%-99.2%), specificity to 90.4% (95% CI, 85.2%-94.2%), and diagnostic accuracy to 95.6% (95% CI, 92.6%-98.7%). At 42% disease prevalence (pretest probability), a positive CH-EUS increased the disease probability to 88%, whereas a negative test decreased the disease probability to 2%. The number needed to diagnose was 1.5 (95% CI, 1.7-1.3) for CE-EUS and just 1.2 (95% CI, 1.3-1.1) for CH-EUS.

CONCLUSIONS

This study provided robust evidence on CE-EUS value for the characterization of mural nodules within PCNs. A dedicated contrast-harmonic mode, namely CH-EUS, provided an increased diagnostic yield in the identification and characterization of malignant mural nodules.

Imaging diagnosis of autoimmune pancreatitis using endoscopic ultrasonography

The diagnosis of autoimmune pancreatitis (AIP) is challenging and should be achieved through the comprehensive evaluation of clinical, radiological, serological, and pathological evidence, as there is currently no single reliable diagnostic modality. Endoscopic ultrasonography (EUS) can reveal pancreatic parenchymal and ductal features in much more detail than any other existing imaging modality. In this article, we focused on three applications of EUS, i.e., conventional EUS imaging, EUS elastography (EUS-EG), and contrast-enhanced harmonic EUS (CEH-EUS), for the diagnosis of AIP. Diffuse hypoechoic areas, diffuse enlargement, bile duct wall thickening, and peripancreatic hypoechoic margins on conventional EUS are characteristic features of AIP, and the frequencies of these findings are significantly higher in AIP than in pancreatic cancer (PC). EUS-EG of the pancreatic parenchyma in AIP showed homogenous stiffness and that the elasticity of the pancreas may change after steroid therapy. CEH-EUS revealed focal or diffuse iso-enhancement in most AIP cases and hypo-enhancement in most PC cases. However, some AIP cases show a contrast enhancement pattern similar to that of PC. It should be noted that EUS findings of AIP may differ depending on its stage or disease activity. Differentiation from PC has become an increasingly important issue in the process of diagnosing AIP, and EUS, including elastography and contrast enhancement, could be a promising imaging modality for this purpose.

Management of pancreatic cysts and guidelines: what the gastroenterologist needs to know

The prevalence of pancreatic cysts has increased significantly over the last decade, partly secondary to increased quality and frequency of cross-sectional imaging. While the majority never progress to cancer, a small number will and need to be followed. The management of pancreatic cysts can be both confusing and intimidating due to the multiple guidelines with varying recommendations. Despite the differences in the specifics of the guidelines, they all agree on several high-risk features that should get the attention of any clinician when assessing a pancreatic cyst: presence of a mural nodule or solid component, dilation of the main pancreatic duct (or presence of main duct intraductal papillary mucinous neoplasm), pancreatic cyst size ⩾3–4 cm, or positive cytology on pancreatic cyst fluid aspiration. Other important criteria to consider include rapid cyst growth (⩾5 mm/year), elevated serum carbohydrate antigen 19-9 levels, new-onset diabetes mellitus, or acute pancreatitis thought to be related to the cystic lesion.

Narrative review of intraductal papillary mucinous neoplasms: pathogenesis, diagnosis, and treatment of a true precancerous lesion

OBJECTIVE

Although considerable progress has been made in our understanding of intraductal papillary mucinous neoplasm (IPMN) of the pancreas, there are still some problems to be solved.

BACKGROUND

IPMN is one of the most important precancerous lesions of pancreatic cancer, but the relationship between IPMN and pancreatic cancer, and the specific mechanism of the development from IPMN to invasive carcinoma, remain to be explored in depth. With the development of imaging, the detection rate of IPMN has been greatly improved. However, the degree of malignancy of IPMN is difficult to assess, and its classification criteria and surgical treatment strategies are still controversial. Therefore, there is an urgent need for the best treatment plan for IPMN and research that can better predict IPMN recurrence and tumor malignancy.

METHODS

From the online database Web of Science (https://webofknowledge.com/) and PubMed (https://pubmed.ncbi.nlm.nih.gov/), we use specific retrieval strategies to retrieve relevant articles based on the topics we discussed, and we review and discuss them.

CONCLUSIONS

This paper discusses the related research and progress of IPMN in recent years to improve the understanding of the incidence, diagnosis, treatment, and prognosis of this disease. The follow-up and monitoring of IPMN is particularly important, but the specific strategy also remains controversial.

The Asian Federation of Societies for Ultrasound in Medicine and Biology (AFSUMB) Guidelines for Contrast-Enhanced Endoscopic Ultrasound

The Asian Federation of Societies for Ultrasound in Medicine and Biology aimed to provide information on techniques and indications for contrast-enhanced harmonic endoscopic ultrasound (CH-EUS), and to create statements including the level of recommendation. These statements are based on current scientific evidence reviewed by a Consensus Panel of 15 internationally renowned experts. The reliability of clinical questions was measured by agreement rates after voting. Six statements were made on techniques, including suitable contrast agents for CH-EUS, differences between contrast agents, setting of mechanical index, dual imaging and duration and phases for observation. Thirteen statements were made on indications, including pancreatic solid masses, pancreatic cancer staging, pancreatic cystic lesions and mural nodules, detection of subtle pancreatic lesions, gallbladder sludge and polyps, hepatic lesions, lymph nodes, subepithelial lesions, visceral vascular diseases, guidance of fine needle aspiration and evaluation for local therapy. These international expert consensus guidelines will assist endosonographers in conducting CH-EUS according to evidence-based information.

Should Contrast-Enhanced Harmonic Endoscopic Ultrasound Be Incorporated into the International Consensus Guidelines to Determine the Appropriate Treatment of Intraductal Papillary Mucinous Neoplasm?

This study aimed to investigate whether the incorporation of contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) into the international consensus guidelines (ICG) for the management of intraductal papillary mucinous neoplasm (IPMN) could improve its malignancy diagnostic value. In this single-center retrospective study, 109 patients diagnosed with IPMN who underwent preoperative CH-EUS between March 2010 and December 2018 were enrolled. We analyzed each malignancy diagnostic value (sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV)) by replacing fundamental B-mode EUS with CH-EUS as the recommended test for patients with worrisome features (WF) (the CH-EUS incorporation ICG) and comparing the results to those obtained using the 2017 ICG. The malignancy diagnostic values as per the 2017 ICG were 78.9%, 42.3%, 60.0%, and 64.7% for Se, Sp, PPV, and NPV, respectively. The CH-EUS incorporation ICG plan improved the malignancy diagnostic values (Se 78.9%/Sp, 53.8%/PPV, 65.2%/NPV 70.0%). CH-EUS may be useful in determining the appropriate treatment strategies for IPMN.

Utility of multiphase contrast enhancement patterns on CEH-EUS for the differential diagnosis of IPMN-derived and conventional pancreatic cancer

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) is reported as a high-risk factor for pancreatic cancer (PC) that includes IPMN-derived cancers (IPMC) and the development of invasive pancreatic ductal adenocarcinoma (PDAC) concomitant with IPMN. Since invasive IPMC and PDAC exhibit different oncological behaviors, their differentiation is clinically important. We aimed to investigate the use of contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS) for the differential diagnosis between invasive IPMC and PDAC.

METHODS

This study involved 183 consecutive patients with PC (invasive IPMC: 42, PDAC concomitant with IPMN: 9, without IPMN: 132) who underwent CEH-EUS preoperatively. While investigating the patterns, enhanced effects in the solid part of the tumor were compared with those in the surrounding pancreatic parenchyma after administration of Sonazoid® and evaluated as hyperenhanced, isoenhanced, or hypoenhanced. We retrospectively compared the enhanced pattern of CEH-EUS by using multiphasic analysis and clinicopathological factors between invasive IPMC and PDAC.

RESULTS

In multiphase evaluations at 20, 40 and 60 s in CEH-EUS, 75.2% (106/141) of PDACs were hypoenhanced (-) at ≥2 of the 3 time points, with significant differences from those of invasive IPMC (P < 0.001). The solid tumor diameter was significantly larger in PDAC than in invasive IPMC, and the tumor stage and preoperative serum carbohydrate antigen 19-9 level were higher. After propensity score matching of stage and solid tumor diameter, contrast enhancement patterns were significantly more persistent in invasive IPMC than in PDAC (P = 0.0013).

CONCLUSIONS

Multiphase evaluation using CEH-EUS is a useful method for differentiating between invasive IPMC and PDAC.

Predictive Features of Malignancy in Branch Duct Type Intraductal Papillary Mucinous Neoplasm of the Pancreas: A Meta-Analysis

Simple Summary

Currently, there are several guidelines that are widely used to establish the treatment strategy for branch duct type intraductal papillary mucinous neoplasms. Although there are some common grounds, there are discrepancies on which features they adopt, how much each feature is weighted, and how the features are combined. Furthermore, some of the features are based on lower level evidences or expert opinions. The aim of this meta-analysis was to investigate important clinical, radiological, and biochemical risk factors for malignancy and their impact as predictors. This study found symptom, size, cyst wall thickening, presence of mural nodule, change in main pancreatic duct caliber, lymphadenopathy, CA 19-9, and CEA as risk factors. Lymphadenopathy (odd ratio [OR]: 8.55), abrupt caliber change (OR: 7.41), and mural nodule (OR: 4.10) had the highest odd ratios. We expect the higher level evidences of this study to help shape better guidelines and reduce discrepancies among future guidelines.

Abstract

The current guidelines on branch duct type intraductal papillary mucinous neoplasm (BD-IPMN) recommend various predictive features of malignancy as well as different treatment strategies. This study aimed to identify the risk factors for malignancy with higher level of evidence. A meta-analysis was performed on 40 literatures published between 2000 and 2019. These literatures included 6301 patients with pathologically proven IPMN. Malignancy was defined as high-grade dysplasia and invasive carcinoma. It was significantly associated with symptoms (odds ratio [OR] 1.35, confidence interval [CI] 1.01–1.79), size ≥ 3 cm (OR 1.90, CI 1.51–2.40), cystic wall thickening (OR 2.53, CI 1.50–4.27), mural nodule (OR 4.10, CI 3.38–4.97), main pancreatic duct dilatation (OR 2.98, CI 2.11–4.21), abrupt caliber change of the pancreatic duct (OR 7.41, CI 2.49–22.06), lymphadenopathy (OR 8.55, CI 3.25–22.51), elevated carbohydrate antigen 19-9 (OR 4.01, CI 2.55–6.28), and elevated carcinoembryonic antigen (OR 2.04, CI 1.60–2.61). Multilocular cysts and multiple cysts did not show a significant association with malignancy. This study examined the clinical, radiological, and biochemical features of BD-IPMN, often used as malignancy predictors according to the widely used guidelines. The results confirmed that all the features currently being used are valid.

Can contrast-enhanced harmonic endoscopic ultrasonography accurately diagnose main pancreatic duct involvement in intraductal papillary mucinous neoplasms?

BACKGROUND

Main pancreatic duct (MPD) involvement in branch duct-type intraductal papillary mucinous neoplasms (BD-IPMNs) is a high risk finding for malignant IPMNs. However, discrepancies exist in the identification of MPD involvement between imaging findings and pathological diagnosis. The purpose of this study was to evaluate the diagnostic accuracy of preoperative assessment of MPD involvement in IPMNs using contrast-enhanced harmonic endoscopic ultrasound (CH-EUS).

METHODS

This study involved 166 consecutive patients with BD-IPMNs who underwent surgical resection. CH-EUS was used to evaluate the MPD involvement according to the presence of mural nodules (MN) that advanced into the MPD or involved the MPD. The CH-EUS findings were compared with the pathological findings. Additionally, we analyzed the risk factors for malignant BD-IPMNs using multivariate analysis.

RESULTS

A total of 77, 51, and 38 patients were pathologically diagnosed with low-grade or intermediate-grade dysplasia, high-grade dysplasia and invasive IPMNs, respectively. MPD involvement was diagnosed using CH-EUS (MPD-inv.-EUS) in 90 (54.2%) patients with a sensitivity, specificity and accuracy of 83.5%, 87.0% and 84.9%, respectively. The malignancy rate in patients with MPD-inv.-EUS was 71.6% (63/90). Multivariate logistic regression analysis showed that MPD-inv.-EUS (OR, 3.61; 95% CI:1.45-8.98), age (OR, 5.70; 95% CI: 1.47-22.2), cyst size (OR, 2.45; 95% CI:1.04-5.78) and MN size (OR, 7.05; 95% CI:2.48-20.0) were significant for malignant BD-IPMNs.

CONCLUSIONS

MPD-inv.-EUS accurately represents the pathological involvement of IPMN and may be a useful predictor of malignant BD-IPMNs.

The Role of Positron Emission Tomography in Clinical Management of Intraductal Papillary Mucinous Neoplasms of the Pancreas

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas represent a heterogeneous group of tumors, increasingly diagnosed in clinical practice. An early differential diagnosis between malignant and benign lesions is crucial to patient management and the choice of surgery or observation. The therapeutic approach is currently based on a patient’s clinical, biochemical, and morphological characteristics. The latest published International Consensus Guidelines (ICG) make no mention of the role of metabolic assessments of IPMNs. The aim of this study was to review the current literature, examining the role of 18-fluorodeoxyglucose (FDG) positron emission tomography (PET) in IPMN management. An extensive literature review was conducted according to the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and 10 articles were analyzed in detail, focusing on the value of PET as opposed to other standard imaging criteria. Data were retrieved on 419 patients. The 18-FDG-PET proved more sensitive, specific, and accurate than the ICG criteria in detecting malignant IPMNs (reaching 80%, 95%, and 87% vs. 67%, 58%, and 63%, respectively). Metabolic assessments may be used as an additional tool for the appropriate management of patients with doubtful imaging findings.

Do we need contrast agents for EUS?

We recently introduced a series of articles that dealt with controversies in EUS. In Part I, the authors discussed which clinical information is necessary prior to EUS and whether other imaging modalities are required before embarking on EUS examinations. Part II focuses on technical details and controversies about the use of EUS in special situations. In this article, important practical issues regarding the application of contrast-enhanced EUS in various clinical settings are raised and controversially discussed from different points of view.

Utility of endoscopic ultrasound and endoscopic ultrasound-guided fine-needle aspiration for the diagnosis and management of pancreatic cystic lesions: Differences between the guidelines

Recent advances and frequent use of cross-sectional imaging studies have increased opportunities for incidental diagnoses of pancreatic cystic lesions (PCL). In the management of PCL, distinguishing between mucinous versus non-mucinous and malignant versus benign cysts is important to diagnose pancreatic cancer in its early stage. For this reason, there have been several guidelines to manage PCL. Endoscopic ultrasound (EUS) and EUS-guided fine-needle aspiration (FNA) play important roles in the guidelines, although there are some differences in their roles. In this review, we aimed to evaluate the current status of EUS and EUS-FNA in the management of PCL and the status of these procedures in the guidelines.

Surgical strategy for intraductal papillary mucinous neoplasms of the pancreas

The current treatment strategy for intraductal papillary mucinous neoplasms (IPMNs), based on the international consensus guideline, has been accepted widely. However, reported outcomes after surgical resection for IPMN show that once the tumor progresses to invasive intraductal papillary mucinous carcinoma (IPMC), recurrence is not uncommon. The surgical treatment for IPMN is invasive and sometimes followed by complications. Therefore, the best timing for resection might be at the point when high-grade dysplasia (HGD) is evident. According to previous reports, main duct type IPMN has a high malignant potential and its surgical resection is universally accepted, whereas, the incidence of HGD/invasive IPMC in branch duct and mixed type IPMNs is thought to be lower. In addition to mural nodules and a dilated main pancreatic duct, cytology and measurement of the carcinoembryonic antigen level in the pancreatic juice might be useful to differentiate HGD/invasive IPMC from low-grade dysplasia. The nomogram proposed recently to predict the risk of HGD/invasive IPMC in IPMN patients might help surgeons decide on the best treatment strategy, depending on the patient's age and general condition. Second resection for high-risk lesions in the remnant pancreas might improve the survival of IPMN patients.

Validation and head-to-head comparison of four models for predicting malignancy of intraductal papillary mucinous neoplasm of the pancreas: A study based on endoscopic ultrasound findings

BACKGROUND

Several models are currently available for predicting the malignancy of pancreatic intraductal papillary mucinous neoplasm (IPMN), namely, the Pancreatic Surgery Consortium (PSC), the Japan Pancreas Society (JPS), the Johns Hopkins Hospital (JHH), and the Japan-Korea (JPN-KOR) models. However, a head-to-head comparison that shows which model is more accurate for this individualized prediction is lacking.

AIM

To perform a head-to-head comparison of the four models for predicting the malignancy of pancreatic IPMN.

METHODS

A total of 181 patients with IPMN who had undergone surgical resection were identified from a prospectively maintained database. The characteristics of IPMN in patients were recorded from endoscopic ultrasound imaging data and report archives. The performance of all four models was examined using Harrell’s concordance index (C-index), calibration plots, decision curve analyses, and diagnostic tests.

RESULTS

Of the 181 included patients, 94 were categorized as having benign disease, and the remaining 87 were categorized as having malignant disease. The C-indexes were 0.842 [95% confidence interval (CI): 0.782-0.901], 0.704 (95%CI: 0.626-0.782), 0.754 (95%CI: 0.684-0.824), and 0.650 (95%CI: 0.483-0.817) for the PSC, JPS, JHH, and JPN-KOR models, respectively. Calibration plots showed that the PSC model had the least pronounced departure from ideal predictions. Of the remaining three models, the JPS and JHH models underestimated the probability of malignancy, while the JPN-KOR model overestimated the malignant potential of branch duct-IPMN. Decision curve analysis revealed that the PSC model resulted in a better clinical net benefit than the three other models. Diagnostic tests also showed a higher accuracy (0.801) for the PSC model.

CONCLUSION

The PSC model exhibited the best performance characteristics. Therefore, the PSC model should be considered the best tool for the individualized prediction of malignancy in patients with pancreatic IPMN.

Diagnosis and management of pancreatic cystic neoplasms: current evidence and guidelines

Pancreatic cystic neoplasms (PCN) are a heterogeneous group of pancreatic cysts that include intraductal papillary mucinous neoplasms, mucinous cystic neoplasms, serous cystic neoplasms and other rare cystic lesions, all with different biological behaviours and variable risk of progression to malignancy. As more pancreatic cysts are incidentally discovered on routine cross-sectional imaging, optimal surveillance for patients with PCN is becoming an increasingly common clinical problem, highlighting the need to balance cancer prevention with the risk of (surgical) overtreatment. This Review summarizes the latest developments in the diagnosis and management of PCN, including the quality of available evidence. Also discussed are the most important differences between the PCN guidelines from the American Gastroenterological Association, the International Association of Pancreatology and the European Study Group on Cystic Tumours of the Pancreas, including diagnostic and follow-up strategies and indications for surgery. Finally, new developments in the management of patients with PCN are addressed.

Endoscopic ultrasonography for the evaluation of pancreatic cystic neoplasms

Endoscopic ultrasonography (EUS) is a modality with high spatial resolution that enables comprehensive observation of the entire pancreas and plays an important role in the diagnosis of pancreatic lesions. Recent advances in diagnostic imaging methods such as ultrasound, computed tomography, and magnetic resonance imaging have increased the incidental detection of pancreatic cystic lesions (PCLs). EUS has been recognized as an essential diagnostic method for the detection and evaluation of PCLs. EUS has two important roles: as a detailed (high-resolution) imaging diagnostic method and as an approach for collecting cyst fluid content by EUS-guided fine needle aspiration for pathological diagnosis or biomarker evaluation. Furthermore, in recent years, the usefulness of contrast-enhanced EUS for the differential diagnosis of PCLs or evaluation of grade of malignancy, and a novel imaging technique called needle-based confocal laser endomicroscopy to observe intraductal structures through a needle, has been reported. An understanding of the morphological characteristics of PCLs depicted by ultrasound imaging and of the benefits and limitations of EUS diagnosis in daily practice is needed.

Endoscopic Ultrasound for Early Diagnosis of Pancreatic Cancer

Detection of small pancreatic cancers, which have a better prognosis than large cancers, is needed to reduce high mortality rates. Endoscopic ultrasound (EUS) is the most sensitive imaging modality for detecting pancreatic lesions. The high resolution of EUS makes it particularly useful for detecting small pancreatic lesions that may be missed by other imaging modalities. Therefore, EUS should be performed in patients with obstructive jaundice in whom computed tomography (CT) or magnetic resonance imaging (MRI) does not identify a definite pancreatic lesion. Interest in the use of EUS for screening individuals at high risk of pancreatic cancer, including those with intraductal papillary mucinous neoplasms (IPMNs) and familial pancreatic cancer is growing. Contrast-enhanced EUS can facilitate differential diagnosis of small solid pancreatic lesions as well as malignant cystic lesions. In addition, EUS-guided fine needle aspiration can provide samples of small pancreatic lesions. Thus, EUS and EUS-related techniques are essential for early diagnosis of pancreatic cancer.

Feasibility and usefulness of endoscopic ultrasonography-guided shear-wave measurement for assessment of autoimmune pancreatitis activity: a prospective exploratory study

Purpose

To assess the feasibility and the clinical usefulness of a newly developed endoscopic ultrasonography (EUS) shear-wave elastography technique (EUS shear-wave measurement: EUS-SWM) in the diagnosis and treatment of autoimmune pancreatitis (AIP).

Methods

Tissue elasticity was measured in the pancreas in 160 patients. The success rate of EUS-SWMs, the velocity of the shear wave (Vs, m/s), and the reliability index of the Vs measurement (VsN) were evaluated, and the elasticity (median Vs) was compared between AIP patients (n = 14) and normal controls.

Results

A total of 3837 EUS-SWMs were performed without adverse events. Overall, 97.6% (3743/3837) were successful. The median VsN was 74%. The median Vs values of the pancreas were as follows: 2.22 m/s in the pancreatic head (push position), 2.36 m/s in the head (pull position), 1.99 m/s in the body, and 2.25 m/s in the tail. The median Vs of the AIP group (2.57 m/s) was significantly higher than that of the normal controls (1.89 m/s) (P = 0.0185). The mean Vs significantly decreased from 3.32 m/s to 2.46 m/s after steroid therapy (n = 6) (P = 0.0234).

Conclusion

EUS-SWM is feasible and generates credible results. EUS-SWM was a useful method for assessment of the effect of steroid therapy in AIP patients.

Electronic supplementary material

The online version of this article (10.1007/s10396-019-00944-4) contains supplementary material, which is available to authorized users.

Impact of endoscopic ultrasonography on diagnosis of pancreatic cancer

Accumulated evidence has revealed that endoscopic ultrasonography (EUS) has had a great impact on the clinical evaluation of pancreatic cancers. EUS can provide high-resolution images of the pancreas with a quality regarded as far surpassing that achieved on transabdominal ultrasound (US), computed tomography (CT), or magnetic resonance imaging (MRI). EUS is particularly useful for the detection of small pancreatic lesions, while EUS and its related techniques such as contrast-enhanced EUS (CE-EUS), EUS elastography, and EUS-guided fine needle aspiration (EUS-FNA) are also useful in the differential diagnosis of solid or cystic pancreatic lesions and the staging (T-staging, N-staging, and M-staging) of pancreatic cancers. In the diagnosis of pancreatic lesions, CE-EUS and EUS elastography play a complementary role to conventional EUS. When sampling is performed using EUS-FNA, CE-EUS and EUS elastography provide information on the target lesions. Thus, conventional EUS, CE-EUS, EUS elastography, and EUS-FNA are essential in the clinical investigation of pancreatic cancer.

Endoscopic diagnosis of cystic lesions of the pancreas

Endoscopic methods are increasingly used in the diagnosis of cystic lesions of the pancreas. The two major endoscopic approaches are endoscopic ultrasonography (EUS) and transpapillary diagnosis. EUS-guided fine-needle aspiration cytology and EUS-guided fine needle-based confocal laser endomicroscopy have been used in the differential diagnosis of mucinous and non-mucinous pancreatic cysts. EUS is the most sensitive modality for detecting mural nodules (MN) in intraductal papillary mucinous neoplasms (IPMN). Contrast-enhanced harmonic EUS (CH-EUS), as an add-on to EUS, is useful for identifying and characterizing MN. Recent studies show that CH-EUS has a sensitivity of 60-100% and a specificity of 75-92.9% for diagnosing malignant cysts. Intraductal ultrasonography and peroral pancreatoscopy are especially useful for detecting MN and IPMN. A recent meta-analysis showed that cytological assessment of pancreatic juice using a transpapillary approach had a pooled sensitivity, specificity, and accuracy of 35.1%, 97.2%, and 92.9%, respectively, for diagnosing malignant IPMN. Further studies are warranted to determine the indications for each of these novel techniques in assessing cystic lesions of the pancreas.

An international, multi-institution survey of the use of EUS in the diagnosis of pancreatic cystic lesions

Background and Objectives:

Currently, pancreatic cystic lesions (PCLs) are recognized with increasing frequency and have become a more common finding in clinical practice. EUS is challenging in the diagnosis of PCLs and evidence-based decisions are lacking in its application. This study aimed to develop strong recommendations for the use of EUS in the diagnosis of PCLs, based on the experience of experts in the field.

Methods:

A survey regarding the practice of EUS in the evaluation of PCLs was drafted by the committee member of the International Society of EUS Task Force (ISEUS-TF). It was disseminated to experts of EUS who were also members of the ISEUS-TF. In some cases, percentage agreement with some statements was calculated; in others, the options with the greatest numbers of responses were summarized.

Results:

Fifteen questions were extracted and disseminated among 60 experts for the survey. Fifty-three experts completed the survey within the specified time frame. The average volume of EUS cases at the experts' institutions is 988.5 cases per year.

Conclusion:

Despite the limitations of EUS alone in the morphologic diagnosis of PCLs, the results of the survey indicate that EUS-guided fine-needle aspiration is widely expected to become a more valuable method.

Current indications and yield of endoscopic ultrasound and ancillary techniques in pancreatic cystic neoplasms

An increase in the diagnosis of pancreatic cystic neoplasm has been described lately. Surgical treatment or surveillance is advised depending on the type of lesion diagnosed. The most accurate diagnostic approach is needed to make the best therapeutic decision. Endoscopic ultrasound is a very valuable tool in the evaluation of pancreatic cystic neoplasm. It generates high-quality images and allows the possibility of sampling the cystic fluid for cytology, microbiological and molecular evaluation. Even with this evaluation, the sensitivity of this approach is not always adequate. New technological resources have been developed to try to improve the diagnostic accuracy of pancreatic cystic neoplasms. The two most promising techniques are needle-based confocal laser endomicroscopy and contrast-enhanced harmonic endoscopic ultrasound. Needle-based confocal laser endomicroscopy allows a microscopic evaluation of mucosal glands and vascular pattern, to differentiate mucinous from non-mucinous lesions. Contrast-enhanced harmonic endoscopic ultrasound is used for the vascular evaluation of the microcirculation of the cyst wall and mural nodule, mainly to make the difference between malignant nodules and mucus plugs. A combination of these different diagnostic techniques can improve the diagnostic accuracy of pancreatic cystic neoplasms to offer the adequate therapeutic decision.

Intraductal papillary mucinous neoplasms of the pancreas: a clinical challenge

The incidental detection rate of intraductal papillary mucinous neoplasms (IPMNs) has significantly increased. However, little is known about the natural history of these tumors. Their optimal management and appropriate follow-up are still unclear. We have, therefore, reviewed the available literature on IPMN focusing on their diagnosis, treatment according to the risk of malignant transformation, and follow-up. Areas covered: Bibliographical searches were performed in PubMed for the terms 'intraductal papillary mucinous neoplasm' and 'natural history' and 'diagnosis' and 'treatment' and 'surgery' and 'follow-up' and 'prognosis.' PubMed was used to search for all the relevant articles published over the last 10 years. A total of 7244 records were identified. After filtering for year range, English language, human studies, article types, and removing duplicates, 74 articles were left with the strongest level of evidence. Expert commentary: Available guidelines for IPMN management are mainly based on expert opinions and may lack strong evidence. Further studies are warranted to better predict the risk of recurrence/future malignancy and to establish standardized guidelines. IPMNs management should be based on multidisciplinary discussion and treatment should be tailored to an individual patient according to patient and tumor characteristics.

Managing Incidental Pancreatic Cysts

PURPOSE OF REVIEW

The goal of this review is to critically analyze the current literature regarding the management of incidental pancreatic cysts. Given their increased rates of detection due to the frequent use of cross-sectional imaging, correctly identifying the subset of high risk lesions that are appropriate for surgical resection is critical. However, the existing consensus and societal guidelines discussed in this review lack high quality data to create evidence-based recommendations, making achieving this important aim challenging.

RECENT FINDINGS

Several recent studies have focused on the natural history of pancreatic cysts and defining the role of endoscopic ultrasound, which remains unclear. EUS-guided diagnostic tools include molecular analysis of obtained fluid; EUS-guided FNA, FNB, and intracystic forceps biopsy of the cyst wall; and confocal endomicroscopy. While their precise role in diagnosing pancreatic cystic neoplasms remains to be defined, they represent promising innovations that may play a future role in cyst assessment and management. Large, long-term, prospective studies of incidentally identified pancreatic cysts are essential to fully understand their natural history and potential for neoplastic progression. Given the absence of such data at present, an individualized patient approach is recommended.

Intraductal Papillary Mucinous Neoplasm of the Pancreas as the Main Focus for Early Detection of Pancreatic Adenocarcinoma

For early detection of pancreatic cancer, interests are now focused on the detection of high-risk individuals to undergo screening examinations. Intraductal papillary mucinous neoplasm (IPMN) is a unique dual precursor of pancreatic cancer, characterized by progression to invasive cancer and the development of pancreatic adenocarcinoma either concomitantly (synchronous occurrence) or even after resection of IPMN (metachronous occurrence). Careful examination and surveillance of patients with IPMN may therefore lead to early detection of pancreatic cancer. By reviewing only reports describing detailed breakdown of the morphological types of IPMN and numbers of patients with noninvasive and invasive carcinoma in each type, the rough frequencies of noninvasive carcinoma in main duct IPMNs and branch duct IPMNs (BD-IPMNs) are 20% and 10%, respectively, and those of invasive carcinoma are 40% and 13%, respectively. Roughly 5% of all patients with IPMN had concomitant adenocarcinoma. The real frequency of carcinoma in BD-IPMNs would be far lower because most patients with small asymptomatic BD-IPMNs do not undergo resection. Intraductal papillary mucinous neoplasm can be the main focus for early detection of pancreatic cancer to achieve favorable prognosis after surgical resection. The optimal protocol for surveillance and method for early detection of pancreatic cancer are to be determined.

Multiphase evaluation of contrast-enhanced endoscopic ultrasonography in the diagnosis of pancreatic solid lesions

BACKGROUND/OBJECTIVES

Time-intensity curve (TIC) under contrast-enhanced EUS (CE-EUS) allows continuous and quantitative evaluation of targeted area in the pancreas. However, TIC is not always available and the procedure is complicated. We aimed to propose a simplified method by evaluating multiple phases of CE-EUS in the diagnosis of pancreatic solid lesions.

METHODS

We retrospectively reviewed 210 patients with pancreatic solid lesions including 142 with pancreatic ductal cancer (PDAC), 31 with pancreatic neuroendocrine neoplasm, 13 with solid pseudopapillary neoplasm and 24 with mass-forming pancreatitis who underwent CE-EUS and achieved final diagnoses. The CE-EUS images were continuously recorded for 60 s, and each image at 20, 40 and 60 s was used for the evaluation. The images were classified into three patterns as hypoechoic, hyperechoic and isoechoic vascular patterns compared with the surrounding pancreas, and the relevance between the multiphase evaluation of CE-EUS and each disease group was investigated.

RESULTS

In PDAC group, majority of the lesions showed hypovascular pattern at 20 or 40 s after injection of contrast medium following early enhancement. The sensitivity, specificity and accuracy of PDAC pattern in the differentiation of PDAC from other lesions was 83.1%, 86.8% and 84.3%, respectively. On histopathological analysis, significant differences were seen in histologic types, infiltration (INF), and neural invasion (ne) between those who showed PDAC pattern and those who didn't.

CONCLUSIONS

Multiphase evaluation of CE-EUS is convenient and useful method for the differentiation of pancreatic solid lesions which can be alternatively used for TIC.

ACG Clinical Guideline: Diagnosis and Management of Pancreatic Cysts

Pancreatic cysts are very common with the majority incidentally identified. There are several types of pancreatic cysts; some types can contain cancer or have malignant potential, whereas others are benign. However, even the types of cysts with malignant potential rarely progress to cancer. At the present time, the only viable treatment for pancreatic cysts is surgical excision, which is associated with a high morbidity and occasional mortality. The small risk of malignant transformation, the high risks of surgical treatment, and the lack of high-quality prospective studies have led to contradictory recommendations for their immediate management and for their surveillance. This guideline will provide a practical approach to pancreatic cyst management and recommendations for cyst surveillance for the general gastroenterologist.

Systematic review, meta-analysis, and a high-volume center experience supporting the new role of mural nodules proposed by the updated 2017 international guidelines on IPMN of the pancreas

BACKGROUND

Mural nodules (MNs) have a predominant role in the 2016 revision of the international guidelines on intraductal papillary mucinous neoplasms (IPMN) of the pancreas. The aim of this study was to evaluate MNs as predictors of invasive cancer (iCa) or high-grade dysplasia (HGD) in IPMNs and to investigate the role of MN size in risk prediction.

METHODS

A PRISMA-compliant systematic review of the literature and meta-analysis on selected studies were conducted. The random effect model was adopted, and the pooled SMD (standardized mean difference) obtained. The surgical series of IPMNs at a single high-volume institution was reviewed.

RESULTS

This review included 70 studies and 2297 resected IPMNs. MNs have a positive predictive value for malignancy of 62.2%. The meta-analysis suggested that MN size has a considerable effect on predicting IPMNs with both iCa or HGD with a mean SMD of 0.79. All studies included in the meta-analysis used contrast-enhanced endosonography (CE-EUS) to assess MNs. Due to the heterogeneity of the proposed thresholds, no reliable MN size cut-off was identified. Of 317 IPMNs resected at our institution, 102 (32.1%) had a preoperative diagnosis of MN. Multivariate analysis showed that MN is the only independent predictor of iCa and HGD for all types of IPMNs.

CONCLUSION

MNs are reliable predictors of iCa and HGD in IPMNs as proposed by the 2016 IAP guidelines. CE-EUS seems to be the best tool for characterizing size and has the best accuracy for predicting malignancy. Further studies should determine potential MN dimensional cut-offs.

Predictive performance of factors associated with malignancy in intraductal papillary mucinous neoplasia of the pancreas

Background

Estimation of the risk of malignancy in intraductal papillary mucinous neoplasia (IPMN) of the pancreas is a clinical challenge. Several routinely used clinical factors form the basis of the current consensus guidelines. This study aimed to determine the predictive values of the most commonly assessed risk factors.

Methods

A meta-analysis of individual risk factors of malignancy in IPMN was performed. Contingency tables were derived from these data, and sensitivity, specificity, negative and positive predictive values, and diagnostic odds ratios (DOR) were determined. Hierarchical summary receiver operating characteristic (HSROC) curves for each factor were calculated and the respective area under the curve (AUC) was assessed.

Results

A total of 3443 studies were screened initially. Analysis of recent literature revealed 60 studies with 13 relevant risk factors including clinical, serological and radiological parameters. The largest area under the HSROC curve was found for weight loss (0·84) and jaundice/raised bilirubin level (0·80), followed by increased carcinoembryonic antigen (CEA) (0·79) or carbohydrate antigen (CA) 19-9 (0·78) levels. The most sensitive factors were patient age (71 per cent) and mural nodules (65 per cent), and jaundice/raised bilirubin level (97 per cent) and increased CEA level (95 per cent) were most specific. None of the analysed factors reached a positive or negative level of prediction beyond 90 per cent.

Conclusion

None of the established criteria safely distinguishes malignant from non-malignant lesions.

Natural history of pancreatic cystic lesions: A multicenter prospective observational study for evaluating the risk of pancreatic cancer

BACKGROUND AND AIM

The aim of this study is to elucidate the natural history of pancreatic cystic lesions (PCLs), including branch duct-type intraductal papillary mucinous neoplasm (BD-IPMN), via midterm follow-up analysis of a multicenter prospective observational study (NSPINAL study).

METHODS

From July 2011 to October 2016, 881 patients with PCLs were enrolled in NSPINAL study, and 664 patients with > 12 months of follow up were analyzed. Every patient was asymptomatic, and endoscopic ultrasound was performed at the initial diagnosis to exclude high-risk individuals. Follow up included endoscopic ultrasound, computed tomography, or magnetic resonance imaging at least once a year. Serial morphological changes and the pancreatic cancer (PC) incidence, including malignant progression of PCLs, were evaluated.

RESULTS

The 664 patients (358 men) were followed for a median of 33.5 months (interquartile range 29). The cyst and main pancreatic duct sizes were 16.6 ± 9.3 and 2.3 ± 1.0 mm, respectively. Morphologically, 518 cases were multilocular, 137 were unilocular, and 9 had a honeycomb pattern; 269 cases involved multifocal lesions. Ninety-six patients (14.5%) showed worsening progression on imaging. There were two resectable and four unresectable cases of pancreatic ductal adenocarcinoma and three cases of malignant BD-IPMN. The 3-year risk of developing PC was 1.2%. The standardized incidence ratio for PC among PCLs was 10.0 (95% confidence interval 3.5-16.5), and the standardized incidence ratio among BD-IPMN was 16.6 (95% confidence interval 5.1-28.1). Multivariate analysis showed that development of symptoms and worsening progression were significant predictors of PC.

CONCLUSIONS

Malignant progression of PCLs, including PC development, is not uncommon. Patients with PCLs should be carefully monitored to detect pancreatic ductal adenocarcinoma at early stages.