Morphologic changes in branch duct intraductal papillary mucinous neoplasms of the pancreas: a midterm follow-up study

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.

A Clinical Guide to the Management of Intraductal Papillary Mucinous Neoplasms: the Need for a More Graded Approach in Clinical Decision-making

Intraductal papillary mucinous neoplasms (IPMNs) have become a very common diagnosis and represent a spectrum of disease that ranges from benign to malignant lesions. Presently, clinical and radiographic features are used to predict the presence of high-grade dysplasia and invasive cancer to inform treatment decisions of whether to pursuit surgical resection or continued surveillance. However, the natural history of IPMNs is still not completely understood, with guidelines from different societies providing contradictory recommendations. This underscores the challenge in balancing the risk of missing cancer with long-term surveillance and the morbidity associated with surgical resection. In this review, we aim to reconcile the differences in the guidelines' recommendations and provide a clinical framework to the management of IPMNs with hopes of adding clarity to how treatment decisions should be made. We also highlight recent advances made in the field and future efforts that can minimize rates of missing cancer while also reducing the number of unnecessary operations.

The spearfishing sign: differentiating mucin from mural nodules in pancreatic cysts

Video 1EUS evaluation of intracystic mucin and demonstration of spearfishing sign.

Assessment of Malignancy Potential in Intraductal Papillary Mucinous Neoplasms of the Pancreas on MDCT

RATIONALE AND OBJECTIVE

To assess the malignancy potential of intraduct papillary mucinous neoplasms (IPMNs) on multidetector-row computerized tomography according to the 2012 International Consensus Guidelines (ICG).

MATERIALS AND METHODS

This study retrospectively collected IPMNs confirmed by surgery from 2016 to 2019. The imaging findings of IPMNs were analyzed. IPMNs were classified as malignancy in the presence of high-grade dysplasia or invasive carcinoma and began in the presence of low- and intermediate-grade dysplasia.

RESULTS

A total of 207 patients (mean age: 63.7 ± 7.9 years) were included, and the prevalence of malignancy was 28.0% (58 of 207). According to the 2012 ICG, the imaging findings of IPMNs were divided into worrisome features (WFs) and high-risk stigmata (HRS). The malignancy of IPMN with only one WF was relatively low (1.4%, 3 of 207). In multivariate regression analyses, the independent factors of IPMNs were enhanced mural nodule ≥5 mm (odds ratio [OR] = 19.5, 95% confidence interval [CI] 6.8-55.4), abrupt change in the main pancreatic duct caliber with distal pancreatic atrophy (OR = 4.6, 95%CI 1.67-12.71), and thickened enhanced cyst walls (OR = 2.9, 95%CI 1.1-8.2). When the presence of more than two WFs or HRS (score ≥ 3) was regarded as indicating the malignancy potential of IPMNs on multidetector-row computerized tomography, the sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were 89.7%, 75.8%, 79.7%, 59.1%, and 95.0%, respectively.

CONCLUSION

According to the ICG in 2012, patients with IPMNs with only one WF have a low risk for malignancy, and the presence of at least two WFs or any HRS (score ≥3) suggests malignant IPMNs.

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

BACKGROUND

Detection of cystic lesions of the pancreas has outpaced our ability to stratify low-grade cystic lesions from those at greater risk for pancreatic cancer, raising a concern for overtreatment.

METHODS

We developed a Markov decision model to determine the cost-effectiveness of guideline-based management for asymptomatic pancreatic cysts. Incremental costs per quality-adjusted life year gained and survival were calculated for current management guidelines. A sensitivity analysis estimated the effect on cost-effectiveness and mortality if overtreatment of low-grade cysts is avoided, and the sensitivity and specificity thresholds required of methods of cyst stratification to improve costs expended.

RESULTS

"Surveillance" using current management guidelines had an incremental cost-effectiveness ratio of $171,143/quality adjusted life year compared with no surveillance or operative treatment ("do nothing"). An incremental cost-effectiveness ratio for surveillance decreases to $80,707/quality adjusted life year if the operative overtreatment of low-grade cysts was avoided. Assuming a societal willingness-to-pay of $100,000/quality adjusted life year, the diagnostic specificity for high-risk cysts must be >67% for surveillance to be preferred over surgery and "do nothing." Changes in sensitivity alone cannot make surveillance cost-effective. Most importantly, survival in surveillance is worse than "do nothing" for 3 years after cyst diagnosis, although long-term survival is improved. The disadvantage is eliminated when overtreatment of low-grade cysts is avoided.

CONCLUSION

Current management of pancreatic cystic lesions is not cost-effective and may increase mortality owing to overtreatment of low-grade cysts. The specificity for risk stratification for high-risk cysts must be greater than 67% to make surveillance cost-effective.

Importance of each high-risk stigmata and worrisome features as a predictor of high-grade dysplasia in intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND

High-risk stigmata (HRS) and 'worrisome features' (WFs) are defined as predictive factors for malignancies of intraductal papillary mucinous neoplasms (IPMNs). We performed this study to determine the importance and odds ratio (OR) of each HRS and WFs as predictors for high-grade dysplasia (HGD).

METHODS

We analyzed 295 patients who underwent pancreatectomy for branch duct and mixed-type IPMN, and evaluated the association between HRS and WFs (as defined by the '2017 Fukuoka Consensus Guidelines') and HGD.

RESULTS

The proportions of patients with low-grade dysplasia (LGD), HGD, and invasive carcinoma were 47%, 28%, and 25%, respectively. Multivariate analysis comparing patients with LGD and HGD using all HRS and WFs revealed that an enhancing mural nodule ≥5 mm (OR: 4.1), pancreatitis (OR: 2.2), and thickened/enhancing cyst walls (OR: 2.2) were independent predictive factors for HGD. Based on the OR (the former factor is two points and the latter two factors are each one point), the incidence of HGD in patients with none (n = 43), one (n = 82), two (n = 25), three (n = 52), and four (n = 19) of these predictive factors were 9%, 26%, 52%, 62%, and 63%, respectively. Assuming a score of one or higher as a surgical indication, the sensitivity, specificity, positive predict value, and negative predict value of HGD were 95, 38, 44, and 91%.

CONCLUSIONS

Our derived scoring system using more important factors in HRS and WFs may be useful for predicting HGD and determining surgical indications of IPMN.

Long-term Risk of Malignancy in Branch-Duct Intraductal Papillary Mucinous Neoplasms

BACKGROUND & AIMS

Long-term outcomes of patients with branch-duct intraductal papillary mucinous neoplasms (IPMNs), particularly those after 5 years of surveillance, have not been fully evaluated in large studies. We analyzed incidences of IPMN-derived carcinoma and concomitant ductal adenocarcinoma (pancreatic ductal adenocarcinoma [PDAC]) over 20 years in a large population of patients.

METHODS

We identified 1404 consecutive patients (52% women; mean age, 67.5 years) with a diagnosis of branch-duct IPMN, from 1994 through 2017, at the University of Tokyo in Japan. Using a competing risk analysis, we estimated cumulative incidence of pancreatic carcinoma, overall and by carcinoma type. We used competing risks proportional hazards models to estimate subdistribution hazard ratios (SHRs) for incidences of carcinomas. To differentiate IPMN-derived and concomitant carcinomas, we collected genomic DNA from available paired samples of IPMNs and carcinomas and detected mutations in GNAS and KRAS by polymerase chain reaction and pyrosequencing.

RESULTS

During 9231 person-years of follow-up, we identified 68 patients with pancreatic carcinomas (38 patients with IPMN-derived carcinomas and 30 patients with concomitant PDACs); the overall incidence rates were 3.3%, 6.6%, and 15.0% at 5, 10, and 15 years, respectively. Among 804 patients followed more than 5 years, overall cumulative incidence rates of pancreatic carcinoma were 3.5% at 10 years and 12.0% at 15 years from the initial diagnosis. The size of the IPMN and the diameter of the main pancreatic duct associated with incidence of IPMN-derived carcinoma (SHR 1.85; 95% confidence interval 1.38-2.48 for a 10-mm increase in the IPMN size and SHR 1.56; 95% confidence interval 1.33-1.83 for a 1-mm increase in the main pancreatic duct diameter) but not with incidence of concomitant PDAC.

CONCLUSIONS

In a large long-term study of patients with branch-duct IPMNs, we found the 5-year incidence rate of pancreatic malignancy to be 3.3%, reaching 15.0% at 15 years after IPMN diagnosis. We observed heterogeneous risk factor profiles between IPMN-derived and concomitant carcinomas.

Management of Intraductal Papillary Mucinous Neoplasms: Controversies in Guidelines and Future Perspectives

Purpose of review

Management of intraductal papillary mucinous neoplasm (IPMN) is currently based on consensus, in the absence of evidence-based guidelines. In recent years, several consensus guidelines have been published, with distinct management strategies. In this review, we will discuss these discrepancies, in order to guide treating physicians in clinical management.

Recent findings

The detection rate of pancreatic cysts has increased substantially with the expanded use of high-quality imaging techniques to up to 45%. Of these cysts, 24–82% are IPMNs, which harbour a malignant potential. Timely detection of high-risk lesions is therefore of great importance. Surgical management is based on the presence of clinical and morphological high-risk features, yet the majority of resected specimens appear to be low risk.

Summary

International collaboration and incentive large-scale prospective registries of individuals undergoing cyst surveillance are needed to accumulate unbiased data and develop evidence-based guidelines. Additionally, development of non-invasive, accurate diagnostic tools (e.g. biomarkers) is needed to differentiate between neoplastic and non-neoplastic pancreatic cysts and detect malignant transformation at an early stage (i.e. high-grade dysplasia).

Higher Growth Rate of Branch Duct Intraductal Papillary Mucinous Neoplasms Associates With Worrisome Features

BACKGROUND & AIMS

For patients with branch duct intraductal papillary mucinous neoplasms (BD-IPMNs, cysts), it is a challenge to identify those at high risk for malignant lesions. We sought to identify factors associated with development of pancreatic cancer, focusing on neoplasm growth rate.

METHODS

We performed a retrospective study of 189 patients with BD-IPMNs who underwent at least 2 contrast-enhanced cross-sectional imaging studies, 1 year or more apart, at a tertiary referral center from January 2003 through 2013. Patients with cysts that had Fukuoka worrisome or high-risk features were excluded. Two radiologists reviewed all images. Cyst size was recorded at the initial and final imaging studies and growth rate was calculated. We collected patient demographic data, cyst characteristics, and clinical outcomes; univariate logistic regression models were used to determine the odds of developing worrisome features. The primary outcomes were to determine growth rate of low-risk BD-IPMNs and to assess whether cyst growth rate correlates high-risk features of IPMNs.

RESULTS

Based on image analyses, cysts were initially a median 11 mm (range, 3-31 mm) and their final size was 12.5 mm (range, 3-42 mm). After a median follow-up time of 56 months (range, 12-163 months), the median cyst growth rate was 0.29 mm/year. Twelve patients developed worrisome features, no patients developed high-risk features, 4 patients had surgical resection, and no cancers developed. The rate of BD-IPMN growth was greater in patients who developed worrisome features than those who did not (2.84 mm/year vs 0.23 mm/year; P < .001). The odds of developing worrisome features increased for each unit (mm) increase in cyst size (odds ratio, 1.149; 95% CI, 1.035-1.276, P = .009).

CONCLUSION

In a retrospective analysis of images from patients with BD-IPMN, we found low-risk BD-IPMNs to grow at an extremely low rate (less than 0.3 mm/year). BD-IPMNs in only about 6% of patients developed worrisome features, and none developed high-risk features or invasive cancers. BD-IPMNs that developed worrisome features were associated with a significantly higher rate of growth than lesions with low-risk features. Low risk BD-IPMNs that grow more than 2.5 mm/year might require surveillance.

Does cyst growth predict malignancy in branch duct intraductal papillary mucinous neoplasms? Results of a large multicenter experience

BACKGROUND

Cyst growth of BD-IPMNs on follow-up imaging remains a concerning sign.

AIMS

To describe cyst size changes over time in BD-IPMNs, and determine whether cyst growth rate is associated with increased risk of malignancy.

METHODS

This is a retrospective study performed at two high volume tertiary centers. Mean cyst size at baseline (MCSB) and mean growth rate percentage (MGRP) were calculated. Rapid cyst growth was defined as MGRP ≥30%/year. Patient and cyst related characteristics were studied.

RESULTS

160 patients were followed for a median of 27.4 (12-114.5) months. MCSB was 15.1 ± 8.0 mm. During follow-up, 73 (45.6%) showed any cyst size increase, of which 15 cysts (9.4%) exhibited MGRP ≥30%/year. Rapid cyst growth was not associated with patient or cyst characteristics. Cyst fluid molecular analysis from 101 cysts showed KRAS mutation in 26. Compared to KRAS-negative cysts, neither MCSB (16.0 mm vs. 17.7 mm; p = 0.3) nor MGRP (3.9%/year vs. 5.8%/year; p = 0.7) was significantly different. Eighteen patients underwent surgery; 15 (83%) had LGD, and 3 had advanced neoplasia. Two cysts with LGD and one cyst with advanced neoplasia had MGRP ≥30%/year.

CONCLUSION

Increase in BD-IPMNs size was not associated with the known high risk patient or cyst-related characteristics. Rapid growth of BD-IPMNs was not associated with advanced neoplasia on surgical pathology.

Long-term Risk of Pancreatic Malignancy in Patients With Branch Duct Intraductal Papillary Mucinous Neoplasm in a Referral Center

BACKGROUND & AIMS

Little is known about the development of branch duct intraductal papillary mucinous neoplasms (BD-IPMNs). We evaluated long-term outcomes of a large cohort of patients with BD-IPMNs to determine risk of malignancy and define a subset of low-risk BD-IPMNs.

METHODS

We performed a retrospective analysis of data from 577 patients with suspected or presumed BD-IPMN under surveillance at the Massachusetts General Hospital. Patients underwent cross-sectional imaging analysis at 3 months or later after their initial diagnosis. The diagnosis of BD-IPMN was based on the presence of unilocular or multilocular cysts of the pancreas and a non-dilated main pancreatic duct (<5 mm). We collected demographic, clinical, and pathology data. Cysts were characterized at the time of diagnosis and during the follow-up period. Follow-up duration was time between initial cyst diagnosis and date of last visit or death for patients without development of pancreatic cancer, date of surgery for patients with histologically confirmed malignancy, or date of first discovery of malignancy by imaging analysis for patients with unresectable tumors or who underwent neoadjuvant treatment before surgery. The primary outcome was risk of malignancy, with a focus on patients followed for 5 years or more, compared with that of the US population, based on standardized incidence ratio.

RESULTS

Of the 577 patients studied, 479 (83%) were asymptomatic at diagnosis and 363 (63%) underwent endoscopic ultrasound at least once. The median follow-up time was 82 months (range, 6-329 months) for the entire study cohort; 363 patients (63%) underwent surveillance for more than 5 years, and 121 (21%) for more than 10 years. Malignancies (high-grade dysplasia or invasive neoplasm) developed after 5 years in 20 of 363 patients (5.5%), and invasive cancer developed in 16 of 363 patients (4.4%). The standardized incidence ratio for patients with BD-IPMNs without worrisome features of malignancy at 5 years was 18.8 (95% confidence interval, 9.7-32.8; P < .001). One hundred and eight patients had cysts ≤1.5 cm for more than 5 years of follow-up; only 1 of these patients (0.9%) developed a distinct ductal adenocarcinoma. By contrast, among the 255 patients with cysts >1.5 cm, 19 (7.5%) developed malignancy (P = .01).

CONCLUSIONS

In a retrospective analysis of patients with BD-IPMNs under surveillance, their overall risk of malignancy, almost 8%, lasted for 10 years or more, supporting continued surveillance after 5 years. Cysts that remain ≤1.5 cm for more than 5 years might be considered low-risk for progression to malignancy.

Endoscopic Ultrasound Imaging for Diagnosing and Treating Pancreatic Cysts

Cystic pancreatic lesions are increasingly diagnosed owing to the abundant use of cross-sectional imaging. Given their malignant potential, true pancreatic cysts should be considered for resection or periodic follow-up. Cystic lesions of the pancreas (CLPs) require further evaluation and management. Therefore, it is important to establish a solid diagnosis at the time of detection. Endoscopic ultrasound examination is the imaging modality of choice. Fine needle aspiration provides fluid for cytologic, biochemical, and molecular assays to classify lesions and predict biological behavior. This review provides an overview of the diagnosis and management of various types of commonly encountered true CLPs.

Revisions of international consensus Fukuoka guidelines for the management of IPMN of the pancreas

The management of intraductal papillary mucinous neoplasm (IPMN) continues to evolve. In particular, the indications for resection of branch duct IPMN have changed from early resection to more deliberate observation as proposed by the international consensus guidelines of 2006 and 2012. Another guideline proposed by the American Gastroenterological Association in 2015 restricted indications for surgery more stringently and recommended physicians to stop surveillance if no significant change had occurred in a pancreatic cyst after five years of surveillance, or if a patient underwent resection and a non-malignant IPMN was found. Whether or not it is safe to do so, as well as the method and interval of surveillance, has generated substantial debate. Based on a consensus symposium held during the meeting of the International Association of Pancreatology in Sendai, Japan, in 2016, the working group has revised the guidelines regarding prediction of invasive carcinoma and high-grade dysplasia, surveillance, and postoperative follow-up of IPMN. As the working group did not recognize the need for major revisions of the guidelines, we made only minor revisions and added most recent articles where appropriate. The present guidelines include updated information and recommendations based on our current understanding, and highlight issues that remain controversial or where further research is required.

Active Surveillance Beyond 5 Years Is Required for Presumed Branch-Duct Intraductal Papillary Mucinous Neoplasms Undergoing Non-Operative Management

OBJECTIVES

To evaluate the results of active surveillance beyond 5 years in patients with branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) without worrisome features (WF) and high-risk stigmata (HRS) undergoing non-operative management.

METHODS

Patients with a minimum follow-up of 5 years who underwent surveillance with at least yearly magnetic resonance imaging were included. New onset of and predictors of WF/HRS during follow-up as well as long-term survival were analyzed.

RESULTS

In all, 144 patients were followed for a median of 84 months. At diagnosis multifocal BD-IPMNs were found in 53% of cases and mean size of the largest cyst was 15.5 mm. Changes during follow-up were observed in 69 patients (48%). New onset of WF/HRS were observed in 26 patients (18%) but the rate of HRS was only 4%. WF and HRS developed after a median follow-up of 71 and 77.5 months from diagnosis, respectively, and without previous changes in 19/26 patients. Independent predictors of WF/HRS development were size at diagnosis>15 mm, increase in number of lesions, main pancreatic duct growth rate ≥0.2 mm/year, cyst growth rate >1 mm/year. Overall, the rate of pancreatic invasive malignancy was 2% and the 12-year disease-specific survival was 98.6%.

CONCLUSIONS

Long-term nonoperative management is safe for BD-IPMNs without WF and HRS. Discontinuation of surveillance cannot be recommended since one out of six patients developed WF/HRS far beyond 5 years of surveillance and without previous relevant modifications. An intensification of follow-up should be considered after 5 years.

Longterm follow-up of small pancreatic cystic lesions in liver transplant recipients

Incidental small pancreatic cystic lesions (PCLs) are often found on preoperative imaging in patients undergoing orthotopic liver transplantation (OLT). Although these are considered benign or of low malignant potential, the influence of immunosuppression after OLT may be of concern. The aim of this study was to observe the longterm outcome of these small PCLs in post-OLT patients. An institutional OLT database of 1778 consecutive OLT patients from January 2000 to December 2010 was analyzed. Computed tomography, magnetic resonance imaging, or endoscopic ultrasound at the time of OLT and all subsequent imaging, cytology, fluid analysis of PCLs, and patient status were evaluated. A total of 70 patients with 182 PCLs, of benign or low malignant potential, were identified with a mean follow-up time of 64 months. At initial diagnosis of PCLs in 48 patients, 7 branch duct-type intraductal papillary mucinous neoplasms (B-IPMNs), 1 serous cystadenoma (SCA), and 40 nonspecific benign cysts were identified. Final diagnosis at the end of the follow-up revealed 16 B-IPMNs, 3 SCAs, and a mixed acinar-neuroendocrine carcinoma, in which the latter developed 9 years after initial diagnosis of B-IPMN. During the follow-up time, average increase in size and number of PCLs were 4.5 mm and 1.4, respectively (P < 0.001 for both). The majority of incidental PCLs in OLT patients showed an indolent behavior despite immunosuppression. Risk of malignancy development was very low and comparable with normal population. Liver Transplantation 23 324-329 2017 AASLD.

International Intraductal Papillary Mucinous Neoplasms Registry: Long-Term Results Based on the New Guidelines

OBJECTIVE

The aim of this study was to analyze the outcomes of a long-term intraductal papillary mucinous neoplasm (IPMN) registry and evaluate new guidelines.

METHODS

A prospectively maintained IPMN registry involving 6 centers in Europe and the United States was used to collect the data. Patients with more than 1-year follow-up and no malignancy diagnosed within the first 3 months of surveillance were included.

RESULTS

From 1999 to 2014, 620 patients were included. The median follow-up time was 3 years. Thirty-seven (6%) patients developed malignancy with a median time from IPMN diagnosis to malignancy of 10.3 months. The 1-, 5-, and 10-year actuarial rates of disease-free survival were 97%, 93%, and 92% respectively. Four hundred thirty-one patients met criteria for low-risk branch duct IPMN consisting of cyst size less than 3 cm, with no solid component or main duct dilation. Eight malignancies were diagnosed in this subgroup, all of them within the first 5 years. From this subcohort, 112 patients had a follow-up time of more than 5 years, and no malignancy was diagnosed.

CONCLUSIONS

In IPMN lesions with low-risk features at baseline, the risk of progression to malignancy after the first 5 years of follow-up was minimal. Furthermore, the main cyst characteristics remained unchanged during their surveillance.

Intraductal papillary mucinous neoplasms and mucinous cystadenomas: current status and recommendations

The real prevalence of pancreatic cystic lesions remains unknown. The malignant potential of some of these lesions remains a cause for significant concern. Thus, it is mandatory to develop a strategy to clearly discriminate those cysts with a potential for malignant transformation from those that do not carry any significant risk. Intraductal papillary mucinous neoplasms and mucinous cystadenomas are mucinous cystic neoplasms with a known malignant potential that have gained greater recognition in recent years. However, despite the numerous studies that have been carried out, their differential diagnosis among other cysts subtypes and their therapeutic approach continue to be a challenge for clinicians. This review contains a critical approach of the current recommendations and management strategies regarding intraductal papillary mucinous neoplasms and mucinous cystadenomas, as well as highlighting the limitations exposed in current guidelines.

Intraductal Papillary Mucinous Neoplasm of the Pancreas: Current State of the Art and Ongoing Controversies

With the widespread use and advances in radiographic imaging, Intraductal Papillary Mucinous Neoplasms (IPMNs) of the pancreas are identified with increasing frequency. Although many studies have addressed its biology and treatment, true understanding of its natural history continues to elude us. Its malignant potential places careproviders in a clinical dilemma of balancing the morbidity of pancreatectomy against the risk of malignant transformation while under continuous surveillance. Recently, there have been conflicting data published in the literature, generating more uncertainty in the field. In this article, we critically analyze the contrasting consensus guidelines from the International Association of Pancreatology and the American Gastroenterology Association, and address lingering questions and controversies. We also synthesize newly published data in the context of current standard of care, and provide a comprehensive review and recommendations for the clinical diagnosis, treatment, and follow-up strategy in the management of patients with Intraductal Papillary Mucinous Neoplasms.

Risk of pancreatic malignancy and mortality in branch-duct IPMNs undergoing surveillance: A systematic review and meta-analysis

BACKGROUND

Safety of non-operative management for low-risk branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) is debated.

AIM

To perform a systematic review/meta-analysis to determine their risk of developing pancreatic malignancy and of pancreatic malignancy-related deaths.

METHODS

A MEDLINE search was performed and methodology was based on PRISMA statement. Incidence rates of overall pancreatic malignancy, malignant BD-IPMN, IPMN-distinct PDAC, and of pancreatic malignancy-related death rates were calculated by dividing the total number of events by the total number of person-years (pyrs) of follow-up. Heterogeneity was determined by I(2) statistic.

RESULTS

20 studies including 2177 patients were included. Mean follow-up ranged from 29.3 to 76.7 months. Overall, 82 patients (3.7%) developed a pancreatic malignancy with a pooled estimate rate of 0.007/pyrs (I(2)=32.8%). The pooled estimate rate of malignant IPMN was 0.004/pyrs (I(2)=40.8%), and the pooled estimate rate of distinct PDAC 0.002/pyrs (I(2)=0%). The rate of death due to pancreatic malignancy during follow-up was 0.9%, with an overall pooled estimate rate of death of 0.002/pyrs (I(2)=0%).

CONCLUSION

Non-operative management of low-risk BD-IPMN is safe, with a very low risk of malignant transformation of IPMN and of distinct PDAC. The rate of pancreatic malignancy-related mortality is low, particularly when compared with the mortality of pancreatic surgery.

Imaging patterns of intraductal papillary mucinous neoplasms of the pancreas: an illustrated discussion of the International Consensus Guidelines for the Management of IPMN

Intraductal papillary mucinous neoplasms (IPMN) are being diagnosed with increasing frequency, necessitating an algorithm to help stratify patients into low- and high-risk groups, for follow-up versus more invasive evaluation. New evidence concerning their natural history and overall risk of malignancy has emerged since the 2006 International Association of Pancreatology consensus guidelines, prompting an update in 2012, that distinguishes radiologic 'worrisome features' from 'high-risk stigmata'. The aim of this article is to illustrate, with case examples, the variable imaging patterns of IPMN and how their radiologic features, such as cyst size and mural nodules, are interpreted in the context of the new 2012 guidelines. The 2012 and 2006 guidelines will be compared and discussed with reference to additional studies that have since been published. Despite these guidelines, lingering uncertainty remains about the natural history of IPMN, a source of unease to both radiologists and referring clinicians alike, mandating further refinement of clinical and radiologic parameters predictive of malignancy. Emerging data regarding the risk of extrapancreatic malignancy, as well as synchronous or metachronous pancreatic ductal adenocarcinoma remote in location from a branch duct IPMN are also reviewed. With the expanding research and evolving understanding of this clinicopathologic entity across the globe, radiologists will continue to play an important role in the management of patients with IPMN.

What Is the Best Way to Identify Malignant Transformation Within Pancreatic IPMN: A Systematic Review and Meta-Analyses

OBJECTIVES

Pancreatic intraductal papillary mucinous neoplasias (IPMNs) represent 25% of all cystic neoplasms and are precursor lesions for pancreatic ductal adenocarcinoma. This study aims to identify the best imaging modality for detecting malignant transformation in IPMN, the sensitivity and specificity of risk features on imaging, and the usefulness of tumor markers in serum and cyst fluid to predict malignancy in IPMN.

METHODS

Databases were searched from November 2006 to March 2014. Pooled sensitivity and specificity of diagnostic techniques/imaging features of suspected malignancy in IPMN using a hierarchical summary receiver operator characteristic (HSROC) approach were performed.

RESULTS

A total of 467 eligible studies were identified, of which 51 studies met the inclusion criteria and 37 of these were incorporated into meta-analyses. The pooled sensitivity and specificity for risk features predictive of malignancy on computed tomography/magnetic resonance imaging were 0.809 and 0.762 respectively, and on positron emission tomography were 0.968 and 0.911. Mural nodule, cyst size, and main pancreatic duct dilation found on imaging had pooled sensitivity for prediction of malignancy of 0.690, 0.682, and 0.614, respectively, and specificity of 0.798, 0.574, and 0.687. Raised serum carbohydrate antigen 19-9 (CA19-9) levels yielded sensitivity of 0.380 and specificity of 0903. Combining parameters yielded a sensitivity of 0.743 and specificity of 0.906.

CONCLUSIONS

PET holds the most promise in identifying malignant transformation within an IPMN. Combining parameters increases sensitivity and specificity; the presence of mural nodule on imaging was the most sensitive whereas raised serum CA19-9 (>37 KU/l) was the most specific feature predictive of malignancy in IPMNs.

Comparison of Endoscopic Ultrasonography, Computed Tomography, and Magnetic Resonance Imaging for Pancreas Cystic Lesions

Consensus regarding which modality is optimal for the measurement of pancreas cystic lesions (PCLs) was not achieved although cyst size is important for clinical decisions. This study aimed to evaluate the properties of endoscopic ultrasonography (EUS) compared with computed tomography (CT) and magnetic resonance imaging (MRI) in measuring the size of PCL.A total of 34 patients who underwent all 3 imaging modalities within 3 months before surgery were evaluated retrospectively. The size measured by each modality was compared with the pathologic size as a reference standard using Bland-Altman analysis and intraclass correlation coefficients (ICCs).The mean size difference was 1.76 mm (ICC 0.86), 7.35 mm (ICC 0.95), and 8.65 mm (ICC 0.93) in EUS, CT, and MRI. EUS had the widest range of 95% limits of agreement (LOA) (-17.54 to +21.07), compared with CT (-6.21 to +20.91), and MRI (-6.82 to +24.12). The size by EUS tended to be read smaller in tail portion, while those by CT and MRI did not. When the size was more than 4 cm, the size on EUS was estimated to be smaller than on pathology (r = 0.492; P = 0.003).Although 3 modalities showed very good reliability for the size measurement on PCL compared with corresponding pathologic size, EUS had the lowest level of agreement, while CT showed the highest level among the 3 modalities. Therefore, the size estimated by EUS has to be interpreted with caution, especially when it is located in tail and relevantly large.

Imaging morphological changes of intraductal papillary mucinous neoplasm of the pancreas was associated with its malignant transformation but not with development of pancreatic ductal adenocarcinoma

BACKGROUND/OBJECTIVE

A considerable number of branch duct intraductal papillary mucinous neoplasm (BD-IPMN) developed not infrequently pancreatic malignancy, either as part of IPMN (malignant IPMN) or as concomitant pancreatic ductal adenocarcinoma (PDAC). To date, imaging morphological changes predicting occurrence of malignancy in BD-IPMN are not well-investigated. This study aimed to evaluate the relationships between occurrence of malignancy in BD-IPMN and imaging morphological changes of the tumors observed during follow-up.

METHODS

515 BD-IPMN patients with mural nodule <10 mm and negative cytology were included. 19 patients developed malignant IPMN and 8 patients developed concomitant PDAC during mean follow-up of 4.7 years. The following imaging morphological features were assessed: cyst/main pancreatic duct (MPD) diameter, occurrence of additional cyst/mural nodule.

RESULTS

Growth rate of cyst/MPD diameter were significantly larger in patients who developed malignant IPMN compared to those in patients whose IPMN remained benign (p = 0.013, p = 0.01). Occurrence of additional cyst/mural nodule were more frequently observed in patients who developed malignant IPMN (p = 0.009, p = 0.04). In contrast, none of the factors associated with imaging morphological changes of IPMN were shown to be significantly different between patients who developed concomitant PDAC and patients whose IPMN remained benign. Growth rate of MPD diameter and occurrence of additional cyst were independent factors associated with development of malignant IPMN (odds ratio 21.5, and 5.62, respectively).

CONCLUSIONS

Imaging morphological changes of IPMN, such as growth rate of MPD diameter and occurrence of additional cyst, could be indicators for development of malignant IPMN, but not for development of concomitant PDAC.

Risk factors for malignant progression of intraductal papillary mucinous neoplasms

BACKGROUND

Intraductal papillary mucinous neoplasms of the pancreas are increasingly diagnosed. Due to their malignant potential, greater understanding of their nature is required.

AIMS

Define risk factors for malignancy in intraductal papillary mucinous neoplasms.

METHODS

An international, multicentre study was performed in Europe and the United States. Clinical databases were reviewed for patients with intraductal papillary mucinous neoplasms diagnosis.

RESULTS

Of 1126 patients, 84 were diagnosed with invasive carcinoma/high-grade dysplasia and were compared to the rest of the cohort. Multivariate logistic analysis showed a statistically significant association between cancer/high-grade dysplasia and the variables smoking history (OR 1.9, 95% CI [1.1-3.1]), body mass index (OR 1.1, 95% CI [1-1.1]), symptoms (OR 3.4, 95% CI [1.9-6]), jaundice (OR 0.1, 95% CI [0-0.3]), and steatorrhea (OR 0.3, 95% CI [0.1-0.8]). Univariate analysis showed no association between malignancy and the cyst number/location (p=0.3 and p=0.5, respectively) although a strong association was shown for cyst size (p<0.001). The presence and size of nodules (p<0.01) and main duct involvement (p<0.001) were also strongly related with malignancy.

CONCLUSION

The presence of jaundice and steatorrhea, smoking, high body mass index, and imaging features such as cyst size, main duct involvement, and the presence and size of mural nodules are associated with high-grade neoplasia in intraductal papillary mucinous neoplasms.

Prevalence and outcomes of cystic lesion of the pancreas in immunosuppressed patients with solid organ transplantation

BACKGROUND

Solid organ transplant recipients have an increased risk of cancer due to immunosuppressive therapy. Pancreatic cystic lesions are increasingly being detected, some with malignant potential. We aimed to determine the prevalence of these lesions and describe their clinical course in these patients.

METHODS

We identified the presence of pancreatic cystic lesions in a retrospective cohort of 3188 consecutive solid organ transplant recipients from 2000 to 2013 and compared lesion characteristics at initial and follow-up imaging, when available.

RESULTS

Lesion prevalence was 11.4% (365/3188), and increased with age. Median diameter of the largest lesions was 7mm (range: 1-31mm). We noted worrisome features in two patients (0.54%) at the time of cyst diagnosis. Of 155 patients who underwent follow-up imaging, the cysts size remained stable in 80%, increased in 16%, and decreased in 4%. Two patients (1.3%) developed features concerning for cancer. One underwent pancreatic surgery, and pathology confirmed the presence of high-grade dysplasia. The other continued with conservative management due to multiple comorbidities.

CONCLUSIONS

Pancreatic cystic lesions are common in solid organ transplant recipients. In lesions without high-risk features, the development of features worrisome for cancer is rare. These lesions can be managed conservatively, and their presence should not affect transplant eligibility.

Incremental value of secretin-enhanced magnetic resonance cholangiopancreatography in detecting ductal communication in a population with high prevalence of small pancreatic cysts

PURPOSE

We investigated the incremental diagnostic yield of S-MRCP in a population with high prevalence of small pancreatic cysts.

METHODS

Standard MRCP protocol was performed with and without secretin using 1.5 T units in subjects undergoing pancreatic screening because of a strong family history of pancreatic cancer as part of the multicenter Cancer of the Pancreas Screening-3 trial (CAPS 3). All studies were reviewed prospectively by two independent readers who recorded the presence and number of pancreatic cysts, the presence of visualized ductal communication before and after secretin, and the degree of confidence in the diagnoses.

RESULT

Of 202 individuals enrolled (mean age 56 years, 46% males), 93 (46%) had pancreatic cysts detected by MRCP, and 64 of the 93 had pre-and post-secretin MRCP images available for comparison. Data from the 128 readings show that 6 (6/128=4.7%) had ductal communication visualized only on the secretin studies compared to pre-secretin studies (odds ratio 1.28, p=0.04). In addition, there was a statistically significant increase in confidence in reporting ductal communication after secretin compared to before secretin (p<0.0005).

CONCLUSION

At 1.5 T MRI, the use of secretin can improve the visualization of ductal communication of cystic pancreatic lesions.

Cyst fluid amylase and CEA levels in the differential diagnosis of pancreatic cysts: a single-center experience with histologically proven cysts

OBJECTIVE

Cyst fluid amylase is a potential marker for pseudocysts and intraductal papillary mucinous neoplasms (IPMN). This study aimed to evaluate the diagnostic role of cyst fluid amylase and to determine the optimal cutoff values of cyst fluid amylase and carcinoembryonic antigen (CEA) for the differential diagnosis of pancreatic cysts.

METHODS

Based on the pancreatic cyst database at Massachusetts General Hospital, a total of 78 patients with histologically proven cysts [pancreatic pseudocyst (PP), n = 16; mucinous cystic neoplasm, mucinous cystic neoplasm (MCN), n = 22; IPMN, n = 40] were selected. Complete cyst fluid amylase and CEA values were analyzed.

RESULTS

Thirty two of 78 patients were male with median age of 60.4 years (range, 24-84). Cyst diameter ranged from 5 to 130 mm. For cyst fluid amylase, there was significant difference between PP and MCN (median, 30,034.50 vs. 4,723.50 U/L; p < 0.05) or IPMN (30,034.50 vs. 1,585.00; p = 0.001), but no difference between MCN and IPMN. For cyst fluid CEA, there was a significant difference between PP and MCN (median, 26.00 vs. 627.50 ng/mL; p < 0.001) or IPMN (26.00 vs. 356.50; p < 0.001). Median amylase and CEA values were significantly different between PP and mucinous neoplasms (MCN/IPMN) (p < 0.01 and p < 0.001). Optimal cutoff values of 6,800 U/mL for amylase and 50 ng/mL for CEA correlated with the crossover of the sensitivity and specificity curves for differentiating PP and mucinous neoplasms. The overall accuracies of cyst fluid amylase and CEA were 69 and 85%, respectively.

CONCLUSIONS

Cyst fluid amylase analysis does not differentiate between MCN and IPMN. The combination of cyst fluid CEA and amylase value may increase the diagnostic accuracy for differentiating mucinous neoplasms from pseudocysts.

Progress in diagnosis and treatment of intraductal papillary mucinous neoplasms

Intraductal papillary mucinous neoplasm (IPMN) is a rare form of exocrine pancreatic neoplasm arising from the ductal epithelium, which is difficult to diagnose in early stages owing to the lack of specific clinical symptoms. In most cases, IPMN is detected incidentally during medical examination. Some imaging studies such as magnetic resonance cholangiopancreatography (MRCP), endoscopic ultrasonography (EUS) and computed tomography (CT) have been considered to be helpful to the preoperative diagnosis of IPMNs. Histologically, IPMNs may demonstrate a spectrum of cellular atypia, ranging from hyperplasia to invasive carcinoma. At present, IPMNs are classified into three types: main duct IPMN (MD-IPMN), branch duct IPMN (BD-IPMN) and mixed type IPMN (MT-IPMN) according to the dominant location of the IPMN where the ductal dilatation occurs. Once diagnosed, all patients with MD-IPMN and MT-IPMN should undergo surgical resection as soon as possible regardless of size and symptoms due to the high risk of canceration. After surgical resection, the survival rate of IPMN patient is excellent. For patients with invasive IPMNs, the 5-year survival rate is 40%-60%, while for those with noninvasive IPMNs, the 5-year survival rate is 80%-100%. Therefore, early diagnosis and timely treatment are strongly recommended for all IPMN patients. The aim of this paper is to systematically review the diagnosis and treatment of IPMNs.

Endoscopic ultrasound in the diagnosis of pancreatic intraductal papillary mucinous neoplasms

Pancreatic cystic lesions are increasingly recognised due to the widespread use of different imaging modalities. Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas represent a common, but also heterogeneous group of cystic tumors with a significant malignant potential. These neoplasms must be differentiated from other cystic tumors and properly classified into their different types, main-duct IPMNs vs branch-duct IPMNs. These types have a different malignant potential and therefore, different treatment strategies need to be implemented. Endoscopic ultrasound (EUS) offers the highest resolution of the pancreas and can aid in the differential diagnosis, classification and differentiation between benign and malignant tumors. The addition of EUS fine-needle aspiration can supply further information by obtaining fluid for cytology, measurement of tumor markers and perhaps DNA analysis. Novel techniques, such as the use of contrast and sophisticated equipment, like intraductal probes can provide information regarding malignant features and extent of these neoplasms. Thus, EUS is a valuable tool in the diagnosis and appropriate management of these tumors.

CT and MR imaging of multilocular acinar cell cystadenoma: comparison with branch duct intraductal papillary mucinous neoplasia (IPMNs)

OBJECTIVES

To describe CT and MR imaging findings of acinar cell cystadenoma (ACC) of the pancreas and to compare them with those of branch duct intraductal papillary mucinous neoplasia (BD-IPMN) to identify distinctive elements.

METHODS

Five patients with ACC and the 20 consecutive patients with histologically proven BD-IPMN were retrospectively included. Clinical and biological information was collected and histological data reviewed. CT and MR findings were analysed blinded to pathological diagnosis in order to identify imaging diagnostic criteria of ACC.

RESULTS

Patients with ACC were symptomatic in all but one case and were younger than those with BD-IPMN (p = 0.006). Four radiological criteria allowed for differentiating ACC from IPMN: five or more cysts, clustered peripheral small cysts, presence of cyst calcifications and absence of communication with the main pancreatic duct (p < 0.05). Presence of at least two or three of these imaging criteria had a strong diagnostic value for ACC with a sensitivity of 100% and 80% and a specificity of 85% and 100%, respectively.

CONCLUSIONS

Preoperative differential diagnosis between ACC and BD-IPMN can be achieved using a combination of four CT and/or MR imaging criteria. Recognition of ACC patients could change patient management and lead to more conservative treatment.

KEY POINTS

Four imaging findings are associated with acinar cell cystadenoma (ACC). Imaging could achieve differential diagnosis between ACC and BD-IPMN. Diagnosis on imaging would change patient management and avoid surgical resection.

Italian consensus guidelines for the diagnostic work-up and follow-up of cystic pancreatic neoplasms

This report contains clinically oriented guidelines for the diagnostic work-up and follow-up of cystic pancreatic neoplasms in patients fit for treatment. The statements were elaborated by working groups of experts by searching and analysing the literature, and then underwent a consensus process using a modified Delphi procedure. The statements report recommendations regarding the most appropriate use and timing of various imaging techniques and of endoscopic ultrasound, the role of circulating and intracystic markers and the pathologic evaluation for the diagnosis and follow-up of cystic pancreatic neoplasms.

In situ proteomic analysis by MALDI imaging identifies ubiquitin and thymosin-β4 as markers of malignant intraductal pancreatic mucinous neoplasms

PURPOSE

Intraductal pancreatic mucinous neoplasms (IPMN) are precancerous cystic lesions. The aim was to investigate the in situ IPMN proteome using MALDI (Matrix-Assisted Laser Desorption/Ionisation) imaging and to characterize biomarkers associated with the grade of dysplasia.

EXPERIMENTAL DESIGN

Frozen human Branch duct -IPMN sections were selected according to dysplasia and proteomic analyses were performed by MALDI imaging to obtain mass spectra distribution. The most discriminating peaks were identified using tissue extraction and nanoLC-ESI-MS/MS. Identified peaks were validated in independent series of IPMN by immunochemistry on surgical specimens (tissue-microarrays (TMA), n = 45) and endoscopic ultrasound fine-needle aspiration (EUS FNA) samples (n = 25).

RESULTS

BD-IPMN samples with low (n = 10) and high (n = 10) grades of dysplasia were analyzed. Differential spectra of proteins were found in the two groups with significantly different intensities (n = 15). The two peaks (intense in high grade IPMN) (m/z 8565 and 4747) were characterized as the monomeric ubiquitin (Mascot score = 319.22) and an acetylated fragment of thymosin-β4 (2-42) (Omssa score = 1.37 E-9). Validation on TMA and EUS FNA samples confirmed that ubiquitin was overexpressed in high grade dysplasia (p = 0.04 and p = 0.0004). Thymosin-β4 expression was confirmed on TMA by immunohistochemistry on high grade IPMN (p = 0.011).

CONCLUSION

Ubiquitin and thymosin-β4 are overexpressed in IPMN with high grade dysplasia. Positive immunochemical staining on EUS-FNA material is a major argument in support of preventive resection.

European experts consensus statement on cystic tumours of the pancreas

Cystic lesions of the pancreas are increasingly recognized. While some lesions show benign behaviour (serous cystic neoplasm), others have an unequivocal malignant potential (mucinous cystic neoplasm, branch- and main duct intraductal papillary mucinous neoplasm and solid pseudo-papillary neoplasm). European expert pancreatologists provide updated recommendations: diagnostic computerized tomography and/or magnetic resonance imaging are indicated in all patients with cystic lesion of the pancreas. Endoscopic ultrasound with cyst fluid analysis may be used but there is no evidence to suggest this as a routine diagnostic method. The role of pancreatoscopy remains to be established. Resection should be considered in all symptomatic lesions, in mucinous cystic neoplasm, main duct intraductal papillary mucinous neoplasm and solid pseudo-papillary neoplasm as well as in branch duct intraductal papillary mucinous neoplasm with mural nodules, dilated main pancreatic duct >6mm and possibly if rapidly increasing in size. An oncological partial resection should be performed in main duct intraductal papillary mucinous neoplasm and in lesions with a suspicion of malignancy, otherwise organ preserving procedures may be considered. Frozen section of the transection margin in intraductal papillary mucinous neoplasm is suggested. Follow up after resection is recommended for intraductal papillary mucinous neoplasm, solid pseudo-papillary neoplasm and invasive cancer.

Classification, morphology and molecular pathology of premalignant lesions of the pancreas

Over the past few years there have been substantial advances in our knowledge of premalignant lesions of the pancreas. Given the dismal prognosis of untreated pancreatic cancer, and the small proportion of patients who are operative candidates, an understanding of these premalignant lesions is essential for the development of strategies for early diagnosis and prevention. The 2010 WHO classification has added new entities, including intraductal tubular papillary neoplasms (ITPNs), and clarified the nomenclature and grading of previously recognised precursor lesions of pancreatic adenocarcinoma, such as intraductal papillary mucinous neoplasms (IPMNs), mucinous cystic neoplasms (MCNs) and pancreatic intraepithelial neoplasia (PanIN). In particular, there has been an upsurge of interest in the natural history of IPMN, driven partly by improvements in imaging modalities and the consequent apparent increase in their incidence, and partly by recognition that subtypes based on location or histological appearance define groups with significantly different behaviours. In mid 2012 revised international guidelines for the classification and management of IPMNs and MCNs were published, although in several respects these guidelines represent a consensus view rather than being evidence-based. In recent years major advances in molecular technologies, including whole-exome sequencing, have significantly enhanced our knowledge of pancreatic premalignancy and have identified potentially highly specific diagnostic biomarkers such as mutations in GNAS and RNF43 that could be used to pre-operatively assess pancreatic cysts.

Pancreatic cystic neoplasms: management and unanswered questions

Approximately 10% of persons 70 years old or older are now diagnosed with pancreatic cysts, but it is not clear which ones require additional analysis, interventions, or follow-up. Primary care doctors rely on gastroenterologists for direction because no one wants to miss a diagnosis of pancreatic cancer, but meanwhile there is pressure to limit use of diagnostic tests and limit costs. We review the different cystic neoplasms of the pancreas and diagnostic strategies based on clinical features and imaging data. We discuss surgical and nonsurgical management of the most common cystic neoplasms, based on the recently revised Sendai guidelines. Intraductal papillary mucinous neoplasm (particularly the branch duct variant) is the lesion most frequently identified incidentally. We report what is known about its pathology, its risk of developing into pancreatic ductal adenocarcinoma, the pros and cons of current guidelines for management, and the potential role of endoscopic ultrasound in determining cancer risk. We also review surgical treatment and strategies for surveillance of pancreatic cysts.

Appropriate indications of initial endoscopic ultrasound evaluation for detecting mural nodules in branch duct intraductal papillary mucinous neoplasms of the pancreas

OBJECTIVE

The presence of mural nodules is a strong predictor of malignancy in patients with branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs). Endoscopic ultrasound (EUS) is the most sensitive imaging for the detection of mural nodules. The aim was to evaluate whether initial EUS evaluation is necessary to detect mural nodules in all patients with BD-IPMNs.

MATERIAL AND METHODS

We reviewed retrospectively the medical records of all 104 patients with BD-IPMNs diagnosed by EUS from January 2008 to December 2011. Of the 104 patients, 13 (12.5%) had mural nodules (MN-positive group) and 91 (87.5%) did not (MN-negative group).

RESULTS

Patients in the MN-positive group were significantly older (69 years vs. 61 years, p = 0.013), had larger-sized cysts on EUS (24.1 ± 8.3 mm vs. 16.2 ± 8.0 mm, p = 0.001), a higher rate of main pancreatic duct dilatation (30.8% vs. 3.3%, p = 0.004), and higher serum CA 19-9 concentrations (67.8 ± 109.4 U/mL vs. 17.5 ± 27.0 U/mL, p = 0.012), than patients in the MN-negative group. Cyst sizes measured by EUS, CT, and MRCP did not differ significantly. Multivariate logistic regression analysis showed that cysts ≥16 mm in size on CT (odds ratio [OR], 9.84; 95% confidential interval [CI], 1.08-89.93; p = 0.043) and main pancreatic duct dilatation (OR, 12.65; 95% CI, 1.62-98.99; p = 0.016) were independent predictors of mural nodules.

CONCLUSIONS

Patients with BD-IPMNs, cyst size ≥16 mm, and main pancreatic duct dilatation should be further evaluated by EUS for the presence of mural nodules.

Biliary findings assist in predicting enlargement of intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND & AIMS

There is controversy over the optimal management strategy for patients with branch-duct type intraductal papillary mucinous neoplasms of the pancreas (BD-IPMNs), precursors to pancreatic cancer. We aimed to identify factors associated with the presence of BD-IPMNs and changes in their diameter.

METHODS

Two separate analyses were conducted in a cohort of patients who underwent magnetic resonance cholangiopancreatography (MRCP) in a single year (2006). MRCP findings and clinical outcomes of these patients were followed for a maximum of 6 years. We evaluated initial MRCP findings and demographics associated with the presence of BD-IPMNs at baseline and increase in BD-IPMN diameter over time.

RESULTS

During the follow-up period, 154 patients developed BD-IPMN and 322 patients did not. Older age, diabetes mellitus, gallbladder adenomyomatosis, and absence of gallstones were associated with the presence of BD-IPMNs at baseline. Increases in diameter of BD-IPMNs were associated with 3 baseline factors: BD-IPMN diameter greater than 17 mm, gallbladder adenomyomatosis, and a common bile duct diameter less than 5.5 mm. Patients with BD-IPMNs could be stratified into 4 groups with varying risk for the enlargement of BD-IPMNs over time: those with 3 risk factors (hazard ratio [HR], 11.4; 95% confidence interval [CI], 3.4-37.8), 2 risk factors (HR, 4.7; 95% CI, 1.7-12.8), or 1 risk factor (HR, 3.1; 95% CI, 1.2-8.2) compared with those without risk factors.

CONCLUSIONS

For patients with BD-IPMNs, careful follow-up evaluation is particularly important for those with BD-IPMN >17 mm in size, common bile duct diameter <5.5 mm, or gallbladder adenomyomatosis.

Invasive carcinoma derived from branch duct-type IPMN may be a more aggressive neoplasm than that derived from main duct-type IPMN

The present study aimed to evaluate the long-term follow-up results of patients with intraductal papillary mucinous neoplasm (IPMN) and to estimate the degree of IPMN malignancy based on pathological and molecular features of resected specimens. The detection rate of IPMN has increased over the last decade; however, the management of this neoplasm remains controversial. This is particularly so for branch duct-type IPMN, which carries a high potential for malignancy and risk of recurrence. We retrospectively reviewed a single institution’s prospective pancreatic resection database to identify IPMN patients who underwent pancreatectomy with curative intent. The clinicopathological variables of 100 patients resected for IPMN were analyzed with a detailed review of histopathological results (borderline lesions, non-invasive carcinoma and invasive carcinoma) to determine the grade of IPMN malignancy based on transforming growth factor (TGF)-β/SMAD4 signaling. The incidence of malignant change was significantly higher in patients with main duct-type IPMN (69.7%) compared with branch duct-type IPMN cases (17.9%). However, patients with an invasive carcinoma had a significantly worse outcome if it was derived from branch duct-type IPMN compared with those derived from main duct-type IPMN, and TGF-β mRNA expression was significantly increased in the former patient group. Immunohistochemistry also showed higher numbers of SMAD4-positive cells in patients with carcinoma derived from branch duct-type IPMN. Our results demonstrated that invasive carcinoma derived from branch duct-type IPMN is more aggressive than that derived from main duct-type IPMN, once invasive morphological change takes place. Determining TGF-β and/or SMAD4 status at initial diagnosis may be useful for stratifying IPMN patients into treatment regimens.

Intraductal papillary mucinous neoplasm of the pancreas: an update

Intraductal papillary mucinous neoplasm (IPMN) is a cystic tumor of the pancreas. The etiology is unknown, but increasing evidence suggests the involvement of several tumorigenesis pathways, including an association with hereditary syndromes. IPMN occurs more commonly in men, with the mean age at diagnosis between 64 and 67 years old. At the time of diagnosis, it may be benign, with or without dysplasia, or frankly malignant with an invasive carcinoma. Tumors arising from the main pancreatic duct are termed main-duct IPMNs, those involving the branch ducts, branch-duct IPMNs. In general, small branch-duct IPMNs are benign, particularly in asymptomatic patients, and can be safely followed. In contrast, main-duct tumors should be surgically resected and examined carefully for an invasive component. In the absence of invasion, patient's survival is excellent, from 94 to 100%. For patients with an IPMN-associated invasive carcinoma, the prognosis overall is better than those with a de novo pancreatic ductal adenocarcinoma, with a 5-year survival of 40% to 60% in some series. However, no survival advantage can be demonstrated if the invasive component in an IPMN patient is that of the conventional tubular type (versus mucinous carcinoma). Several histomorphologic variants are recognized, although the clinical significance of this "subtyping" is not well defined.

International consensus guidelines 2012 for the management of IPMN and MCN of the pancreas

The international consensus guidelines for management of intraductal papillary mucinous neoplasm and mucinous cystic neoplasm of the pancreas established in 2006 have increased awareness and improved the management of these entities. During the subsequent 5 years, a considerable amount of information has been added to the literature. Based on a consensus symposium held during the 14th meeting of the International Association of Pancreatology in Fukuoka, Japan, in 2010, the working group has generated new guidelines. Since the levels of evidence for all items addressed in these guidelines are low, being 4 or 5, we still have to designate them "consensus", rather than "evidence-based", guidelines. To simplify the entire guidelines, we have adopted a statement format that differs from the 2006 guidelines, although the headings are similar to the previous guidelines, i.e., classification, investigation, indications for and methods of resection and other treatments, histological aspects, and methods of follow-up. The present guidelines include recent information and recommendations based on our current understanding, and highlight issues that remain controversial and areas where further research is required.

Endoscopic ultrasound-guided pancreatic cyst ablation

Pancreatic cystic neoplasms represent a wide spectrum of invariably benign to precancerous and malignant tumors. Endoscopic ultrasound-guided pancreatic cyst ablation with ethanol and/or paclitaxel offers a nonoperative treatment for patients refusing or not eligible for surgery. Histopathology after resection in these patients has shown variable degrees of cyst epithelial ablation ranging from 0% to 100%. Future research investigating the safety of this procedure, modifications of reported ablation techniques, choice and number of the lavage agents used, and criteria to optimize selection of the appropriate pancreatic cysts for treatment is needed.

The long term risk of malignancy in patients with branch duct intraductal papillary mucinous neoplasms of the pancreas

In patients (pts) with branch duct intraductal papillary mucinous neoplasms of the pancreas (BD-IPMN), the risk of malignant progression is well described at short- and mid-term. Few data beyond 5 years are available.

PATIENTS AND METHODS

Prospective study in consecutive patients (pts) with BD-IPMN and follow-up (F/U) ≥60 months to assess long term risk of malignant progression. All computed tomographies and magnetic resonance cholangiopancreatographies performed every 1 or 2 years (depending on the maximum size of cyst) were read by the same radiologist. EUS was performed in case of occurrence of main pancreatic duct (MPD) dilation or mural nodule >5 mm. Size increase was considered significant if >5 mm. Size variation, criteria suggestive of malignancy, operative therapy and pathology were recorded.

RESULTS

53 pts were included (median age at diagnosis: 61 years, median F/U: 84 months (range: 60-132) including 5 F/U >120 months). Lesions were stable in 38 pts (72%). Size increased in 8 pts (15%) (median increase : 11 (5-33) mm) without mural nodule (MN). One of those was operated on (low-grade dysplasia). A MN appeared in 5 pts (9%). ≥5 mm in 2 pts (5 and 15 mm) who were operated on (intermediate-grade dysplasia in both). The 3 remaining pts (MN < 5 mm) were carefully followed-up. Invasive advanced carcinoma occurred in 2 pts, both after 84 months F/U. In one of these, no imaging changes were noted 12 months before diagnosis of malignancy.

CONCLUSION

In BD-IPMN, the risk of malignant evolution persists after 60 months F/U including invasive carcinomas. F/U imaging surveillance is still necessary beyond this delay in patients fit for potential surgery.