Long-term follow-up of intraductal papillary mucinous neoplasm of the pancreas with ultrasonography

Ductal Dilatation of ≥5 mm in Intraductal Papillary Mucinous Neoplasm Should Trigger the Consideration for Pancreatectomy: A Meta-Analysis and Systematic Review of Resected Cases

Simple Summary

Intraductal papillary mucinous neoplasms (IPMN) are common but difficult to manage since accurate tools for diagnosing malignancy are unavailable. This study evaluates the diagnostic value of main pancreatic duct (MPD) diameter for detecting IPMN malignancy, using a meta-analysis of published data. The result suggests that malignancy is highly prevalent in IPMN with ductal dilatation of >5 mm.

Abstract

Intraductal papillary mucinous neoplasms (IPMN) are common but difficult to manage since accurate tools for diagnosing malignancy are unavailable. This study tests the diagnostic value of the main pancreatic duct (MPD) diameter for detecting IPMN malignancy using a meta-analysis of published data of resected IPMNs. Collected from a comprehensive literature search, the articles included in this analysis must report malignancy cases (high-grade dysplasia (HGD) and invasive carcinoma (IC)) and MPD diameter so that two MPD cut-offs could be created. The sensitivity, specificity, and odds ratios of the two cutoffs for predicting malignancy were calculated. A review of 1493 articles yielded 20 retrospective studies with 3982 resected cases. A cutoff of ≥5 mm is more sensitive than the ≥10 mm cutoff and has pooled sensitivity of 72.20% and 75.60% for classification of HGD and IC, respectively. Both MPD cutoffs of ≥5 mm and ≥10 mm were associated with malignancy (OR = 4.36 (95% CI: 2.82, 6.75) vs. OR = 3.18 (95% CI: 2.25, 4.49), respectively). The odds of HGD and IC for patients with MPD ≥5 mm were 5.66 (95% CI: 3.02, 10.62) and 7.40 (95% CI: 4.95, 11.06), respectively. OR of HGD and IC for MPD ≥10 mm cutoff were 4.36 (95% CI: 3.20, 5.93) and 4.75 (95% CI: 2.39, 9.45), respectively. IPMN with MPD of >5 mm could very likely be malignant. In selected IPMN patients, pancreatectomy should be considered when MPD is >5 mm.

Role of transabdominal ultrasonography in the diagnosis of pancreatic cystic lesions

Pancreatic cystic lesions (PCLs) are incidental findings that are being increasingly identified because of recent advancements in abdominal imaging technologies. PCLs include different entities, with each of them having a peculiar biological behavior, and they range from benign to premalignant or malignant neoplasms. Therefore, accurate diagnosis is important to determine the best treatment strategy. As transabdominal ultrasonography (US) is noninvasive, inexpensive, and widely available, it is considered to be the most appropriate imaging modality for the initial evaluation of abdominal diseases, including PCLs, and for follow-up assessment. We present a review of the possibilities and limits of US in the diagnosis of PCLs, the technical development of US, and the ultrasonographic characteristics of PCLs.

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.

Meta-analysis of mortality in patients with high-risk intraductal papillary mucinous neoplasms under observation

BACKGROUND

Although consensus guidelines suggest that patients with high-risk intraductal papillary mucinous neoplasms (IPMNs) should have surgery, a non-operative strategy is often selected in patients who are poor surgical candidates. The aim was to determine the risk of disease-related death from IPMN in patients with worrisome features or high-risk stigmata who were kept under observation.

METHODS

A PubMed literature search was undertaken of articles published from August 1992 to June 2016 (updated October 2017). The methodology was developed from PRISMA and MOOSE checklists. Incidence proportions and rates of overall and IPMN-related deaths were calculated, with subgroup analyses for main-duct/mixed-type and branch-duct IPMNs. Quality of the studies, publication bias and heterogeneity were explored.

RESULTS

Six studies reported data on overall mortality and eight described disease-specific mortality for 556 patients during follow-up ranging from 24·9 to 60·0 months. Pooled rates of overall and IPMN-related mortality were 30·9 (95 per cent c.i. 19·6 to 45·1) and 11·6 (6·0 to 21·2) per cent respectively. The pooled incidence rate for overall mortality was substantially higher than that for IPMN-related mortality: 78 (95 per cent c.i. 44 to 111) and 23 (9 to 37) per 1000 patient-years respectively. The pooled incidence rate for disease-specific mortality was considerably lower for branch-duct than for main-duct or mixed-type IPMNs: 5 (0 to 10) and 32 (12 to 52) per 1000 patient-years respectively.

CONCLUSION

In patients unfit for surgery, IPMN-related mortality among patients with worrisome features and high-risk stigmata is low, and the risk of death from other causes much higher.

Effect of low-dose aspirin use on pancreatic cancer development and morphological changes on imaging in IPMN: A long-term cohort study

Background

Aspirin use may reduce the incidence of pancreatic cancer (PC), but no data are available regarding its chemopreventive effects on intraductal papillary mucinous neoplasm (IPMN). We aimed to determine whether low-dose aspirin (LDA) reduces PC development and morphological changes on imaging in IPMN patients.

Methods

A cohort of 448 IPMN patients periodically followed up with imaging tests was analyzed. We used one-to-two propensity score matching to adjust for differences between an LDA group (n = 63) and a non-LDA group (n = 385). Outcomes included increasing cyst diameter, increasing main pancreatic duct (MPD) diameter, mural nodule (MN) appearance and PC development.

Results

After matching, 63 LDA and 126 non-LDA patients were selected. During follow-up (median, 5.5 years), no significant differences were found in increasing cyst diameter, MN appearance, or PC development. However, there were significantly fewer cases of increasing MPD diameter in the LDA group (4.8% vs. 12.7%; p = 0.02). After adjustment for age and sex, LDA still decreased the risk of increasing MPD diameter (hazard ratio, 0.17; p = 0.02).

Conclusion

Our results do not support a chemopreventive effect of LDA on PC development. However, LDA reduces further MPD dilation in IPMN patients.

Surveillance and Outcomes of Nonresected Presumed Branch-Duct Intraductal Papillary Mucinous Neoplasms: A Meta-analysis

OBJECTIVES

Guidelines regarding the surveillance of intraductal papillary mucinous neoplasms (IPMNs) are controversial because of uncertain risk of malignancy, agnosticism regarding the use of endoscopic ultrasound, and their recommendation to stop surveillance after 5 years. We present a systematic review and meta-analysis of the risk of malignancy and other end points and estimate the value of endoscopic ultrasound for surveillance.

METHODS

We systematically searched MEDLINE for studies with a cohort of patients with presumed branch-duct IPMN who initially were managed nonsurgically. Data regarding study characteristics, surveillance, and outcomes were extracted. Incidence rates of morphologic progression, malignancy, surgery, and death were calculated with a random effects model.

RESULTS

Twenty-four studies with 3440 patients and 13,097 patient-years of follow-up were included. Rates of morphologic progression, surgery, malignancy, and death were 0.0379, 0.0250, 0.0098, and 0.0043 per patient-year, respectively. Endoscopic ultrasound was not associated with significantly different rates of these outcomes.

CONCLUSIONS

The risk of malignancy calculated in this study was low and in line with recent systematic reviews. Endoscopic ultrasound does not have marginal use in surveillance. Given the limitations of a systematic review of nonrandomized studies, further studies are needed to determine the optimal surveillance of branch-duct IPMNs.

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.

Progression of Incidental Intraductal Papillary Mucinous Neoplasms of the Pancreas in Liver Transplant Recipients

OBJECTIVES

Intraductal papillary mucinous neoplasms (IPMNs) are premalignant pancreatic cysts commonly found incidentally. Immunosuppression accelerates carcinogenesis.Thus, we aimed to compare IPMN progression in liver transplant (LT) recipients on chronic immunosuppression to progression among an immunocompetent population.

METHODS

We retrospectively assessed adult LT recipients between 2008 and 2014 for imaging evidence of IPMN. Diagnosis of IPMN was based on history, imaging, and cyst fluid analysis. The immunocompetent control group consisted of nontransplant patients from our pancreatic cyst surveillance program with IPMN under surveillance for greater than 12 months between 1997 and 2013. Four hundred fifty-four patients underwent LT in the study period and had cross-sectional imaging.

RESULTS

The prevalence of suspected IPMN was 6.6% (30 of 454). Compared with 131 controls, the transplant cohort was younger, with increased prevalence of diabetes and smoking. The prevalence of other risk factors for IPMN progression (history of pancreatitis, family history of pancreatic cancer) was similar. After an average follow-up of 31 months, most cysts increased in diameter, with a similar increase of dominant cyst (0.4 cm vs 0.5 cm; P = 0.6). Type of immunosuppression was not associated with the increased rate of cyst growth.

CONCLUSIONS

Our findings suggest that LT recipients with incidental IPMN can be managed under similar guidelines as immunocompetent patients.

Rapid Growth Rates of Suspected Pancreatic Cyst Branch Duct Intraductal Papillary Mucinous Neoplasms Predict Malignancy

BACKGROUND

The majority of branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) are recommended for surveillance imaging based on consensus guidelines. However, growth rates that should prompt concern for malignant transformation of BD-IPMN are unknown.

AIMS

To determine whether BD-IPMN growth can predict an increased risk of malignancy and define growth rates concerning for malignant BD-IPMN.

METHODS

The study is a retrospective, multicenter study of suspected BD-IPMN patients undergoing imaging surveillance. All patients underwent EUS evaluation followed by surveillance imaging.

RESULTS

Two hundred and eighty-four patients with suspected BD-IPMN without worrisome features or high-risk stigmata were followed for a median 56 months and underwent a median of four imaging studies. Nine patients (3.2 %) developed malignant BD-IPMN. Malignant BD-IPMN grew at a faster rate (18.6 vs. 0.8 mm/year; P = 0.05) compared to benign BD-IPMN. BD-IPMN growth rate between 2 and 5 mm/year was associated with an increased risk of malignancy with hazard ratio (HR) of 11.4 (95 % CI 2.2-58.6) when compared to subjects with BD-IPMN growth rate <2 mm/year (P = 0.004). BD-IPMN growth rate ≥5 mm/year had a hazard ratio of 19.5 (95 % CI 2.4-157.8) (P = 0.005). BD-IPMN growth rate of 2 mm/year had a sensitivity of 78 %, specificity of 90 %, and accuracy of 88 % to identify malignancy. Total BD-IPMN growth was also associated with increased risk of malignancy (P = 0.003) with all malignant IPMNs growing at least 10 mm prior to cancer diagnosis.

CONCLUSIONS

BD-IPMN growth rates ≥2 mm/year and total growth of ≥10 mm should be considered worrisome features for BD-IPMN at increased risk of malignancy.

Demographic features and natural history of intermediate-risk multifocal versus unifocal intraductal papillary mucinous neoplasms

OBJECTIVES

This study compares the progression of multifocal (MF) intraductal papillary mucinous neoplasms (IPMNs) to unifocal (UF) lesions.

METHODS

We performed a retrospective review of demographics, risk factors, and cyst characteristics of a prospectively maintained database of 999 patients with pancreatic cysts. Patients included had IPMN under surveillance for 12 months or more. Those with high-risk stigmata were excluded. Cyst size progression and development of worrisome features were compared between MF and UF cohorts. We evaluated whether the dominant cyst in MF-IPMN had more significant growth than did the other cysts.

RESULTS

Seventy-seven patients with MF-IPMN and 54 patients with UF-IPMN, with mean follow-up of 27 and 34 months, met the criteria. There were no significant differences between demographics, risk factors, or initial cyst sizes. Fifty-seven percent of MF dominant cysts and 48% of UF cysts increased in size (P = 0.31). Progression in MF was more likely in the dominant cyst (P < 0.05). There were no significant differences in the development of mural nodules or increase in cyst size to more than 3 cm.

CONCLUSIONS

Demographics of both cohorts were similar, as was the overall incidence of worrisome features. Because meaningful size progression primarily occurred in the dominant cyst, our findings support surveillance based on the dominant cyst in MF disease.

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.

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.

Malignant potential in incidental pancreatic cysts

Although pancreatic cysts are being diagnosed with greater frequency, a uniform agreement on management is still lacking. This is mainly because accurate and reliable preoperative determination of the exact pathology of a pancreatic cyst remains elusive. Although ultrasound-guided fine needle aspiration represents a significant advancement in our ability to characterize pancreatic cysts preoperatively, significant limitations persist. In this article, we review the roles of clinical characteristics, imaging features and biochemical markers in the correct classification of incidental pancreatic cysts. The correct diagnosis and management of these cysts still hinges, to a large extent, on clinical experience and multidisciplinary cooperation.

Predictive factors for invasive intraductal papillary mucinous neoplasm of the pancreas

BACKGROUNDS/AIMS

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas has malignant potential. Predicting invasive IPMN has proven difficult and controversial. We tried to identify predictive factors for invasive IPMN.

METHODS

Thirty six patients underwent resection for IPMN from February 2001 to July 2011. Clinicopathological features including demographic, imaging, microscopic, and serological findings were retrospectively reviewed. Receiver operating characteristic (ROC) curve analysis was used to analyze sensitivity and specificity of all possible cut-off values for the diameter of the main pancreatic duct and mass size predicting invasive IPMN. Student t-test, chi-square test, and logistic regression were used for univariate and multivariate analysis.

RESULTS

The mean age was 63.5±8.4 years. Males were more commonly affected (58.3% vs 41.7%). Pancreaticoduodenectomy was performed in 55.6% of patients, distal pancreatectomy in 36.1%, and central pancreatic resection in 8.3%. Non-invasive IPMNs were present in 80.6% (n=29), whereas invasive IPMNs were present in 19.4% (n=7). In univariate analysis, tumor location (p=0.036), Kuroda classification (p=0.048), mural nodule (p=0.016), and main duct dilatation (≥8 mm) (p=0.006) were statistically significant variables. ROC curve analysis showed that a value of 8 mm for the main duct dilatation and a value of 35 mm for the size of the mass lesion have 80% sensitivity and 75% specificity and 100% sensitivity and 82.6% specificity, respectively. However, in multivariate analysis, main ductal dilatation (≥8 mm) was identified to be the only independent factor for invasive IPMN (p=0.049).

CONCLUSIONS

Main duct dilatation appears to be a useful indicator for predicting invasive IPMN.

Volumetric and morphological analysis of intraductal papillary mucinous neoplasm of the pancreas using computed tomography and magnetic resonance imaging

OBJECTIVE

The purpose of this study was to predict the malignancy of intraductal papillary mucinous neoplasm (IPMN) based on data obtained by computed tomography and magnetic resonance imaging.

METHODS

Sixty-nine patients with IPMN underwent computed tomography, magnetic resonance imaging, and surgery. The tumors were classified pathologically as IPMN (adenoma), IPMN (in situ carcinoma), and invasive carcinoma derived from IPMN, and analyzed morphologically for the following characteristics: tumor size, main pancreatic duct (MPD) diameter, tumor area, MPD area, tumor volume, MPD volume, and intraductal volume (tumors volume + MPD volume).

RESULTS

Main pancreatic duct diameter (P = 0.017) and intraductal volume (P = 0.0013) showed significant differences among IPMN (adenoma), IPMN (in situ carcinoma), and invasive carcinoma derived from IPMN. When IPMN (in situ carcinoma) and invasive carcinoma derived from IPMN were classified as malignant IPMN, an MPD diameter of 6 mm or more and an intraductal volume of 10 cm or more were set as cutoff levels predictive of malignancy using receiver operating characteristic curve analysis. On the basis of these criteria, the sensitivity and specificity for identifying malignancy in MPD were 83% and 59%, and those for intraductal volume were 70% and 73%, respectively.

CONCLUSION

Intraductal volume (≥10 cm) determined by volumetric analysis is useful for diagnosis of malignant IPMN.

Intraductal papillary mucinous neoplasm

Intraductal papillary mucinous neoplasm (IPMN) is a grossly visible (≥1 cm), mucin-producing neoplasm that arises in the main pancreatic duct and/or its branches. Patients with intraductal papillary mucinous neoplasm can present with symptoms caused by obstruction of the pancreatic duct system, or they can be asymptomatic. There are 3 clinical subtypes of intraductal papillary mucinous neoplasm: main duct, branch duct, and mixed. Five histologic types of intraductal papillary mucinous neoplasm are recognized: gastric foveolar type, intestinal type, pancreatobiliary type, intraductal oncocytic papillary neoplasm, and intraductal tubulopapillary neoplasm. Noninvasive intraductal papillary mucinous neoplasms are classified into 3 grades based on the degree of cytoarchitectural atypia: low-, intermediate-, and high-grade dysplasia. The most important prognosticator, however, is the presence or absence of an associated invasive carcinoma. Some main duct-intraductal papillary mucinous neoplasms progress into invasive carcinoma, mainly tubular adenocarcinoma (conventional pancreatic ductal adenocarcinoma) and colloid carcinoma. Branch duct-intraductal papillary mucinous neoplasms have a low risk for malignant transformation. Preoperative prediction of the malignant potential of an intraductal papillary mucinous neoplasm is of growing importance because pancreatic surgery has its complications, and many small intraductal papillary mucinous neoplasms, especially branch duct-intraductal papillary mucinous neoplasms, have an extremely low risk of progressing to an invasive cancer. Although most clinical decision making relies on imaging, a better understanding of the molecular genetics of intraductal papillary mucinous neoplasm could help identify molecular markers of high-risk lesions. When surgery is performed, intraoperative frozen section assessment of the pancreatic resection margin can guide the extent of resection. Intraductal papillary mucinous neoplasms are often multifocal, and surgically resected patients should be followed for metachronous disease.

Natural history of branch duct intraductal papillary mucinous neoplasms of the pancreas: a multicenter study in Japan

OBJECTIVE

The aim of this study was to evaluate the long-term follow-up results of patients with branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) without mural nodules (MNs) at 10 representative institutions in Japan.

METHODS

We analyzed 349 follow-up BD-IPMN patients who had no MNs on endoscopic ultrasonography at initial diagnosis.

RESULTS

Observation periods ranged from 1 to 16.3 years (median, 3.7 years). Sixty-two (17.8%) patients exhibited disease progression during follow-up. Twenty-two underwent surgery, leading to a pathological diagnosis of carcinoma in 9 and adenoma in 13. Although the remaining 287 (82.2%) showed no changes, 7 underwent surgery because of symptoms (n = 2), choice (n = 2), or development of pancreatic ductal adenocarcinoma (n = 3); all of them were diagnosed pathologically as adenomas. Of the 29 patients undergoing surgery, all 9 with carcinoma exhibited signs of progression, such as increased main pancreatic duct diameter and/or appearance of MNs. Pancreatic ductal adenocarcinomas and additional BD-IPMNs developed in 7 (2.0%) and 13 (3.7%), respectively. Overall, 320 (91.7%) patients were followed without surgery.

CONCLUSIONS

Most BD-IPMN patients who had no MNs on endoscopic ultrasonography could be managed without surgery. However, careful attention should be paid to disease progression and the development of pancreatic ductal adenocarcinomas during follow-up.

Cyst growth rate predicts malignancy in patients with branch duct intraductal papillary mucinous neoplasms

BACKGROUND & AIMS

Little information is available about the clinico-pathologic characteristics of pancreatic branch duct intraductal papillary mucinous neoplasm (Br-intraductal papillary mucinous neoplasm [IPMN]) because of difficulties in diagnosis based on radiologic and tissue information. We investigated the natural history of Br-IPMN using imaging and surgical pathology data from patients.

METHODS

Data were collected from patients admitted to a single tertiary referral institution from January 2000 to March 2009 (median follow up of 27.9 months); 201 patients were diagnosed with Br-IPMN with an initial cyst less than 30 mm without main pancreatic duct dilatation or mural nodules. The patients were followed for more than 3 months and examined by computed tomography (CT) at least twice.

RESULTS

The mean size of the patients' initial cysts was 14.7 mm; the mean cyst growth rate was 1.1 mm/year. Thirty-five patients received surgery during follow up and 8 were confirmed to have malignant cysts. The malignant cysts were greater in final size than nonmalignant cysts (24.3 mm vs 16.9 mm; P = .003); they also grew by a greater percentage (69.8% vs 19.4%; P = .046) and at a greater rate (4.1 mm vs 1.0 mm/year; P = .001). The actuarial 5-year risk of malignancy was 41.6% in the group that received surgery and 10.9% for all patients. Cysts that grew more than 2 mm/year had a higher risk of malignancy (5-year risk = 45.5% vs 1.8%; P < .001).

CONCLUSIONS

In combination with cyst size and the presence of mural nodules, cyst growth rate could be used to predict malignancy in patients with Br-IPMN.

Vascular patterns in nodules of intraductal papillary mucinous neoplasms depicted under contrast-enhanced ultrasonography are helpful for evaluating malignant potential

OBJECTIVES

The purpose of this study is to evaluate the feasibility of contrast-enhanced ultrasonography (CE-US) to differentiate between benign and malignant intraductal papillary mucinous neoplasms (IPMN).

PATIENTS AND METHODS

Contrast-enhanced ultrasonography with a contrast agent was performed on 22 consecutive patients with IPMN suspected of being malignant. This revealed 10 carcinomas, 1 borderline lesion and 11 adenomas. All patients underwent surgery, and the histological diagnosis was confirmed by examination of resected specimens. CE-US was performed using a contrast agent. The detection rates of mural nodules were compared between CE-US and contrast-enhanced computed tomography (CE-CT), and the imaging of mural nodules depicted under CE-US was analyzed.

RESULTS

Seventeen of 22 resected specimens (77.3%) had mural nodules. There was no significant difference in the detection rate between CE-US (n=15; 88.2%) and CE-CT (n=12; 70.6%). In 12 (80.0%) of these patients, CE-US revealed small vessels in the mural nodule. The spotty or linear-shaped pattern was detected in 4 patients and the branch-shaped pattern in 8. The branch-shaped pattern lesion was associated with carcinoma. These mural nodules were 10mm or more in height. In the perfusion image phase, cystic walls and mural nodules were also enhanced in all cases.

CONCLUSION

The vessel shapes of the mural nodules depicted under CE-US were associated with size and pathological findings. These results suggested that CE-US with a contrast agent is a powerful modality with which to evaluate the malignant potential of IPMN.

Familial pancreatic cancer in Italy. Risk assessment, screening programs and clinical approach: a position paper from the Italian Registry

In Italy, pancreatic cancer is the fifth leading cause of tumor related death with about 7000 new cases per year and a mortality rate of 95%. In a recent prospective epidemiological study on the Italian population, a family history was found in about 10% of patients suffering from a ductal adenocarcinoma of the pancreas (PDAC). A position paper from the Italian Registry for Familial Pancreatic Cancer was made to manage these high-risk individuals. Even though in the majority of high-risk individuals a genetic test to identify familial predisposition is not available, a screening protocol seems to be reasonable for subjects who have a >10-fold greater risk for the development of PDAC. However this kind of screening should be included in clinical trials, performed in centers with high expertise in pancreatic disease, using the least aggressive diagnostic modalities.

Malignant potential of intraductal papillary mucinous neoplasms of the pancreas

An intraductal papillary mucinous neoplasm (IPMN) is now a well-recognized disease entity. In general, the prognosis of IPMN is much more favorable than that of pancreatic ductal adenocarcinoma (PDAC). However, IPMN has a broad biological spectrum and it sometimes progresses, slowly showing neoplastic transformations. International consensus guidelines have been recently proposed for the management of IPMN. While they significantly contribute to appropriate management of IPMN, various issues including the natural history and malignant potential of IPMN are not fully elucidated. This review focuses on the malignant potential, including the postoperative recurrence of IPMN, coincidence of IPMN with PDAC, and extrapancreatic malignancy that may affect the long-term survival of the patients rather than IPMN itself.

Asymptomatic pancreatic cystic neoplasms: maximizing survival and quality of life using Markov-based clinical nomograms

BACKGROUND & AIMS

The natural history and management of pancreatic cysts, especially for branch duct intraductal papillary mucinous neoplasms (BD-IPMNs), remain uncertain. We developed evidence-based nomograms to assist with clinical decision making.

METHODS

We used decision analysis with Markov modeling to compare competing management strategies in a patient with a pancreatic head cyst radiographically suggestive of BD-IPMN, including the following: (1) initial pancreaticoduodenectomy (PD), (2) yearly noninvasive radiographic surveillance, (3) yearly invasive surveillance with endoscopic ultrasound, and (4) "do nothing." We derived probability estimates from a systematic literature review. The primary outcomes were overall and quality-adjusted survival. We depicted the results in a series of nomograms accounting for age, comorbidities, and cyst size.

RESULTS

Initial PD was the dominant strategy to maximize overall survival for any cyst greater than 2 cm, regardless of age or comorbidities. In contrast, surveillance was the dominant strategy for any lesion less than 1 cm. However, when measuring quality-adjusted survival, the do-nothing approach maximized quality of life for all cysts less than 3 cm in patients younger than age 75. Once age exceeded 85 years, noninvasive surveillance dominated. Initial PD did not maximize quality of life in any age group or cyst size.

CONCLUSIONS

Management of pancreatic cysts can be guided using novel Markov-based clinical nomograms, and depends on age, cyst size, comorbidities, and whether patients value overall survival vs quality-adjusted survival. For patients focused on overall survival, regardless of quality of life, surgery is optimal for lesions greater than 2 cm. For patients focused on quality-adjusted survival, a 3-cm threshold is more appropriate for surgery except for the extreme elderly.

Multidisciplinary approach to diagnosis and management of intraductal papillary mucinous neoplasms of the pancreas

Intraductal papillary mucinous neoplasms have gained recognition in recent years as premalignant precursors to pancreatic cancer that enable early detection and often are found incidentally at imaging. Accurate diagnosis and optimal, finely tuned management of these lesions are important and require collaboration across various disciplines, including radiology, endoscopy, surgery, and pathology. Several imaging modalities can visualize these lesions adequately, each with specific advantages and disadvantages. Multidetector computed tomography and magnetic resonance cholangiopancreatography are generally the first-line imaging modalities; endoscopic imaging such as endoscopic ultrasound and endoscopic retrograde cholangiopancreatography are beneficial when the former 2 modalities are equivocal. Surgical candidates generally include patients with main duct lesions or branch duct lesions greater than 3 cm or any possessing a solid component. A management algorithm indicating when surgery should be pursued is proposed. For nonsurgical and postsurgical patients, follow-up management is important to monitor growth and recurrence, and risks from repeated radiation exposure should be taken into account. Furthermore, issues of multifocality and increased predisposition of the pancreas to ductal adenocarcinoma must be addressed at follow-up evaluation. A follow-up management algorithm also is proposed in this review.

Management and outcomes of pancreatic cystic lesions

The management of pancreatic cystic lesions offers a challenge to clinicians. Mucinous cystic lesions pose a low risk of the development of neoplasia that must be taken into account in long-term management. Although the natural history has not been well defined, it is likely that malignant change in the mucinous epithelium takes place over years, very similar to what is observed with Barrett's esophagus. The traditional therapy of mucinous cystic lesions has been surgical resection. Lesions in the head of the pancreas will require a Whipple resection whereas tail lesions are managed with a distal pancreatectomy and splenectomy. In patients at high risk for surgical resection, the risk/benefit ratio may be excessively high, not supporting the use of resection therapy. Ethanol ablation therapy has been thoroughly studied in hepatic, renal, and thyroid cysts. Epithelial ablation with ethanol appears to be highly effective and relatively safe. Recently, ethanol ablation has been evaluated in pancreatic cystic neoplasms. In macrocystic lesions between 1 and 5 cm, ethanol lavage will result in epithelial ablation and cyst resolution in a high percentage of patients. Pancreatitis is rarely observed clinically and is not present in resection specimens. A randomised prospective clinical trial is currently underway.

Advances in pancreatitic intraductal papillary mucinous neoplasms

Intraductal papillary mucinous neoplasms (IPMNs) are a well-characterized group of intraductal mucin-producing cystic neoplasms of pancreas with clear malignant potential. It has a favorable prognosis and distinct molecular or clicinopathologic features compared with other types of pancreatic tumors. In addition, IPMNs can be divided into several subtypes in accordance with the papillary structure and mucin expression profile. Importantly, as IPMNs are acknowledged as key stages during pancreatic carcinogenesis, it can better reveal the mechanism and biological characteristics of IPMNs through further investigation of the pathologic features and the molecular aberrations harbored in different subtypes of IPMNs. This paper reviewed relevant literatures and elucidated its progression in terms of the molecular and clicinopathologic characteristics, diagnosis, treatment and prognosis of IPMNs.

Do consensus indications for resection in branch duct intraductal papillary mucinous neoplasm predict malignancy? A study of 147 patients

BACKGROUND AND AIMS

Recent consensus guidelines suggest that presence of > or =1 of the following is an indication for resection (IR) of branch duct intraductal papillary mucinous neoplasm (IPMN-Br): cyst-related symptoms, main pancreatic duct diameter > or =10 mm, cyst size > or =30 mm, intramural nodules, or cyst fluid cytology suspicious/positive for malignancy. Among a cohort of patients with IPMN-Br we determined if the consensus IR (CIR), presence of multifocal IPMN-Br, or growth of cyst size on follow-up predict malignancy.

METHODS

We identified 147 patients with IPMN-Br of whom 66 underwent surgical resection at diagnosis and 81 were followed conservatively, of whom 11 were resected during follow-up. Clinical, imaging, histological, and cyst fluid characteristics from all 147 patients with IPMN-Br were obtained from clinical records and/or by contacting the patients. In all cases, presence of CIR at baseline and during follow-up (N = 66), presence of multifocal cysts (N = 57), and increase in cyst size (N = 38) were noted.

RESULTS

Among the 77 resected IPMN-Brs, at initial evaluation 61 had at least one CIR and 16 had none. Malignancy was present in 9/61 (15%) with CIR and 0/16 without IR (P= 0.1). When presence of any one of the CIR was taken as an indicator of malignancy, the CIR had a sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 23%, 14%, and 100%, respectively. Prevalence of malignancy in those with single versus multifocal IPMN-Br was similar (13%vs 11%). No patient has developed malignancy after a median follow-up of 15 months. So far, none of the 38 patients with increase in cyst size on follow-up has developed malignancy related symptoms.

CONCLUSIONS

Suggested consensus indications for resection identify all patients with malignancy; however, their specificity is low. In the short term it would be safe to follow patients without these features.

Clinical importance of precursor lesions in the pancreas

Three distinct noninvasive precursor lesions to invasive ductal adenocarcinoma of the pancreas have been described. These include the mucinous cystic neoplasm, intraductal papillary mucinous neoplasm, and pancreatic intraepithelial neoplasia. The early detection and treatment of these lesions can interrupt the progression of a curable noninvasive precursor to an almost uniformly deadly invasive cancer.

New advances in pancreatic imaging

PURPOSE OF REVIEW

This review serves to highlight new technology and novel applications of existing techniques and their role in the management of pancreatic diseases, including acute and chronic pancreatitis, pancreatic cancer, and pancreatic cystic neoplasms.

RECENT FINDINGS

Contrast-enhanced ultrasound has shown promise in evaluating the severity of acute pancreatitis, staging pancreatic cancer, and predicting malignancy in cystic neoplasms. Optical coherence tomography within the pancreatic duct appears to be able to differentiate malignant and normal pancreatic ducts. Spectroscopy may prove useful in differentiating focal chronic pancreatitis from malignancy. Multidetector-row computed tomography may provide more accurate information regarding cancer respectability and differentiation between ductal type of intraductal papillary mucinous tumors.

SUMMARY

These new developments will help with the diagnosis and staging of pancreatic diseases.