Are the Sendai and Fukuoka consensus guidelines for cystic mucinous neoplasms of the pancreas useful in the initial triage of all suspected pancreatic cystic neoplasms? A single-institution experience with 317 surgically-treated patients

Can we predict the progression of premalignant pancreatic cystic tumors to ductal adenocarcinoma?

Pancreatic ductal adenocarcinoma (PDAC) is the most prevalent malignant pancreatic tumor. Few studies have shown how often PDACs arise from cystic precursor lesions. This special report aims to summarize the evidence on the progression of precancerous lesions to PDAC. A review of the literature found four studies that discussed pancreatic intraepithelial lesions (PanINs), three that discussed mucinous cystic neoplasms (MCN) and five that discussed intraductal papillary neoplasms (IPMNs). PanINs were the most common precursors lesion, with approximately 80% of PDACs originating from this lesion. The lack of evidence characterizing the features of PDAC precursor cystic lesions potentially leads to a subset of patients undergoing surgery unnecessarily. Advancements in molecular techniques could allow the study of cystic lesions at a genetic level, leading to more personalized management.

Intraductal Papillary Mucinous Neoplasms: Have IAP Consensus Guidelines Changed our Approach?: Results from a Multi-institutional Study

OBJECTIVE

To evaluate the influence of consensus guidelines on the management of intraductal papillary mucinous neoplasms (IPMN) and the subsequent changes in pathologic outcomes.

BACKGROUND

Over time, multiple guidelines have been developed to identify high-risk IPMN. We hypothesized that the development and implementation of guidelines should have increased the percentage of resected IPMN with high-risk disease.

METHODS

Memorial Sloan-Kettering (MSK), Johns Hopkins (JH), and Massachusetts General Hospital (MGH) databases were queried for resected IPMN (2000-2015). Patients were categorized into main-duct (MD-IPMN) versus branch-duct (BD-IPMN). Guideline-specific radiographic/endoscopic features were recorded. High-risk disease was defined as high-grade dysplasia/carcinoma. Fisher's exact test was used to detect differences between institutions. Logistic regression evaluated differences between time-points [preguidelines (pre-GL, before 2006), Sendai (SCG, 2006-2012), Fukuoka (FCG, after 2012)].

RESULTS

The study included 1210 patients. The percentage of BD-IPMN with ≥1 high-risk radiographic feature differed between centers (MSK 69%, JH 60%, MGH 45%; P < 0.001). In MD-IPMN cohort, the presence of radiographic features such as solid component and main pancreatic duct diameter ≥10 mm also differed (solid component: MSK 38%, JH 30%, MGH 18%; P < 0.001; duct ≥10 mm: MSK 49%, JH 32%, MGH 44%; P < 0.001). The percentage of high-risk disease on pathology, however, was similar between institutions (BD-IPMN: P = 0.36, MD-IPMN: P = 0.48). During the study period, the percentage of BD-IPMN resected with ≥1 high-risk feature increased (52% pre-GL vs 67% FCG; P = 0.005), whereas the percentage of high-risk disease decreased (pre-GL vs FCG: 30% vs 20%). For MD-IPMN, there was not a clear trend towards guideline adherence, and the rate of high-risk disease was similar over the time (pre-GL vs FCG: 69% vs 67%; P = 0.63).

CONCLUSION

Surgical management of IPMN based on radiographic criteria is variable between institutions, with similar percentages of high-risk disease. Over the 15-year study period, the rate of BD-IPMN resected with high-risk radiographic features increased; however, the rate of high-risk disease decreased. Better predictors are needed.

A nomogram for predicting pancreatic mucinous cystic neoplasm and serous cystic neoplasm

OBJECTIVES

To develop and validate a nomogram for the preoperative prediction of pancreatic serous cystic neoplasm (SCN) and mucinous cystic neoplasm (MCN) based on multidetector computed tomography (MDCT).

MATERIALS AND METHODS

In this retrospective study, the data of 227 patients with SCN and MCN were analyzed. Each patient underwent MDCT and surgical resection. A multivariable logistic regression model was developed using a training set consisting of 129 patients with SCN and 38 patients with MCN who were admitted between October 2012 and April 2019. The model was validated in 60 consecutive patients, 44 of whom had SCN and 16 of whom had MCN, admitted between May 2019 and April 2020. The regression model was adopted to establish a nomogram. Nomogram performance was determined by its discriminative ability and clinical utility.

RESULT

The multivariable logistic regression model included sex, size, location, shape, cyst characteristic, and cystic wall thickening. The individualized prediction nomogram showed good discrimination in the training sample (AUC 0.89; 95% CI 0.83-0.95) and in the validation sample (AUC 0.81; 95% CI 0.70-0.94). If the threshold probability is between 0.03 and 0.9, and > 0.93 in the prediction model, using the nomogram to predict SCN and MCN is more beneficial than the treat-all-patients as SCN scheme or the treat-all-patients as MCN scheme. The prediction model showed better discrimination than the radiologists' diagnosis (AUC = 0.68).

CONCLUSION

The nomogram could predict SCN and MCN preoperatively and may aid clinical decision-making.

Pancreatic cyst characterization: maximum axial diameter does not measure up

BACKGROUND

Unidimensional size is commonly used to risk stratify pancreatic cysts (PCs) despite inconsistent performance. The current study aimed to determine if unidimensional size, demonstrated by maximum axial diameter (MAD), is an appropriate surrogate measurement for volume and surface area.

METHODS

Patients with cross-sectional imaging of PCs from 2012 to 2013 were identified. Cyst MAD, volume, and surface area were measured using quantitative imaging software. Non-pseudocystic PCs >1 cm were selected for inclusion to assess MAD correlation with volume and surface area. Cysts imaged twice >1 year apart were selected to evaluate volumetric growth rate.

RESULTS

In total, 195 cysts were included. Overall, MAD was strongly correlated with volume (r = 0.83) and surface area (r = 0.93). However, cysts 1-2 cm and 2-3 cm were weakly correlated with volume and surface area: r = 0.78, 0.57 and 0.82, 0.61, respectively. Cyst volumes and surface areas varied widely within unidimensional size groups with 51% and 40% of volumes and surface areas overlapping unidimensional size groups, respectively. Estimated changes in volume poorly predicted measured changes in volume with 42% of cysts having >100% absolute percent difference.

CONCLUSIONS

Pancreatic cyst volume and surface area may be useful adjunct measurements to risk stratify patients and surveil cyst changes and deserves further study.

Changing trends in the clinicopathological features, practices and outcomes in the surgical management for cystic lesions of the pancreas and impact of the international guidelines: Single institution experience with 462 cases between 1995-2018

INTRODUCTION

The impact on clinical practice of the international guidelines including the Sendai Guidelines (SG06) and Fukuoka Guidelines (FG12) on the management of cystic lesions of the pancreas (CLP) has not been well-studied. The primary aim was to examine the changing trends and outcomes in the surgical management of CLP in our institution over time and to determine the impact of these guidelines on our institution practice.

METHODS

462 patients with surgically-treated CLP were retrospectively reviewed and classified under the 2 guidelines. The cohort was divided into 3 time periods: 1998-2006, 2007-2012 and 2013 to 2018.

RESULTS

Comparison across the 3 time periods demonstrated significantly increasing frequency of older patients, asymptomatic CLP, male gender, smaller tumor size, elevated Ca 19-9, use of magnetic resonance imaging (MRI) and use of endoscopic ultrasound (EUS) prior to surgery. There was also significantly increasing frequency of adherence to the international guidelines as evidenced by the increasing proportion of HR^SG06 and HR^FG12 CLP with a corresponding lower proportion of LR^SG06 and LR^FG12 being resected. This resulted in a significantly higher proportion of resected CLP whereby the final pathology confirmed that a surgery was actually indicated.

CONCLUSIONS

Over time, there was increasing adherence to the international guidelines for the selection of patients for surgical resection as evidenced by the significantly increasing proportion of HR^SG06 and HR^FG06 CLPs undergoing surgery. This was associated with a significantly higher proportion of patients with a definitive indication for surgery. These suggested that over time, there was a continuous improvement in our selection of appropriate CLP for surgical treatment.

Significance of Uncinate Duct Dilatation in IPMNs: A New High-risk Criterion?

OBJECTIVE

To evaluate the significance of UDD in IPMNs.

BACKGROUND

The uncinate process of the pancreas has an independent ductal drainage system. International consensus guidelines of IPMNs still consider it as a branch-duct, even though it is the main drainage system for the uncinate process.

METHODS

A retrospective review of all surgically treated IPMNs at our institution after 2008 was performed. Preoperative radiological studies were reviewed by an abdominal radiologist who was blinded to the pathological results. In addition to the Fukuoka criteria, presence of UDD was recorded. Using multivariate analysis, the pathological significance of UDD in predicting advanced neoplasia [high grade dysplasia or invasive carcinoma (HGD/IC)] was determined.

RESULTS

Two hundred sixty patients were identified (mean age at diagnosis was 68 years and 49% were females): 122 (47%) had HGD/IC. UDD was noted in 59 (23%), of which 36 (61%) had HGD/IC (P < 0.003). On multivariate analysis, UDD was an independent predictor of HGD/IC (odds ratio = 2.99, P < 0.04). Subgroup analysis on patients with IPMNs confined to the dorsal portion of the gland (n = 161), also demonstrated UDD to be a significant predictor of HGD/IC in those remote lesions (odds ratio: 4.41, P = 0.039).

CONCLUSIONS

This is the largest study to evaluate the significance of UDD in IPMNs and shows it to be a high-risk feature. This association persisted for remote IPMNs limited to the dorsal pancreas, suggesting UDD may be associated with an aggressive phenotype even in remote IPMN lesions.

Clinical implication of serum CA125 for the prediction of malignancy in mucinous cystic neoplasms of the pancreas

Mucinous cystic neoplasms (MCNs) of the pancreas have malignant potential. Carbohydrate antigen 125 (CA125) is a common widely used biomarker for cancers. However, the role of CA125 in predicting the malignant change of MCNs is currently unidentified. Patients with resected and pathologically confirmed MCN were identified from a prospectively maintained database. The predictive role of serum CA125 in assessing malignant change of MCNs was analyzed and compared with serum carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA). This study included 164 patients with MCN (low/moderate grade, 153 cases; high grade and invasive, 11 cases). The serum levels of CA125 in the high grade and invasive group (45.1±42.1 U/ml) was significantly higher than those in the low/moderate grade group (21.0±46.2 U/ml, P=0.006). The area under the receiver operating characteristic (ROC) curve of CA125 (0.75) for predicting malignancy of MCNs was higher than that of CA19-9 (0.68) or CEA (0.72). The prediction value of CA125 was improved when combined with CEA (CA125 alone, sensitivity 36.4%, specificity 90.6%, accuracy 86.6%; combined with CEA, sensitivity 45.5%, specificity 88.2%, accuracy 85.0%). It was concluded that serum CA125 shows value in predicting the malignant change of MCNs, especially when combined with serum CEA.

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.

Validation of the clinical utility of 4 guidelines in the initial triage of mucinous cystic lesions of the pancreas based on cross-sectional imaging: Experience with 188 surgically-treated patients

INTRODUCTION

Over the years, several guidelines have been introduced to guide management of mucinous pancreatic cystic neoplasms (mPCN). In this study, we aimed to evaluate and compare the clinically utility of the Sendai-06, Fukuoka-12, Fukuoka-17 and European-18 guidelines in predicting malignancy of mPCN.

METHODS

One hundred and eighty-eight patients with mucinous cystic neoplasms (MCN) or intraductal papillary mucinous neoplasm (IPMN) who underwent surgery were retrospectively reviewed and classified under the 4 guidelines. Malignancy was defined as high grade dysplasia and invasive carcinoma.

RESULTS

Raised CA19-9>37U/ml, enhancing mural nodule≥5 mm and main pancreatic duct≥10 mm were significantly associated with malignancy on multivariate analysis. Increasing number of high risk features, absolute indications (European-18), worrisome risk or relative indications (European-18) were significantly associated with an increased likelihood of malignancy. The positive predictive values (PPV) of high risk features for Sendai-06, Fukuoka-12, Fukuoka-17 and absolute indications (European-18) for malignancy were 53%, 76%, 78% and 78% respectively. The negative predictive values (NPV) of the Sendai-06, Fukuoka-12 and Fukuoka-17 were 100%, while that of the European-18 was 92%. Risk of malignancy for patients with ≥4 worrisome features (Fukuoka-17) and ≥3 relative indications (European-18) was 66.7% and 75.0% respectively.

CONCLUSIONS

All 4 guidelines studied were useful in the initial triage of mPCN for the risk stratification of malignancy. The Fukuoka-17 had the highest PPV and NPV.

Branch Duct Intraductal Papillary Mucinous Neoplasms: Recommendations for Follow-Up and Surgery

BACKGROUND AND AIMS

Pancreatic cysts are increasingly diagnosed, mainly during abdominal imaging performed for other reasons. Between pancreatic cystic neoplasm, intraductal papillary mucinous neoplasms are the most common pre-malignant entities. Intraductal papillary mucinous neoplasms involving side branches overall harbor a low risk of malignancy, and in the recent past, a progressively more conservative approach has been consolidated. Purpose of this report is to summarize the evidence supporting the current practice for the management of branch duct intraductal papillary mucinous neoplasm and to offer a useful practical guide from first observation to post-operative follow-up.

MATERIALS AND METHODS

Review of the most important scientific literature on intraductal papillary mucinous neoplasms was made. In this review article, we also report the experience of a high volume center in managing Pancreatic cystic neoplasms.

RESULTS

The correct management during surveillance still is a matter of debate, since many guidelines have been published suggesting different clinical approaches. Recently, follow-up discontinuation has also been proposed in selected cases.

CONCLUSION

Despite significant improvements made by the increase of evidence, selecting surgical candidates because of an increased risk of malignant progression remains an unsolved issue and a hot topic for pancreatologists.

Clinical and radiological features that predict malignant transformation in cystic lesions of the pancreas: a retrospective case note review

Background: Pancreatic cystic lesions (PCL) are being detected with increasing frequency. Current methods of stratifying risk of malignant transformation are imperfect. This study aimed to determine the frequency of pancreatic malignancy in patients with PCL and define clinical and radiological features that predict malignant transformation in patients managed by surgery and/or surveillance.

Methods: A retrospective cohort of adults who were evaluated in a tertiary hepatopancreaticobiliary centre between January 2000 - December 2013 with a confirmed PCL and followed up for at least 5 years. All cystic lesions were discussed at a weekly multidisciplinary meeting.

Results: Of the 1,090 patients diagnosed with a PCL, 768 patients were included in the study: 141 patients were referred for immediate pancreatic resection, 570 entered surveillance while 57 had a malignant PCL which was unresectable at diagnosis (n=47) or were unfit for surgery (n=10). In those who were resected following presentation, malignancy was present in 38%. During follow-up 2% of those entering a surveillance programme underwent malignant transformation. Clinical and radiological features associated with a high-risk PCL included older age, symptoms, associated solid component or dilated main pancreatic duct. In intraductal papillary mucinous neoplasms, larger size was not a feature of malignant transformation (benign vs. malignant 30mm vs. 23mm; P= 0.012).

Conclusion: The sensitivity of standard diagnostic tests leading to immediate surgery for high-risk PCL (malignant or mucinous) was 92% but with a specificity of just 5%. Surveillance of PCL without high-risk features within a multidisciplinary meeting was associated with a low incidence of cancer development, supporting the use of worrisome clinical and radiological features in the initial stratification of PCL.

Differential diagnosis of pancreatic serous cystadenoma and mucinous cystadenoma: utility of textural features in combination with morphological characteristics

Background

Texture analysis of medical images has been reported to be a reliable method for differential diagnosis of neoplasms. This study was to investigate the performance of textural features and the combined performance of textural features and morphological characteristics in the differential diagnosis of pancreatic serous and mucinous cystadenomas.

Methods

We retrospectively reviewed 59 patients with pancreatic serous cystadenoma and 32 patients with pancreatic mucinous cystadenoma at our hospital. A three-dimensional region of interest (ROI) around the margin of the lesion was drawn manually in the CT images of each patient, and textural parameters were retrieved from the ROI. Textural features were extracted using the LifeX software. The least absolute shrinkage and selection operator (LASSO) method was applied to select the textural features. The differential diagnostic capabilities of morphological features, textural features, and their combination were evaluated using receiver operating characteristic (ROC) analysis, and the area under the receiver operating characteristic curve (AUC) was used as the main indicator. The diagnostic accuracy based on the AUC value is defined as follows: 0.9–1.0, excellent; 0.8–0.9, good; 0.7–0.8, moderate; 0.6–0.7, fair; 0.5–0.6, poor.

Results

In the differential diagnosis of pancreatic serous and mucinous cystadenomas, the combination of morphological characteristics and textural features (AUC 0.893, 95% CI 0.816–0.970) is better than morphological characteristics (AUC 0.783, 95% CI 0.665–0.900) or textural features (AUC 0.777, 95% CI 0.673–0.880) alone.

Conclusions

In conclusion, our preliminary results highlighted the potential of CT texture analysis in discriminating pancreatic serous cystadenoma from mucinous cystadenoma. Furthermore, the combination of morphological characteristics and textural features can significantly improve the diagnostic performance, which may provide a reliable method for selecting patients with surgical intervention indications in consideration of the different treatment principles of the two diseases.

Pancreatic Cysts in the Elderly

PURPOSE OF REVIEW

Incidental pancreatic cysts are common, and management strategies continue to evolve. This review summarizes diagnostic and management recommendations in older patients with these lesions based on guidelines and best clinical evidence.

RECENT FINDINGS

Diagnosis of cyst type has been enhanced with improved imaging and cyst fluid analysis and visualization. Recent outcome studies indicate that certain cyst types should be followed independent of patient age as long as certain criteria which are reviewed are met. Differentiation of pancreatic cyst type is important as this dictates the need for long-term follow-up. Because most cyst-related neoplasia occurs in older patients, surveillance should continue within certain guidelines.

Elevating pancreatic cystic lesion stratification: Current and future pancreatic cancer biomarker(s)

Pancreatic ductal adenocarcinoma (PDAC) is an incredibly deadly disease with a 5-year survival rate of 9%. The presence of pancreatic cystic lesions (PCLs) confers an increased likelihood of future pancreatic cancer in patients placing them in a high-risk category. Discerning concurrent malignancy and risk of future PCL progression to cancer must be carefully and accurately determined to improve survival outcomes and avoid unnecessary morbidity of pancreatic resection. Unfortunately, current image-based guidelines are inadequate to distinguish benign from malignant lesions. There continues to be a need for accurate molecular and imaging biomarker(s) capable of identifying malignant PCLs and predicting the malignant potential of PCLs to enable risk stratification and effective intervention management. This review provides an update on the current status of biomarkers from pancreatic cystic fluid, pancreatic juice, and seromic molecular analyses and discusses the potential of radiomics for differentiating PCLs harboring cancer from those that do not.

Clinical criteria for integrated molecular pathology in intraductal papillary mucinous neoplasm: less is more

BACKGROUND

For pancreatic cysts with negative cytology, Integrated Molecular Pathology (IMP) is a malignancy risk score integrating clinical criteria with pancreatic cyst fluid DNA profiling. Aside from main pancreatic duct (MPD) diameter, integrated clinical criteria are not International Consensus Guidelines High-Risk Stigmata. We predicted exclusion of clinical criteria except MPD diameter could simplify the IMP and better distinguish invasive/malignant disease.

METHODS

Records of >1100 patients with IPMN were reviewed retrospectively. Sensitivity, specificity, and accuracy of conventional IMP for invasive/malignant disease was compared to DNA profile including only MPD ≥10mm (IMP-10.) Invasive outcomes were invasive-IPMN/adenocarcinoma on surgical pathology, pathologic or radiographic evidence of invasive/metastatic disease during surveillance. Malignant outcomes included high grade dysplastic IPMN (HGD-IPMN).

RESULTS

225 patients who met study criteria underwent 283 IMP evaluations: 98 followed by surgery, 185 followed by ≥ 23 months surveillance. IMP-10 had greater specificity (90.1% vs. 73.7%) and accuracy (89.8% vs. 74.2%) for invasive disease compared to IMP in surgery + surveillance patients, but lower sensitivity (77.8% vs. 88.9%). Trends were similar in surgery patients alone and malignant outcome analyses.

CONCLUSION

IMP-10 excludes less-reliable clinical factors resulting in greater accuracy in predicting invasive/malignant disease and fewer patients with benign disease being recommended for surgery.

Surveillance of Cystic Lesions of the Pancreas: Whom and How to Survey?

The sudden prevalence increase of pancreatic cystic neoplasms (PCN) related to the use of cross-sectional imaging has raised several concerns. Even if there is a tangible risk of progression towards pancreatic cancer (PC), surgical resection cannot be offered to all patients due to the high risk of morbidity and mortality. Available guidelines are useful tools to identify patients at higher risk for harboring cancer thanks to their sensitivity. Because of their low specificity, however, such a risk is often overestimated. Recent evidence deriving from large observational series of surveilled patients suggests that the overall risk of PC is low. A large proportion of patients affected by PCN can be safely observed over time. Several follow-up schedules have been proposed in guidelines but none of them proved to be the most cost-effective. Moreover, it must still be demonstrated that any surveillance protocol can be associated with a reduction in PC-related mortality. By now, with most studies reporting a lifelong risk of malignancy, the only evidence-based recommendation regarding surveillance is that follow-up should never be discontinued as repeated observations are crucial for PC risk stratification.

The 2012 International Consensus Guidelines of Intraductal Papillary Mucinous Neoplasms of the Pancreas (Fukuoka Criteria) Predict the Malignant Potential, Even in Actual Clinical Situations

OBJECTIVES

The aim of the present study was to validate the use of the 2012 International Consensus Guidelines for intraductal papillary mucinous neoplasm (IPMN) (Fukuoka criteria) in patients without findings of obstructive jaundice and/or an enhanced solid component.

METHODS

This retrospective study included patients who underwent pancreatectomy for IPMN between October 2002 and September 2016. The sensitivity, specificity, and positive and negative predictive values for malignancy were calculated for each feature of high-risk stigmata.

RESULTS

Of the 135 patients who underwent surgery for IPMN, 50 (37.0%) had low/intermediate-grade dysplasia, 25 (18.5%) had high-grade dysplasia, and the remaining 60 (44.5%) had invasive carcinoma. A malignant potential was, thus, present in 63% of all resected cases. Considering an actual clinical situation, the predictors for malignant potential were assessed in 62 patients without findings of obstructive jaundice and/or an enhanced solid component. A multivariate analysis revealed that the Fukuoka criteria were the only independent factor for predicting the malignant potential (odds ratio, 5.69; P = 0.036).

CONCLUSIONS

The present study suggested that malignant potential can be accurately detected by faithfully keeping to the Fukuoka criteria. Using these criteria enables us to identify patients with malignant potential, even in the actual clinical situations.

Vanishing Pancreatic Cysts during Follow-Up: Another Step Towards De-Emphasizing Cyst Size as a Major Clinical Predictor of Malignancy

INTRODUCTION

In the management of pancreatic cystic neoplasms (PCN), size plays a crucial role as the expression of disease progression. While many evidences regarding the natural history of growing pancreatic cysts exist, almost no data are available regarding cysts with a reduction in size.

METHODS

Radiological and clinical data from patients of the dedicated pancreatic cysts outpatient clinic of the Department of General and Pancreatic Surgery, University of Verona Hospital were retrospectively reviewed. Patients diagnosed with PCNs reducing in size during follow-up were reviewed.

RESULTS

From a total of 3,146 patients, we identified 12 (0.38%) vanishing/reducing cysts without a history of pancreatitis. Most of them were presumed IPMN (66.6%). The median follow-up was 69 months and the median cyst's size 30 mm (range 10-49). Most of the patients (75%) experienced a reduction in cyst size (median reduction of 8 mm, range 6-22) after a median time of 12 months (range 6-63), 3 patients experienced a complete disappearance of the cyst.

CONCLUSION

Cyst size reduction during follow-up is a rare phenomenon of unknown explanation. It adds to the debate regarding the role of size as a clinical predictor whenever a definite diagnosis of a PCN cannot be reached.

Intraductal Papillary Mucinous Neoplasms of the Pancreas: Strategic Considerations

Intraductal papillary mucinous neoplasms (IPMN) are cystic neoplasms with the potential for progression to pancreatic cancer. Recognized by the global medical community just over two decades ago, IPMN have gained great epidemiological and clinical relevance thanks to the widespread use of cross-sectional abdominal imaging, which has led to a surge in the number of incidental pancreatic cysts being diagnosed. As our understanding of this disease has improved, we now know that some IPMN have a very elevated risk of cancer and require surgical resection, while others are low-risk lesions and can be followed. The approach to IPMN must therefore strike a balance between preventing the over-utilization of surgery and the timely recognition and treatment of patients with high-risk lesions. Several clinical, radiographic, and laboratory parameters have been proposed to risk-stratify IPMN, leading to the publication of management guidelines that do not always converge in their recommendations. The goal of this clinical therapeutic review is to describe the strategic approach to IPMN at the Massachusetts General Hospital, and how our current understanding, management algorithm, and future directions have been informed by research efforts at our institution and other centers.

My Treatment Approach: Pancreatic Cysts

Our treatment approach for either symptomatic or incidentally found pancreatic cysts continues to improve. The true incidence of pancreatic cysts is not known, and pancreatic cystic neoplasms, especially intraductal papillary mucinous neoplasms, are currently most commonly diagnosed and resected. This is a result of increasing awareness, widespread availability of imaging, and better understanding of the nature of pancreatic cysts as well. Recent studies on molecular analysis and devices such as microbiopsy forceps help us better define and select the treatment approach to alleviate symptoms and to prevent malignant tumors while avoiding unnecessary surgery.

Advantage of endoscopic-ultrasound-fine-needle aspiration associated to Sendai clinical guidelines in detecting the malignant risk in patients with undetermined pancreatic cysts: Long-term follow-up

Aims: Contradictory information exists on whether different clinical guidelines are effective in detecting the malignant risk in patients with pancreatic cysts. We have retrospectively evaluated the accuracy and the long-term outcome in patients with pancreatic cysts with a diameter ≥ 2 cm when indication for surgery was established by clinical evaluation of their malignant risk according to Sendai Clinical Guidelines associated to endoscopic-ultrasound-fine-needle aspiration. Material and Methods: Patients with pancreatic cysts with a diameter ≥2 cm were evaluated for their potential malignant risk by endoscopic-ultrasound-fine-needle aspiration associated to the clinical evaluation by Sendai Clinical Guidelines. Long-term outcome and comparison in patients survival as well as the accuracy in detecting malignancies were evaluated with the combined clinical and endoscopic evaluation. Results: Two hundred eighteen patients with pancreatic cysts were observed during a nine-year period of the study and 74 of them (33.9%) presenting with a pancreatic cyst ≥2 cm were eligible for the study. Fourteen malignant neoplasms (18.9%) were detected. The accuracy in detecting malignancy of combined clinical and endoscopic evaluation was very high (0.99). The five-year survival rates for patients who underwent surgery with benign and malignant pancreatic cysts and for patients in observational follow-up were similar (70% and 85%). The cohort of patients with malignant pancreatic cysts with ductal adenocarcinoma showed a five-year survival rate of 41%. Conclusion: Endoscopic ultrasound fine-needle aspiration associated to Sendai clinical guidelines showed a high accuracy in detecting malignant risk in patients with pancreatic cysts with a diameter ≥ 2 cm. allowing appropriate selection for surgical treatment with satisfactory long-term survival.

Novel Biomarkers for Pancreatic Cysts

With increased utilization and ongoing advancements in cross-sectional abdominal imaging, the identification of a pancreatic cyst has become a frequent finding. While many pancreatic cysts are associated with a benign clinical course, others may transform into pancreatic ductal adenocarcinoma. However, distinguishing a benign from a malignant pancreatic cyst or pancreatic cyst with malignant potential on the basis of standard clinical findings, imaging parameters and ancillary studies can be challenging. Hence, a significant interest within the past decade has been the identification of novel biomarkers to accurately classify and prognosticate a pancreatic cyst. Within this review, we discuss novel DNA, miRNA, protein and metabolite biomarkers, and their relevance in clinical practice. In addition, we focus on future areas of research that have the potential to change pancreatic cyst management.

Pancreatic Cysts and Guidelines

Pancreatic cysts, especially incidental asymptomatic ones seen on noninvasive imaging such as CT or MR imaging, remain a clinical challenge. The etiology of such cysts may range from benign cysts without any malignant potential such as pancreatic pseudocysts and serous cystadenomas to premalignant or frankly malignant cysts such as mucinous cystic neoplasms, intraductal papillary mucinous neoplasms, cystic degeneration associated with solid tumors such as pancreatic ductal adenocarcinoma or pancreatic endocrine neoplasms, and solid pseudopapillary neoplasms. The clinical challenge in 2017 is to accurately preoperatively diagnose them and their malignant potential before deciding about surgery, surveillance or doing nothing. This review will focus on the currently available clinical guidelines for doing so.

Evaluation of the 2015 AGA guidelines on pancreatic cystic neoplasms in a large surgically confirmed multicenter cohort

Background and study aims The American Gastroenterological Association (AGA) recently published guidelines for the management of asymptomatic pancreatic cystic neoplasms (PCNs). We aimed to evaluate the diagnostic characteristics of the AGA guidelines in appropriately recommending surgery for malignant PCNs. Patients and methods A retrospective multicenter study was performed of patients who underwent endoscopic ultrasound (EUS) for evaluation of PCNs who ultimately underwent surgical resection from 2004 - 2014. Demographics, EUS characteristics, fine-needle aspiration (FNA) results, type of resection, and final pathologic diagnosis were recorded. Patients were categorized into 2 groups (surgery or surveillance) based on what the AGA guidelines would have recommended. Performance characteristics for the diagnosis of cancer or high-grade dysplasia (HGD) on surgical pathology were calculated. Results Three hundred patients underwent surgical resection for PCNs, of whom the AGA guidelines would have recommended surgery in 121 (40.3 %) and surveillance in 179 (59.7 %) patients. Among patients recommended for surgery, 45 (37.2 %) had cancer, whereas 76 (62.8 %) had no cancer/HGD. Among patients recommended for surveillance, 170 (95.0 %) had no cancer/HGD; however, 9 (5.0 %) patients had cancer that would have been missed. For the finding of cancer/HGD on surgical pathology, the AGA guidelines had 83.3 % sensitivity (95 % CI 70.7 - 92.1), 69.1 % specificity (95 % CI 62.9 - 74.8), 37.2 % positive predictive value (95 % CI 28.6 - 46.4), 95.0 % negative predictive value (95 % CI 90.7 - 97.7), and 71.7 % accuracy (95 % CI 67.4 - 74.6). Conclusions The 2015 AGA guidelines would have resulted in 60 % fewer patients being referred for surgical resection, and accurately recommended surveillance in 95 % of patients with asymptomatic PCNs. Future prospective studies are required to validate these guidelines. Meeting presentations: Presented in part at Digestive Diseases Week 2016.

DNA testing of pancreatic cyst fluid: is it ready for prime time?

Pancreatic cysts are a clinical quandary in both diagnosis and management. Although many cysts, such as pseudocysts and serous cystadenomas, are benign and can be monitored clinically, mucinous cysts, such as intraductal papillary mucinous neoplasms and mucinous cystic neoplasms, have the potential to progress to pancreatic cancer. Considering the poor prognosis of pancreatic cancer, the detection of a pancreatic cyst can be a source of anxiety for both the patient and physician. This diagnosis in turn can lead to expensive, invasive, and even harmful surveillance and treatment options. As a consequence, several national and international guidelines for the management of pancreatic cysts have been developed over the past decade. However, these guidelines rely on standard clinical assessment, radiographical imaging, and ancillary fluid studies that have insufficient sensitivity and specificity. The application of DNA-based molecular techniques has emerged as an adjunct to the assessment of pancreatic cysts. The cellular content of pancreatic cyst fluid aspirate is often suboptimal for analysis, but DNA isolated from lysed or exfoliated cells within the cyst can be analysed for genetic abnormalities. Moreover, whole exome sequencing and targeted sequencing of the major pancreatic cysts has identified unique mutational profiles for cyst type and genetic alterations that coincide with the development of pancreatic cancer. In this Review, we discuss the major cystic lesions of the pancreas and their underlying molecular pathology, current management guidelines for pancreatic cysts, and integration of DNA-based molecular testing within this field.

Preoperative characteristics and cytological features of 136 histologically confirmed pancreatic mucinous cystic neoplasms

BACKGROUND

Mucinous cystic neoplasms (MCNs) of the pancreas present a management conundrum. The majority are benign but all are resected due to their malignant potential. Recent studies have recommended nonsurgical management. In the current study, the authors analyzed the preoperative imaging, cytology, and cyst fluid characteristics of 136 histologically confirmed MCNs to assess predictors of a high-risk (HR) cyst for surgical triage.

METHODS

MCNs resected at the Massachusetts General Hospital between 1990 and 2014 formed the study cohort. Patient demographics, cyst size, and mural nodules (MNs) by endoscopic ultrasound, cytology, and cyst fluid carcinoembryonic antigen and amylase levels were correlated with histological grade. A HR cyst was defined as high-grade dysplasia or invasive carcinoma on histology. Performance characteristics were assessed for each parameter, with a cyst size ≥3 cm or a MN on imaging and malignant cytology considered to be "true-positive" results for predicting malignancy.

RESULTS

Only 15 of the 136 cysts had HR histology (11%). On average, patients with HR cysts were older than those with low-risk cysts (55 years vs 49 years, respectively). High-grade cytology was the most accurate predictor of malignancy (95%) followed by MN and cyst size together (88%) and MN alone (83%). The average carcinoembryonic antigen level (in ng/mL) increased with the grade of dysplasia but the ranges overlapped between low risk and HR cysts.

CONCLUSIONS

To the authors' knowledge, the current study is the largest series to date analyzing the cytological features of histologically confirmed MCN. Cytology is insensitive but very specific for detecting a HR MCN and outperformed imaging for the detection of HR MCN. Endoscopic ultrasound-guided fine-needle aspiration and cytology should be performed on any clinically suspected MCN that is being considered for conservative management. Cancer Cytopathol 2017;125:169-177. © 2016 American Cancer Society.

Enucleation: A treatment alternative for branch duct intraductal papillary mucinous neoplasms

BACKGROUND

Small, asymptomatic, branch-duct intraductal papillary mucinous neoplasms of the pancreas are often kept under surveillance despite their malignant potential. The management of branch-duct intraductal papillary mucinous neoplasm is controversial with regard to indications and extent of any operative intervention. The present study aimed to evaluate enucleation as an alternative operative approach for branch-duct intraductal papillary mucinous neoplasms to exclude and prevent malignancy.

METHODS

For branch-duct intraductal papillary mucinous neoplasms of <30 mm in diameter and an acceptable distance from the main pancreatic duct, enucleation was considered as the operative approach of choice. All patients scheduled for enucleation of branch-duct intraductal papillary mucinous neoplasm on the basis of these features between January 2004 and September 2014 were analyzed. Among these, patients with successful enucleation were compared with those who were scheduled for enucleation but converted intraoperatively to pancreatic resection (intention-to-treat analysis). End points were hospital morbidity and mortality as well as histopathology and functional outcome at a mean follow-up of 32 months.

RESULTS

In the study, 115 patients with presumed branch-duct intraductal papillary mucinous neoplasm and the intention to perform pancreatic enucleation were included; 87 enucleations were performed in 74 patients. In 41 patients, enucleation was converted to a pancreatic resection (procedure-specific success rate 64%); indications for conversion included location or size (46%), presence of multicystic lesions (39%), or involvement of the main pancreatic duct (15%). Of the 74 patients with enucleation, 64 branch-duct intraductal papillary mucinous neoplasms revealed low- (85%), 11% moderate dysplasia-, and 4% high-grade dysplasia on histology. Among converted resections, 6 intraductal papillary mucinous neoplasms revealed high-grade dysplasia or invasive carcinoma (15%). Intention-to-treat analysis with patients converted to pancreatic resection showed that enucleations resulted in less blood loss (100 vs 400 mL) and a shorter operation time (146 vs 255 minutes; P < .001 each). Postoperative morbidity including postoperative pancreatic fistula was similar in both groups. No mortality occurred after enucleation; after formal resection, 1 patient died due to multiorgan failure. Both hospital stay (10 vs 14 days) and rates of postoperative endocrine and exocrine dysfunction rates were less after enucleation (P < .02 each). Intraductal papillary mucinous neoplasm-specific recurrence rates (3% vs 6%) were similar in both groups.

CONCLUSION

Enucleation is a safe procedure that can be performed successfully in a high proportion of branch-duct intraductal papillary mucinous neoplasms and should be considered instead of standard resections as an important function-preserving alternative. Limitations may occur due to malignancy, size, localization, multilocularity, or main-duct involvement requiring conversion to a formal, anatomic resection. Beside the advantages in the short-term course, functional outcome seems to be superior after enucleation, and intraductal papillary mucinous neoplasm-specific recurrence rates are not increased compared with standard resections, at least at a mean follow-up of 32 months.

Outcome of long interval radiological surveillance of side branch pancreatic duct-involved intraductal papillary mucinous neoplasm in selected patients

INTRODUCTION

Side branch IPMN (SB-IPMN) of the pancreas has a malignancy rate between 10 and 20%. We hypothesized that surveillance at longer intervals on selected patients with SB-IPMN might be indicated.

METHODS

This is a retrospective study of prospectively collected data of 276 patients presenting from 2000 to 2010. After 2007, we opted to screen our patients with longer intervals, initially at 12 months then 24 months using MR if no "worrisome features" were present.

RESULTS

Complete data sets for 261 patients were analysed and patients were aged 78 (40-91) years. 232 patients had sole SB-IPMN while 92% were incidental (n = 209) and 8% were symptomatic (n = 24). Single SB-IPMN accounted for 84% (n = 195) of all cases; maximum diameter of 15.5 (5-60) mm. The median follow up duration was 46 (32-53) months. Short interval radiological surveillance (3-9 months) was 39% (n = 90), while long interval surveillance (12-36 months) was performed in 61% (n = 142). The rate of pancreatic resection, due to concern for the development of pancreatic cancer, in the short and long interval surveillance groups was 4.4% (n = 4) and 3.5% (n = 5) respectively; p = 0.78.

CONCLUSION

Our data suggests no difference in outcome between long and short interval MR surveillance of SB-IPMN patients.

Utility of the 2006 Sendai and 2012 Fukuoka guidelines for the management of intraductal papillary mucinous neoplasm of the pancreas: A single-center experience with 138 surgically treated patients

This study aimed to evaluate the utility of the 2006 Sendai and 2012 Fukuoka guidelines for differentiating malignant intraductal papillary mucinous neoplasm (IPMN) of the pancreas from benign IPMN.Between January 2000 and March 2015, a total of 138 patients underwent surgery and had a pathologically confirmed pancreatic IPMN. Clinicopathological parameters were reviewed, and all patients were classified according to both the 2006 Sendai and 2012 Fukuoka guidelines. Univariate and multivariate analyses were used for identifying significant factors associated with malignancy in IPMN.There were 9 high-grade dysplasia (HGD) and 37 invasive cancers (ICs) in the 138 patients. The positive predictive value (PPV) and negative predictive value (NPV) of the Sendai and Fukuoka guidelines for HGD/IC was 35.1%, 43.3%, 100%, and 85.4%, respectively. Of the 36 patients with worrisome features using the Fukuoka guideline, 7 patients had HGD/IC in their IPMNs. According to the multivariate analysis, jaundice, tumors of ≥3 cm, presence of mural nodule on imaging, and aged <65 years were associated with HGD/IC in patients with IPMN.The Sendai guideline had a better NPV, but the Fukuoka guideline had a better PPV. We suggest that patients with worrisome features based on the Fukuoka guideline be aggressively managed.

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.

Imaging comparison of tubular and colloid pancreatic adenocarcinoma arising from intraductal papillary mucinous neoplasm on multidetector CT

PURPOSE

This study aims to compare tubular pancreatic ductal adenocarcinoma (tPDAC) and colloid subtype pancreatic ductal adenocarcinoma (cPDAC) associated with intraductal papillary mucinous neoplasms (IPMNs) on computed tomography.

METHODS

An institutional review board-approved retrospective study included patients with either IPMN tPDAC or cPDAC. Enhancing mural nodules (MN), solid component (SC), main pancreatic duct (MPD) diameter, and abrupt change in MPD caliber were evaluated.

RESULTS

A total of 22 patients with cPDAC and 17 patients with tPDAC showed no significant difference in MPD size. MN and SC were seen in cPDAC/tPDAC in 55%/18% and 9%/53%, respectively. Abrupt change in MPD caliber was seen in cPDAC/tPDAC at 18%/59%.

CONCLUSION

cPDAC and tPDAC differ in the frequency of MN, SC, and changes in MPD caliber.

Preoperative platelet-to-lymphocyte ratio improves the performance of the international consensus guidelines in predicting malignant pancreatic cystic neoplasms

INTRODUCTION

To determine if neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were predictive of malignancy in pancreatic cystic neoplasms (PCN) and if these improved the performance of the international consensus guidelines (ICG) in the initial triage of these patients.

METHODS

318 patients with surgically-treated suspected PCN were retrospectively reviewed. Malignant neoplasms were defined as neoplasms harbouring invasive carcinoma. The optimal cut-off for NLR and PLR were determined by plotting the receiver operating characteristics (ROC) curves of NLR/PLR in predicting malignant PCN and utilizing the Youden index.

RESULTS

The optimal NLR and PLR cut-offs were determined to be 3.33 and 205, respectively. Univariate analyses demonstrated that symptomatic PCNs, age, obstructive jaundice, presence of solid component, dilatation of main pancreatic duct ≥10 mm, high NLR and high PLR were predictive of a malignant PCN. Multivariate analyses demonstrated that obstructive jaundice, presence of solid component, MPD ≥10 mm and high PLR but not NLR were independent predictors of a malignant PCN. A high PLR significantly predicted invasive carcinoma in patients classified within the ICG(HR) group. Comparison between the ROC curves of the ICG versus ICG plus high PLR in predicting malignant PCN demonstrated a significant improvement in the accuracy of the ICG when PLR was included [AUC 0.784 (95% CI: 0.740-0.829) vs AUC 0.822 (95% CI: 0.772-0.872) (p = 0.0032)].

CONCLUSIONS

High PLR is an independent predictor of malignancy in PCN. The addition of PLR as a criterion to the ICG improved the accuracy of these guidelines in detecting invasive neoplasms.

Main-duct Intraductal Papillary Mucinous Neoplasm: High Cancer Risk in Duct Diameter of 5 to 9 mm

OBJECTIVE

The 2012 international consensus guidelines for the management of intraductal papillary mucinous neoplasms (IPMN) recommend surgical treatment in main-duct IPMN patients with a main pancreatic duct (MPD) diameter of ≥10 mm. Aim of the present study was to analyze cancer risk in patients with an MPD diameter of less than 10 mm.

METHODS

All consecutive patients (prospective data protocol) with histological proof of IPMN who underwent surgery between January 2004 and December 2013 were included in the study. Clinical characteristics, particularly preoperative imaging with regard to morphology of the MPD, were correlated with final histopathology.

RESULTS

Among a total of 605 patients who underwent surgery for IPMN, there were 320 patients with MPD involvement, 238 patients with mixed-type IPMN, and 82 patients with main-duct IPMN alone. The total malignancy rate including high-grade dysplasia and invasive carcinoma in IPMNs with MPD involvement was 68%. When the MPD diameter was 5 to 9 mm, malignancy rate was 59%, whereas in MPD diameter more than 10 mm, it was 73%. No statistical correlations were observed between MPD diameter and clinical and/or IPMN features such as age, cyst location, mural nodules, serum tumor markers, or bilirubin.

CONCLUSIONS

Main-duct IPMNs with a MPD between 5 and 9 mm already bear a significant risk of malignancy. Therefore, surgical treatment is clearly indicated in patients with a MPD diameter of ≥5 mm and the 2012 guidelines should be discussed and adapted with regard to this topic.

A MicroRNA Panel in Pancreatic Cyst Fluid for the Risk Stratification of Pancreatic Cysts in a Prospective Cohort

A subset of pancreatic cystic neoplasms are regarded as precursor lesions of pancreatic cancer, but only a minority of all pancreatic cystic neoplasms will undergo malignant transformation. MicroRNAs are increasingly recognized as molecular targets in carcinogenesis. Previously, a 9-microRNA (miR) signature was suggested to discriminate between high risk and low risk pancreatic cystic neoplasm. In this study, we aimed to validate this 9-miR panel in a prospective cohort. Total miR was isolated from pancreatic cyst fluid and expression of miR18a, miR24, miR30a-3p, miR92a, miR99b, miR106b, miR142-3p, miR342-3p, and miR532-3p was analyzed by singleplex Taqman MicroRNA Assay. A total of 62 patient samples were analyzed. During follow-up, 24 (38.7%) patients underwent resection, of which 6 (9.7%) patients showed at least high grade dysplasia. A logistic regression model presented a “predicted risk” score which significantly differed between low and high risk cysts, either including all patients or only those with histological confirmation of diagnosis. Using a set cut-off of 50%, the sensitivity of the model for the total cohort was 10.0%, specificity 100.0%, positive predicted value 100.0%, negative predicted value 85.2%, and diagnostic accuracy of 85.5%. Thus, while observing a significant difference between low and high risk cysts, clinical implementation of this biomarker panel is as yet unlikely to be beneficial in the management of pancreatic cysts.

Predictors for Surgical Referral in Patients With Pancreatic Cystic Lesions Undergoing Endoscopic Ultrasound: Results From a Large Multicenter Cohort Study

OBJECTIVE

Endoscopic ultrasound (EUS) plays an integral role in the evaluation of pancreatic cysts lesions (PCLs). The aim of the study was to determine predictors of surgical referral in patients with PCLs undergoing EUS.

METHODS

We performed a multicenter retrospective study of patients undergoing EUS for evaluation of PCLs. Demographics, EUS characteristics, and fine-needle aspiration results were recorded. Patients were categorized into surgery or surveillance groups on the basis of post-EUS recommendations. Univariate and multivariate analyses were performed to identify predictors of surgical referral.

RESULTS

1804 patients were included. 1301 patients were recommended to undergo surveillance and 503 patients were referred for surgical evaluation, of which 360 patients underwent surgery. Multivariate analysis revealed the following 5 independent predictors of surgical referral: symptoms of weight loss on presentation (odds ratio [OR], 2.69; 95% confidence interval [CI], 1.44-5.03), EUS findings of associated solid mass (OR, 7.34; 95% CI, 3.81-14.16), main duct communication (OR, 4.13; 95% CI, 1.71-9.98), multilocular macrocystic morphology (OR, 2.79; 95% CI, 1.78-4.38), and fine-needle aspiration findings of mucin on cytology (OR, 3.06; 95% CI, 1.94-4.82).

CONCLUSIONS

This study identifies factors associated with surgical referral in patients with PCLs undergoing EUS. Future studies should focus on creation of risk stratification models to determine the need for surgery or enrollment in surveillance programs.

Distinguishing benign from malignant main duct intraductal papillary mucinous neoplasms of the pancreas by multislice helical computed tomography

Main duct intraductal papillary mucinous neoplasms (MD-IPMNs) of the pancreas are located in the dilated main pancreatic duct and associated with mucin overproduction. They may have a high degree of malignancy and lack specific clinical manifestations. With advantages of thin slice thickness, high resolution, multi-phase dynamic scan and multiple post-processing techniques, multislice helical computed tomography (MSCT) can accurately diagnose and differentiate malignant from benign MD-IPMNs. This paper will review the current advances in differentiating malignant from benign MD-IPMNs by MSCT.

International consensus on the management of intraductal papillary mucinous neoplasm of the pancreas

International consensus guidelines for the management of intraductal papillary mucinous neoplasm (IPMN) of the pancreas revised in 2012 (Fukuoka consensus) seem to be accepted well worldwide. Division of various factors to predict malignant transformation into two categories, i.e., "high-risk stigmata" and "worrisome features", is also accepted as practically useful for stratifying the risk factors. Our current interest resides in the development of noninvasive and/or invasive pancreatic cancer in areas of the pancreas distinct from IPMN. Invasive pancreatic cancers derived from and concomitant with IPMN should be distinguished to clarify the incidence of each entity, although some more definitive method for differentiation has to be devised in some cases where histological distinction is obscure. IPMN is a clue to early detection of pancreatic cancer. The optimal surveillance protocol for IPMN on observation should be determined in consideration of both of these different pancreatic cancers.

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.