Intraductal papillary-mucinous tumors of the pancreas: differential diagnosis between benign and malignant tumors by endoscopic ultrasonography

Endoscopic Imaging of Pancreatic Cysts

Pancreatic cystic lesions (PCLs) have been diagnosed with increasing frequency likely due to the widespread use of cross-sectional imaging. A precise diagnosis of the PCL is important because it helps identify patients in need of surgical resection and those who can undergo surveillance imaging. A combination of clinical and imaging findings as well as cyst fluid markers can help classify PCLs and guide management. This review focuses on endoscopic imaging of PCLs including endoscopic and endosonographic features and fine needle aspiration. We then review the role of adjunct techniques, such as microforceps, contrast-enhanced endoscopic ultrasound, pancreatoscopy, and confocal laser endomicroscopy.

Diagnosis and Management of Pancreatic Cysts: A Comprehensive Review of the Literature

The prevalence of pancreatic cysts has been rising due to the widespread use of cross-sectional imaging (CT scan and MRI) of the abdomen. While most pancreatic cysts are benign and do not require treatment or surveillance, a significant minority are premalignant and rarely malignant. The risk stratification of these lesions is not straightforward, and individual risk assessment, cyst size, distribution, and alarming morphologic features (when present) can guide the next steps in management. Neoplastic pancreatic cysts are mucinous or non-mucinous. Endoscopic ultrasound with fine-needle aspiration is often required to classify pancreatic cysts into mucinous and non-mucinous cysts and to assess the malignant potential. Advances in endoscopic techniques (confocal laser endomicroscopy, microforceps biopsy) can provide a definitive diagnosis of pancreatic cysts in some cases; however, the use of these techniques involves a higher risk of adverse events.

Imaging Features for Predicting High-Grade Dysplasia or Malignancy in Branch Duct Type Intraductal Papillary Mucinous Neoplasm of the Pancreas: A Systematic Review and Meta-Analysis

BACKGROUND

The consensus guidelines for branch-duct intraductal papillary mucinous neoplasm (BD-IPMN) of the pancreas are mostly based on imaging features. This study aimed to determine imaging features and their diagnostic accuracy for predicting high-grade dysplasia (HGD)/malignancy in BD-IPMN, including mixed type.

METHODS

The PubMed, Embase, and Cochrane databases were searched, and data were extracted from relevant studies. As the main diagnostic accuracy index, diagnostic odds ratios (DORs) of imaging features for diagnosing HGD/malignancy in BD-IPMNs were pooled using the random-effects model. A bivariate random-effects approach was used to construct summary receiver operating characteristic curves for sensitivity and specificity estimation.

RESULTS

The pooled DOR was the highest for the enhanced solid component/mural nodule (MN) (DOR, 12.21; 95 % confidence interval [CI], 6.14-24.27), followed by a main pancreatic duct (MPD) diameter of 10 mm or greater (DOR, 7.93; 95 % CI, 3.02-20.83), solid component (DOR, 4.85; 95 % CI, 2.49-9.42), lymphadenopathy (DOR, 4.84; 95 % CI, 1.11-21.06), MN (DOR, 4.48; 95 % CI, 3.15-6.39), an MPD diameter of 5 mm or greater (DOR, 3.69; 95 % CI, 2.62-5.19), abrupt change in MPD caliber with distal pancreatic atrophy (DOR, 2.65; 95 % CI, 1.66-4.24), thickened/enhancing walls (DOR, 2.38; 95 % CI, 1.57-3.60), and cyst size of 3 cm or larger (DOR, 1.98; 95 % CI, 1.48-2.64). The largest area under the curve (0.89 and 0.95, respectively) and high specificity (0.95 and 0.98, respectively) also were found for enhanced solid component/MN and an MPD diameter of 10 mm or greater, albeit with low sensitivity (0.38 and 0.14, respectively).

CONCLUSIONS

The aforementioned imaging features could aid in predicting HGD/malignancy of BD-IPMN. Furthermore, enhanced solid component/MN and an MPD diameter of 10 mm or greater were the most important predictors of HGD/malignancy in BD-IPMN and should be considered as indications for surgery.

The diagnostic role of CT, MRI/MRCP, PET/CT, EUS and DWI in the differentiation of benign and malignant IPMN: A meta-analysis

PURPOSE

The objective of this study was to assess the diagnostic properties of computed tomography (CT), magnetic resonance imaging (MRI/MRCP) /Magnetic Resonance Cholangiopancreatography (MRCP), positron emission tomography/computed tomography (PET/CT), endoscopic ultrasound (EUS) and diffusion-weighted magnetic resonance imaging (DWI) in distinguishing benign and malignant intraductal papillary mucinous neoplasm (IPMN).

MATERIALS AND METHODS

Eligible databases were searched for eligible studies, published through July 2020 on the diagnostic accuracy of these modalities. Diagnostic accuracy parameters, including sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver operating characteristic curves (SROC) were calculated. Meta-regression was performed to identify the source of heterogeneity.

RESULTS

In total, 28 studies were included. Pooled sensitivities for CT, MRI/MRCP, PET/CT, EUS and DWI were 0.7, 0.76, 0.8, 0.6 and 0.72, respectively. Pooled specificities were 0.78, 0.83, 0.9, 0.8 and 0.97. The DORs were 8, 16, 35, 6 and 88. The areas under the curve (AUC) of SROC for CT, MRI/MRCP/MRCP, PET/CT, EUS and DW were 0.8, 0.87, 0.92, 0.79 and 0.82, respectively.

CONCLUSION

PET/CT showed the highest AUC and the overall diagnostic accuracy results support the use of MRI/MRCP, PET/CT interchangeably as a first-line examination in the diagnosis of malignant IPMN. With regard to DWI, EUS and CT, each techniques have their advantages and supportive to MRI/MRCP.

Usefulness of septal thickness measurement on endoscopic ultrasound as a predictor of malignancy of branched-duct and mixed-type intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND AND AIM

Septal thickness (ST) can predict a malignant branch-duct (BD) and mixed-type intraductal papillary mucinous neoplasm (IPMN) of the pancreas, but its cut-off value has not been established. The aim of the present study was to determine the optimal ST cut-off value to predict malignancy using endoscopic ultrasound (EUS).

METHODS

We retrospectively identified 200 patients with IPMN, including 132 with BD- and mixed-IPMN, who underwent surgical resection between 1989 and 2017. ST was defined as the septum or lesion wall with the maximum diameter in BD- and mixed-IPMN. The possibility of ST as a malignant predictor was examined, as well as the diagnostic ability of ST combined with mural nodule (MN) height for malignant IPMN.

RESULTS

Among the 132 IPMN patients, pathological diagnosis was benign in 81 (61.4%) and malignant in 51 (38.6%). Area under the curve for the diagnosis of malignancy using ST was 0.74 for pathological specimens, 0.70 for EUS and 0.56 for computed tomography. Multivariate analysis showed that the odds ratios for ST ≥2.5 mm and MN height ≥5 mm were 3.51 [95% confidence interval (CI), 1.55-7.97, P = 0.003] and 3.36 (95% CI, 1.52-7.45, P = 0.003), respectively.

CONCLUSIONS

Septal thickness was an independent predictive factor similar to MN height for malignant IPMN in a multivariate analysis. The ST on EUS appeared to be the thickness of a fibrotic septum associated with the malignant transformation of IPMN. An ST cut-off value of 2.5 mm might provide an accurate prediction of malignant IPMN.

Intraductal papillary mucinous neoplasms of the pancreas and European guidelines: importance of the surgery type in the decision-making process

BACKGROUND

The European Consensus 2018 established a new algorithm with absolute and relative criteria for intraductal papillary mucinous neoplasms of the pancreas (IPMN) management. The aim of this study was to validate these criteria and analyse the outcomes in function of the surgical procedure and IPMN subtype.

METHODS

Clinical, radiological and surgical data (procedure, morbidity/mortality rates) of patients who underwent surgery for IPMN between 2007 and 2017. The predictive value of the different criteria was analysed.

RESULTS

124 patients (men 67%; mean age 65 years) underwent surgery for IPMN (n = 62 malignant tumours; 50%). Jaundice, cyst ≥4 cm and Wirsung duct size 5-9.9 mm or ≥ 10 mm were significantly associated with malignancy (4.77 < OR < 11.85 p < 0.0001). The positive predictive value of any isolated criterion ranged from 71 to 87%, whereas that of three relative criteria together reached 100%. The mortality and morbidity (grade III-IV complications according to the Dindo-Clavien classification) rates were 3 and 8%, respectively. Morbidity/mortality after duodenopancreatectomy and total pancreatectomy were significantly higher for benign IPMN (p = 0.01).

CONCLUSION

Considering the morbidity associated with extended surgery, particularly for benign IPMN, the results of the present study suggest that high-risk surgery should be considered only in the presence of three relative criteria and including the surgery type in the decision-making algorithm.

Transmembrane mucin MUC13 distinguishes intraductal papillary mucinous neoplasms from non-mucinous cysts and is associated with high-risk lesions

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMN) are currently managed based on imaging characteristics and cyst fluid sampling. This study was designed to determine if MUC13, a glycoprotein aberrantly overexpressed in pancreatic adenocarcinoma, might aid in distinguishing high-risk lesions (high grade dysplasia/invasive disease) from low-grade lesions.

METHODS

MUC13 immunohistochemical staining was performed on surgically resected formalin-fixed tissue specimens from 49 IPMNs and 23 non-mucinous cysts. Membranous MUC13 expression was measured by H-score, which quantifies staining intensity and the percentage of cells involved (range 0-300).

RESULTS

MUC13 expression was detected in all IPMNs and was significantly greater than in non-mucinous cysts (median 210 vs 40, p < 0.001). MUC13 expression was similar among main (n = 26), branch (n = 15), and mixed (n = 8) duct lesions (median 210, 200, 225, respectively). The highest expression was observed in tumors with intestinal and pancreatobiliary histologic features (both median 225) and the lowest in gastric type lesions (median 200). MUC13 expression was significantly greater in high-risk lesions (n = 21) compared to those with low-grade dysplasia (n = 28) (median 250 vs 195, p < 0.001).

CONCLUSION

MUC13 expression was significantly greater in high-risk IPMNs in this analysis. The preoperative assessment of MUC13 in cyst fluid samples warrants further investigation.

Managing Incidental Pancreatic Cysts

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

ACG Clinical Guideline: Diagnosis and Management of Pancreatic Cysts

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

Intraductal Papillary Mucinous Neoplasms of the Pancreas: Current Understanding and Future Directions for Stratification of Malignancy Risk

The incidence of intraductal papillary mucinous neoplasms (IPMNs) has been increasing over the past decade, mainly owing to increased awareness and the increased use of cross-sectional imaging. The Sendai and Fukuoka consensus guidelines provide us with clinical management guidelines and algorithms; however, the clinical management of IPMNs continues to be challenging. Our incomplete understanding of the natural history of the disease, and the events and pathways that permit progression to adenocarcinoma, result in difficulties predicting which tumors are high risk and will progress to invasive disease. In this review, we summarize the current management guidelines and describe ongoing efforts to more clearly stratify IPMNs by risk of malignancy and identify IPMNs with malignant potential or ongoing malignant transformation.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Endoscopic Ultrasound Imaging for Diagnosing and Treating Pancreatic Cysts

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

Imaging modalities for characterising focal pancreatic lesions

BACKGROUND

Increasing numbers of incidental pancreatic lesions are being detected each year. Accurate characterisation of pancreatic lesions into benign, precancerous, and cancer masses is crucial in deciding whether to use treatment or surveillance. Distinguishing benign lesions from precancerous and cancerous lesions can prevent patients from undergoing unnecessary major surgery. Despite the importance of accurately classifying pancreatic lesions, there is no clear algorithm for management of focal pancreatic lesions.

OBJECTIVES

To determine and compare the diagnostic accuracy of various imaging modalities in detecting cancerous and precancerous lesions in people with focal pancreatic lesions.

SEARCH METHODS

We searched the CENTRAL, MEDLINE, Embase, and Science Citation Index until 19 July 2016. We searched the references of included studies to identify further studies. We did not restrict studies based on language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We planned to include studies reporting cross-sectional information on the index test (CT (computed tomography), MRI (magnetic resonance imaging), PET (positron emission tomography), EUS (endoscopic ultrasound), EUS elastography, and EUS-guided biopsy or FNA (fine-needle aspiration)) and reference standard (confirmation of the nature of the lesion was obtained by histopathological examination of the entire lesion by surgical excision, or histopathological examination for confirmation of precancer or cancer by biopsy and clinical follow-up of at least six months in people with negative index tests) in people with pancreatic lesions irrespective of language or publication status or whether the data were collected prospectively or retrospectively.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched the references to identify relevant studies and extracted the data. We planned to use the bivariate analysis to calculate the summary sensitivity and specificity with their 95% confidence intervals and the hierarchical summary receiver operating characteristic (HSROC) to compare the tests and assess heterogeneity, but used simpler models (such as univariate random-effects model and univariate fixed-effect model) for combining studies when appropriate because of the sparse data. We were unable to compare the diagnostic performance of the tests using formal statistical methods because of sparse data.

MAIN RESULTS

We included 54 studies involving a total of 3,196 participants evaluating the diagnostic accuracy of various index tests. In these 54 studies, eight different target conditions were identified with different final diagnoses constituting benign, precancerous, and cancerous lesions. None of the studies was of high methodological quality. None of the comparisons in which single studies were included was of sufficiently high methodological quality to warrant highlighting of the results. For differentiation of cancerous lesions from benign or precancerous lesions, we identified only one study per index test. The second analysis, of studies differentiating cancerous versus benign lesions, provided three tests in which meta-analysis could be performed. The sensitivities and specificities for diagnosing cancer were: EUS-FNA: sensitivity 0.79 (95% confidence interval (CI) 0.07 to 1.00), specificity 1.00 (95% CI 0.91 to 1.00); EUS: sensitivity 0.95 (95% CI 0.84 to 0.99), specificity 0.53 (95% CI 0.31 to 0.74); PET: sensitivity 0.92 (95% CI 0.80 to 0.97), specificity 0.65 (95% CI 0.39 to 0.84). The third analysis, of studies differentiating precancerous or cancerous lesions from benign lesions, only provided one test (EUS-FNA) in which meta-analysis was performed. EUS-FNA had moderate sensitivity for diagnosing precancerous or cancerous lesions (sensitivity 0.73 (95% CI 0.01 to 1.00) and high specificity 0.94 (95% CI 0.15 to 1.00), the extremely wide confidence intervals reflecting the heterogeneity between the studies). The fourth analysis, of studies differentiating cancerous (invasive carcinoma) from precancerous (dysplasia) provided three tests in which meta-analysis was performed. The sensitivities and specificities for diagnosing invasive carcinoma were: CT: sensitivity 0.72 (95% CI 0.50 to 0.87), specificity 0.92 (95% CI 0.81 to 0.97); EUS: sensitivity 0.78 (95% CI 0.44 to 0.94), specificity 0.91 (95% CI 0.61 to 0.98); EUS-FNA: sensitivity 0.66 (95% CI 0.03 to 0.99), specificity 0.92 (95% CI 0.73 to 0.98). The fifth analysis, of studies differentiating cancerous (high-grade dysplasia or invasive carcinoma) versus precancerous (low- or intermediate-grade dysplasia) provided six tests in which meta-analysis was performed. The sensitivities and specificities for diagnosing cancer (high-grade dysplasia or invasive carcinoma) were: CT: sensitivity 0.87 (95% CI 0.00 to 1.00), specificity 0.96 (95% CI 0.00 to 1.00); EUS: sensitivity 0.86 (95% CI 0.74 to 0.92), specificity 0.91 (95% CI 0.83 to 0.96); EUS-FNA: sensitivity 0.47 (95% CI 0.24 to 0.70), specificity 0.91 (95% CI 0.32 to 1.00); EUS-FNA carcinoembryonic antigen 200 ng/mL: sensitivity 0.58 (95% CI 0.28 to 0.83), specificity 0.51 (95% CI 0.19 to 0.81); MRI: sensitivity 0.69 (95% CI 0.44 to 0.86), specificity 0.93 (95% CI 0.43 to 1.00); PET: sensitivity 0.90 (95% CI 0.79 to 0.96), specificity 0.94 (95% CI 0.81 to 0.99). The sixth analysis, of studies differentiating cancerous (invasive carcinoma) from precancerous (low-grade dysplasia) provided no tests in which meta-analysis was performed. The seventh analysis, of studies differentiating precancerous or cancerous (intermediate- or high-grade dysplasia or invasive carcinoma) from precancerous (low-grade dysplasia) provided two tests in which meta-analysis was performed. The sensitivity and specificity for diagnosing cancer were: CT: sensitivity 0.83 (95% CI 0.68 to 0.92), specificity 0.83 (95% CI 0.64 to 0.93) and MRI: sensitivity 0.80 (95% CI 0.58 to 0.92), specificity 0.81 (95% CI 0.53 to 0.95), respectively. The eighth analysis, of studies differentiating precancerous or cancerous (intermediate- or high-grade dysplasia or invasive carcinoma) from precancerous (low-grade dysplasia) or benign lesions provided no test in which meta-analysis was performed.There were no major alterations in the subgroup analysis of cystic pancreatic focal lesions (42 studies; 2086 participants). None of the included studies evaluated EUS elastography or sequential testing.

AUTHORS' CONCLUSIONS

We were unable to arrive at any firm conclusions because of the differences in the way that study authors classified focal pancreatic lesions into cancerous, precancerous, and benign lesions; the inclusion of few studies with wide confidence intervals for each comparison; poor methodological quality in the studies; and heterogeneity in the estimates within comparisons.

New criteria to differentiate between mucinous cystic neoplasm and serous cystic neoplasm in pancreas by endoscopic ultrasound: A preliminarily confirmed outcome of 41 patients

Background and Objectives:

The ability to distinguish between mucinous cystic neoplasm (MCN) and serous cystic neoplasm (SCN) in the pancreas preoperatively by endoscopic ultrasound (EUS) remains a clinical challenge. To address this problem, we have developed new criteria using EUS findings and cyst fluid carcinoembryonic antigen (CEA) in the clinic. In this study, the validity and reliability of these criteria were assessed.

Materials and Methods:

Between April of 2015 and May of 2016, a total of 59 patients with pancreatic cystic neoplasms underwent EUS and ultimately received surgery in our hospital. Of the 59 patients, 21 were pathologically verified to have MCN while 20 were verified to have SCN in the pancreas. For these 41 patients with MCN or SCN, EUS findings and cyst fluid CEA were reviewed.

Results:

For the 41 patients reviewed, the new criteria were found to identify MCN with 85.71% sensitivity (95% confidence interval [CI], 64%–97%), 80.00% specificity (CI, 56%-94%), and 82.93% accuracy (CI, 68%–93%).

Conclusion:

These new criteria were preliminarily found to produce excellent results, with 82.93% accuracy determined for the differential diagnosis between MCN and SCN by EUS. However, a further prospective study with a larger population must be carried out to fully assess these new criteria.

Oncocytic Intraductal Papillary Mucinous Neoplasms of the Pancreas: Imaging and Histopathological Findings

OBJECTIVES

To evaluate and correlate computed tomography/magnetic resonance findings and histopathologic features of oncocytic intraductal papillary mucinous neoplasms (O-IPMNs).

METHODS

Computed tomography/magnetic resonance examinations and resection specimens of 16 O-IPMNs were retrospectively reviewed. Qualitative and quantitative imaging features were analyzed according to "worrisome features" and "high risk stigmata." Correlations between radiological and histopathological findings were evaluated using Fisher test.

RESULTS

Most O-IPMNs (75%) presented as large mixed- or main duct-type lesions (mean size, 56.9 mm; range, 20-180); all branch-duct type lesions were larger than 3 cm. Ten lesions presented main pancreatic duct dilation of 10 mm or greater. Solid enhancing nodules were found in 10 cases. Two lesions presented foci of invasion at histopathologic analysis, the remaining presented high-grade dysplasia. Neither invasive carcinoma nor nodal metastases were found. No significant correlations were found between radiological predictors of malignancy and histopathological features.

CONCLUSIONS

Oncocytic tumors are rare subtypes of pancreatic IPMN, whose imaging features are similar to other IPMN subtypes. Imaging predictors of malignancy as large size and huge solid internal nodules are frequently encountered in O-IPMNs; despite this, these features are not correlated with histopathological findings, being probably inapplicable to O-IPMNs.

Risk Factors for Malignancy of Branch-Duct Intraductal Papillary Mucinous Neoplasms: A Critical Evaluation of the Fukuoka Guidelines With a Systematic Review and Meta-analysis

OBJECTIVES

This study aimed to evaluate the accuracy of the risk factors proposed by Fukuoka guidelines in detecting malignancy of branch-duct intraductal papillary mucinous neoplasms.

METHOD

Diagnostic meta-analysis of cohort studies. A systematic literature search was conducted using MEDLINE, the Cochrane Library, Scopus, and the ISI-Web of Science databases to identify all studies published up to 2014.

RESULTS

Twenty-five studies (2025 patients) were suitable for the meta-analysis. The "high risk stigmata" showed the highest pooled diagnostic odds ratio (jaundice, 6.3; positive citology, 5.5; mural nodules, 4.8) together with 2 "worrisome features" (thickened/enhancing walls, 4.2; duct dilatation, 4.0) and 1 "other parameters" (carbohydrate antigen 19-9 serum levels, 4.6).

CONCLUSIONS

An "ideal risk factor" capable of recognizing all malignant branch-duct intraductal papillary mucinous neoplasms was not identified and some "dismal areas" remain. However, "high risk stigmata" were strongly related to malignancy, mainly enhancing mural nodules. Among the "worrisome features," duct dilatation and thickened/enhancing walls were underestimated, and their diagnostic performance was similar to those of "high risk stigmata." The carbohydrate antigen 19-9 serum level should be added to the Fukuoka algorithm because this value could help in carrying out correct management.

Management of branch-duct intraductal papillary mucinous neoplasms: a large single-center study to assess predictors of malignancy and long-term outcomes

BACKGROUND AND AIMS

Management of branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) remains challenging. We determined factors associated with malignancy in BD-IPMNs and long-term outcomes.

METHODS

This retrospective cohort study included all patients with established BD-IPMNs by the International Consensus Guidelines (ICG) 2012 and/or pathologically confirmed BD-IPMNs in a tertiary care referral center between 2001 and 2013. Main outcome measures were the association between high-risk stigmata (HRS)/worrisome features (WFs) of the ICG 2012 and malignant BD-IPMNs, performance characteristics of EUS-FNA for the diagnosis of malignant BD-IPMNs, and recurrence and long-term outcomes of BD-IPMN patients undergoing surgery or imaging surveillance.

RESULTS

Of 364 BD-IPMN patients, 229 underwent imaging surveillance and 135 underwent surgery. Among the 135 resected BD-IPMNs, HRS/WFs on CT/magnetic resonance imaging (MRI) were similar between the benign and malignant groups, but main pancreatic duct (MPD) dilation (5-9 mm) was more frequently identified in malignant lesions. On EUS-FNA, mural nodules, MPD features suspicious for involvement, and suspicious/positive malignant cytology were more frequently detected in the malignant group with a sensitivity, specificity, and accuracy of 33%, 94%, and 86%; 42%, 91%, and 83%; and 33% 91%, and 82%, respectively. Mural nodules identified by EUS were missed by CT/MRI in 28% in the malignant group. Patients with malignant lesions had a higher risk of any IPMN recurrence during a mean follow-up period of 131 months (P = .01).

CONCLUSIONS

Among HRS and WFs of the ICG 2012, an MPD size of 5 to 9 mm on CT/MRI was associated with malignant BD-IPMNs. EUS features including mural nodules, MPD features suspicious for involvement, and suspicious/malignant cytology were accurate and highly specific for malignant BD-IPMNs. Our study highlights the incremental value of EUS-FNA over imaging in identifying malignant BD-IPMNs, particularly in patients without WFs and those with smaller cysts. Benign IPMN recurrence was observed in some patients up to 8 years after resection.

Advanced endoscopic ultrasound management techniques for preneoplastic pancreatic cystic lesions

Pancreatic cystic lesions can be benign, premalignant or malignant. The recent increase in detection and tremendous clinical variability of pancreatic cysts has presented a significant therapeutic challenge to physicians. Mucinous cystic neoplasms are of particular interest given their known malignant potential. This review article provides a brief but comprehensive review of premalignant pancreatic cystic lesions with advanced endoscopic ultrasound (EUS) management approaches. A comprehensive literature search was performed using PubMed, Cochrane, OVID and EMBASE databases. Preneoplastic pancreatic cystic lesions include mucinous cystadenoma and intraductal papillary mucinous neoplasm. The 2012 International Sendai Guidelines guide physicians in their management of pancreatic cystic lesions. Some of the advanced EUS management techniques include ethanol ablation, chemotherapeutic (paclitaxel) ablation, radiofrequency ablation and cryotherapy. In future, EUS-guided injections of drug-eluting beads and neodymium:yttrium aluminum agent laser ablation is predicted to be an integral part of EUS-guided management techniques. In summary, International Sendai Consensus Guidelines should be used to make a decision regarding management of pancreatic cystic lesions. Advanced EUS techniques are proving extremely beneficial in management, especially in those patients who are at high surgical risk.

Intraductal Papillary Mucinous Neoplasm of Pancreas

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are neoplasms that are characterized by ductal dilation, intraductal papillary growth, and thick mucus secretion. This relatively recently defined pathology is evolving in terms of its etiopathogenesis, clinical features, diagnosis, management, and treatment guidelines. A PubMed database search was performed. All the relevant abstracts in English language were reviewed and the articles in which cases of IPMN could be identified were further scrutinized. Information of IPMN was derived, and duplication of information in several articles and those with areas of persisting uncertainties were excluded. The recent consensus guidelines were examined. The reported incidence of malignancy varies from 57% to 92% in the main duct-IPMN (MD-IPMN) and from 6% to 46% in the branch duct-IPMN (BD-IPMN). The features of high-risk malignant lesions that raise concern include obstructive jaundice in a patient with a cystic lesion in the pancreatic head, the findings on radiological imaging of a mass lesion of >30 mm, enhanced solid component, and the main pancreatic duct (MPD) of size ≥10 mm; while duct size 5-9 mm and cyst size <3 mm are considered as “worrisome features.” Magnetic resonance imaging (MRI) and endoscopic ultrasound (EUS) are primary investigations in diagnosing and following up on these patients. The role of pancreatoscopy and the analysis of aspirated cystic fluid for cytology and DNA analysis is still to be established. In general, resection is recommended for most MD-IPMN, mixed variant, and symptomatic BD-IPMN. The 5-year survival of patients after surgical resection for noninvasive IPMN is reported to be at 77-100%, while for those with invasive carcinoma, it is significantly lower at 27-60%. The follow-up of these patients could vary from 6 months to 1 year and would depend on the risk stratification for invasive malignancy and the pathology of the resected specimen. The understanding of IPMN has evolved over the years. The recent guidelines have played a role in this regard.

Predictors of malignancy in pure branch duct type intraductal papillary mucinous neoplasm of the pancreas: A nationwide multicenter study

BACKGROUND/OBJECTIVES

Prediction of malignancy in patients with BD-IPMNs is critical for the management. The aim of this study was to elucidate predictors of malignancy in patients with 'pure' BD-IPMNs who had a main pancreatic duct (MPD) diameter of ≤5 mm according to the most recent international consensus criteria and in whom MPD involvement was excluded on postoperative histology.

METHODS

We identified 177 patients with 'pure' BD-IPMNs based on preoperative imaging and postoperative histology from 15 tertiary referral centers in Korea. BD-IPMNs with low-grade (n = 72) and moderate-grade (n = 66) dysplasia were grouped as benign and BD-IPMNs with high-grade dysplasia (n = 10) and invasive carcinoma (n = 29) were grouped as malignancy.

RESULTS

On univariate analysis, particular symptoms (jaundice and clinical pancreatitis), CT findings (cyst size > 3 cm, the presence of enhancing mural nodules) and EUS features (the presence of mural nodules, the mural nodule size > 5 mm) were significant risk factors predicting malignant BD-IPMNs. Multivariate analysis revealed that the cyst size > 3 cm (odds ratio = 9.9), the presence of enhancing mural nodules on CT (odds ratio = 19.3) and the mural nodule size > 5 mm on EUS (odds ratio = 14.9) were the independent risk factors for the presence of malignancy in BD-IPMNs (p < 0.001).

CONCLUSIONS

The cyst size > 3 cm, the presence of enhancing mural nodules on CT, the mural nodule size > 5 mm on EUS are three independent predictors of malignancy in patients with 'pure' BD-IPMNs.

Invasive carcinoma derived from "flat type" branch duct intraductal papillary mucinous neoplasms of the pancreas: impact of classification according to the height of mural nodule on endoscopic ultrasonography

BACKGROUND

It has been reported that many branch duct intraductal papillary mucinous neoplasms (BD-IPMN) with a mural nodule (MN) reveal adenocarcinomas. On the other hand, invasive cancer derived from BD-IPMN without MN on endoscopic ultrasound (EUS) also exists. The aim of this study was to elucidate the clinicopathological features of invasive cancer derived from BD-IPMN without MN on EUS.

METHODS

Twenty-one patients pathologically diagnosed with invasive cancer derived from BD-IPMN were included in this study.

RESULTS

Based on the height of MNs on EUS, the subjects could be clearly classified as 12 patients whose background BD-IPMNs had high MNs (nodule-forming type IPMN) and nine whose background BD-IPMNs showed no MNs (flat type IPMN). The background BD-IPMN of the 12 patients with nodule-forming type IPMN were non-gastric type. On the other hand, the background BD-IPMN of the nine patients with flat type IPMN was gastric type. The recurrence rate was higher (33% vs. 67%) and the 5-year survival was worse (76% vs. 33%) in flat type IPMN.

CONCLUSIONS

There may be a pathway for the development of invasive cancer without the formation of an MN in BD-IPMN, and attention should be paid even to the patients with BD-IPMN which does not present an MN.

Intraductal papillary mucinous neoplasm: clinical surveillance and management decisions

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a relatively rare cystic neoplasm. Although most IPMNs appear to be benign and may be managed by surveillance, all IPMNs are considered premalignant lesions with malignant potential. As such, current efforts are focused on identifying those neoplasms that are at high risk for malignancy to optimize treatment strategy and outcome. IPMNs with invasive carcinoma have clinical outcomes that approach those of conventional pancreatic ductal adenocarcinoma. Management guidelines recommend surgical resection for IPMNs with high-risk imaging or cytologic features. The role of adjuvant therapy is unclear, and we review the evidence for chemoradiation here. Some studies suggest adjuvant chemoradiation may have the greatest impact in malignant IPMNs with adverse histologic features, that is, lymph node metastasis at the time of diagnosis or positive surgical margins. As more IPMNs are recognized and treated, more evidence will accumulate to guide clinicians regarding appropriate use of radiotherapy in the management of IPMN.

Prediction of malignancy with endoscopic ultrasonography in patients with branch duct-type intraductal papillary mucinous neoplasm

OBJECTIVE

We evaluated the accuracy of a new endoscopic ultrasonography (EUS) scoring system to predict malignancy in branch duct-type intraductal papillary mucinous neoplasms (BD-IPMNs).

METHODS

We performed a retrospective multicenter study of patients who underwent EUS within 3 months before surgery and were diagnosed as having BD-IPMNs by postoperative pathologies at 8 hospitals in Korea from August 2002 to December 2011. To predict the malignancy, we applied the EUS scoring system consisting of pancreatic cyst size, height of mural nodules, main duct dilatation, septal thickening, and patulous orifice. We evaluated the diagnostic accuracy of the new EUS scoring system and compared it with previous individual risk factors.

RESULTS

Eighty-four patients (male-to-female ratio, 55:29; mean [SD] age, 64.7 [7.1] years) had 68 benign BD-IPMNs and 16 malignant intraductal papillary mucinous neoplasms. The EUS scoring system showed 75.0% sensitivity and 94.1% specificity at 7 points. This system (area under the curve, 0.939; 95% confidence interval, 0.884-0.994) resulted in a more accurate prediction than the previous known other factors including Sendai criteria, dilatation of ducts, size of the cyst, and presence of septal thickening and mural nodules.

CONCLUSIONS

The EUS scoring system predicted BD-IPMN malignancy more accurately than the Sendai criteria and individual risk factors.

Progress in diagnosis and treatment of intraductal papillary mucinous neoplasms

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

The role of cytopathology and cyst fluid analysis in the preoperative diagnosis and management of pancreatic cysts >3 cm

BACKGROUND

Pancreatic cyst size >3 cm is a worrisome rather than high-risk feature for malignancy based on the 2012 International Guidelines for the management of mucinous cysts. The value of cytology in preoperative evaluation and surgical triage is unclear.

METHODS

All pancreatic cysts >3 cm resected over a 7-year period were evaluated for clinical, radiologic, and pathologic information. Performance of cytology for the detection of malignancy and surgical triage compared with imaging was assessed.

RESULTS

There were 93 histologically confirmed cysts, 52 of which were mucinous and 41 of which were nonmucinous. Of these, 37% were malignant, including 16 nonmucinous malignancies and 18 mucinous cysts (12 with invasive carcinoma, 6 with high-grade dysplasia). Thirty-nine cysts (41% malignant, 59% benign) were not subject to endoscopic ultrasound-fine needle aspiration (EUS-FNA) prior to resection (average size, 6.0 cm). Fifty-four were evaluated by EUS-FNA, with 35 available for review (average size, 5.4 cm). Cytology/cyst fluid analysis had the highest specificity (88.9%) compared with imaging, whereas magnetic resonance imaging (MRI) showed the highest sensitivity (100%). MRI had the highest predictive value for mucinous (100%) versus nonmucinous cysts (100%). MRI and EUS were able to predict malignancy from the presence of high-risk imaging features in all cases. Some benign cases also showed high-risk imaging features on MRI (28.6%), computed tomography (32.3%), and EUS (45.8%). Cytology correctly classified 5 of 6 benign cysts with high-risk imaging as benign.

CONCLUSIONS

Preoperative evaluation of pancreatic cysts >3 cm is warranted, as many are nonmucinous cysts and not high-grade. Cytology is more specific than imaging for the detection of malignancy in cysts >3 cm.

Endoscopic ultrasound in the diagnosis of pancreatic intraductal papillary mucinous neoplasms

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

Endoscopic ultrasound and pancreatic cystic lesions-diagnostic and therapeutic applications

Pancreatic cystic lesions are being detected with an increasing frequency. Endoscopic ultrasound (EUS) provides both diagnostic and therapeutic means for pancreatic cystic lesions. Detailed imaging and EUS-guided fine-needle aspiration provide additional information on pancreatic cystic lesions. EUS-guided pseudocyst drainage has advantages over conventional drainage modalities. EUS-guided cyst ablation is a promising therapeutic modality.

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

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

Can long-term follow-up strategies be determined using a nomogram-based prediction model of malignancy among intraductal papillary mucinous neoplasms of the pancreas?

OBJECTIVES

This study investigated whether a risk assessment nomogram can predict the malignant potential of intraductal papillary mucinous neoplasms (IPMNs) and provide valuable information for the follow-up and counseling strategies of such patients.

METHODS

We studied 126 of 589 patients with IPMN who were followed up for at least 36 months with annual endoscopic ultrasonography. We analyzed scores derived from our nomogram, incorporating the parameters of sex, lesion type, mural nodule height, and pancreatic juice cytology determined at the initial IPMN evaluation.

RESULTS

The rate of malignant IPMNs was 5.5% (7/126). The initial average nomogram score was 19.8 (range, 0-55), and the final follow-up average was 23.8 (range, 0-109). When a cutoff score was set at 35 points, the sensitivity, specificity, and accuracy of the nomogram to assess malignancy risk were 87.5%, 96.6%, and 96%, respectively. The area under the receiver operating characteristic curve of malignant IPMN prediction during follow-up was 0.865.

CONCLUSIONS

The ability of the nomogram to predict malignancy in patients with IPMN was validated. Our findings can suggest that a follow-up for patients at high and low risk for cancer progression could be scheduled every 3 to 6 and 12 months, respectively.

Imaging features to distinguish malignant and benign branch-duct type intraductal papillary mucinous neoplasms of the pancreas: a meta-analysis

OBJECTIVE

To systematically determine the imaging findings for distinguishing malignant and benign branch-duct type intraductal papillary mucinous neoplasms (BD-IPMNs), including mixed type, and their diagnostic value through meta-analysis of published studies.

BACKGROUND

Management of BD-IPMNs, including mixed type, largely relies on imaging findings. The current knowledge on imaging findings to distinguish malignant and benign BD-IPMNs has weak evidence and is mostly from scattered individual retrospective studies.

METHODS

Thorough literature search in Ovid-MEDLINE and EMBASE databases was conducted to identify studies where findings of computed tomography, magnetic resonance imaging, and endoscopic ultrasonography of BD-IPMNs with or without main pancreatic duct (MPD) dilatation were correlated with surgical/pathological findings. Review of 1128 article candidates, including full-text review of 102 articles, identified 23 eligible articles with a total of 1373 patients for meta-analysis. Dichotomous data regarding distinction between malignant and benign BD-IPMNs were pooled using random effects model to obtain the diagnostic odds ratios (DORs) and their 95% confidence intervals (CIs) of various individual imaging findings for diagnosing malignant BD-IPMN.

RESULTS

Presence of mural nodules revealed the highest pooled DOR (95% CI) of 6.0 (4.1-8.8) followed by MPD dilatation [3.4 (2.3-5.2)], thick septum/wall [unadjusted, 3.3 (1.5-6.9); publication bias-adjusted, 2.3 (0.9-5.5)], and cyst size greater than 3 cm [2.3 (1.5-3.5)]. Multilocularity and multiplicity of the cystic lesions did not reveal statistically significant association with malignancy.

CONCLUSIONS

Presence of mural nodules should be regarded highly suspicious for malignancy warranting a surgical excision whereas cyst size greater than 3 cm, MPD dilatation (5-9 mm), or thick septum/wall may better be managed by careful observation and/or further evaluation.

Pancreatic cystic neoplasms: a review of preoperative diagnosis and management

Pancreatic cystic neoplasms (PCNs) are a diverse group of neoplasms in the pancreas, and are more increasingly encountered with widespread abdominal screening and improved imaging techniques. The most common types of PCNs are serous cystic neoplasms (SCNs), mucinous cystic neoplasms (MCNs), and intraductal papillary mucinous neoplasms (IPMNs). Clinicians frequently feel bewildered in the differential diagnosis and subsequent management among the various types of lesions in the pancreas, which may lead to overtreatment or delayed treatment. The current review provides recent developments in the understanding of the three most common types of PCNs, the latest modalities used in preoperative diagnosis and differential diagnosis, as well as the most up to date management. Suggestions for diagnosis and differential diagnosis of SCNs, MCNs, and IPMNs are also provided for young surgeons. Better understanding of these neoplasms is essential for clinicians to make accurate diagnosis and to provide the best management for patients.

Diagnosis and management of cystic pancreatic lesions

OBJECTIVE

The purpose of this review is to outline the management guidelines for the care of patients with cystic pancreatic lesions.

CONCLUSION

The guidelines are as follows: Annual imaging surveillance is generally sufficient for benign serous cystadenomas smaller than 4 cm and for asymptomatic lesions. Asymptomatic thin-walled unilocular cystic lesions smaller than 3 cm or side-branch intraductal papillary mucinous neoplasms should be followed up with CT or MRI at 6 and 12 months interval after detection. Cystic lesions with more complex features or with growth rates greater than 1 cm/year should be followed more closely or recommended for resection if the patient's condition allows surgery. Symptomatic cystic lesions, neoplasms with high malignant potential, and lesions larger than 3 cm should be referred for surgical evaluation. Endoscopic ultrasound with fine-needle aspiration (FNA) biopsy can be used preoperatively to assess the risk of malignancy.

Differentiating Branch Duct and Mixed IPMN in Endoscopically Collected Pancreatic Cyst Fluid via Cytokine Analysis

Background. Differentiating branch duct from mixed intraductal papillary mucinous neoplasm (BD-IPMN) is problematic, but clinically important as mixed IPMNs are managed surgically, while some BD-IPMN may be followed. Inflammatory mediator proteins (IMPs) have been implicated in acute and chronic inflammatory and malignant pancreatic diseases. Aim. To compare IMP profile of pancreatic cyst fluid collected endoscopically from BD-IPMN and mixed IPMN. Methods. Pancreatic cyst fluid from ten patients (5 BD-IPMN and 5 mixed IPMN) was collected by endoscopic ultrasound-guided fine needle aspiration or endoscopic retrograde cholangiopancreatography. Concentrations of 89 IMPs in these samples were determined using a multiplexed bead-based microarray protein assay and compared between BD-IPMN and mixed IPMN. Results. Eighty-six of 89 IMPs were detected in at least one of the 10 samples. Fourteen IMPs were detected only in mixed IPMN, while none were only in BD-IPMN. Of these, TGF-β1 was most prevalent, present in 3 of 5 mixed IPMNs. Seventy-two IMPs were detected in both BD-IPMN and mixed IPMNs. Of these, only G-CSF (P < 0.05) was present in higher concentrations in mixed IPMNs. Conclusion. TGF-β1 and G-CSF detected in endoscopically collected pancreatic cyst fluid are potential diagnostic biomarkers capable of distinguishing mixed IPMN from BD-IPMN.

One case of common bile duct cancer mimicking cystic neoplasm of the pancreas, arising 9 years after excision of a choledochal cyst

A 42-years-old woman had undergone operation for cholecochal cyst with gallbladder cancer 9 years ago. Pathology revealed a polypoid mass in the gallbladder with liver infiltration as poorly differentiated adenocarcinoma. Computed tomography, magnetic resonance cholangiopancreatography, and endoscopic ultrasound showed a newly developed suspected solid nodule in the peripheral portion of cystic lesion in the pancreas head. She underwent a pylorus preserving pancreaticoduodenectomy for the suspected mucinous cystic neoplasm of the pancreas. Pathology revealed poorly differentiated adenocarcinoma. The remnant choledochal cyst had developed to cholangiocarcinoma, which mimicked cystic neoplasm of the pancreas.

Pancreatico-biliary endoscopic ultrasound: A systematic review of the levels of evidence, performance and outcomes

Our aim was to record pancreaticobiliary endoscopic ultrasound (EUS) literature of the past 3 decades and evaluate its role based on a critical appraisal of published studies according to levels of evidence (LE). Original research articles (randomized controlled trials, prospective and retrospective studies), meta-analyses, reviews and surveys pertinent to gastrointestinal EUS were included. All articles published until September 2011 were retrieved from PubMed and classified according to specific disease entities, anatomical subdivisions and therapeutic applications of EUS. The North of England evidence-based guidelines were used to determine LE. A total of 1089 pertinent articles were reviewed. Published research focused primarily on solid pancreatic neoplasms, followed by disorders of the extrahepatic biliary tree, pancreatic cystic lesions, therapeutic-interventional EUS, chronic and acute pancreatitis. A uniform observation in all six categories of articles was the predominance of LE III studies followed by LE IV, IIb, IIa, Ib and Ia, in descending order. EUS remains the most accurate method for detecting small (< 3 cm) pancreatic tumors, ampullary neoplasms and small (< 4 mm) bile duct stones, and the best test to define vascular invasion in pancreatic and peri-ampullary neoplasms. Detailed EUS imaging, along with biochemical and molecular cyst fluid analysis, improve the differentiation of pancreatic cysts and help predict their malignant potential. Early diagnosis of chronic pancreatitis appears feasible and reliable. Novel imaging techniques (contrast-enhanced EUS, elastography) seem promising for the evaluation of pancreatic cancer and autoimmune pancreatitis. Therapeutic applications currently involve pancreaticobiliary drainage and targeted fine needle injection-guided antitumor therapy. Despite the ongoing development of extra-corporeal imaging modalities, such as computed tomography, magnetic resonance imaging, and positron emission tomography, EUS still holds a leading role in the investigation of the pancreaticobiliary area. The major challenge of EUS evolution is its expanding therapeutic potential towards an effective and minimally invasive management of complex pancreaticobiliary disorders.

[Radiological evaluation of intraductal papillary mucinous neoplasm]

The intraductal papillary mucinous neoplasm (IPMN) is the most frequent cystic neoplasm of the pancreas. Due to the widespread use of cross-sectional imaging IPMN is being incidentally recognized with increasing frequency. The most common type is branch- duct IPMN which occurs multifocally in about 20-30%. Patients with IPMN may present with symptoms resembling chronic pancreatitis and episodes of acute pancreatitis are increasingly being reported which usually have a mild course. The most important diagnostic technique is contrast-enhanced multidetector computed tomography (MDCT), which most frequently allows the differentiation from other cystic lesions and enables the attribution to branch duct or main duct IPMN. Magnetic resonance imaging (MRI) in combination with magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasound are superior in depicting the fine architecture of cystic tumors. Particularly for evaluation of malignant transformation and extent of malignant disease, high resolution imaging is essential. Whereas main duct IPMN is an indication for resection therapy for small and asymptomatic branch duct IPMN periodic surveillance at 6-12 month intervals is recommended.

[Surgical therapy of intraductal papillary mucinous neoplasms of the pancreas]

Intraductal papillary mucinous neoplasms (IPMN) of the pancreas constitute an increasingly recognized entity of cystic pancreatic tumors which are characterized by mucin production and epithelial growth within the pancreatic ducts and show a wide spectrum of morphologic variants. They may arise in the main pancreatic duct, its major side branches or in both (mixed type). Furthermore, IPMNs are considered as precursor lesions to pancreatic adenocarcinoma. However, it is not clear what the time course of such potential neoplastic transformation might be and whether all lesions progress to malignant tumors. As currently no diagnostic test can reliably differentiate between benign and malignant tumors the majority of newly diagnosed IPMNs should be surgically resected. According to current treatment guidelines (Sendai criteria), only asymptomatic side branch IPMNs of less than 3 cm in diameter without suspicious radiologic features, such as nodules, thickness of the cystic wall or size progression, should be treated conservatively without the need for surgical resection. Recently, this approach has become controversial due to a relevant number of reported Sendai negative IPMNs which revealed malignant transformation on final histological examination. The focus of this review is on the surgical treatment of IPMNs with regard to the current state of knowledge.

Pancreatic cystic neoplasms: diagnosis and management

PCNs are composed of a wide range of lesions from benign cysts to malignancies . Although a cross-sectional imaging provides a sensitive screening test, EUS with FNA and cyst fluid analysis greatly increase the diagnostic certainty. Cyst fluid CEA offers the greatest accuracy in the differentiation between mucinous and nonmucinous PCNs. In the future, endoscopic ablation therapy might offer an alternative to the traditional surgical approach.

Endoscopic ultrasonographic findings predict the risk of carcinoma in branch duct intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND

The preoperative diagnosis of branch duct intraductal papillary mucinous neoplasm (IPMN) of the pancreas can be very difficult, since low-risk and high-risk lesions can be difficult to differentiate even after cytological analysis. The purpose of this study was to evaluate the preoperative diagnostic value of endoscopic ultrasonography (EUS) in differentiating low-risk and high-risk IPMNs.

METHODS

We retrospectively identified 36 patients who underwent preoperative EUS for branch duct IPMNs. The pathological diagnosis after surgical resection was low-grade dysplasia (n = 26), moderate dysplasia (n = 1), high-grade dysplasia or carcinoma in situ (n = 5), and invasive carcinoma (n = 4). We divided the patients into two groups: low risk (low-grade dysplasia or moderate dysplasia) and high risk (high-grade dysplasia or carcinoma). We focused on the diameter of the cystic dilated branch duct, the main pancreatic duct, and the mural nodule as measured using the EUS findings.

RESULTS

The cystic dilated branch duct diameter (31.5 mm vs. 41.9 mm, P = 0.0225) was significantly correlated with low-risk and high-risk IPMNs, but the main pancreatic duct diameter (5.37 mm vs. 5.44 mm, P = 0.9418) was not significantly correlated with the low-risk and high-risk IPMNs. The mural nodule diameter of the papillary protrusions (4.3 mm vs. 16.4 mm, P < 0.0001) and the width diameter of the mural nodule (5.7 mm vs. 23.2 mm, P < 0.0001) were significantly correlated with low-risk and high-risk IPMNs.

CONCLUSIONS

The mural nodule of papillary protrusions diameter and width diameter observed using EUS was a reliable preoperative diagnostic finding capable of distinguishing low-risk and high-risk IPMNs.

Development of pancreatic ductal adenocarcinoma associated with intraductal papillary mucinous neoplasia

We retrospectively investigated the incidence of pancreatic ductal adenocarcinoma among patients with intraductal papillary mucinous neoplasms of the pancreas. Based on imaging in 195 such patients, we chose surgery as initial treatment for 54, and periodic evaluation over 6 to 192 months (mean, 52) for 141. In 6 of the 141 patients observed for intraductal papillary mucinous neoplasm (4.2%), pancreatic ductal adenocarcinoma developed. Further, careful monitoring for cancer occurrence in the remnant pancreas proved essential in the surgical resection group; 2 of 26 patients (7.7%) subsequently developed pancreatic ductal adenocarcinoma in the remnant pancreas, at 41 months and 137 months after surgery. Serial observation of patients with intraductal papillary mucinous neoplasms by contrast-enhanced computed tomography or magnetic resonance cholangiopancreatography therefore is critical, whether or not surgical treatment initially was performed.

Current status on the diagnosis and management of pancreatic cysts in the Asia-Pacific region: role of endoscopic ultrasound

Endoscopic ultrasound (EUS) and EUS-guided fine-needle aspiration (EUS-FNA) play increasingly prominent roles in the diagnosis and management of pancreatic cysts. The Asian Consortium of Endoscopic Ultrasound was recently formed to conduct collaborative research in this area. This is a review of literature on true pancreatic cysts. Due to the lack of systematic studies, there are no robust data on the true incidence of pancreatic cystic lesions in Asia and any change in over the recent decades. Certain EUS morphological features have been used to predict particular types of pancreatic cysts. Pancreatic cyst fluid viscosity, cytology, pancreatic enzymes, and tumor markers, in particular carcinoembryonic antigen, can aid in the diagnosis of pancreatic cysts. Hemorrhage and infection are the most common complications of EUS-FNA of pancreatic cysts. Pancreatic cysts can either be observed or resected depending on the benign or malignant nature, or malignant potential of the lesions. Guidelines from an international consensus did not require positive cytological findings to be present in their recommendation for resection, which included all mucinous cystic neoplasms, all main-duct intraductal papillary mucinous neoplasms (IPMN), all mixed IPMN, symptomatic side-branch IPMN, and side-branch IPMN larger than 3 cm. In patients with poor surgical risks, EUS-guided cyst ablation of mucinous pancreatic cysts is an alternative. As long-term prospective data on pancreatic cysts are still not available in Asia, management strategies are largely based on risk stratification by surgical risk and malignant potential. Gene expression profiling of pancreatic cyst fluid and confocal laser endomicroscopic examination of pancreatic cysts are novel techniques currently being studied.

Diagnosis and treatment of cystic pancreatic tumors

Cystic pancreatic tumors (CPTs) have more frequently been identified in the last decade because of increased use of cross-sectional abdominal imaging. Although serous CPTs follow an indolent course and do not necessarily require surgical resection or long-term follow-up, mucinous CPTs (mucinous cystic neoplasms and intraductal papillary mucinous neoplasms) have a greater risk for malignancy. Although most CPTs are initially detected with imaging modalities such as computed tomography or magnetic resonance imaging, these tests alone rarely permit an accurate clinical diagnosis. Endoscopic ultrasound and endoscopic ultrasound-guided, fine-needle aspiration allow real-time examination and biopsy analysis of CPTs, which increases diagnostic accuracy because cytopathology features and tumor markers in cyst fluid can be analyzed. Management of patients with mucinous CPTs by surgery or imaging surveillance is controversial, partially because of limited information about disease progression and the complexities of surgical resection. We review approaches to diagnosis and management of common CPTs.

Cystic pancreatic lesions: current evidence for diagnosis and treatment

Pancreatic cystic neoplasms are detected at an increasing frequency due to an increased use and quality of abdominal imaging. There are well known differential diagnostic difficulties concerning these lesions. The aim is to review current literature on the diagnostic options and the following treatment for cystic lesions in the pancreas focusing on serous cystadenomas, primary mucinous neoplasm of the pancreas and mucinous cystadenocarcinomas, as well as intraductal papillary mucinous neoplasms, starting with excluding pseudocysts. A conservative approach is feasible in patients with a clinical presentation suggestive of an asymptomatic serous cystadenoma. Surgical management, as well as follow-up, is discussed for each of the types of neoplastic lesions, including an uncharacterized cyst, based on patient data, symptoms, serum analysis, cyst fluid analysis and morphological features. Aspects for future diagnostics and management of these neoplasia are commented upon.

Determination of malignant and invasive predictors in branch duct type intraductal papillary mucinous neoplasms of the pancreas: a suggested scoring formula

Prediction of malignancy or invasiveness of branch duct type intraductal papillary mucinous neoplasm (Br-IPMN) is difficult, and proper treatment strategy has not been well established. The authors investigated the characteristics of Br-IPMN and explored its malignancy or invasiveness predicting factors to suggest a scoring formula for predicting pathologic results. From 1994 to 2008, 237 patients who were diagnosed as Br-IPMN at 11 tertiary referral centers in Korea were retrospectively reviewed. The patients' mean age was 63.1 ± 9.2 yr. One hundred ninty-eight (83.5%) patients had nonmalignant IPMN (81 adenoma, 117 borderline atypia), and 39 (16.5%) had malignant IPMN (13 carcinoma in situ, 26 invasive carcinoma). Cyst size and mural nodule were malignancy determining factors by multivariate analysis. Elevated CEA, cyst size and mural nodule were factors determining invasiveness by multivariate analysis. Using the regression coefficient for significant predictors on multivariate analysis, we constructed a malignancy-predicting scoring formula: 22.4 (mural nodule [0 or 1]) + 0.5 (cyst size [mm]). In invasive IPMN, the formula was expressed as invasiveness-predicting score = 36.6 (mural nodule [0 or 1]) + 32.2 (elevated serum CEA [0 or 1]) + 0.6 (cyst size [mm]). Here we present a scoring formula for prediction of malignancy or invasiveness of Br-IPMN which can be used to determine a proper treatment strategy.

Size of mural nodule as an indicator of surgery for branch duct intraductal papillary mucinous neoplasm of the pancreas during follow-up

BACKGROUND

A mural nodule is a strong predictive factor for malignancy in branch duct intraductal papillary mucinous neoplasm (IPMN) of the pancreas, but the nodule size has hardly been considered. The aim of this study was to investigate whether a mural nodule of 10 mm was appropriate as an indicator of surgery for IPMN during follow-up.

METHODS

The follow-up outcomes of 100 patients who had branch duct IPMN without mural nodules or who had branch duct IPMN with mural nodules of less than 9 mm in a tertiary care setting were investigated retrospectively. The patients underwent abdominal ultrasound (US) every 3 months and additional imaging examinations or cytologic examination of pancreatic juice when necessary. Surgery was recommended to them when a mural nodule developed or when a nodule enlarged and reached 10 mm.

RESULTS

During an average follow-up period of 97 months, branch duct IPMNs developed mural nodules that reached 10 mm in 5 patients (0.62% per year). In one patient the IPMN was revealed to be non-invasive carcinoma by resection, 1 IPMN was shown to be malignant by further follow-up, and 3 were not resected because of refusal or the patient's age. In 7 patients, mural nodules stayed within 9 mm. The remaining 88 patients lacked mural nodules in their branch duct IPMNs throughout the follow-up. The occurrence of invasive carcinoma around the IPMN was not indicated by imaging examinations in any patient. Univariate analysis showed that the size of the cyst at baseline significantly predicted the development of a mural nodule that reached 10 mm during follow-up (P = 0.05).

CONCLUSIONS

A mural nodule of 10 mm is appropriate as an indicator of surgery in the follow-up of branch duct IPMN.

Primary pancreatic cystic neoplasms revisited. Part III. Intraductal papillary mucinous neoplasms

Intraductal papillary mucinous neoplasms (IPMNs) represent about 25% of all primary pancreatic cystic neoplasms and are increasingly recognized during the last two decades. They are characterized by intraductal proliferation of neoplastic mucinous cells forming papillary projections into the pancreatic ductal system, which is typically dilated and contains globules of mucus. IPMNs may be multifocal and have malignant potential. Modern imaging is essential in establishing preoperative diagnosis and in differentiating different subtypes of IPMNs (i.e., main-duct vs. branch-type disease). Endoscopic retrograde or magnetic resonance cholangiopancreatography accurately delineate the morphologic changes of the pancreatic ductal system. Endoscopic ultrasonography (usually used in conjunction with image-guided FNA and analysis of the aspirated material) is commonly used for differential diagnosis of IPMNs from other pancreatic cystic lesions. Surgical resection (usually anatomic pancreatectomy, depending on the location of the disease) is the treatment of choice. Total pancreatectomy may occasionally be required in selected patients, but is associated with formidable long-term morbidity. A conservative approach has recently been proposed for carefully selected patients with branch-duct IPMNs. Recurrences following surgical resection can be observed, especially in patients with multifocal disease or in the presence of underlying malignancy.

Transforming growth factor α levels in pancreatic fluid

To determine if the level of transforming growth factor α (TGF-α) in the pancreatic fluid (PF) can diagnose intraductal papillary mucinous neoplasm (IPMN) versus other cystic lesions of the pancreas in patients.

METHODS

Pancreatic fluid was prospectively obtained from patients during routine endoscopy and/or operation at Indiana University Hospital. Pancreatic fluid TGF-α levels were analyzed by enzyme-linked immunosorbent assay. Intraductal papillary mucinous neoplasm tissue was also analyzed by TGF-α immunohistochemistry.

RESULTS

Sixty-nine fluid samples from 58 patients with the following pathologically confirmed pancreatic disorders were analyzed: IPMN (26 patients), serous cystadenoma (6), mucinous cystic neoplasm (9), pseudocysts (5), non-IPMNY associated pancreatic ductal adenocarcinoma (6), and sphincter of Oddi dysfunction (6). There was no significant difference between the mean PF-TGF-α levels in each category or between different dysplastic grades of IPMN. However, of all the diagnoses examined, only IPMN demonstrated PF-TGF-α levels greater than 95 pg/mL. In low-grade IPMN specimens, TGF-α immunohistochemistry correlated with enzyme-linked immunosorbent assay levels.

CONCLUSIONS

The mean PF-TGF-α levels are not significantly different in IPMN lesions compared with those in other cystic pancreatic lesions, pancreatic ductal adenocarcinoma, or sphincter of Oddi dysfunction. However, PF-TGF-α levels more than 95 pg/mL may be useful in diagnosing IPMN. This assertion requires prospective validation.