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

Progress in diagnosis and treatment of intraductal papillary mucinous neoplasms

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

Endoscopic techniques for diagnosis and therapy of pancreatic intraductal papillary mucinous neoplasm

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a cystic neoplasm with potential malignancy. In the past, screening of IPMN depended on traditional imaging examinations, such as transabdominal ultrasonography and computed tomography (CT). With the development of endoscopic techniques, endoscopic ultrasound (EUS), endoscopic retrograde cholangiopancreatography (ERCP) and other endoscopic techniques are becoming significant diagnostic methods for IPMN. Meanwhile, endoscopic interventional therapy with the advantage of minimal invasiveness has been used to treat some patients who cannot tolerate or refuse surgery. This paper elucidates the advances in diagnosis and therapy of pancreatic IPMNs using endoscopic techniques.

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.

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.

Prevalence of malignancy in patients with pure main duct intraductal papillary mucinous neoplasms

BACKGROUND

Risk of malignancy in main duct intraductal papillary mucinous neoplasm (MD-IPMN) ranges from 36% to 100% in the literature. Although surgical resection is recommended for all MD-IPMNs, the risk of malignancy based on main pancreatic duct (MPD) size alone remains unclear.

OBJECTIVE

To assess the prevalence of malignancy in symptomatic and asymptomatic patients with pure MD-IPMN based on MPD size.

DESIGN

Single-center retrospective study of prospectively collected data.

SETTINGS

Tertiary referral center.

PATIENTS AND INTERVENTIONS

Fifty-two patients with pure low-risk MD-IPMN. Clinical, endoscopic, radiographic, and pathologic data were reviewed.

MAIN OUTCOME MEASUREMENTS

Prevalence of malignancy in patients with pure MD-IPMN based on histopathology of resected lesions.

RESULTS

Sixteen asymptomatic patients had pure MD-IPMN on surgical pathology, 4 (25%) with malignant disease, compared with 25 of 36 symptomatic patients (69%) with pure MD-IPMN. Logistic regression identified symptoms and MPD size as predictors of malignancy. Receiver operating characteristic curve analysis demonstrated that MPD size (optimal cutoff of 8 mm) produced the greatest area under the curve to discriminate between benign and malignant MD-IPMN (.83; 95% CI, .72-.94). MPD size greater than 8 mm has a relative risk of 2.8 for malignancy (95% CI, 1.6-4.9).

LIMITATIONS

Retrospective, single-center study at a tertiary referral hospital. Study population included only patients who underwent surgical resection.

CONCLUSION

Asymptomatic MD-IPMN patients with a duct size of no more than 8 mm have a lower prevalence of malignancy and may represent a distinct group of patients with less aggressive biologic behavior. Further studies are needed to confirm our observations.

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.

Potential predictors of disease progression for main-duct intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND AND AIM

The evidence for main pancreatic duct intraductal papillary mucinous neoplasms (MPD-IPMN) malignancy is based predominantly on investigation of resected cases, and the natural history is still unclear. The aim of the present study is to investigate the natural history of MPD-IPMN and examine potential predictors of disease progression in MPD-IPMN patients who conformed to "high-risk stigmata" criteria.

METHODS

This study included consecutive 20 follow-up patients and 19 surgical patients with "high-risk stigmata" MPD-IPMN, in whom the diameter of the MPD was > 10 mm, branch duct was < 5 mm, and who underwent clinical follow up for ≥ 2 years.

RESULTS

Among surgical patients, mural nodules and MPD diameter of invasive patients were significantly different compared with non-invasive patients. On the other hand, among follow-up patients, univariate analysis revealed the following potential predictors for disease progression: diameter of MPD ≥ 15 mm (hazard ratio [HR], 20.9; 95% confidence interval [CI], 2.59-173.4; P < 0.01); and diffuse lesions of MPD-IPMN (HR, 4.46; 95% CI, 1.10-18.0; P = 0.04). On the other hand, multivariate analysis identified only diameter of MPD ≥ 15 mm (HR, 19.2; 95% CI, 1.87-198.5; P = 0.01) as a potential predictor of disease progression.

CONCLUSION

If MPD-IPMN patients have other severe complications or reasons for not undergoing surgical treatment, MPD diameter < 15 mm, negative cytology, and no mural nodules, conservative clinical follow up for several years may be an option.

Three-dimensional contrast-enhanced ultrasonography of intraductal papillary mucinous neoplasms of the pancreas: a comparison with magnetic resonance imaging

OBJECTIVES

The objective of this study was to prospectively compare the diagnostic accuracy of 3-dimensional contrast-enhanced ultrasonography (3D-CEUS) with that of magnetic resonance imaging (MRI) in the study of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas.

METHODS

Thirty consecutive patients with IPMN were studied.

RESULTS

Three patients (10.0%) did not undergo diagnostic 3D-CEUS because of technical problems. Three dimensional CEUS identified 12 (44.4%) main-duct IPMNs versus no cases by MRI (P < 0.001). Intraductal papillary mucinous neoplasm localization showed poor agreement between 3D-CEUS and MRI (κ = 0.058), whereas good agreement was found in detecting the pancreatic calcifications (κ = 1.000). Significant differences between 3D-CEUS and MRI were found regarding the number of lesions detected (1.4 ± 0.8 vs 3.8 ± 3.6; P < 0.001), the detection of mucinous plugs (3.7% vs 50.0%; P < 0.001), chronic pancreatitis (7.4% vs 26.7%; P = 0.031), pancreatic atrophy (0% vs 50.0%; P < 0.001), thick septa (22.2% vs 53.3%; P = 0.004), and mural nodules (25.9% vs 3.3%; P = 0.016). Three dimensional CEUS showed similar results as compared with MRI in evaluating IPMNs smaller than 1 cm of diameter or greater than 2 cm.

CONCLUSIONS

Even if MRI remains the criterion standard technique for the diagnosis of IPMNs, 3D-CEUS can be safely used to follow patients with IPMNs of less than 1 cm.

IPMN: surgical treatment

PURPOSE

Cystic pancreatic tumors are being detected more frequently, and particularly, intraductal papillary mucinous neoplasia (IPMN) has recently attracted increased attention. The detection rate of IPMN has increased over the last decade; however, management of this neoplasm remains controversial.

METHODS

Based on a review of the relevant literature and the international guidelines, we discuss the diagnostic evaluation of IPMN, its treatment, and prognosis.

RESULTS

While IPMN represents only a distinct minority of all pancreatic cancers, they appear to be a relatively frequent neoplastic form of pancreatic cystic neoplasm. It may not be possible to differentiate main duct disease from branch duct disease (MD-IPMN vs. BD-IPMN) prior to surgery. This distinction has not only an impact on treatment but also on prognosis, as MD-IPMN is more often malignant. IPMN has updated consensus guideline indications for conservative and surgical resection.

CONCLUSIONS

Since patients with IPMN of the pancreas are at risk of developing recurrent IPMN and pancreatic ductal adenocarcinoma in the remnant pancreas and extrapancreatic malignancies, early recognition, treatment, and systemic surveillance are of great importance. No conclusions can be drawn from the available evidence with respect to the efficacy of surveillance and follow-up treatment programs. A better understanding of the natural course of IPMN and the biology of pancreatic cancer is mandatory to enable further diagnostic and treatment improvements.

Cyst features and risk of malignancy in intraductal papillary mucinous neoplasms of the pancreas: a meta-analysis

BACKGROUND & AIMS

International guidelines for the management of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas recommend surgical resection of those with specific characteristics. We performed a meta-analysis to evaluate the risk of malignancy associated with each of these features of IPMNs.

METHODS

We performed a comprehensive search of MEDLINE from January 1, 1996, to November 11, 2011, for studies that included any of the features mentioned in the consensus guidelines for surgical resection of main duct and branch duct IPMNs. Data were analyzed from 41 studies for the following features: cyst size greater than 3 cm, the presence of mural nodules, dilated main pancreatic duct, symptoms, and main duct vs branch duct IPMNs. Malignant IPMNs were defined as those with carcinoma in situ or more advanced histology. A separate meta-analysis was performed for each risk factor to calculate pooled odds ratios (ORs). A random-effects model was used, based on the assumption of variation among study populations.

RESULTS

The risks of malignancy associated with individual cyst features were as follows: cyst size greater than 3 cm (OR, 62.4; 95% confidence interval [CI], 30.8-126.3), presence of a mural nodule (OR, 9.3; 95% CI, 5.3-16.1), dilatation of the main pancreatic duct (OR, 7.27; 95% CI, 3.0-17.4), and main vs branch duct IPMN (OR, 4.7; 95% CI, 3.3-6.9). There was a moderate level of heterogeneity among studies (I(2) range, 34-67).

CONCLUSIONS

Based on a meta-analysis, cyst features proposed by the international guidelines for resection of IPMN were highly associated with malignancy. However, based on our findings, not all cyst features should be weighted equally when considering risk of malignancy; cyst size greater than 3 cm was associated most strongly with malignant IPMN.

Prevalence and risk factors of extrapancreatic malignancies in a large cohort of patients with intraductal papillary mucinous neoplasm (IPMN) of the pancreas

BACKGROUND

The objectives of this study are to estimate prevalence and incidence of extrapancreatic malignancies (EPMs) among intraductal papillary mucinous neoplasms (IPMNs) of the pancreas, and to identify risk factors for their occurrence.

PATIENTS AND METHODS

We conducted multicentric cohort study in Italy from January 2010 to January 2011 including 390 IPMN cases. EPMs were grouped as previous, synchronous (both prevalent) and metachronous (incident). We calculated the observed/expected (O/E) ratio of prevalent EPMs, and compared the distribution of demographic, medical history and lifestyle habits.

RESULTS

Ninety-seven EPMs were diagnosed in 92 patients (23.6%), among them 78 (80.4%) were previous, 14 (14.4%) were synchronous and 5 (5.2%) were metachronous. O/E ratios for prevalent EPMs were significantly increased for colorectal carcinoma (2.26; CI 95% 1.17-3.96), renal cell carcinoma (6.00; CI 95% 2.74-11.39) and thyroid carcinoma (5.56; CI 95% 1.80-12.96). Increased age, heavy cigarette smoking, alcohol consumption and first-degree family history of gastric cancer are significant risk factors for EPMs, while first-degree family history of colorectal carcinoma was borderline.

CONCLUSION

We report an increased prevalence of EPMs in Italian patients with IPMN, especially for colorectal carcinoma, renal cell and thyroid cancers. A systematic surveillance of IPMN cases for such cancer types would be advised.

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

OBJECTIVE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Cystic and ductal tumors of the pancreas: diagnosis and management

Incidentally discovered cystic tumors of the pancreas (CTP) are an increasingly frequent entity. It is essential to differentiate lesions whose malignant potential is either nil or negligible (pseudocyst, serous cystadenoma, simple cysts) from lesions with intermediate malignant potential (intraductal papillary mucinous tumor of the pancreas [IPMN] involving the secondary ducts, cystic endocrine tumor) or those with high malignant potential (mucinous cystadenoma, solid pseudopapillary tumors and IPMN involving the main pancreatic duct). The approach to defining malignant potential is based on diagnostic CT scan, magnetic resonance imaging (MRI), and endoscopic ultrasound (EUS), often complemented by EUS-guided cyst puncture for biochemical and cytological analysis of cyst fluid. Surgery for diagnostic purposes should be avoided because of its significant morbidity. For pseudocysts, simple cysts and serous cystadenomas, abstention is the general rule. Resection, preserving as much pancreatic parenchyma as possible, is the rule for IPMN involving the main pancreatic duct, mucinous cystadenomas, solid and pseudopapillary tumors, and cystic endocrine tumors. Resection is rarely indicated at the outset for IPMN involving secondary pancreatic ducts; morphologic observation is the general rule and preventive excision may be indicated secondarily. Good collaboration between surgeons, radiologists and endosonographists is necessary for optimal management of CTP.

Percutaneous fine needle biopsy in pancreatic tumors: a study of 42 cases

The technological progress within the range of methods of pancreas imaging and their more common accessibility selects a group of patients requiring a microscopic diagnosis. Percutaneous fine needle aspiration biopsy under the control of ultrasonography (PCFNA/USG) is the method commonly used in determining the character of a focal pancreatic lesion. Aim of the Work. An assessment of the accessibility of PCFNA biopsy in the assessment of solid and cystic changes in a pancreas and the correlation of the results of imaging examination, cytological smear and concentration of a serous marker CA19-9. Material and Methodology. In our material we analysed 43 cases of tumors of the pancreas among the patients who were at the average age of 59 ± 10.4 (14 women, 28 men) diagnosed by PCFNA biopsy. Results. In a group we are 23 cases of cancer, 12 cases of inflammation and 7 cases of cellular atypia for which 2 cases of IPMN were included. The sensitivity of the method was 92.5% but specificity was 68%. In our opinion PCFNA/USG is a method of the comparable sensitivity and specificity with fine needle aspiration biopsy with EUS control and its efficiency depends to a considerable degree on experience and interdisciplinary collaboration.

Contrast-enhanced harmonic endoscopic ultrasonography in pancreatic diseases

Endoscopic ultrasonography (EUS) is the most sensitive imaging method for diagnosis of pancreatic tumors. However, it still has limits in the differentiation between pancreatic cancers and inflammatory tumor-like masses. A novel technology, contrast-enhanced harmonic EUS (CH-EUS), has been developed recently. It can visualize both parenchymal perfusion and microvasculature in pancreas without Doppler-related artifacts. Therefore, it is superior to EUS and CT in detecting small pancreatic masses and differential diagnosis of pancreatic masses. CH-EUS could be used for adequate sampling of pancreatic tumors and may predict the pathological features of the pancreatic solid lesions but still cannot replace EUS-FNA now.

Contrast-enhanced endoscopic ultrasonography in digestive diseases

Contrast-enhanced endoscopic ultrasonography (CE-EUS) was introduced in the early 1990s. The concept of the injection of carbon dioxide microbubbles into the hepatic artery as a contrast material (enhanced ultrasonography) led to "endoscopic ultrasonographic angiography". After the arrival of the first-generation contrast agent, high-frequency (12 MHz) EUS brought about the enhancement of EUS images in the diagnosis of pancreatico-biliary diseases, upper gastrointestinal (GI) cancer, and submucosal tumors. The electronic scanning endosonoscope with both radial and linear probes enabled the use of high-end ultrasound machines and depicted the enhancement of both color/power Doppler flow-based imaging and harmonic-based imaging using second-generation contrast agents. Many reports have described the usefulness of the differential diagnosis of pancreatic diseases and other abdominal lesions. Quantitative evaluation of CE-EUS images was an objective method of diagnosis using the time-intensity curve (TIC), but it was limited to the region of interest. Recently developed Inflow Time Mapping™ can be generated from stored clips and used to display the pattern of signal enhancement with time after injection, offering temporal difference of contrast agents and improved tumor characterization. On the other hand, three-dimensional CE-EUS images added new information to the literature, but lacked positional information. Three-dimensional CE-EUS with accurate positional information is awaited. To date, most reports have been related to pancreatic lesions or lymph nodes. Hemodynamic analysis might be of use for diseases in other organs: upper GI cancer diagnosis, submucosal tumors, and biliary disorders, and it might also provide functional information. Studies of CE-EUS in diseases in many other organs will increase in the near future.

Malignant transformation of branch duct-type intraductal papillary mucinous neoplasms of the pancreas based on contrast-enhanced endoscopic ultrasonography morphological changes: focus on malignant transformation of intraductal papillary mucinous neoplasm itself

OBJECTIVES

The natural history of branch duct-type intraductal papillary mucinous neoplasms (BD-IPMNs) of the pancreas remains unclear. We conducted a retrospective long-term follow-up study for malignant transformation (MT) of BD-IPMNs focusing on morphological changes.

METHODS

The subjects consisted of 142 patients who underwent contrast-enhanced endoscopic ultrasonography for initial diagnosis from January 2001 with more than 12 months of follow-up. The MT rate, including the co-occurrence of invasive ductal cancer, was evaluated by univariate and multivariate analysis. In addition, on the basis of morphological changes in patients who underwent surgery, the predictive factors for malignant IPMNs were evaluated.

RESULTS

Median follow-up term was 42.5 months (range, 12-105 months). Thirty patients who exhibited morphological changes underwent surgery. Malignant transformation occurred in 9 patients (6.3%), and 5-year MT rate was 10.7%. The co-occurrence of invasive ductal cancer was seen in 5 patients. Multivariate analysis showed that the existence of mural nodules at initial diagnosis and involvement of main pancreatic duct were significant predictors of MT of BD-IPMN.

CONCLUSIONS

Malignant transformation of BD-IPMN is not rare. The observation of morphological changes of main pancreatic duct and nodules, mainly on contrast-enhanced endoscopic ultrasonography, is practical and useful for predicting MT of BD-IPMN itself.

Interobserver agreement in contrast harmonic endoscopic ultrasound

BACKGROUND AND AIM

Contrast harmonic endoscopic ultrasound (CH-EUS) was recently introduced to clinical practice; its reproducibility among endosonographers is unknown. Our aim was to assess the interobserver agreement (IA) in CH-EUS.

METHODS

Fifteen endosonographers (eight experienced and seven non-experienced) from 11 Italian EUS centers evaluated 80 video-cases (40 solid pancreatic lesions, 20 pancreatic cystic lesions and 20 submucosal lesions) of CH-EUS, according to the degree of enhancement, the pattern of distribution and the washout of the contrast agent. IA within each group and between the two groups of observers was assessed with the Fleiss kappa statistic.

RESULTS

Overall IA was moderate for the uptake and fair for the pattern of distribution and the washout. In solid pancreatic lesions, IA was moderate for the uptake and fair for the pattern and the washout. In cystic pancreatic lesions, IA was uniformly moderate for the assessment of uptake, slight for the pattern and fair for the washout. In submucosal tumors, IA was substantial for the uptake, slight for the pattern and fair for the washout. Non-experienced endosonographers demonstrated, in most cases, comparable IA with the experienced ones.

CONCLUSIONS

Interobserver agreement among endosonographers for CH EUS was satisfactory. In particular, overall IA varied from slight to substantial, being fair in the majority of cases. Inherent structural features of the lesions, as well as technical differences between the variables assessed, could have accounted for the fluctuation of the results. Outcomes of IA were reproducible between experienced and non-experienced endosonographers.

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

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

Histologic and imaging features of mural nodules in mucinous pancreatic cysts

BACKGROUND & AIMS

Mural nodules predict malignancy within pancreatic cysts, but it is not clear whether endoscopic ultrasound (EUS) and computed tomography (CT) accurately identify nodules. We assessed images and the histology of mural nodules in branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) and mucinous cystic neoplasms (MCNs) and identified criteria to distinguish mural nodules from mucus.

METHODS

We reviewed pathology specimens and EUS and CT images from consecutive patients with resected BD-IPMNs or MCNs. A blinded interobserver study of the EUS images was then conducted to identify features that distinguished nodules from mucus. After education about these features, the raters interpreted the EUS images again.

RESULTS

On the basis of histologic analysis, 22 of 57 cases had epithelial nodules. Cancer or high-grade dysplasia was found in 23% of cysts with nodules versus 3% without nodules (P = .02). On the basis of reports, EUS detected epithelial nodules with 75% sensitivity and 83% specificity, whereas these values were 24% and 100%, respectively, for CT. Mucus accounted for 65% of intracystic lesions detected by EUS and was often diagnosed by using change in body position and fine-needle aspiration. Interobserver analysis identified 3 features that were detected by EUS (echogenicity, edge, and rim) that distinguished mucus from epithelial nodules. The diagnostic accuracy of the raters improved from a mean of 57% to 79% after education about these features (P = .004); accuracy was 90% when all 3 features of mucus were present.

CONCLUSIONS

Malignancy is associated with epithelial nodules in BD-IPMNs and MCNs, but most echogenic lesions detected in cysts by EUS are mucus. Knowledge of features that discriminate mucus from mural nodules improves the diagnostic accuracy of EUS.

Comparison of International Consensus Guidelines versus 18-FDG PET in detecting malignancy of intraductal papillary mucinous neoplasms of the pancreas

OBJECTIVE

To assess the reliability of the International Consensus Guidelines (ICG) and 18-fluorodeoxyglucose positron emission tomography (PET) in distinguishing benign from malignant intraductal papillary mucinous neoplasms (IPMNs) of the pancreas.

BACKGROUND

Since 2006 the ICG have been used to choose immediate surgery or surveillance for IPMN patients, but their low specificity increases the number of benign IPMNs that undergo resective surgery. PET has proved highly sensitive and specific in detecting malignancy in cystic neoplasms of the pancreas, including IPMNs.

METHODS

Patients suspected with IPMNs of the pancreas seen at our Department from January 1989 to July 2010 were identified and classified as cases of main duct, mixed type and branch type IPMN. The indication for resection or surveillance was verified a posteriori for all patients according to the ICG. PET was considered positive for a Standardized Uptake Value ≥2.5. Surveillance included clinical examination, laboratory tests, CA 19-9 serum levels, and computed tomography and/or magnetic resonance and magnetic resonance cholangiopancreatography every 6 months for 2 years and yearly thereafter. Endoscopic ultrasound was rarely performed. PET was repeated in clinically or radiologically suspect cases, or if tumor markers increased.

RESULTS

Sixty-one main duct or mixed type and 101-branch type IPMNs were included in the study. A histological diagnosis was available for 81 of 162 patients, missing for 1 locally advanced IPMN, whereas 62 patients are under surveillance and it proved impossible to contact 18. Conservative surgery was performed in 16 of 68 patients with benign IPMNs. The sensitivity, specificity, positive and negative predictive value, and accuracy of the ICG in detecting malignancy were 93.2, 22.2, 59.4, 72.7, and 61.2, whereas for PET they were 83.3, 100, 100, 84.6, and 91.3.

CONCLUSIONS

PET is more accurate than the ICG in distinguishing benign from malignant (invasive and noninvasive) IPMNs. Prophylactic IPMN resection in young patients fit for surgery should be guided by the ICG, whereas PET should be performed in older patients, cases at increased surgical risk, or when the feasibility of parenchyma-sparing surgery demands a reliable preoperative exclusion of malignancy.

Comparison of pancreatic head resection with segmental duodenectomy and pylorus-preserving pancreatoduodenectomy for benign and low-grade malignant neoplasms of the pancreatic head

OBJECTIVE

The aim of this study was to investigate the clinical benefits of pancreatic head resection with segmental duodenectomy (PHRSD) with a particular emphasis on the long-term outcome.

METHODS

A retrospective analysis of PHRSD (77 patients) and pylorus-preserving pancreatoduodenectomy (PPPD; 55 patients) was performed for benign and low-grade malignant neoplasms of the pancreatic head. The zintraoperative and postoperative courses and long-term nutritional statuses were compared.

RESULTS

The mean operative time and blood loss were significantly less in the PHRSD group than in the PPPD group (351 vs 395 minutes, P = 0.005; and 474 vs 732 mL, P < 0.0001, respectively). Fewer overall postoperative complications occurred in the PHRSD group than in the PPPD group (33.8% vs 52.7%, respectively, P = 0.03). Postoperative weight loss and changes in the serum total protein and albumin levels were significantly milder in the PHRSD group than in the PPPD group (P = 0.04, P = 0.04, and P = 0.046, respectively). The overall recurrence-free survival rates in patients with noninvasive intraductal papillary mucinous neoplasms were equivalent in both groups.

CONCLUSIONS

The present results suggest that PHRSD fulfills the operative safety, long-term nutritional status, and curative goals and could be the best option for patients with benign or low-grade malignant pancreatic lesions.

Dynamic quantitative evaluation of contrast-enhanced endoscopic ultrasonography in the diagnosis of pancreatic diseases

OBJECTIVES

This study aimed to investigate the usefulness of contrast-enhanced endoscopic ultrasonography (EUS) with time-intensity curve (TIC) in differentiating pancreatic diseases.

METHODS

Patients who underwent contrast-enhanced EUS between January 2007 and June 2009 were analyzed retrospectively, including 48 with pancreatic ductal cancer (PC), 14 with autoimmune pancreatitis (AIP), 13 with mass-forming pancreatitis (MFP), and 16 with pancreatic endocrine tumor (PET). After intravenous injection of contrast agent, contrast imaging pattern, TIC-based quantitative evaluation, and diagnostic ability of EUS in combination with TIC to diagnose benignancy or malignancy were assessed.

RESULTS

Hypovascular and heterogeneous pattern (42/48) in PC, isovascular and homogenous (21/27) in AIP and MFP, and hypervascular and rapid stained (16/16) in PET were observed. The echo intensity reduction rate from the peak at 1 minute was the greatest in PC followed by MFP, AIP, and PET (P < 0.05). The diagnostic accuracies based on contrast imaging pattern (84.0%) and TIC (88.0%) were higher than those based on B-mode imaging (82.6%) and dynamic computed tomography (81.3%). In EUS in combination with TIC, sensitivity, specificity, and accuracy rose up to 95.8%, 92.6%, and 94.7%, respectively.

CONCLUSIONS

Contrast-enhanced EUS with the dynamic quantitative analysis preparing TIC increased the diagnostic accuracy for pancreatic diseases.

Clinical oncology for pancreatic and biliary cancers: Advances and current limitations

In the early 2000s, the main stream of endoscopic ultrasonography (EUS) changed from a mechanical scanning method to electronic radial or linear scanning methods. Subsequently, useful applications in trans-abdominal ultrasonography came within reach of EUS. In particular, contrast-enhanced EUS (CE-EUS) and EUS-elastography became cutting-edge diagnostic modalities for pancreatic disorders. Each type of pancreatic disorder has characteristic hemodynamics. CE-EUS uses color Doppler flow imaging and harmonic imaging to classify pancreatic lesions. EUS-elastography can assess tissue hardness by measuring its elasticity. This parameter appears to correlate with the malignant potential of the lesions. Tissue elasticity studies can provide information on both its pattern and distribution. The former is the conventional method of morphological diagnosis, but it is restricted to observations made in a region of interest (ROI). The latter is an unbiased analysis that can be performed by image analysis software and is theoretically constant, regardless of the ROI. Though EUS-fine needle aspiration (FNA) is also a very useful diagnostic tool, there are several limitations. Diagnostic EUS-FNA of pancreatic cystic lesions has marginal utility mainly due to low sensitivity. Therefore, in particular, endoscopists should keep this limitation in mind.

Endoscopic ultrasound may be unnecessary in the preoperative evaluation of intraductal papillary mucinous neoplasm

OBJECTIVES

Several imaging modalities are commonly performed during work-up of intraductal papillary mucinous neoplasm (IPMN), but guidelines do not suggest any one technique. The aim of this study was to evaluate tumour and duct measurements by computed tomography (CT) and endoscopic ultrasound (EUS) and their ability to predict high-grade dysplasia (HGD) and cancer within pancreatic IPMN.

METHODS

Patients with IPMN who underwent preoperative CT and EUS between 2001 and 2009 were selected. Data were gathered retrospectively from medical records.

RESULTS

The study group was comprised of 52 patients, 33% (17/52) of whom had HGD or cancer. On fine needle aspirate (FNA), neither carcinoembryonic antigen (CEA) >200 nor cytological analysis correlated with malignancy. In multivariate analysis, duct size ≥ 1.0 cm (P= 0.034) was a significant predictor of HGD or cancer, and diameter on CT scan (P= 0.056) approached significance. Lesion diameter of ≥ 2.5 cm on CT scan identified malignancy in 71% (12/17) of patients (P= 0.037). When analysed, all patients with HGD or cancer had a lesion diameter ≥ 2.5 cm and/or a duct diameter ≥ 1.0 cm by CT scan.

CONCLUSIONS

The use of radiographic criteria on CT including lesion size ≥ 2.5 cm and/or pancreatic duct diameter ≥ 1.0 cm appears to reliably identify patients with either HGD or invasive cancer. High-resolution CT scanning may obviate the need for EUS and FNA in patients with suspected IPMN.

Factors in intraductal papillary mucinous neoplasms of the pancreas predictive of lymph node metastasis

BACKGROUND

Little is known about the frequency of lymph node metastasis (LNM) in intraductal papillary mucinous neoplasms (IPMNs), and we have not been able to determine how much lymph node dissection is necessary in individual cases. The aim of this study was to investigate the predictive factors for the LNM in IPMNs.

METHODS

Medical records of 120 patients pathologically diagnosed as having IPMN were reviewed, and 16 possible predictive factors regarding the LNM were analyzed.

RESULTS

LNM was observed in 7 patients (6%), all of whom were diagnosed as having mural nodules preoperatively. Sensitivity, specificity, and accuracy of preoperative imaging for detecting mural nodules of IPMNs in this study were 84, 97, and 90%, respectively. Univariate analysis using 61 patients having mural nodules preoperatively revealed that the size of mural nodules ≥10 mm and positive imaging findings for invasive tumor and possible LNM were significant predictive factors for the LNM. Multivariate analysis demonstrated that only an imaging finding for invasive tumor was an independent significant predictive factor. Positive and negative predictive values of the imaging finding of invasive IPMNs for LNM were 50 and 98%, respectively.

CONCLUSIONS

Standard lymph node dissection would be recommended in patients with IPMNs with mural nodules demonstrating preoperative imaging findings for invasive carcinomas. and IAP.

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Role of frozen section assessment for intraductal papillary and mucinous tumor of the pancreas

Intraductal papillary mucinous neoplasms (IPMN) of the pancreas include a spectrum of dysplasia ranging from minimal mucinous hyperplasia to invasive carcinoma and are extensive tumors that often spread along the ductal tree. Several studies have demonstrated that preoperative imaging is not accurate enough to adapt the extent of pancreatectomy and have suggested routinely using frozen sectioning (FS) to evaluate the completeness of resection and also to check if ductal dilatation is active or passive, in order to avoid an excessive pancreatic resection. Separate main duct and branch duct analysis is needed due to the difference in the natural history of the disease. FS accuracy averages 95%. Eroded epithelium on the main duct, severe ductal inflammation mimicking dysplasia and reactive epithelial changes secondary to obstruction can lead to inappropriate FS results. FS results change the planned extent of resection in up to 30% of cases. The optimal cut-off leading to extend pancreatectomy is not consensual and our standard option is to extend pancreatectomy if FS reveals: (1) at least IPMN adenoma on the main duct; or (2) at least borderline IPMN on branch ducts; or (3) invasive carcinoma. However, the decision to extend resection must be taken after a multidisciplinary discussion since it does not exclusively depend on the FS result but also on age, general condition and expected prognosis after resection. The main limitation of using FS is the existence of discontinuous (“skip”) lesions which account for approximately 10% of IPMN in surgical series and can lead to reoperation in up to 8% of cases.

Contrast harmonic echo-endoscopic ultrasound improves accuracy in diagnosis of solid pancreatic masses

BACKGROUND & AIMS

Contrast harmonic echo (CHE) has been developed for endoscopic ultrasound (EUS). This new technique detects echo signals from microbubbles in vessels with very slow flow, without artifacts. We assessed whether CHE-EUS increases the accuracy of diagnosis of pancreatic solid lesions.

METHODS

At a tertiary-care EUS center, we examined 90 patients who were suspected of having pancreatic solid neoplasm. Radial and linear echoendoscopes were used with dedicated software for CHE. Sonovue (Bracco International BV, Amsterdam, The Netherlands) uptake, pattern, and washout were studied; data were compared for pancreatic lesions and adjacent parenchyma. The final diagnosis was obtained based on results of surgical pathology and/or EUS-fine needle aspiration (FNA) analyses.

RESULTS

The finding of a hypoenhancing mass with an inhomogeneous pattern was a sensitive and accurate identifier of patients with adenocarcinoma (96% and 82%, respectively) (49 of 51 patients with primary pancreatic adenocarcinoma had a hypoenhancing mass that was inhomogeneous and had fast washout). This finding was more accurate in diagnosis than the finding of a hypoechoic lesion using standard EUS (P < .000). Hyperenhancement specifically excluded adenocarcinoma (98%), although sensitivity was low (39%). Of neuroendocrine tumors, 11 of 13 were non-hypo-enhancing (9 hyperenhancing, 2 isoenhancing). Interestingly, CHE-EUS allowed detection of small lesions in 7 patients who had uncertain standard EUS findings because of biliary stents (n = 5) or chronic pancreatitis (n = 2). Targeted EUS-FNA was performed on these lesions.

CONCLUSIONS

Detection of a hypoenhancing and inhomogeneous mass accurately identified patients with pancreatic adenocarcinoma. CHE-EUS increased the detection of malignant lesions in difficult cases (patients with chronic pancreatitis or biliary stents) and helped guide EUS-FNA. A hyperenhancing pattern could be used to rule out adenocarcinoma.

Usefulness of EUS combined with contrast-enhancement in the differential diagnosis of malignant versus benign and preoperative localization of pancreatic endocrine tumors

BACKGROUND

Pancreatic endocrine tumors (PETs) develop in relatively few patients, but they are often difficult to diagnose because of their small size and various clinical symptoms.

OBJECTIVE

The aim of this study was to investigate the usefulness of EUS combined with contrast enhancement (CE-EUS) in the preoperative localization of PETs and the differentiation between malignant and benign PETs.

DESIGN AND SETTING

Single-center retrospective study.

PATIENTS

Sixty-two pathologically certified PETs of 41 patients who underwent EUS, multiphasic multidetector computed tomography (MDCT), and transabdominal US at our institute since 2001.

INTERVENTIONS

Intravenous injection of US contrast media.

MAIN OUTCOME MEASUREMENTS

Comparison of EUS, MDCT, and US in the preoperative identification of PETs, and the characteristic findings of EUS with malignancy.

RESULTS

EUS showed high sensitivity (95.1%) in identifying PETs compared with MDCT (80.6%) and US (45.2%). Multivariable logistic regression analysis showed that heterogeneous ultrasonographic texture was the most significant factor for malignancy (OR = 53.33; 95% CI, 10.79-263.58). Most heterogeneous hypoechoic areas and anechoic areas corresponded to hemorrhage or necrosis on pathologic examination. They were identified as filling defects in CE-EUS and were more clearly recognized than in conventional EUS.

LIMITATIONS

Retrospective study.

CONCLUSION

EUS has higher sensitivity in preoperative localization of PETs compared with MDCT and US. The characteristics of EUS and CE-EUS findings in malignant PETs were clarified, and they will improve the diagnostic accuracy of PETs.

Pancreatic cystic neoplasms

Cystic neoplasms of the pancreas have been recognized for almost 2 centuries, but the principles of management continue to evolve. Clinicians have a better understanding now of the diverse pathologies and behaviors of cystic neoplasms, and can characterize them more precisely into benign, malignant, and of uncertain potential in their manifestations. Treatment is dependent on accurate diagnosis and tailored to the potential aggressiveness of the lesion, the surgical fitness of the patient, and the probability of effecting long-term palliation or survival of the patient. In this article the authors review the classification based on the World Health Organization classification and the latest evidence-based literature of cystic neoplasms, and present their considerations for surgical management of the various lesions. A better understanding of the biologic potential of cystic neoplasms such as intraductal papillary mucinous neoplasms allows for a more patient-specific evidence-based management plan.

Diagnosis of pancreatic disorders using contrast-enhanced endoscopic ultrasonography and endoscopic elastography

Contrast-enhanced endoscopic ultrasonography (CE-EUS) and EUS-elastography are cutting-edge diagnostic modalities for pancreatic disorders. Each pancreatic disorder has characteristic hemodynamics. CE-EUS uses color Doppler flow imaging to classify pancreatic lesions into a spectrum of solid and cystic patterns. Although there is overlap in the patterns generated by specific types of tumors, some types of tumors tend to produce distinct flow images. EUS-elastography can assess tissue hardness by measuring its elasticity. This parameter appears to correlate with the malignant potential of the lesions. Tissue elasticity studies can provide information on both its pattern and distribution. The former is the conventional method of morphologic diagnosis, but it is restricted to observations made in a region of interest. The latter is an unbiased analysis that can be performed by image analysis software and is theoretically constant, regardless of regions of interest. The evolving modalities of CE-EUS and EUS-elastography might provide clinical utility in the diagnosis of pancreatic disorders.

Usefulness of 18F-FDG PET, combined FDG-PET/CT and EUS in diagnosing primary pancreatic carcinoma: a meta-analysis

The aim was to evaluate the diagnostic value of (18)F-fluorodeoxyglucose-positron emission tomography ((18)F-FDG PET), combined (18)F-fluorodeoxyglucose-positron emission tomography/computed tomography ((18)F-FDG PET/CT) and endoscopic ultrasonography (EUS) in diagnosing patients with pancreatic carcinoma. MEDLINE, EMBASE, Cochrane library and some other databases, from January 1966 to April 2009, were searched for initial studies. All the studies published in English or Chinese relating to the diagnostic value of (18)F-FDG PET, PET/CT and EUS for patients with pancreatic cancer were collected. Methodological quality was assessed. The statistic software called "Meta-Disc 1.4" was used for data analysis.

RESULTS

51 studies were included in this meta-analysis. The pooled sensitivity estimate for combined PET/CT (90.1%) was significantly higher than PET (88.4%) and EUS (81.2%). The pooled specificity estimate for EUS (93.2%) was significantly higher than PET (83.1%) and PET/CT (80.1%). The pooled DOR estimate for EUS (49.774) was significantly higher than PET (32.778) and PET/CT (27.105). SROC curves for PET/CT and EUS showed a little better diagnostic accuracy than PET alone. For PET alone, when interpreted the results with knowledge of other imaging tests, its sensitivity (89.4%) and specificity (80.1%) were closer to PET/CT. For EUS, its diagnostic value decreased in differentiating pancreatic cancer for patients with chronic pancreatitis. In conclusion, PET/CT was a high sensitive and EUS was a high specific modality in diagnosing patients with pancreatic cancer. PET/CT and EUS could play different roles during different conditions in diagnosing pancreatic carcinoma.

Pancreatic surgery

PURPOSE OF REVIEW

Surgery of the pancreas is evolving as the understanding of pancreatic disease improves. This report reviews the work published over the last year related to pancreatic surgery and the diseases addressed by surgical techniques.

RECENT FINDINGS

Obesity is an important risk factor for many diseases of the pancreas, including pancreatic adenocarcinoma. Recent evidence suggests that obese patients with pancreatic cancer appear to have more advanced disease at the time of diagnosis and a worse outcome following resection. The issues surrounding adjuvant treatment for pancreatic cancer with chemotherapy and/or radiation therapy continue to be evaluated. Cystic lesions of the pancreas remain a vexing treatment dilemma, but as we learn more about their natural history, more thoughtful recommendations for management become possible. Resection of pancreatic endocrine neoplasms is often appropriate, even in the face of metastatic disease. Minimally invasive approaches to the drainage of infected pancreatic necrosis are beginning to gain acceptance. The pain of chronic pancreatitis may be lessened by operative intervention and possibly radiation.

SUMMARY

Each year more is learned about the natural history of pancreatic lesion. For those dedicated to the study and treatment of this gland, several new advances help the clinician with treatment decisions.