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

Effect of deep learning reconstruction on the assessment of pancreatic cystic lesions using computed tomography

This study aimed to compare the image quality and detection performance of pancreatic cystic lesions between computed tomography (CT) images reconstructed by deep learning reconstruction (DLR) and filtered back projection (FBP). This retrospective study included 54 patients (mean age: 67.7 ± 13.1) who underwent contrast-enhanced CT from May 2023 to August 2023. Among eligible patients, 30 and 24 were positive and negative for pancreatic cystic lesions, respectively. DLR and FBP were used to reconstruct portal venous phase images. Objective image quality analyses calculated quantitative image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) using regions of interest on the abdominal aorta, pancreatic lesion, and pancreatic parenchyma. Three blinded radiologists performed subjective image quality assessment and lesion detection tests. Lesion depiction, normal structure illustration, subjective image noise, and overall image quality were utilized as subjective image quality indicators. DLR significantly reduced quantitative image noise compared with FBP (p < 0.001). SNR and CNR were significantly improved in DLR compared with FBP (p < 0.001). Three radiologists rated significantly higher scores for DLR in all subjective image quality indicators (p ≤ 0.029). Performance of DLR and FBP were comparable in lesion detection, with no statistically significant differences in the area under the receiver operating characteristic curve, sensitivity, specificity and accuracy. DLR reduced image noise and improved image quality with a clearer depiction of pancreatic structures. These improvements may have a positive effect on evaluating pancreatic cystic lesions, which can contribute to appropriate management of these lesions.

Groove pancreatitis: From enigma to future directions-A comprehensive review

Groove pancreatitis (GP) is a rare and clinically distinct form of chronic pancreatitis affecting the pancreaticoduodenal groove comprising the head of the pancreas, duodenum, and the common bile duct. It is more prevalent in individuals in their 4-5th decade of life and disproportionately affects men compared with women. Excessive alcohol consumption, tobacco smoking, pancreatic ductal stones, pancreatic divisum, annular pancreas, ectopic pancreas, duodenal wall thickening, and peptic ulcers are significant risk factors implicated in the development of GP. The usual presenting symptoms include severe abdominal pain, nausea, vomiting, diarrhea, weight loss, and jaundice. Establishing a diagnosis of GP is often challenging due to significant clinical and radiological overlap with numerous benign and malignant conditions affecting the same anatomical location. This can lead to a delay in initiation of treatment leading to increasing morbidity, mortality, and complication rates. Promising research in artificial intelligence (AI) has garnered immense interest in recent years. Due to its widespread application in diagnostic imaging with a high degree of sensitivity and specificity, AI has the potential of becoming a vital tool in differentiating GP from pancreatic malignancies, thereby preventing a missed or delayed diagnosis. In this article, we provide a comprehensive review of GP, covering the etiology, pathogenesis, clinical presentation, radiological and endoscopic evaluation, management strategies, and future directions. This article also aims to increase awareness about this lesser known and often-misdiagnosed clinical entity amongst clinicians to ultimately improve patient outcomes.

Basic Principles and Role of Endoscopic Ultrasound in Diagnosis and Differentiation of Pancreatic Cancer from Other Pancreatic Lesions: A Comprehensive Review of Endoscopic Ultrasound for Pancreatic Cancer

Pancreatic cancer is one of the leading causes of cancer-related deaths worldwide. Pancreatic lesions consist of both neoplastic and non-neoplastic lesions and often pose a diagnostic and therapeutic challenge due to similar clinical and radiological features. In recent years, pancreatic lesions have been discovered more frequently as incidental findings due to the increased utilization and widespread availability of abdominal cross-sectional imaging. Therefore, it becomes imperative to establish an early and appropriate diagnosis with meticulous differentiation in an attempt to balance unnecessary treatment of benign pancreatic lesions and missing the opportunity for early intervention in malignant lesions. Endoscopic ultrasound (EUS) has become an important diagnostic modality for the identification and risk stratification of pancreatic lesions due to its ability to provide detailed imaging and acquisition of tissue samples for analysis with the help of fine-needle aspiration/biopsy. The recent development of EUS-based technology, including contrast-enhanced endoscopic ultrasound, real-time elastography-endoscopic ultrasound, miniature probe ultrasound, confocal laser endomicroscopy, and the application of artificial intelligence has significantly augmented the diagnostic accuracy of EUS as it enables better evaluation of the number, location, dimension, wall thickness, and contents of these lesions. This article provides a comprehensive overview of the role of the different types of EUS available for the diagnosis and differentiation of pancreatic cancer from other pancreatic lesions while discussing their key strengths and important limitations.

Risk Assessment and Radiomics Analysis in Magnetic Resonance Imaging of Pancreatic Intraductal Papillary Mucinous Neoplasms (IPMN)

Intraductal papillary mucinous neoplasms (IPMNs) are a very common incidental finding during patient radiological assessment. These lesions may progress from low-grade dysplasia (LGD) to high-grade dysplasia (HGD) and even pancreatic cancer. The IPMN progression risk grows with time, so discontinuation of surveillance is not recommended. It is very important to identify imaging features that suggest LGD of IPMNs, and thus, distinguish lesions that only require careful surveillance from those that need surgical resection. It is important to know the management guidelines and especially the indications for surgery, to be able to point out in the report the findings that suggest malignant degeneration. The imaging tools employed for diagnosis and risk assessment are Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) with contrast medium. According to the latest European guidelines, MRI is the method of choice for the diagnosis and follow-up of patients with IPMN since this tool has a highest sensitivity in detecting mural nodules and intra-cystic septa. It plays a key role in the diagnosis of worrisome features and high-risk stigmata, which are associated with IPMNs malignant degeneration. Nowadays, the main limit of diagnostic tools is the ability to identify the precursor of pancreatic cancer. In this context, increasing attention is being given to artificial intelligence (AI) and radiomics analysis. However, these tools remain in an exploratory phase, considering the limitations of currently published studies. Key limits include noncompliance with AI best practices, radiomics workflow standardization, and clear reporting of study methodology, including segmentation and data balancing. In the radiological report it is useful to note the type of IPMN so as the morphological features, size, rate growth, wall, septa and mural nodules, on which the indications for surveillance and surgery are based. These features should be reported so as the surveillance time should be suggested according to guidelines.

The effectiveness of endoscopic ultrasonography findings to distinguish benign and malignant intraductal papillary mucinous neoplasm

BACKGROUND AND AIMS

Accurate evaluation of intraductal papillary mucinous neoplasm (IPMN) is necessary to inform clinical decision-making. But it is still difficult to distinguish benign and malignant IPMN preoperatively. This study aims to evaluate the utility of EUS to predict the pathology of IPMN.

METHODS

Patients with IPMN who underwent endoscopic ultrasound within 3 months before surgery were collected from six centers. Logistic regression model and random forest model were used to determine risk factors associated with malignant IPMN. In both models, 70% and 30% of patients were randomly assigned to the exploratory group and validation group, respectively. Sensitivity, specificity, and ROC were used in model assessment.

RESULTS

Of the 115 patients, 56 (48.7%) had low-grade dysplasia (LGD), 25 (21.7%) had high-grade dysplasia (HGD), and 34 (29.6%) had invasive cancer (IC). Smoking history (OR = 6.95, 95%CI: 1.98-24.44, p = 0.002), lymphadenopathy (OR = 7.91, 95%CI: 1.60-39.07, p = 0.011), MPD > 7 mm (OR = 4.75, 95%CI: 1.56-14.47, p = 0.006) and mural nodules > 5 mm (OR = 8.79, 95%CI: 2.40-32.24, p = 0.001) were independent risk factors predicting malignant IPMN according to the logistic regression model. The sensitivity, specificity, and AUC were 0.895, 0.571, and 0.795 in the validation group. In the random forest model, the sensitivity, specificity, and AUC were 0.722, 0.823, and 0.773, respectively. In patients with mural nodules, random forest model could reach a sensitivity of 0.905 and a specificity of 0.900.

CONCLUSIONS

Using random forest model based on EUS data is effective to differentiate benign and malignant IPMN in this cohort, especially in patients with mural nodules.

Artificial Intelligence-The Rising Star in the Field of Gastroenterology and Hepatology

Artificial intelligence (AI) is a term that covers a multitude of techniques that are used in a manner that tries to reproduce human intelligence. AI is helpful in various medical specialties that use imaging for diagnostic purposes, and gastroenterology is no exception. In this field, AI has several applications, such as detecting and classifying polyps, detecting the malignancy in polyps, diagnosing Helicobacter pylori infection, gastritis, inflammatory bowel disease, gastric cancer, esophageal neoplasia, and pancreatic and hepatic lesions. The aim of this mini-review is to analyze the currently available studies regarding AI in the field of gastroenterology and hepatology and to discuss its main applications as well as its main limitations.

Basic pancreatic lesions: Radiologic-pathologic correlation

The basic pancreatic lesions include location, size, shape, number, capsule, calcification/calculi, hemorrhage, cystic degeneration, fibrosis, pancreatic duct alterations, and microvessel. One or more basic lesions form a kind of pancreatic disease. As recognizing the characteristic imaging features of pancreatic basic lesions and their relationships with pathology aids in differentiating the variety of pancreatic diseases. The purpose of this study is to review the pathological and imaging features of the basic pancreatic lesions.

Radiomic nomogram based on MRI to predict grade of branching type intraductal papillary mucinous neoplasms of the pancreas: a multicenter study

Background

Accurate diagnosis of high-grade branching type intraductal papillary mucinous neoplasms (BD-IPMNs) is challenging in clinical setting. We aimed to construct and validate a nomogram combining clinical characteristics and radiomic features for the preoperative prediction of low and high-grade in BD-IPMNs.

Methods

Two hundred and two patients from three medical centers were enrolled. The high-grade BD-IPMN group comprised patients with high-grade dysplasia and invasive carcinoma in BD-IPMN (n = 50). The training cohort comprised patients from the first medical center (n = 103), and the external independent validation cohorts comprised patients from the second and third medical centers (n = 48 and 51). Within 3 months prior to surgery, all patients were subjected to magnetic resonance examination. The volume of interest was delineated on T1-weighted (T1-w) imaging, T2-weighted (T2-w) imaging, and contrast-enhanced T1-weighted (CET1-w) imaging, respectively, on each tumor slice. Quantitative image features were extracted using MITK software (G.E.). The Mann-Whitney U test or independent-sample t-test, and LASSO regression, were applied for data dimension reduction, after which a radiomic signature was constructed for grade assessment. Based on the training cohort, we developed a combined nomogram model incorporating clinical variables and the radiomic signature. Decision curve analysis (DCA), a receiver operating characteristic curve (ROC), a calibration curve, and the area under the ROC curve (AUC) were used to evaluate the utility of the constructed model based on the external independent validation cohorts.

Results

To predict tumor grade, we developed a nine-feature-combined radiomic signature. For the radiomic signature, the AUC values of high-grade disease were 0.836 in the training cohort, 0.811 in external validation cohort 1, and 0.822 in external validation cohort 2. The CA19–9 level and main pancreatic duct size were identified as independent parameters of high-grade of BD-IPMNs using multivariate logistic regression analysis. The CA19–9 level and main pancreatic duct size were then used to construct the radiomic nomogram. Using the radiomic nomogram, the high-grade disease-associated AUC values were 0.903 (training cohort), 0.884 (external validation cohort 1), and 0.876 (external validation cohort 2). The clinical utility of the developed nomogram was verified using the calibration curve and DCA.

Conclusions

The developed radiomic nomogram model could effectively distinguish high-grade patients with BD-IPMNs preoperatively. This preoperative identification might improve treatment methods and promote personalized therapy in patients with BD-IPMNs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40644-021-00395-6.

Pearls and pitfalls of imaging features of pancreatic cystic lesions: a case-based approach with imaging-pathologic correlation

A variety of neoplastic and non-neoplastic lesions of the pancreas can present with a predominantly cystic architecture. These lesions are increasingly being detected as incidental findings on routine cross-sectional imaging following technological advances in these techniques and their widespread use. The different histopathological behaviors show various common and uncommon imaging findings, and some cases show similar appearance in spite of different histopathology. Each lesion requires specific management because of the differing risk of progression to malignancy, and an accurate imaging diagnosis is crucial. The typical imaging characteristics that differentiate pancreatic cystic lesions have been well described and fully summarized. However, in addition to a small percentage of cases that shows uncommon imaging findings, a substantial percentage of cystic lesions shows overlapping imaging findings that can lead to radiological misdiagnosis. For appropriate diagnosis and optimal treatment strategy, it is important to know the uncommon and overlapping imaging findings of these lesions, in addition to familiarity with the typical aspects. In this article, we reconfirm the well-known characteristic imaging features of pancreatic cystic lesions and present several diagnostically challenging cases, focusing on the uncommon and overlapping imaging findings.

Role of endoscopic ultrasound in pediatric gastrointestinal diseases

Endoscopic ultrasound (EUS) is a well-established diagnostic and therapeutic modality for adults. It is extremely helpful for a broad range of diagnostic indications including upper gastrointestinal (GI) malignancies, submucosal lesions, pancreatic lesions (masses, cystic lesions), chronic pancreatitis, etiological workup of recurrent acute pancreatitis, common bile duct evaluation (calculi versus tumor), gallbladder lesions/microliths, and rectal malignancy; well-established therapeutic roles include fine-needle aspiration of lesions/lymph nodes, pancreatic fluid collection drainage, pancreatic duct drainage, biliary drainage, gallbladder drainage, pelvic abscess drainage, celiac plexus block, or neurolysis. Some recent studies have reported the use of EUS in the pediatric population. EUS is safe and easy to perform in the pediatric population also. However, there is paucity of data on use of EUS in pediatric population. In contrast with its regular therapeutic use in adults, EUS is not commonly performed in children for therapeutic reasons and most of the data are available on diagnostic use only. All of studies have shown that EUS is safe and a useful modality with a positive impact on management in majority of study population. EUS is very useful in pediatric population for the evaluation of upper GI tract submucosal lesions or rectal masses, pancreaticobiliary disorders, characterization of esophageal strictures, and for evaluation of enteric duplication cysts. The advent of miniprobe that can be passed through conventional endoscopes has increased the applicability of EUS in infants and children. Although there are limited data regarding use of EUS in pediatric population, it appears to be a very promising diagnostic and therapeutic tool.

CT radiomics to predict high-risk intraductal papillary mucinous neoplasms of the pancreas

PURPOSE

Intraductal papillary mucinous neoplasms (IPMNs) are radiographically visible precursor lesions of pancreatic cancer. Despite standard criteria for assessing risk, only 18% of cysts are malignant at resection. Thus, a large number of patients undergo unnecessary invasive surgery for benign disease. The ability to identify IPMNs with low or high risk of transforming into invasive cancer would optimize patient selection and improve surgical decision-making. The purpose of this study was to investigate quantitative CT imaging features as markers for objective assessment of IPMN risk.

METHODS

This retrospective study analyzed pancreatic cyst and parenchyma regions extracted from CT scans in 103 patients to predict IPMN risk. Patients who underwent resection between 2005 and 2015 with pathologically proven branch duct (BD)-IPMN and a preoperative CT scan were included in the study. Expert pathologists categorized IPMNs as low or high risk following resection as part of routine clinical care. We extracted new radiographically inspired features as well as standard texture features and designed prediction models for the categorization of high- and low-risk IPMNs. Five clinical variables were also combined with imaging features to design prediction models.

RESULTS

Using images from 103 patients and tenfold cross-validation technique, the novel radiographically inspired imaging features achieved an area under the receiver operating characteristic curve (AUC) of 0.77, demonstrating their predictive power. The combination of these features with clinical variables obtained the best performance (AUC = 0.81).

CONCLUSION

The present study demonstrates that features extracted from pretreatment CT images can predict the risk of IPMN. Development of a preoperative model to discriminate between low-risk and high-risk IPMN will improve surgical decision-making.

Radiological Workup of Cystic Neoplasms of the Pancreas

Pancreatic cystic lesions are being detected with increasing frequency because of increased use and improved quality of cross-sectional imaging techniques. Pancreatic cystic lesions encompass non-neoplastic lesions (such as pancreatitis-related collections) and neoplastic tumors. Common cystic pancreatic neoplasms include serous cystadenomas, mucinous cystic neoplasms, intraductal papillary mucinous neoplasms, and solid pseudopapillary tumors. These cystic pancreatic neoplasms may have typical morphology, but at times show overlapping imaging features on cross-sectional examinations. This article reviews the classical and atypical imaging features of commonly encountered cystic pancreatic neoplasms and presents the limitations of current cross-sectional imaging techniques in accurately classifying pancreatic cystic lesions.

Diagnostic Accuracy of Preoperative Imaging for Differentiation of Branch Duct Versus Mixed Duct Intraductal Papillary Mucinous Neoplasms

OBJECTIVE

The aim of this study is to determine the diagnostic accuracy of preoperative evaluation to detect main pancreatic duct involvement in pancreatic cystic lesions thus differentiating mixed intraductal papillary mucinous neoplasm (IPMN) from branch duct (BD)-IPMN.

METHODS

The pathology database of pancreatic resections from 2000 to 2014 was reviewed. Main pancreatic duct-IPMNs and IPMNs with intracystic mass/nodules were excluded. The preoperative test characteristics were analyzed using surgical histopathology as the "gold standard."

RESULTS

Sixty BD-IPMNs and 23 mixed-IPMNs were identified. Mixed-IPMNs were larger (mean [standard deviation], 4.14 [2.9] vs 2.74 [1.9] mm; P = 0.03) and demonstrated frequent high-grade dysplasia/adenocarcinoma (43% vs 12%, P = 0.004) than BD-IPMNs. Endoscopic ultrasound (EUS) (sensitivity, 80%; specificity, 78%; accuracy, 79%) had the best diagnostic accuracy, whereas magnetic resonance imaging (MRI) (sensitivity, 83%; specificity, 63%; accuracy, 68%) had the highest sensitivity for the diagnosis of mixed-IPMN. A combination of EUS and MRI reached maximum sensitivity but with decreased accuracy (sensitivity, 100%; specificity, 64%; accuracy, 67%). The area under the curve for receiver operation curve was 0.71 whereas the optimal cyst size to detect main duct involvement was 3 cm.

CONCLUSIONS

For preoperative evaluation of pancreatic cystic lesions without evidence of intracystic nodules, a combination of MRI and EUS should be considered for improved detection of main duct involvement.

Short-term outcomes and risk factors for pancreatic fistula after pancreatic enucleation: A single-center experience of 142 patients

BACKGROUND

Enucleation is increasingly used for benign or low-grade pancreatic neoplasms. Enucleation preserves the pancreatic parenchyma as well as decreases the risk of long-term endocrine and exocrine dysfunction, but may be associated with a higher rate of postoperative pancreatic fistula (POPF). The aim of this study was to assess short-term outcomes, in particular, POPF.

METHODS

Data were collected retrospectively from all 142 patients who underwent pancreatic enucleation between 2009 and 2014 in our institution were analyzed.

RESULTS

Lesions were most frequently located in the head and uncinate process of the pancreas (60.6%), and the most common types were neuroendocrine neoplasms (52.1%). Overall morbidity was 66%, mainly due to POPF (53.5%), and severe morbidity was only 8.4%, including one death (0.7%). Clinical POPF (Grade B or C) occurred in 22 patients (15.5%). Independent risk factors for clinical POPF were age ≥60 years, an episode of acute pancreatitis, and cystic morphology. Tumor size, coverage, histological differentiation, and prolonged operative time were not associated with the risk of POPF.

CONCLUSIONS

Enucleation is a safe and feasible procedure for benign or low-grade pancreatic neoplasms. The rate of clinical POPF is acceptable, and clinical POPF occurs more frequently in elderly patients (≥60 years of age), patients with cystic neoplasms, or patients with an episode of acute pancreatitis.

Imaging and Screening of Pancreatic Cancer

Given the low disease prevalence of both exocrine and endocrine cancers in the general population, screening is not recommended. However, in as many as 25% of cases there is a precursor lesion or an identifiable genetic predisposition. For these patients at increased risk, screening with imaging is recommended. Multidetector computed tomography, MR imaging or magnetic resonance cholangiopancreatography, and endoscopic ultrasound examination can be used as screening modalities. Recent advances in dual energy CT and total body MR imaging have increased the suitability of these noninvasive modalities as first-line imaging screening options.

Paraduodenal pancreatitis: benign and malignant mimics at MRI

Paraduodenal pancreatitis, also known as groove pancreatitis, is a rare form of chronic pancreatitis that masquerades as pancreatic adenocarcinoma affecting the pancreaticoduodenal groove, a potential space between the head of the pancreas, duodenum, and common bile duct. Two forms of groove pancreatitis have been described. The segmental form involves the pancreatic head with development of scar tissue within the groove, whereas the pure form affects the groove only, sparing the pancreatic head. Imaging findings of groove pancreatitis often overlap with primary duodenal, ampullary, or pancreatic neoplasms, which often results in a diagnostic challenge. In addition, paraduodenal pancreatitis can be mistaken for cystic pancreatic lesions, especially when there is involvement of the duodenal wall. Preoperative recognition of this entity is very important in order to avoid unnecessary procedures, although surgery, such as pancreaticoduodenectomy, may still be required to relieve obstructive symptoms. In this article, the pathophysiology and magnetic resonance imaging characteristics of paraduodenal pancreatitis and important benign and malignant mimics are discussed.

Natural History of Pancreatic Cysts

Pancreatic cystic neoplasms are discovered with increasing frequency. Accurate knowledge of the natural history of cystic neoplasms is crucial to develop useful and cost-effective strategies for surveillance and surgical resection. To date, the natural history of cystic neoplasms is still incomplete due to lack of adequate diagnostic accuracy in the absence of surgical pathology. Nevertheless, current evidence points to risk factors for malignant transformation to help clinical management. New biomarkers that accurately distinguish cyst neoplasms and those most likely to progress to cancer would help clarify the natural history of cystic neoplasms.

Pancreatic carcinosarcoma mimics malignant intraductal papillary mucinous neoplasm: A rare case report and literature review

RATIONALE

Carcinosarcoma, an extremely rare pancreatic primary tumor, is characterized by coexistence of both carcinomatous and sarcomatous components. Due to its rarity, the clinical manifestation and imaging features have not been recognized. An accurate diagnostic method has not been available and a widely accepted guidelines instructing treatment has not been established.

PATIENT CONCERNS

We present an uncommon case of pancreatic carcinosarcoma (PCS) which has been preoperatively diagnosed as pancreatic malignant intraductal papillary mucinous neoplasm. A radical resection, including total pancreatectomy (TP) and splenectomy, was performed.

DIAGNOSIS

The diagnosis of PCS was confirmed by postoperative pathology.

INTERVENTIONS

A radical resection, including TP and splenectomy, was performed. The patient was followed up by abdominal contrast-enhanced computed tomography scan and blood tumor marker examination.

OUTCOMES

The patient is still alive and self-sufficient 7 months after the surgery. No evidence of tumor recurrence is found during follow-up.

LESSONS

Although, until recently, there are no widely accepted guidelines instructing treatment for PCS, a radical resection is still a possible way. All the pancreatic neoplastic patients with high surgical risk should be transferred to a specialized high-volume pancreatic center to get precise preoperative evaluation, fine operation technique, and careful postoperative management.

Clinical importance of Familial Pancreatic Cancer Registry in Japan: a report from kick-off meeting at International Symposium on Pancreas Cancer 2012

Pancreatic cancer is still a highly lethal disease with a 5-year survival rate of approximately 5 %. Early detection offers one of the best hopes for improving survival. Previous cohort studies and case-control studies showed that 4-10 % of pancreatic cancers have a hereditary basis, and individuals with a family history have an increased risk of developing pancreatic and extra-pancreatic malignancies. Since individuals with a family history of pancreatic cancer and those with a known genetic syndrome that predisposes to pancreatic cancer will be the first to benefit from early detection tests as they become available, familial pancreatic cancer (FPC) registries have been established in the US and Europe, but not yet in Japan. Such registries form the basis for epidemiological studies, clinical trials, and basic research on familial pancreatic cancer. There is a need for FPC registries in Japan as cancer risk varies among different populations and discoveries made in Western populations may not translate to the Japanese population. These registries in Japan will align with ongoing international efforts and add to a better understanding of the natural history, risk factors, screening strategies, and responsible genes, for improving survival of this dismal disease.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Diagnosis and management of cystic lesions of the pancreas

Pancreatic cystic lesions (PCLs) are being increasingly identified in recent years. They show a wide spectrum of imaging and clinical features. The diagnosis and discrimination of these lesions are very important because of the risk for concurrent or later development of malignancy. PCLs are usually first diagnosed and characterized by conventional imaging modalities such as trans-abdominal ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI). However, their ability to differentiate the benign and malignant lesions remains limited. Endoscopic US may be more helpful for the diagnosis and differentiation of PCLs because of its high resolution and better imaging characteristics than cross-sectional imaging modalities. It also allows for fine-needle aspiration (FNA) of cystic lesions for biochemical, cytological and DNA analysis that might be further helpful for diagnosis and differentiation. The management options of PCLs are to observe, endoscopic treatment or surgical resection. However, the decision for management is sometimes hampered by limitations in current diagnostic and tissue sampling techniques. As further diagnostic and non-invasive management options become available, clinical decision-making will become much easier for these lesions.

Is it safe to follow side branch IPMNs?

Management of Bd-IPMN remains challenging. Critical appraisal of the published literature reveals that the actual treatment of what is presumed to be Bd-IPMN remains unsatisfactory, with a high rate of surgically overtreated patients. Until we accrue more precise knowledge of the natural history of Bd-IPMN, management of patients with this presumed diagnosis should be individually tailored and preferably carried out in centers with a high expertise. For now, the authors strongly think that the old guidelines should be followed in most patients because these have proven to correctly identify lesions that can be safely followed. Although the new guidelines allow for follow-up of lesions greater than 3 cm, and for the most part this is safe, they should be used cautiously in younger patients because very close surveillance would be required for their long remaining lifespan.

Moving beyond morphology: new insights into the characterization and management of cystic pancreatic lesions

The frequency of detection of cystic pancreatic lesions with cross-sectional imaging, particularly with multidetector computed tomography, magnetic resonance (MR) imaging, and MR cholangiopancreatography, is increasing, and many of these cystic pancreatic lesions are being detected incidentally in asymptomatic patients. Because there is considerable overlap in the cross-sectional imaging findings of cystic pancreatic lesions, and because many of these lesions being detected are smaller than 3 cm in diameter and lack any specific cross-sectional imaging features, it has become difficult to make informed decisions about patient management when the precise diagnosis remains uncertain. This article presents the limitations of cross-sectional imaging in patients with cystic pancreatic lesions, details advances in knowledge of the genomic and epigenomic changes that lead to progression of carcinogenesis, outlines the current understanding of the natural history of mucinous cystic lesions, and includes the current use and future potential of novel tumor markers and molecular analysis to characterize cystic pancreatic lesions more precisely. The need to move beyond cross-sectional imaging morphology and toward the use of new techniques to diagnose these lesions accurately is emphasized. An algorithm that uses these techniques is proposed and will hopefully lead to improved patient management.

Cystic neuroendocrine tumor in the pancreas detected by endoscopic ultrasound and fine-needle aspiration: a case report

Background

Pancreatic neuroendocrine tumors are typically solid neoplasms but in very rare cases present as cystic lesions. The diagnosis of cystic tumors in the pancreas is extremely difficult and the use of endoscopic ultrasound and fine-needle aspiration might be helpful in the work-up of patients with cystic neuroendocrine tumors in the pancreas.

Case presentation

A 78-year-old Caucasian man was admitted with a history of epigastric pain. Laboratory tests were normal. The patient underwent transabdominal ultrasound, computed tomography and magnetic resonance cholangiopancreatography demonstrating an unclear cystic mass in the head of the pancreas. The patient was referred for endoscopic ultrasound. Endoscopic ultrasound showed a hypoechoic lesion (42 × 47 mm) in the head of the pancreas with regular borders and large cystic components. The main pancreatic duct was normal without any connection to the cystic process. The lesion underwent fine-needle aspiration (22 Gauge). Cytological examination demonstrated cohesive groups of plasmacytoid cells staining positively for synaptophysin and chromogranin A, which is suggestive of a neuroendocrine tumor.

Conclusions

Differential diagnosis of cystic lesions in the pancreas is very difficult with conventional radiology, such as computed tomography and magnetic resonance imaging. This unusual case with a pancreatic cystic neuroendocrine tumor highlights the clinical importance of endoscopic ultrasound in the work-up of patients with unclear lesions in the pancreas.

Endoscopic ultrasonography for surveillance of individuals at high risk for pancreatic cancer

Pancreatic cancer is a highly lethal disease with a genetic susceptibility and familial aggregation found in 3%-16% of patients. Early diagnosis remains the only hope for curative treatment and improvement of prognosis. This can be reached by the implementation of an intensive screening program, actually recommended for individuals at high-risk for pancreatic cancer development. The aim of this strategy is to identify pre-malignant precursors or asymptomatic pancreatic cancer lesions, curable by surgery. Endoscopic ultrasound (EUS) with or without fine needle aspiration (FNA) seems to be the most promising technique for early detection of pancreatic cancer. It has been described as a highly sensitive and accurate tool, especially for small and cystic lesions. Pancreatic intraepithelial neoplasia, a precursor lesion which is highly represented in high-risk individuals, seems to have characteristics chronic pancreatitis-like changes well detected by EUS. Many screening protocols have demonstrated high diagnostic yields for pancreatic pre-malignant lesions, allowing prophylactic pancreatectomies. However, it shows a high interobserver variety even among experienced endosonographers and a low sensitivity in case of chronic pancreatitis. Some new techniques such as contrast-enhanced harmonic EUS, computer-aided diagnostic techniques, confocal laser endomicroscopy miniprobe and the detection of DNA abnormalities or protein markers by FNA, promise improvement of the diagnostic yield of EUS. As the resolution of imaging improves and as our knowledge of precursor lesions grows, we believe that EUS could become the most suitable method to detect curable pancreatic neoplasms in correctly identified asymptomatic at-risk patients.

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.

To cease or 'de-cyst'? The evaluation and management of pancreatic cystic lesions

Due to the widespread use of cross-sectional imaging and advances in imaging technology, pancreatic cystic lesions are increasingly being detected. The diagnosis and management of such cysts remains challenging and continues to evolve. Different pancreatic cyst types have varying malignant potential. Thus, accurate cyst characterization is essential to appropriate management; the most clinically important distinction is differentiating mucinous lesions, which have malignant potential and may benefit from surgical resection, from non-mucinous cystic lesions. Endoscopic ultrasound with fine needle aspiration with cytologic, chemical,, and tumor marker analysis appears to be the best currently available method for accurately characterizing a cyst's malignant potential, and therefore impacts the most important management decision for a pancreatic cyst-continued surveillance or surgical resection.

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.

F18-FDG-PET/CT for evaluation of intraductal papillary mucinous neoplasms (IPMN): a review of the literature

Intraductal papillary mucinous neoplasms (IPMN) are intraductal mucin-producing neoplasms with tall columnar, mucin-containing epithelium, with or without papillary projections, involving the main pancreatic duct and/or major side branches. They account for approximately 25 % of all cystic neoplasms and can be subdivided into benign lesions, borderline lesions, and carcinoma. In this clinical scenario accurate preoperative diagnosis can eliminate unnecessary surgery, which is risky and potentially harmful, yet enable effective selection of patients who are candidates for surgery. In this review we try to provide a complete evaluation of the use of F18-FDG-PET/CT for diagnosis of this neoplasm on the basis of published papers. F18-FDG-PET/CT seems to be an useful technique for preoperative work-up of patients with suspected IPMN and is an improvement over conventional imaging in distinguishing benign from malignant lesions, especially for selecting patients for surgical treatment or for long-term follow-up.

Pancreatic cystic lesions: How endoscopic ultrasound morphology and endoscopic ultrasound fine needle aspiration help unlock the diagnostic puzzle

Cystic lesions of the pancreas are being diagnosed with increasing frequency, covering a vast spectrum from benign to malignant and invasive lesions. Numerous investigations can be done to discriminate between benign and non-evolutive lesions from those that require surgery. At the moment, there is no single test that will allow a correct diagnosis in all cases. Endoscopic ultrasound (EUS) morphology, cyst fluid analysis and cytohistology with EUS-guided fine needle aspiration can aid in this difficult diagnosis.

Cystic tumors of the pancreas: imaging and management

Cystic tumors of the pancreas are a subset of rare pancreatic tumors that vary from benign to malignant. Many have specific imaging findings that allow them to be differentiated from each other. This article (1) reviews the imaging features of the common cystic pancreatic lesions, including serous microcystic adenoma, mucinous cystic tumor, intraductal papillary mucinous tumor, and solid pseudopapillary tumor, and including the less common lesions such as cystic endocrine tumors, cystic metastases, cystic teratomas, and lymphangiomas; and (2) provides comprehensive algorithms on how to manage the individual lesions, with recommendations on when to reimage patients.

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.

Individuals at high-risk for pancreatic cancer development: management options and the role of surgery

Pancreatic cancer (PC) is a highly lethal disease. Despite advances regarding the safety and long-term results of pancreatectomies, early diagnosis remains the only hope for cure. This necessitates the implementation of an intensive screening program (based mainly on modern imaging), which - given the incidence of PC - is not cost effective for the general population. However, this screening program is recommended for individuals at high-risk for PC development. Indications for screening include the following three clinical settings: hereditary cancer predisposition syndromes associated with PC, hereditary pancreatitis and familial pancreatic cancer syndrome. The aim of this strategy is to identify pre-invasive (precursor) lesions, which are curable. Surgery is recommended in the presence of recognizable lesion on imaging lesions. Partial (anatomic) pancreatectomy - depending on the location of the suspicious lesion - is the most widely accepted type of surgical intervention in this setting; occasionally, however, total pancreatectomy may be required, in carefully selected patients. Despite that experience still remains limited, there is evidence that this aggressive strategy allows early detection of neoplastic lesions, thereby improving the effectiveness of surgery and prognosis.

Potential pitfalls in the management of primary pancreatic cystic neoplasms

Primary pancreatic cystic neoplasms (PCN) have been increasingly recognized over the last 2 decades, mainly as a result of the widespread use of modern imaging techniques in patients with abdominal complaints. Biological behavior and management greatly differ between subgroups of PCN. Accurate preoperative diagnosis is required to select the optimal management strategy for each individual patient with PCN. An in-depth knowledge of the biological, imaging, macroscopic/microscopic features, and laboratory findings of each subtype of PCN is required on the part of the clinician, in order to select a cost-effective diagnostic evaluation of the patient. Clinical judgment is also required on the part of the surgeon to select the optimal procedure and to avoid severe pitfalls in the surgical management of these neoplasms.