Characterization of cystic tumors of the pancreas: CT accuracy

Analytical Validation of Loss of Heterozygosity and Mutation Detection in Pancreatic Fine-Needle Aspirates by Capillary Electrophoresis and Sanger Sequencing

Pancreatic cystic disease, including duct dilation, represents precursor states towards the development of pancreatic cancer, a form of malignancy with relatively low incidence but high mortality. While most of these cysts (>85%) are benign, the remainder can progress over time, leading to malignant transformation, invasion, and metastasis. Cytologic diagnosis is challenging, limited by the paucity or complete absence of cells representative of cystic lesions and fibrosis. Molecular analysis of fluids collected from endoscopic-guided fine-needle aspiration of pancreatic cysts and dilated duct lesions can be used to evaluate the risk of progression to malignancy. The basis for the enhanced diagnostic utility of molecular approaches is the ability to interrogate cell-free nucleic acid of the cyst/duct and/or extracellular fluid. The allelic imbalances at tumor suppressor loci and the selective oncogenic drivers are used clinically to help differentiate benign stable pancreatic cysts from those progressing toward high-grade dysplasia. Methods are discussed and used to determine the efficacy for diagnostic implementation. Here, we report the analytical validation of methods to detect causally associated molecular changes integral to the pathogenesis of pancreatic cancer from pancreatic cyst fluids.

The efficacy of low-dose CT with deep learning image reconstruction in the surveillance of incidentally detected pancreatic cystic lesions

PURPOSE

To evaluate the efficacy of low-dose CT (LDCT) with deep learning image reconstruction (DLIR) for the surveillance of pancreatic cystic lesions (PCLs) compared with standard-dose CT (SDCT) with adaptive statistical iterative reconstruction (ASIR-V).

METHODS

The study enrolled 103 patients who underwent pancreatic CT for follow-up of incidentally detected PCLs. The CT protocol included LDCT in the pancreatic phase with 40% ASIR-V, DLIR at medium (DLIR-M) and high levels (DLIR-H), and SDCT in the portal-venous phase with 40% ASIR-V. The overall image quality and conspicuity of PCLs were qualitatively assessed using five-point scales by two radiologists. The size of PCLs, presence of thickened/enhancing walls, enhancing mural nodules, and main pancreatic duct dilatation were reviewed. CT noise and cyst-to-pancreas contrast-to-noise ratio (CNR) were measured. Qualitative and quantitative parameters were analyzed using the chi-squared test, one-way ANOVA, and t-test. Additionally, interobserver agreement was analyzed using the kappa and weighted-kappa statistics.

RESULTS

The volume CT dose-indexes in LDCT and SDCT were 3.0 ± 0.6 mGy and 8.4 ± 2.9 mGy, respectively. LDCT with DLIR-H showed the highest overall image quality, the lowest noise, and the highest CNR. The PCL conspicuity in LDCT with either DLIR-M or DLIR-H was not significantly different from that in SDCT with ASIR-V. Other findings depicting PCLs also revealed no significant differences between LDCT with DLIR and SDCT with ASIR-V. Moreover, the results revealed good or excellent interobserver agreement.

CONCLUSION

LDCT with DLIR has a comparable performance with SDCT for the follow-up of incidentally detected PCLs.

Cystic pancreatic lesions, the endless dilemma

Cystic pancreatic lesions involve a wide variety of pathological entities that include neoplastic and non-neoplastic lesions. The proper diagnosis, differentiation, and staging of these cystic lesions are considered a crucial issue in planning further management. There are great challenges for their diagnostic models. In our time, new emerging methods for this diagnosis have been discovered. Endoscopic ultrasonography-guided fine-needle aspiration cytology with chemical and molecular analysis of cyst fluid and EUS-guided fine needle-based confocal laser endomicroscopy, through the needle microforceps biopsy, and single-operator cholangioscopy/pancreatoscopy are promising methods that have been used in the diagnosis of cystic pancreatic lesions. Hereby we discuss the diagnosis of cystic pancreatic lesions and the benefits of various diagnostic models.

Focal Pancreatic Lesions: Role of Contrast-Enhanced Ultrasonography

The introduction of contrast-enhanced ultrasonography (CEUS) has led to a significant improvement in the diagnostic accuracy of ultrasound in the characterization of a pancreatic mass. CEUS, by using a blood pool contrast agent, can provide dynamic information concerning macro- and micro-circulation of focal lesions and of normal parenchyma, without the use of ionizing radiation. On the basis of personal experience and literature data, the purpose of this article is to describe and discuss CEUS imaging findings of the main solid and cystic pancreatic lesions with varying prevalence.

Diagnostic Accuracy of MRI for Differentiation of Benign and Malignant Pancreatic Cystic Lesions Compared to CT and Endoscopic Ultrasound: Systematic Review and Meta-analysis

BACKGROUND

Differentiation of benign and malignant pancreatic cystic lesions on MRI, computed tomography (CT), and endoscopic ultrasound (EUS) is critical for determining management.

PURPOSE

To perform a systematic review evaluating the diagnostic accuracy of MRI for diagnosing malignant pancreatic cystic lesions, and to compare the accuracy of MRI to CT and EUS.

STUDY TYPE

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus were searched until February 2020 for studies reporting MRI accuracy for assessing pancreatic cystic lesions.

FIELD STRENGTH

1.5T or 3.0T.

ASSESSMENT

Methodologic and outcome data were extracted by two reviewers (AU and MA, 2 years of experience each). All studies of pancreatic cystic lesions on MRI were identified. Studies with incomplete MRI technique were excluded. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 tool.

STATISTICAL TESTS

Sensitivity/specificity was pooled using bivariate random-effects meta-analysis with 95% confidence intervals (95%CI). Pairwise-comparison of MRI to CT and EUS was performed. The impact of gadolinium-based contrast agents, mucinous lesions, and risk of bias were explored using meta-regression.

RESULTS

MRI pooled sensitivity was 76% (95%CI 67% to 84%) and specificity was 80% (95%CI 74% to 85%) for distinguishing benign and malignant lesions. MRI and CT had similar sensitivity (P = 0.822) and specificity (P = 0.096), but MRI was more specific than EUS (80% vs. 75%, P < 0.05). Studies including only contrast-enhanced MRI were more sensitive than those including unenhanced exams (P < 0.05). MRI sensitivity and specificity did not differ for mucinous lesions (P = 0.537 and P = 0.384, respectively) or for studies at risk of bias (P = 0.789 and P = 0.791, respectively).

DATA CONCLUSION

MRI and CT demonstrate comparable accuracy for diagnosing malignant pancreatic cystic lesions. EUS is less specific than MRI, which suggests that, in some cases, management should be guided by MRI findings rather than EUS.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY STAGE: 2.

Differentiating benign from malignant pancreatic cysts on computed tomography

•

CT can distinguish between benign and premalignant or malignant pancreatic cysts.

•

Solid component and septation were the only CT features that could differentiate benign from malignant cysts.

•

Cyst wall enhancements on CT were more commonly observed in premalignant or malignant cysts than in benign cysts.

•

CT is a necessary diagnostic modality to preoperatively detect and characterize pancreatic lesions.

Purpose

It is important to identify features on computed tomography (CT) that can distinguish between benign and premalignant or malignant pancreatic cysts to avoid unnecessary surgeries. This study investigated the preoperative diagnostic evaluation of cystic pancreatic lesions to determine how advanced imaging and clinical factors should guide management.

Methods

In total, 53 patients with 27 benign and 26 premalignant or malignant cysts were enrolled. CT features of the cysts were compared using univariate and multivariate analyses.

Results

On univariate analysis, a solid component (p < 0.01), septation (p < 0.01), location (p < 0.01), border (p < 0.01), wall enhancement (p = 0.01), lesion margins (p < 0.01), pancreatic atrophy (p = 0.04), and a cystic wall (p < 0.01) were all significantly different between benign and premalignant or malignant cysts. On multivariate analysis, only a solid component (p < 0.01) and septation (p < 0.01) were significant.

Conclusion

A thin cystic wall, uniform homogeneity, a clear border, the presence of septation, pancreatic atrophy, and the absence of both wall enhancements and solid components were more frequently seen in benign cysts. A thick wall, lack of homogeneity, the presence of wall enhancements and solid components, absence of septation, only a small degree of pancreatic atrophy, and unclear borders were more frequent among premalignant or malignant cysts. The only CT features to differentiate benign from premalignant or malignant cysts were a solid component and septation.

Role of Cross-sectional Imaging (CT/MRI) in Characterization and Distinguishing Benign from Malignant/Potentially Malignant Cystic Lesions of Pancreas

Objectives:

The aim of the study was to evaluate the accuracy of computed tomography/magnetic resonance imaging (CT/MRI) in characterizing cystic lesions of the pancreas and in differentiating between benign and malignant/potentially malignant lesions.

Material and Methods:

A retrospective study was performed on patients with pancreatic cystic lesions who underwent pre-operative imaging and surgery between October 2004 and April 2017 at a tertiary care teaching hospital. The images were reviewed for specific characteristics and diagnoses recorded independently by two radiologists who were blinded to the histopathological examination (HPE) report. Radiological diagnostic accuracy was assessed with HPE as reference standard.

Results:

A total of 80 patients fulfilled the inclusion criteria (M: F = 27:53). The final HPE diagnoses were solid pseudopapillary neoplasm (32.5%), walled off necrosis/pseudocyst (27.5%), mucinous cystadenoma (15%), serous cystadenoma (11.25%), intraductal papillary mucinous neoplasm (8.75%), mucinous cystadenocarcinoma (2.5%), simple epithelial cyst (1.25%), and unspecified benign cystic lesion (1.25%). Observer1 correctly identified the diagnosis in 73.75% of cases while observer 2 did so in 72.5%. Sensitivity for distinguishing benign versus malignant/potentially malignant lesions was 85.1% for observer 1 and 80.9% for observer 2. On multivariate logistic regression analysis: Solid cystic morphology, presence of mural nodule, and female gender were associated with premalignant/malignant lesions.

Conclusion:

Cross-sectional imaging is a valuable tool for characterization of pancreatic cystic lesions within its limitations.

Clinical use of contrast-enhanced ultrasound beyond the liver: a focus on renal, splenic, and pancreatic applications

Contrast-enhanced ultrasound (CEUS) is a relatively novel, but increasingly used, diagnostic imaging modality. In recent years, due to its safety, quickness, and repeatability, several studies have demonstrated the accuracy, specificity, and sensitivity of CEUS. The European Federation of Societies for Ultrasound in Medicine and Biology has recently updated the previous guidelines from 2012 for the use of CEUS in non-hepatic applications. This review deals with the clinical use and applications of CEUS for the evaluation of non-hepatic abdominal organs, focusing on renal, splenic, and pancreatic applications.

Diagnosis and management of pancreatic cystic neoplasms

This review outlines the current classification of pancreatic cystic lesions, with a particular emphasis on pancreatic cystic neoplasms (PCNs). It will describe the diagnostic approach to PCNs, with reference to clinicopathological features, cross-sectional radiology and endoscopic ultrasound. This review will conclude with an evidence-based discussion of the management of PCNs focused on recent clinical guidelines.

Preoperative contrast-enhanced computed tomographic characterisation of pancreatic cystic lesions: A prospective study

Background

Characterisation of pancreatic cystic lesions has a direct role in their management and computed tomography is the mainstay of investigation for diagnosing and characterising them.

Objectives

The aim of this study was to prospectively assess the diagnostic accuracy of contrast-enhanced computed tomography (CECT) in preoperative characterisation of pancreatic cystic lesions with histopathology as the reference standard.

Method

A total of 38 patients with cystic pancreatic lesions diagnosed after clinical, laboratory and sonographic evaluation, irrespective of age, were preoperatively evaluated with CECT. Images were reviewed for the general characteristics of the lesions on pre-contrast and portal venous phase images and overall diagnostic accuracy calculated. Imaging findings were compared with histopathology, or cytology and/or intra-operative findings.

Results

Serous cystadenoma (SCA) was the most common cystic pancreatic lesion found in 31.6% of patients followed by mucinous cystadenoma (MCA) (26.3%), solid pseudo-papillary tumour (SPT) (21.1%) and intra-ductal papillary mucinous neoplasm (IPMN) (10.5%). Three patients (7.9%) had simple cysts and one patient (2.6%) had a lymphangioma. The diagnostic accuracy of CECT for pancreatic cystic lesions was found to be 72.5.

Conclusion

The diagnostic accuracy of computed tomography (CT) was high for SCA, IPMN and pancreatic cysts, and low for MCA and SPT. Combination of a multiloculated cystic lesion with locule size of less than 20 mm, septal enhancement with relative lack of wall enhancement, central scar and lobulated outline are highly specific for SCA. Unilocular or macro-cystic pattern with locule size of more than 20 mm, female gender and wall enhancement with smooth external contour are pointers towards MCA. Solid cystic pancreatic head lesions in young females may be suggestive of SPT. A dilated main pancreatic duct in a cystic lesion with internal septations may point towards IPMN. Fluid attenuation lesions with imperceptible non-enhancing wall indicate pancreatic cysts. Lastly, pseudocysts and neuroendocrine tumours with cystic components are great mimickers of pancreatic cystic lesions, and a history of pancreatitis and hormonal profile of patients should always be sought.

Impact of endoscopic ultrasound on diagnosis and management of presumed mucinous neoplasms when done for pancreatic cyst morphology change on non-invasive surveillance imaging

Background and study aims  Guidelines for management of presumed neoplastic pancreatic cysts have encouraged noninvasive imaging for low-risk surveillance, while reserving endoscopic ultrasound for worrisome features including morphologic change. We aim to study the impact of endoscopic ultrasound on diagnosis and management compared with non-invasive imaging. Patients and methods  A single-institution pancreatic cyst database was retrospectively queried for patients who underwent endoscopic ultrasound for the indication of change in cyst morphology. Diagnoses were classified as presumed mucinous neoplasm with or without worrisome features or high-risk stigmata and non-mucinous lesions. Management decisions were defined a priori as surgical evaluation for patients with high-risk stigmata, positive cytology or mural nodule, or continued surveillance for all others. Results  Between January 2013 and October 2016, 709 pancreas cyst endoscopic ultrasounds were performed of which 89 were for cyst morphology change seen on noninvasive imaging including 10 presumed pseudocysts, nine presumed serous cystadenomas, and 70 presumed mucinous cystic neoplasms. Cyst morphologic changes included increase in caliber of the main pancreatic duct (7 cases), increase in cyst size (68 cases), cyst ≥ 30 mm (10 cases), and presence of a solid nodule (1 case). Median cyst size increase was 5 mm with interquartile range of 4 mm over 2.1 ± 1.9 years. Endoscopic ultrasound done for morphologic change resulted in a change in diagnosis and management in 16 % and 13 % of cases, respectively. Conclusion  Endoscopic ultrasound has a modest but clinically significant role in impacting diagnosis and management for presumed mucinous cystic neoplasms when performed for the indication of cyst morphology change.

Tumor growth rate of pancreatic serous cystadenomas: Endosonographic follow-up with volume measurement to predict cyst enlargement

BACKGROUND

Serous cystadenomas are benign lesions of the pancreas. Usually they are diagnosed incidentally on cross-sectional imaging studies. Endosonography is a valuable tool in the diagnosis and follow-up of these cystic lesions. Given its benign nature, surgical resection is advised only in symptomatic patients. The interval and length of surveillance is not well established.

METHODS

A retrospective single center study was done. All the patients with a pancreatic serous cystadenoma sent for an endosonographic evaluation, between December 2008 and December 2015 were included. The lesions were follow-up endosonographically at least once, in a 12 months interval. Volume was measured with the formula π/6 × (d1 x d1 x d2). Two groups were evaluated: patients with a volume under 10 mL (Group 1) and those with a volume of 10 mL or more at presentation (Group 2). Growth rate between these two groups was compared.

RESULTS

Thirty-one patients were analyzed, with a mean age of 58.2 years. Patients were mainly women (87%). Twenty-four patients in Group 1 had a mean enlargement of 0.67 ml per year, whereas patients in Group 2 had a mean enlargement of 9.8 ml per year. The growth rate difference between these two groups was statistically significant (p = 0.0001).

CONCLUSION

Asymptomatic patients with pancreatic serous cystadenomas should be follow-up for enlargement. Small volume lesions have a low risk of enlargement compared with high volume and macrocystic serous cystadenomas. Volume at presentation is a feature to analyze when defining surveillance interval.

New horizons in the endoscopic ultrasonography-based diagnosis of pancreatic cystic lesions

Pancreatic cystic lesions (PCLs) are increasingly being identified because of the widespread use of high-resolution abdominal imaging. These cysts encompass a spectrum from malignant disease to benign lesions, and therefore, accurate diagnosis is crucial to determine the best management strategy, either surgical resection or surveillance. However, the current standard of diagnosis is not accurate enough due to limitations of imaging and tissue sampling techniques, which entail the risk of unnecessary burdensome surgery for benign lesions or missed opportunities of prophylactic surgery for potentially malignant PCLs. In the last decade, endoscopic innovations based on endoscopic ultrasonography (EUS) imaging have emerged, aiming to overcome the present limitations. These new EUS-based technologies are contrast harmonic EUS, needle-based confocal endomicroscopy, through-the-needle cystoscopy and through-the needle intracystic biopsy. Here, we present a comprehensive and critical review of these emerging endoscopic tools for the diagnosis of PCLs, with a special emphasis on feasibility, safety and diagnostic performance.

Molecular analysis of pancreatic cyst fluid changes clinical management

Background and Objectives

DNA molecular analysis has been suggested as a tool to evaluate pancreatic cysts. This study assesses whether the addition of DNA molecular analysis alters clinical management.

Methods

This is a retrospective review of 46 consecutive patients who underwent EUS-FNA of pancreatic cysts with DNA molecular analysis at two major academic institutions. Cases were presented to two pancreaticobiliary surgeons first without and then with DNA molecular analysis data. The primary outcome was the frequency with which clinical management was altered with the addition of DNA molecular analysis.

Results

Forty-six patients with a mean age of 62.0 (±13.4) years and mean cyst size of 3.2 (±2.3) cm were included in the study. Cyst carcinoembryonic antigen (CEA) was available in 30 patients and ranged from 0.4 to 15,927 ng/mL. DNA molecular analysis was described as benign in 23 (50%), statistically indolent in 13 (28%), statistically higher risk in 9 (20%), and indeterminate in 1 (2%). Surgeon #1 changed the management in 13/46 cases (28%) and surgeon #2 changed the management in 12/46 cases (26%) with the addition of DNA molecular analysis. When organized by CEA concentration, those with an intermediate CEA (45-800 ng/mL) or without a CEA concentration had a management changed more frequently (40%) compared to all others (P < 0.05).

Conclusions

The addition of DNA molecular analysis alters the clinical management of pancreatic cystic lesions most often when CEA levels are intermediate (45-800 ng/mL) or when no CEA concentration is available. Use of DNA molecular analysis can be considered in this cohort. Further study of molecular markers in pancreatic cystic lesions is recommended.

Endoscopic ultrasonography evaluation for pancreatic cysts: Necessity or overkill?

Incidental pancreatic cysts have become gradually more recognized in clinical practice as a result of increased use of transabdominal ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI). These lesions consist of inflammatory cysts (pseudocysts) and pancreatic cystic neoplasms (PCN) which have been classified as benign, premalignant and malignant. The diagnosis and management strategy of incidentally discovered pancreatic cysts can be challenging as the majority of them are PCN and CT or MRI alone may not be sufficient to provide an accurate diagnosis. Endoscopic ultrasound (EUS)-guided fine-needle aspiration provides a method to obtain cyst fluid for analysis and the recently developed EUS-based technology including contrast-enhanced ultrasound, cystoscopy and needle-based confocal laser endomicroscopy allows endosonographers to gain additional useful information. The current data suggest that EUS evaluation of pancreatic cysts offers some benefits especially in cases of inconclusive CT or MRI.

Current perspectives on pancreatic serous cystic neoplasms: Diagnosis, management and beyond

Pancreatic cystic neoplasms have been increasingly recognized recently. Comprising about 16% of all resected pancreatic cystic neoplasms, serous cystic neoplasms are uncommon benign lesions that are usually asymptomatic and found incidentally. Despite overall low risk of malignancy, these pancreatic cysts still generate anxiety, leading to intensive medical investigations with considerable financial cost to health care systems. This review discusses the general background of serous cystic neoplasms, including epidemiology and clinical characteristics, and provides an updated overview of diagnostic approaches based on clinical features, relevant imaging studies and new findings that are being discovered pertaining to diagnostic evaluation. We also concisely discuss and propose management strategies for better quality of life.

Cystic Neoplasm of the Pancreas

Cystic neoplasms of the pancreas (CNPs) are not considered as rare entities any more. Imaging-based population studies attested an overall prevalence of 2 %, but that becomes five times higher on individuals of more than 70 year old. This family of neoplasms includes a wide spectrum of benign, borderline, and malignant lesions whose actual biological behavior has not been completely clarified yet. Moreover, the management of CNPs still represents a challenge for gastrointestinal (GI) specialists. While many CNPs have an indolent behavior that justifies surveillance, others should be resected because of the risk of progression to invasive cancer. Due to the high morbidity related to pancreatic resections, the surgeon should balance very carefully the advantages of a radical resection with the risks of an unrequested dangerous procedure. We reviewed the current issues regarding CNPs, with a particular focus on the clinical and radiological features that are integrated in the current guidelines and that drive the management of these patients.

Automated pancreatic cyst screening using natural language processing: a new tool in the early detection of pancreatic cancer

INTRODUCTION

As many as 3% of computed tomography (CT) scans detect pancreatic cysts. Because pancreatic cysts are incidental, ubiquitous and poorly understood, follow-up is often not performed. Pancreatic cysts may have a significant malignant potential and their identification represents a 'window of opportunity' for the early detection of pancreatic cancer. The purpose of this study was to implement an automated Natural Language Processing (NLP)-based pancreatic cyst identification system.

METHOD

A multidisciplinary team was assembled. NLP-based identification algorithms were developed based on key words commonly used by physicians to describe pancreatic cysts and programmed for automated search of electronic medical records. A pilot study was conducted prospectively in a single institution.

RESULTS

From March to September 2013, 566,233 reports belonging to 50,669 patients were analysed. The mean number of patients reported with a pancreatic cyst was 88/month (range 78-98). The mean sensitivity and specificity were 99.9% and 98.8%, respectively.

CONCLUSION

NLP is an effective tool to automatically identify patients with pancreatic cysts based on electronic medical records (EMR). This highly accurate system can help capture patients 'at-risk' of pancreatic cancer in a registry.

Does EUS-FNA molecular analysis carry additional value when compared to cytology in the diagnosis of pancreatic cystic neoplasm? A systematic review

BACKGROUND

Endoscopic ultrasonography with fine needle aspiration (EUS-FNA) has become an integral tool in the diagnosis of pancreatic cystic lesions (PCLs) and the analysis of molecular/DNA abnormalities might improve the accuracy of pre-operative diagnosis. A review was conducted of all studies using EUS-FNA aspirates of PCLs to assess the accuracy and added benefit that molecular analysis provides to cytological analysis.

METHODS

A systematic review of the literature was conducted using PRISMA guidelines and electronic databases: PubMed/SCOPUS/EMBASE/Cochrane/CINAHL. Surgical pathology was used as the definitive reference standard. The QUADAS-2 tool was used for quality assessment.

RESULTS

In total, 162 articles were identified; 12 articles met inclusion/exclusion criteria. Ten studies reported on cytology and 8 studies reported k-ras mutational analysis. 362 patients (of 1115 total) had surgical pathology available. The sensitivity and specificity of cytology was 0.42 and 0.99; the sensitivity and specificity of k-ras was 0.39 and 0.95; and the sensitivity and specificity of the combined test of cytology and k-ras was 0.71 and 0.88, respectively.

CONCLUSIONS

k-ras mutational analysis used as an individual screening test has a poor diagnostic accuracy, as does cytology when used alone. The benefit comes with utilization in a combined fashion. More studies are needed to evaluate the correct sequence and utility of these tests for cyst differentiation.

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.

Differential diagnosis of pancreatic serous oligocystic adenoma and mucinous cystic neoplasm with spectral CT imaging: initial results

AIM

To investigate the imaging characteristics of pancreatic serous oligocystic adenoma (SOA) and mucinous cystic neoplasms (MCNs) using spectral computed tomography (CT) and to evaluate whether quantitative information derived from spectral imaging can improve the differential diagnosis of these diseases.

MATERIALS AND METHODS

From February 2010 to June 2013, 44 patients (24 SOAs and 20 MCNs) who underwent spectral CT imaging were included in the study. Conventional characteristics and quantitative parameters were compared between the two disease groups. Logistic regression was used for multiparametric analysis. The receiver-operating characteristic curve was used to evaluate the diagnostic performance of single parameter and multiparametric analysis. Two radiologists diagnosed the diseases blinded and independently, without and with the information of the statistical analysis.

RESULTS

Tumour location, contour, size, and monochromatic CT values at 40 keV to 70 keV, iodine concentration, and effective atomic number (effective-Z) in the late arterial phase were the independent factors correlated with category. Multiparametric analysis with logistic regression showed that tumour size, location, and contour were the most effective variations, and obtained an area under the ROC curve (AUC) of 0.934. With the knowledge of statistical analysis, the accuracy of the first reader increased from 70.5% to 86.4%, and the accuracy of the second reader increased from 81.8% to 90.9%.

CONCLUSIONS

Although CT spectral imaging provided additional information and multiparametric analysis obtained better performance than single-parameter analysis in differentiating MCNs from SOAs, multiparametric analysis with the combination of quantitative parameters derived from CT spectral imaging did not improve the diagnostic performance. Tumour size, location, and contour played an important role in differentiating MCNs from SOAs.

Performance characteristics of molecular (DNA) analysis for the diagnosis of mucinous pancreatic cysts

BACKGROUND

Diagnosis of mucinous pancreatic cysts (MPCs) is challenging due to the poor sensitivity of cytology provided by EUS-guided-FNA (EUS-FNA).

OBJECTIVE

To quantify the test characteristics of molecular (DNA) analysis in suspected low-risk MPCs.

DESIGN

A prospective cohort study performed in between 2008 and 2011.

SETTING

Academic referral center.

PATIENTS

Consecutive patients who underwent EUS-FNA of suspected MPCs.

INTERVENTION

EUS-FNA and molecular (DNA) analysis of cyst fluid.

MAIN OUTCOME MEASUREMENTS

The sensitivity and specificity of molecular analysis in the diagnosis of MPCs using the criterion standard of surgical pathology in resected cysts.

RESULTS

Patients with suspected MPCs underwent EUS-FNA and cyst fluid DNA analysis. Surgical resection was performed in 48 patients (17%), confirming a mucinous pathology in 38 (79%). In this group, molecular analysis had a sensitivity of 50% and a specificity of 80% in identifying MPCs (accuracy of 56.3%). The combination of molecular analysis with cyst fluid carcinoembryonic antigen (CEA) and cytology resulted in higher MPC diagnostic performance than either one of its individual components, with a sensitivity, specificity, and accuracy of 73.7%, 70%, and 72.9%, respectively. There was no significant difference in accuracy between molecular analysis and CEA/cytology in this group.

LIMITATIONS

Single-center experience.

CONCLUSION

Molecular analysis aids in the diagnosis of MPCs when cytology is nondiagnostic or cyst fluid is insufficient for CEA or its level is indeterminate. Our results do not support the routine use of molecular analysis, which should be used selectively after review of imaging findings and cyst fluid studies. Further studies are needed to assess DNA's performance in malignant cysts.

Incidentally detected cystic lesions of the pancreas on CT: review of literature and management suggestions

PURPOSE

To facilitate a better understanding of incidentally noted cystic pancreatic lesions, since these lesions often pose a challenge regarding appropriate management.

METHODS

This article reviews pathophysiology, prevalence, significance, and recommendations for management of the various pancreatic cystic lesions. Illustrative cases are demonstrated.

RESULTS

Diagnostic benign lesions can be left alone. Cross-sectional imaging can be used to follow-up benign appearing lesions and to stage more aggressive ones. Endoscopic ultrasound with fine needle aspiration and cyst fluid analysis can be performed on certain indeterminate lesions. Lesions with high malignant potential should undergo resection.

CONCLUSIONS

A better understanding of the variety of incidentally detected pancreatic cystic lesions can help direct appropriate management.

Fine-needle aspirations of pancreatic serous cystadenomas: improving diagnostic yield with cell blocks and α-inhibin immunohistochemistry

BACKGROUND

The diagnosis of serous cystadenoma (SCA), a rare benign pancreatic neoplasm, can alter the management of patients with pancreatic masses. Although characteristic imaging findings and fluid chemical analysis have been described, SCAs are not always recognized preoperatively. Furthermore, scant cellular yield on fine-needle aspiration (FNA) often leads to a nondiagnostic or nonspecific benign diagnosis. α-Inhibin (AI), a sensitive marker for SCA, is infrequently required for diagnosis in surgical specimens due to their characteristic histologic appearance. The objective of the current study was to determine whether AI staining can improve SCA diagnosis on FNA specimens.

METHODS

Fifteen confirmed cases of SCA with prior FNA specimens were selected for this study. FNAs were evaluated for cellularity, cellular arrangement, and cytomorphology. Resection specimens were reviewed.

RESULTS

Of the 15 FNA cases, approximately 75% demonstrated scant cellularity (11 of 15 cases). On smears, the cells were arranged as flat sheets, corresponding to strips of cells on cell block sections. The cells were small and round to cuboidal, with clear cytoplasm; occasional plasmacytoid cells and oncocytic cells were identified. Flattened cells, corresponding to attenuated epithelial cells lining macrocysts on the resections, were also noted. Stromal fragments were present in 5 FNAs and correlated with the hyalinized stroma in the resection specimens. AI immunostaining was positive in 88% of cases (7 of 8 of cases), thereby supporting the diagnosis of SCA.

CONCLUSIONS

The results of the current study indicate that low cellularity and bland cytology are inherent to SCAs. Performing cell blocks and AI staining on FNA specimens is useful for establishing the diagnosis of SCA. An immunohistochemical panel including AI, chromogranin, and synaptophysin may enhance the diagnostic accuracy of pancreatic FNA specimens.

Imaging of indeterminate pancreatic cystic lesions: a systematic review

BACKGROUND

Pancreatic cystic lesions are an increasing problem and investigation of these cysts can be fraught with difficulty. There is currently no gold standard for diagnosis or surveillance. This review was undertaken to determine the present reliability of the characterisation, assessment of malignant potential and diagnosis of pancreatic cystic lesions using available imaging modalities.

METHODS

A Medline search using the terms 'pancreatic', 'pancreas', 'cyst', 'cystic', 'lesions', 'imaging', 'PET'. 'CT', 'MRI' and 'EUS' was performed. Publications were screened to include studies examining the performance of CT, MRI, MRCP, EUS and 18-FDG PET in the determination of benign or malignant cysts, cyst morphology and specific diagnoses.

RESULTS

Nineteen studies were identified that met the inclusion criteria. 18-FDG PET had a sensitivity and specificity of 57.0-94.0% and 65.0-97.0% and an accuracy of 94% in determining benign versus malignant cysts. CT had a sensitivity and specificity of 36.3-71.4% and 63.9-100% in determining benign disease but had an accuracy of making a specific diagnosis of 39.0-44.7%. MRI had a sensitivity and specificity of 91.4-100.0% and 89.7% in assessing main pancreatic duct communication.

CONCLUSION

CT is a good quality initial investigation to be used in conjunction with clinical data. MRCP can add useful information regarding MPD communication but should be used judiciously. PET may have a role in equivocal cases to determine malignancy. Further examination of CT-PET in this patient group is warranted.

Cystic lesions of the pancreas: radiologic-endosonographic correlation

Cystic lesions of the pancreas are relatively common findings at cross-sectional imaging; however, classification of these lesions on the basis of imaging features alone can sometimes be difficult. Complementary evaluation with endoscopic ultrasonography and fine-needle aspiration may be helpful in the diagnosis of these lesions. Cystic lesions of the pancreas may range from benign to malignant and include both primary cystic lesions of the pancreas (including intraductal papillary mucinous neoplasms, mucinous cystic neoplasms, serous cystadenomas, pseudocysts, and true epithelial cysts) and solid neoplasms undergoing cystic degeneration (including neuroendocrine tumors, solid pseudopapillary neoplasms, and, rarely, adenocarcinoma and its variants). Familiarity with the imaging features of these lesions and the basic treatment algorithms is essential for radiologists, as collaboration with gastroenterologists and surgeons is often necessary to obtain an early and accurate diagnosis.

Preoperative classification of pancreatic cystic neoplasms: the clinical significance of diagnostic inaccuracy

BACKGROUND

The potential for malignant transformation varies among pancreatic cystic neoplasms (PCN) subtypes. Imaging and cyst fluid analysis are used to identify premalignant or malignant cases that should undergo operative resection, but the accuracy of operative decision-making process is unclear. The objective of this study was to characterize misdiagnoses of PCN and determine how often operations are undertaken for benign, non-premalignant disease.

METHODS

A retrospective analysis of patients undergoing pancreatic resection for the preoperative diagnosis of PCN was undertaken. Preoperative and pathological diagnoses were compared to measure diagnostic accuracy.

RESULTS

Between 1999 and 2011, 74 patients underwent pancreatic resection for the preoperative diagnosis of PCN. Preoperative classification of mucinous vs. non-mucinous PCN was correct in 74%. The specific preoperative PCN diagnosis was correct in 47%, but half of incorrect preoperative diagnoses were clinically equivalent to the pathological diagnoses. The likelihood that the pathological diagnosis was of higher malignant potential than the preoperative diagnosis was 7%. In 20% of cases, the preoperative diagnosis was premalignant or malignant, but the pathological diagnosis was benign. Diagnostic accuracy and the rate of undercall diagnoses and overcall operations did not change with the use of EUS or during the time period of this analysis.

CONCLUSIONS

Precise, preoperative classification of PCN is frequently incorrect but results in appropriate clinical decision-making in three-quarters of cases. However, one in five pancreatic resections performed for PCN was for benign disease with no malignant potential. An appreciation for the rate of diagnostic inaccuracies should inform our operative management of PCN.

Association between KRAS mutation, detected in pancreatic cyst fluid, and long-term outcomes of patients

BACKGROUND & AIMS

Endoscopic ultrasound (EUS) with fine-needle aspiration is routinely used to evaluate pancreatic cysts. We investigated the association between results from DNA analysis of cyst fluid and patient outcomes.

METHODS

In a retrospective analysis, we collected data from 113 patients with pancreatic cysts who underwent EUS with fine-needle aspiration at a tertiary care center from June 2004 to June 2007. Detailed follow-up data were obtained through October 2010 (mean, 47 months). Pancreatic cysts were categorized as nonbenign or benign on the basis of pathology analysis of surgical samples and patients' outcomes. We compared the patient characteristics, presenting symptoms, EUS imaging characteristics, and results from analysis of cyst fluid, including cytology results, levels of carcinoembryonic antigen, and DNA sequencing results.

RESULTS

Fifty-one patients underwent pancreatic surgery (10 had malignant, 18 had mucinous, and 16 had benign cysts), 63 patients were followed long-term, and 13 patients died of pancreatic cancer. On the basis of multivariate regression analysis, the presence of cyst solid component, patient symptoms, cyst size >3 cm, and detection of KRAS mutations at codons 12 and 13 in cyst fluid were independently associated with a nonbenign course.

CONCLUSIONS

KRAS mutations, detected in pancreatic cyst fluid, are associated with mucinous cysts and progression and development of malignancy and should be considered in assessing pancreatic cysts. The presence of a cyst solid component, patient symptoms, and cyst size greater than 3 cm were additional high-risk factors for a malignant course of disease.

Imaging investigation of pancreatic cystic lesions and proposal for therapeutic guidelines

AIM: To propose a diagnostic algorithm for preoperatively predicting the need for surgical intervention.

METHODS: The study included 56 patients (27 men and 29 women) with a final diagnosis of cystic pancreatic lesions. The following materials were used: ultrasonic equipment with 3.5 and 7 MHz linear, convex and biopsical transducers. Multidetector computed tomography (MDCT) investigations were performed using a 16-slice scanner. Images were obtained following the oral administration of 200 mL water and 100 mL intravenous iopamidol (300 mg/mL) administered by pump injector at a rate of 3 mL/s (40 and 60 s post-injection, respectively) using 0.5 mm detectors, reconstructed at 1 mm (pancreatic phase) or 2 mm (portal venous phase) increments. The table feed was 10 mm per rotation. Images were acquired in the pancreatic and portal venous phases of contrast enhancement. The “Chiba” needles 18, 20, 22, 23 G and an automatic aspiration system were used in conjunction with the following methods of guiding the interventional procedures: (1)“free-hand” biopsy and puncture method under ultrasound (US) or computed tomography (CT) control; (2) guiding method using biopsical transducer.

RESULTS: All 56 patients in this study underwent at least two cuts imaging survey methods, such as US, CT or magnetic resonance imaging (MRI). The most common preoperative diagnostic examination was US scan - 56 patients (100%). MDCT studies were conducted in 49 (87.50%) and MRI in 13 (23.21%). More than half of patients surveyed (37) underwent some type of interventional procedure: 25-fine-needle aspiration and 29-fine needle aspiration biopsy (FNAB), as part of the examination. Thirty-four patients of all 56 patients underwent surgery because of histological evidence of malignancy after the FNAB for cystic lesions of the pancreas. Distal pancreatectomy with splenectomy was the most common operative approach in 13 patients, followed by Whipple resection in 11 and distal pancreatectomy without splenectomy in 7. Three patients were treated with total pancreatectomy due to the presence of a multifocal mucinous neoplasm. Comparing the diagnostic results of US examination with those of MDCT examination and histological verification true positive results were found in 31 patients, true negative in 11 patients, false positive in 5 and false negative in 9 patients. Accordingly we estimated the power of the diagnostic imaging methods for cystic lesions of the pancreas. A specificity of 68.75%, sensitivity of 79.48%, accuracy of 75.00%, positive predictive value of 86.11% and negative predictive value of 55% were obtained. The power increased after applying invasive procedures with immunohistochemical analysis of CEA and P-53 (Fig. 4). In 15 patients with cytological feature of malignant tumour cells, the tumour markers were positive. In our opinion the higher the percentage of reacting cells the higher the percent of malignancy. In patients with clear symptoms and/or clear imaging features of malignant or premalignant cystic neoplasm, the need for surgery was confirmed by histological verification in 34 (60.71%) of cases.

CONCLUSION: By using the proposed algorithm, cystic mucinous tumors of the pancreas were detected and proper operative interventions would have been rendered with fewer diagnostic examinations.

Malignant potential in incidental pancreatic cysts

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

Diagnostic and radiological management of cystic pancreatic lesions: important features for radiologists

Cystic pancreatic neoplasms are often an incidental finding, the frequency of which is increasing. The understanding of such lesions has increased in recent years, but the numerous types of lesions involved can hinder differential diagnosis. They include, in particular, intraductal papillary mucinous neoplasms (IPMN), serous cystic neoplasms (SCN), and mucinous cystic neoplasms (MCN). Knowledge of their histological and radiological structure, as well as distribution in terms of localization, age, and sex, helps to differentiate such tumours from common pancreatic pseudocysts. Several types of cystic pancreatic neoplasms can undergo malignant transformation and, therefore, require differentiated radiological management. This review aims to develop a broader understanding of the pathological and radiological characteristics of cystic pancreatic neoplasms, and provide a guideline for everyday practice based on current concepts in the radiological management of the given lesions.

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.

Prospective evaluation of reader performance on MDCT in characterization of cystic pancreatic lesions and prediction of cyst biologic aggressiveness

OBJECTIVE

Our objective was to evaluate the accuracy of MDCT features of pancreatic cystic lesions in cyst characterization and in predicting cyst biologic aggressiveness.

SUBJECTS AND METHODS

In this prospective study, 114 patients (40 men and 74 women; age range, 23-89 years) with 130 cystic lesions (size range, 31-160 mm) in the pancreas underwent contrast-enhanced dual-phase (n = 92) and portal phase (n = 22) examinations with 16- or 64-MDCT scanners. Using defined morphologic features of cystic lesions on MDCT, two readers performed blinded evaluations for cystic characterization and predicting biologic aggressiveness (invasive lesions, carcinoma in situ, and moderate grade dysplasias) before pancreatic surgery. Receiver operating characteristic analysis was performed to assess the accuracy of MDCT using pathologic evaluation of the surgical specimen as a reference standard.

RESULTS

On the basis of MDCT features, the radiologic accuracy (reader 1 and reader 2) for stratifying lesions into mucinous and nonmucinous subtypes was 85% and 82% and for recognizing cysts with aggressive biology was 86% and 85%, respectively. Predictive values of MDCT were superior for lesions > 30 mm and nonmucinous lesions. Features favoring aggressive biology were main pancreatic duct dilation > 10 mm (p < 0.0001), biliary obstruction (p=0.01), mural nodule (p < 0.0001), main-duct intraductal papillary mucinous neoplasm (p < 0.0001), and advanced age (p = 0.0001). Sensitivity of detecting morphologic features was higher with the dual-phase pancreatic protocol CT.

CONCLUSION

Morphologic features of pancreatic cystic lesions on MDCT allow reliable characterization into mucinous and nonmucinous subtypes and enable prediction of biologic aggressiveness.

Diagnosis and management of cystic lesions of the pancreas

Pancreatic cysts are challenging lesions to diagnose and to treat. Determining which of the five most common diagnoses—pancreatic pseudocyst, serous cystic neoplasm (SCN), solid pseudopapillary neoplasm (SPN), mucinous cystic neoplasm (MCN), and intraductal mucinous papillary neoplasm (IPMN)—is likely the correct one requires the careful integration of many historical, radiographic, laboratory, and other factors, and management is markedly different depending on the type of cystic lesion of the pancreas. Pseudocysts are generally distinguishable based on historical, clinical and radiographic characteristics, and among the others, the most important differentiation is between the mucin-producing MCN and IPMN (high risk for cancer) versus the serous SCN and SPN (low risk for cancer). EUS with FNA and cyst-fluid analysis will continue to play an important role in diagnosis. Among mucinous lesions, those that require treatment (resection currently) are any MCN, any MD IPMN, and BD IPMN larger than 3 cm, symptomatic, or with an associated mass, with the understanding that SCN or pseudocysts may be removed inadvertently due to diagnostic inaccuracy, and that a certain proportion of SPN will indeed be malignant at the time of removal. The role of ethanol ablation is under investigation as an alternative to resection in selected patients.

Diagnosis and treatment of cystic pancreatic tumors

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

Differentiation of pancreatic cysts with optical coherence tomography (OCT) imaging: an ex vivo pilot study

We demonstrate for the first time that optical coherence tomography (OCT) imaging can reliably distinguish between morphologic features of low risk pancreatic cysts (i.e., pseudocysts and serous cystadenomas) and high risk pancreatic cysts (i.e., mucinous cystic neoplasms and intraductal papillary mucinous neoplasms). In our study fresh pancreatectomy specimens (66) from patients with cystic lesions undergoing surgery were acquired and examined with OCT. A training set of 20 pathology-OCT correlated tissue specimens were used to develop criteria for differentiating between low and high risk cystic lesions. A separate (validation) set of 46 specimens were used to test the OCT criteria by three clinicians, blinded to histopathology findings. Histology was finally used as a 'gold' standard for testing OCT findings. OCT was able to reveal specific morphologic features of pancreatic cysts and thus to differentiate between low-risk and high-risk cysts with over 95% sensitivity and specificity. This pilot study suggests that OCT could be used by clinicians in the future to more reliably differentiate between benign and potentially malignant pancreatic cysts. However, in vivo use of OCT requires a probe that has to fit the bore of the pancreas biopsy needle. Therefore, we have developed such probes and planned to start an in vivo pilot study within the very near future.

Cystic lesions of the pancreas: changes in the presentation and management of 1,424 patients at a single institution over a 15-year time period

BACKGROUND

Cystic lesions of the pancreas are being identified more frequently, and a selective approach to resection is now recommended. The aim of this study was to assess the change in presentation and management of pancreatic cystic lesions evaluated at a single institution over 15 years.

STUDY DESIGN

A prospectively maintained registry of patients evaluated between 1995 and 2010 for the ICD-9 diagnosis of pancreatic cyst was reviewed. The 539 patients managed from 1995 to 2005 were compared with the 885 patients managed from 2005 to 2010.

RESULTS

A total of 1,424 patients were evaluated, including 1,141 with follow-up >6 months. Initial management (within 6 months of first assessment) was operative in 422 patients (37%) and nonoperative in 719 patients (63%). Operative mortality in patients initially submitted to resection was 0.7% (n = 3). Median radiographic follow-up in patients initially managed nonoperatively was 28 months (range 6 to 175 months). Patients followed radiographically were more likely to have cysts that were asymptomatic (72% versus 49%, p < 0.001), smaller (1.5 versus 3 cm, p < 0.001), without solid component (94% versus 68%, p < 0.001), and without main pancreatic duct dilation (88% versus 61%, p < 0.001). Changes prompting subsequent operative treatment occurred in 47 patients (6.5%), with adenocarcinoma identified in 8 (17%) and pancreatic endocrine neoplasm in 4 (8.5%). Thus, of the 719 patients initially managed nonoperatively, invasive malignancy was identified in 12 (1.7%), with adenocarcinoma seen in 1.1%.

CONCLUSION

Cystic lesions of the pancreas are being identified more frequently, yet are less likely to present with concerning features of malignancy. Carefully selected patients managed nonoperatively had a risk of malignancy that was equivalent to the risk of operative mortality in those patients who initially underwent resection.

Cystic lymphangioma of the pancreas with spontaneous rupture: report of a case

Lymphangioma is a benign and congenital malformation of the lymphatic system. Most lymphangiomas are preferentially located in the head and neck region. The abdominal organs are uncommon sites of origin. Several cases of lymphangioma in abdominal organs were reported, however, the pancreas is one of the rarest origins. Generally, intra-abdominal lymphangioma is asymptomatic and found incidentally, but in some cases, the patient complains of abdominal distension or a palpable mass. We describe the case of a 38-year-old male who presented with sudden-onset upper abdominal pain. Rupture of a cystic tumor of the pancreatic head was suspected, based on the findings of computed tomography, magnetic resonance imaging and endoscopic ultrasonography. Subtotal stomach-preserving pancreaticoduodenectomy was undertaken. The tumor, which was 4 × 4.5 × 8 cm in size, was pathologically diagnosed as a cystic lymphangioma. In conclusion, pancreatic lymphangioma is mostly asymptomatic, a ruptured case causing ‘acute abdomen’ has never been reported. Since lymphangioma is benign, it could be observed with accurate diagnosis. The surgical indication would be limited to cases of symptomatic lymphangiomas.

Diffusion-weighted imaging in characterization of cystic pancreatic lesions

AIM

To evaluate whether apparent diffusion coefficient (ADC) measurements from diffusion-weighted imaging (DWI) can characterize or predict the malignant potential of cystic pancreatic lesions.

MATERIALS AND METHODS

Retrospective review of the magnetic resonance imaging (MRI) database over a 2-year period revealed 136 patients with cystic pancreatic lesions. Patients with DWI studies and histological confirmation of cystic mass were included. In patients with known pancreatitis, lesions with amylase content of >1000 IU/l that resolved on subsequent scans were included as pseudocysts. ADC of cystic lesions was measured by two independent reviewers. These values were then compared to categorize these lesions as benign or malignant using conventional MRI sequences.

RESULTS

Seventy lesions were analysed: adenocarcinoma (n=4), intraductal papillary mucinous neoplasm (IPMN; n=28), mucinous cystic neoplasm (MCN; n=9), serous cystadenoma (n=16), and pseudocysts (n=13). There was no difference between ADC values of malignant and non-malignant lesions (p=0.06), between mucinous and serous tumours (p=0.12), or between IPMN and MCN (p=0.42). ADC values for low-grade IPMN were significantly higher than those for high-grade or invasive IPMN (p=0.03).

CONCLUSION

ADC values may be helpful in deciding the malignant potential of IPMN. However, they are not useful in differentiating malignant from benign lesions or for characterizing cystic pancreatic lesions.

Focal cystic pancreatic lesions: assessing variation in radiologists' management recommendations

PURPOSE

To estimate the prevalence of focal cystic pancreatic lesions (FCPLs) among patients undergoing computed tomographic (CT) or magnetic resonance (MR) imaging at one institution and to examine any variation in radiologists' recommendation practice pattern with regards to FCPLs.

MATERIALS AND METHODS

Institutional review board approval was obtained for this retrospective HIPPA-compliant study. The requirement to obtain informed consent was waived. A cohort of patients with FCPLs was identified from radiology reports by using natural language processing. Patient-specific (ie, age, sex, symptoms, history of pancreatitis), radiologist-specific (ie, years of experience, area of expertise), and FCPL-specific (ie, size, location, septation, calcification, mural nodularity, pancreatic duct involvement, and presence of multiple cysts) variables were obtained. The outcome measure was whether a follow-up study was recommended. A logistic regression model was used to identify relative recommendation rates after controlling for key explanatory variables.

RESULTS

Between January 1 and December 31, 2009, a total of 1067 FCPLs were identified in 765 patients. Prevalence rates ranged from 2.2% at CT to 15.9% at MR imaging. Radiologists recommended a follow-up imaging study in 23.7% of cases of a FCPL. A 2.8-fold difference in the rate of recommendation of further imaging existed across radiologists after controlling for explanatory variables such as lesion-, radiologist-, and patient-specific characteristics. A history of pancreatitis was associated with a nearly two-fold decrease in recommending further imaging.

CONCLUSION

FCPLs are common, and nearly one-quarter of radiology reports recommend at least one follow-up imaging study. Significant variation exists in the rate of recommendation for further imaging studies by radiologists, even after controlling for key explanatory variables.

Primary pancreatic cystic neoplasms revisited. Part I: serous cystic neoplasms

Primary pancreatic cystic neoplasms have been recognized increasingly during the two recent decades and include mainly serous cystic neoplasms, mucinous cystic neoplasms, and intraductal papillary mucinous neoplasms. Serous cystic neoplasms represent about 30% of all cystic neoplasms of the pancreas and are characterized by their microcystic appearance (on imaging, macroscopically, and microscopically) and their benign biologic behavior. Modern diagnostic methodology allows the preoperative diagnosis with an acceptable accuracy. Currently, indications for resection of serous cystic neoplasms of the pancreas include the presence of symptoms, size > 4 cm (because these 'large' neoplasms have a more rapid growth rate and probably will soon become symptomatic), and any uncertainty about the diagnosis of a serous versus a mucinous cystic neoplasm. Resection should also be considered for lesions in the body/tail of the pancreas. Conservative treatment is a reasonable option in selected patients (for example in the presence of small, asymptomatic lesions in the pancreatic head, especially in the frail or elderly patient).

The incidental pancreatic cyst

The discovery of a pancreatic cyst in an asymptomatic patient presents an immediate challenge to the interpreting radiologist, the clinician who manages the patient, and patients themselves. When a cyst is discovered on imaging in a patient without symptoms directly referable to the pancreas, the following questions are immediately raised: can the lesion be accurately diagnosed or is the appropriate management clear from the examination, is the best management approach to suggest watchful waiting with follow-up imaging, what is the best method for imaging follow-up, and what is the optimal frequency of follow-up? This article recommends an approach to analyzing patients with incidental pancreatic cysts.

Pleomorphic giant cell carcinoma of the pancreas with hepatic metastases--initially presenting as a benign serous cystadenoma: a case report and review of the literature

INTRODUCTION

Pleomorphic giant cell pancreatic cancer is a very rare and aggressive pancreatic neoplasm. A case of pleomorphic giant cell pancreatic cancer presenting as a cystic lesion and in association with a serous cystadenoma presents a unique case which has not been described before.

CASE PRESENTATION

A 44-year-old alcoholic man presented with abdominal pain, vomiting, and weight loss. Initially, imaging suspected a pancreatic pseudocyst measuring 4.2 cm. Endoscopic ultrasound- (EUS-) guided fine-needle aspiration revealed a serous cystadenoma. With conservative intervention only (fluid resuscitation, analgesia, and antiemetics) the patient improved and was discharged under close observation. Follow-up scan at four months revealed minimal change. Three months later, he was admitted acutely. Repeat scans demonstrated mild cyst enlargement with new liver lesions. Laparoscopic biopsy revealed pleomorphic giant cell carcinoma with the organ of origin the pancreas.

CONCLUSION

This unusual case highlights the challenges in managing pancreatic cystic lesions and emphasizes the importance of considering less common forms of pancreatic cystic masses when the findings are atypical for the presentation. Surgical excision in these cases over conservative steps may be the most appropriate management.