Prospective preoperative determination of mucinous pancreatic cystic neoplasms

Quantitative MRI of Pancreatic Cystic Lesions: A New Diagnostic Approach

The commonly used magnetic resonance (MRI) criteria can be insufficient for discriminating mucinous from non-mucinous pancreatic cystic lesions (PCLs). The histological differences between PCLs’ fluid composition may be reflected in MRI images, but cannot be assessed by visual evaluation alone. We investigate whether additional MRI quantitative parameters such as signal intensity measurements (SIMs) and radiomics texture analysis (TA) can aid the differentiation between mucinous and non-mucinous PCLs. Fifty-nine PCLs (mucinous, n = 24; non-mucinous, n = 35) are retrospectively included. The SIMs were performed by two radiologists on T2 and diffusion-weighted images (T2WI and DWI) and apparent diffusion coefficient (ADC) maps. A total of 550 radiomic features were extracted from the T2WI and ADC maps of every lesion. The SIMs and TA features were compared between entities using univariate, receiver-operating, and multivariate analysis. The SIM analysis showed no statistically significant differences between the two groups (p = 0.69, 0.21–0.43, and 0.98 for T2, DWI, and ADC, respectively). Mucinous and non-mucinous PLCs were successfully discriminated by both T2-based (83.2–100% sensitivity and 69.3–96.2% specificity) and ADC-based (40–85% sensitivity and 60–96.67% specificity) radiomic features. SIMs cannot reliably discriminate between PCLs. Radiomics have the potential to augment the common MRI diagnosis of PLCs by providing quantitative and reproducible imaging features, but validation is required by further studies.

Mass Spectrometry-Based Comprehensive Analysis of Pancreatic Cyst Fluids

Pancreatic cyst fluids (PCFs) enriched in tumour-derived proteins are considered a potential source of new biomarkers. This study aimed to determine compositional and quantitative differences between the degradome and proteome of PCFs aspirated from different types of pancreatic cyst lesions (PCLs). 91 patients who underwent endoscopic ultrasound-fine needle aspiration under routine clinical diagnosis of PCLs were enrolled. Four cysts were malignant (CAs), and 87 were nonmalignant and consisted of 18 intraductal papillary mucinous neoplasms (IPMNs), 14 mucinous cystic neoplasms (MCNs), nine serous cystic neoplasms (SCNs), 29 pseudocysts (PCs), and 17 unclassified. Profiles of the <5 kDa fraction, the degradome, and the trypsin-digested proteome were analysed using an LTQ-Orbitrap Elite mass spectrometer coupled with a nanoACQUITY LC system. Qualitative analyses identified 796 and 366 proteins in degradome and proteome, respectively, and 689 (77%) and 285 (78%) of them were present in the Plasma Proteome Database. Gene Ontology analysis showed a significant overrepresentation of peptidases and peptidases inhibitors in both datasets. In the degradome fraction, quantitative values were obtained for 6996 peptides originating from 657 proteins. Of these, 2287 peptides were unique to a single type, and 515 peptides, derived from 126 proteins, were shared across cyst types. 32 peptides originating from 12 proteins had differential (adjusted p-value ≤0.05, FC ≥1.5) abundance in at least one of the five cysts types. In proteome, relative expression was measured for 330 proteins. Of them, 33 proteins had significantly (adjusted p-value ≤0.05, FC ≥1.5) altered abundance in at least one of the studied groups and 19 proteins appeared to be unique to a given cyst type. PCFs are dominated by blood proteins and proteolytic enzymes. Although differences in PCF peptide composition and abundance could aid classification of PCLs, the unpredictable inherent PCF proteolytic activity may limit the practical applications of PCF protein profiling.

Management of Incidental Pancreatic Cysts: A White Paper of the ACR Incidental Findings Committee

The ACR Incidental Findings Committee (IFC) presents recommendations for managing pancreatic cysts that are incidentally detected on CT or MRI. These recommendations represent an update from the pancreatic component of the JACR 2010 white paper on managing incidental findings in the adrenal glands, kidneys, liver, and pancreas. The Pancreas Subcommittee-which included abdominal radiologists, a gastroenterologist, and a pancreatic surgeon-developed this algorithm. The recommendations draw from published evidence and expert opinion, and were finalized by informal iterative consensus. Algorithm branches successively categorize pancreatic cysts based on patient characteristics and imaging features. They terminate with an ascertainment of benignity and/or indolence (sufficient to discontinue follow-up), or a management recommendation. The algorithm addresses most, but not all, pathologies and clinical scenarios. Our goal is to improve quality of care by providing guidance on how to manage incidentally detected pancreatic cysts.

Suboptimal accuracy of carcinoembryonic antigen in differentiation of mucinous and nonmucinous pancreatic cysts: results of a large multicenter study

BACKGROUND AND AIMS

The exact cutoff value at which pancreatic cyst fluid carcinoembryonic antigen (CEA) level distinguishes pancreatic mucinous cystic neoplasms (MCNs) from pancreatic nonmucinous cystic neoplasms (NMCNs) is unclear. The aim of this multicenter retrospective study was to evaluate the diagnostic accuracy of cyst fluid CEA levels in differentiating between MCNs and NMCNs.

METHODS

Consecutive patients who underwent EUS with FNA at 3 tertiary care centers were identified. Patients with histologic confirmation of cyst type based on surgical specimens served as the criterion standard for this analysis. Demographic characteristics, EUS morphology, FNA fluid, and cytology results were recorded. Multivariate logistic regression analysis to identify predictors of MCNs was performed. Receiver-operating characteristic (ROC) curves were generated for CEA levels.

RESULTS

A total of 226 patients underwent surgery (mean age, 61 years, 96% white patients, 39% female patients) of whom 88% underwent Whipple's procedure or distal pancreatectomy. Based on surgical histopathology, there were 150 MCNs and 76 NMCNs cases. The median CEA level was 165 ng/mL. The area under the ROC curve for CEA levels in differentiating between MCNs and NMCNs was 0.77 (95% confidence interval, 0.71-0.84, P < .01) with a cutoff of 105 ng/mL, demonstrating a sensitivity and specificity of 70% and 63%, respectively. The cutoff value of 192 ng/mL yielded a sensitivity of 61% and a specificity of 77% and would misdiagnose 39% of MCN cases.

CONCLUSIONS

Cyst fluid CEA levels have a clinically suboptimal accuracy level in differentiating MCNs from NMCNs. Future studies should focus on novel cyst fluid markers to improve risk stratification of pancreatic cystic neoplasms.

Cytopathological Analysis of Cyst Fluid Enhances Diagnostic Accuracy of Mucinous Pancreatic Cystic Neoplasms

Widespread use of cross-sectional imaging and increasing age of the general population has increased the number of detected pancreatic cystic lesions. However, several pathological entities with a variety in malignant potential have to be discriminated to allow clinical decision making. Discrimination between mucinous pancreatic cystic neoplasms (PCNs) and nonmucinous pancreatic lesions is the primary step in the clinical work-up, as malignant transformation is mostly associated with mucinous PCN. We performed a retrospective analysis of all resected PCN in our tertiary center from 2000 to 2014, to evaluate preoperative diagnostic performance and the results of implementation of the consensus guidelines over time. This was followed by a prospective cohort study of patients with an undefined pancreatic cyst, where the added value of cytopathological mucin evaluation to carcinoembryonic antigen (CEA) in cyst fluid for the discrimination of mucinous PCN and nonmucinous cysts was investigated. Retrospective analysis showed 115 patients operated for a PCN, with a correct preoperative classification in 96.2% of the patients. High-grade dysplasia or invasive carcinoma was observed in only 32.3% of mucinous PCN. In our prospective cohort (n = 71), 57.7% of patients were classified as having a mucinous PCN. CEA ≥ 192 ng/mL had an accuracy of 63.4%, and cytopathological mucin evaluation an accuracy of 73.0%. Combining these 2 tests further improved diagnostic accuracy of a mucinous PCN to 76.8%. CEA level and mucin evaluation were not predictive of the degree of dysplasia. These findings show that adding cytopathology to cyst fluid biochemistry improves discrimination between mucinous PCN and nonmucinous cysts.

Role of endoscopic ultrasound-guided fine needle aspiration and ultrasound-guided fine-needle aspiration in diagnosis of cystic pancreatic lesions

BACKGROUND AND OBJECTIVE

The addition of fine-needle aspiration (FNA) to different imaging modalities has raised the accuracy for diagnosis of cystic pancreatic lesions. We aim to differentiate benign from neoplastic pancreatic cysts by evaluating cyst fluid carcinoembryonic antigen (CEA), carbohydrate antigen (CA19-9), and amylase levels and cytopathological examination, including mucin stain.

PATIENTS AND METHODS

This prospective study included 77 patients with pancreatic cystic lesions. Ultrasound-FNA (US-FNA) or endoscopic ultrasound-FNA (EUS-FNA) was done according to the accessibility of the lesion. The aspirated specimens were subjected to cytopathological examination (including mucin staining), tumor markers (CEA, CA19-9), and amylase level.

RESULTS

Cyst CEA value of 279 or more showed high statistical significance in differentiating mucinous from nonmucinous lesions with sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of 73%, 60%, 50%, 80%, and 65%, respectively. Cyst amylase could differentiate between neoplastic and nonneoplastic cysts at a level of 1043 with sensitivity of 58%, specificity of 75%, PPV of 73%, NPV of 60%, and accuracy of 66%. CA19-9 could not differentiate between neoplastic and nonneoplastic cysts. Mucin examination showed a sensitivity of 85%, specificity of 95%, PPV of 92%, NPV of 91%, and accuracy of 91% in differentiating mucinous from non-mucinous lesions. Cytopathological examination showed a sensitivity of 81%, specificity of 94%, PPV of 94%, NPV of 83%, and accuracy of 88%.

CONCLUSION

US or EUS-FNA with analysis of cyst CEA level, CA19-9, amylase, mucin stain, and cytopathological examination increases the diagnostic accuracy of cystic pancreatic lesions.

Diagnosis of pancreatic cysts: EUS-guided, through-the-needle confocal laser-induced endomicroscopy and cystoscopy trial: DETECT study

BACKGROUND

The diagnosis of pancreatic cystic neoplasms (PCNs), which now depends on morphology, cytology, and fluid analysis, is still challenging. A novel confocal laser endomicroscopy probe that can be inserted through a 19-gauge FNA needle allows needle-based confocal laser endomicroscopy (nCLE), and the feasibility of nCLE has been reported in PCNs. The combination of cystoscopy by using a through-the-needle fiberoptic probe in combination with nCLE under EUS guidance may improve the diagnosis of PCNs.

OBJECTIVE

To assess the feasibility, safety, and diagnostic yield of the combination of cystoscopy and nCLE in the clinical diagnosis of PCNs.

DESIGN

A prospective feasibility study.

SETTING

An academic tertiary referral center.

PATIENTS

Thirty patients with PCNs.

INTERVENTIONS

EUS-guided dual through-the-needle imaging (cystoscopy and nCLE) for PCNs.

MAIN OUTCOME MEASUREMENTS

Technical feasibility and safety. Associations of cystoscopy and nCLE findings with clinical diagnosis of PCNs.

RESULTS

The procedure was technically successful with the exception of 1 probe exchange failure. In 2 patients (7%), postprocedure pancreatitis developed. Specific features associated with the clinical diagnosis of mucinous cysts were identified: mucin on cystoscopy and papillary projections and dark rings on nCLE. The sensitivity of cystoscopy was 90% (9/10), and that of nCLE was 80% (8/10), and the combination was 100% (10/10) in 18 high-certainty patients.

LIMITATIONS

A single-center study and lack of complete pathologic correlation.

CONCLUSION

The combination of dual through-the-needle imaging (cystoscopy and nCLE) of pancreatic cysts appears to have strong concordance with the clinical diagnosis of PCN. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01447238.).

Accuracy of endoscopic ultrasound in the evaluation of cystic pancreatic neoplasms: a community hospital experience

OBJECTIVES

Reports on the use of endoscopic ultrasound (EUS) in differentiating benign, premalignant, and malignant pancreatic lesions have been widely variable, particularly with cystic neoplasms. We evaluated the use of EUS for cystic pancreatic lesions in a community hospital setting.

METHODS

All patients who underwent EUS for cystic pancreatic neoplasms from 2007 to 2010 were reviewed. A final EUS diagnosis was determined based on the examiner's impression and fine-needle aspiration results if available. Lesions were stratified as benign, premalignant, or malignant. Patients underwent surgical resection, serial imaging studies, or medical oncology/palliative care consultation as indicated.

RESULTS

One hundred eighteen patients with cystic pancreatic lesions underwent EUS during the study period. Endoscopic ultrasound diagnoses included 75 benign (63.6%), 35 premalignant (29.7%), and 8 malignant (4.2%) lesions. Thirty-eight patients (32.2%) underwent surgery, 77 (65.3%) were monitored with imaging, and 3 (2.5%) had unresectable malignancies. Elevated carcinoembryonic antigen levels showed a trend toward predicting mucinous cysts (P = 0.062). Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for cystic lesions were 87.3%, 86.8%, 87.5%, 76.7%, and 93.3%, respectively.

CONCLUSIONS

Endoscopic ultrasound is a valuable diagnostic modality in the evaluation of cystic pancreatic neoplasms in a community hospital setting.

A review of pancreatic cyst fluid analysis in the differential diagnosis of pancreatic cyst lesions

Diagnosis and management of pancreatic cyst lesions is challenging as there is currently no investigation that offers both high diagnostic sensitivity and high specificity for the identification of potentially malignant lesions. Accurate classification of these lesions is vital in order to avoid unnecessary treatment of benign lesions and missed opportunities for early treatment of lesions that are malignant/pre-malignant. Pancreatic cyst fluid analysis has an important role in diagnosis, although all currently available investigations based on fluid analysis have significant limitations. Cytological analysis can reveal features that are specific for a certain class of cyst, but offers limited sensitivity in detecting malignant/pre-malignant cysts. Measurement of tumour markers, particularly carcinoembryonic antigen can also be informative. Concentrations of cyst fluid carcinoembryonic antigen tend to be higher in malignant/pre-malignant cysts, although there is a wide overlap between the various classes of cyst. A number of studies have suggested that diagnostic carcinoembryonic antigen cut-offs can be chosen that provide a high degree of specificity but limited sensitivity. Studies of the analytical validity of tumour marker assays in pancreatic cyst fluid analysis have highlighted discrepancies in some fluid specimens, which require further investigation. DNA analysis also has a role. In particular, K-Ras-2 mutational analysis appears to provide high specificity for detection of malignant/pre-malignant lesions. A number of diagnostic algorithms have been published, integrating use of available investigations in order to achieve the optimum discrimination of benign and potentially malignant cysts. Research into new biochemical markers and optimal use of available pancreatic cyst fluid analyses is ongoing.

MicroRNA from pancreatic duct aspirate differentiates cystic lesions of the pancreas

INTRODUCTION

Prognostication for cystic neoplasms of the pancreas continues to evolve. Beyond simple size and cystic fluid CEA determination, microRNA (miRNA) detection holds great promise as molecular diagnostics for cancer risk. In this study, we sought to identify miRNAs that could predict malignant potential of pancreatic cystic lesions.

METHODS

RNA was harvested from the pancreatic duct aspirate of 72 cystic neoplasms of the pancreas. Samples with adequate RNA concentration (≥ 3 ng/μL) were selected for qRTPCR profiling using assays to 379 of the most common miRNAs. miRNA profiles were correlated with histopathology from resected specimens and grouped by benign (serous cystadenomas), premalignant (intraductal papillary mucinous neoplasms and mucinous cystadenomas), or malignant lesions (adenocarcinoma).

RESULTS

Adequate RNA for analysis was obtained from 42 (58.3 %) of the samples. Malignant lesions were more likely to have adequate RNA (n = 17, 81 %) than either benign (n = 6, 33 %) or premalignant lesions (n = 19, 59 %; p = 0.011). Nine miRNA were identified as differentially expressed between benign and premalignant/malignant lesions (p < 0.05). A significant correlation was found between the number of differentially expressed miRNA and the likelihood of a premalignant/malignant lesion. All premalignant or malignant lesions expressed at least one miRNA surpassing the threshold of mean miRNA expression, whereas no benign lesions had more than one miRNA surpassing the threshold.

CONCLUSIONS

The presence of RNA in the duct aspirate from patients with pancreatic cystic neoplasms may be a predictor of premalignancy or malignancy. miRNA may be utilized to further differentiate between benign, premalignant, and malignant cystic lesions of the pancreas.

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.

The prevention and genetics of pancreatic cancer: a programmatic approach

Pancreatic cancer (PC) is typically a fatal disease due to its rapid growth and the lack of early diagnostic -techniques. Because approximately 10% of PCs are attributable to a hereditary susceptibility, identifying and studying patients with a family history of PC or known genetic predisposition to PC can improve the prevention, diagnosis, and treatment of PC. A skilled team of study investigators, physicians, genetic counselors, and data managers must work with patients and families to confidentially store and organize data from PC patients and high-risk patients. This data, collected in conjunction with patients' tissue and blood specimens, will contribute to the understanding of the biology, etiology, and epidemiology of PC, and can ultimately improve screening and management for patients with an underlying hereditary predisposition to PC.

Fluid analysis prior to surgical resection of suspected mucinous pancreatic cysts. A single centre experience

OBJECTIVE

EUS-FNA cytology and fluid analysis are frequently utilized to evaluate pancreatic cysts. Elevated cyst fluid CEA is usually indicative of a mucinous pancreatic cyst but whether CEA or amylase values can subclassify various mucinous cysts is unknown. The purpose of this study is to determine whether cyst fluid CEA and amylase obtained by EUS-FNA can differentiate between mucinous cystic neoplasms (MCNs) and intraductal papillary mucinous neoplasms (IPMNs).

METHODS

Using our prospective hospital EUS and surgical databases, we identified all patients who underwent EUS of a pancreatic cyst prior to surgical resection, in the last 10 years. Cysts were pathologically sub-classified as MCNs or IPMNs; all other cysts were considered non-mucinous. Values of cyst fluid CEA and amylase were correlated to corresponding surgical histopathology and compared between the two groups.

RESULTS

134 patients underwent surgery for pancreatic cysts including 82 (63%) that also had preoperative EUS. EUS-FNA was performed in 61/82 (74%) and cyst fluid analysis in 35/61 (57%) including CEA and amylase in 35 and 33 patients, respectively. Histopathology in these 35 cysts demonstrated nonmucinous cysts in 10 and mucinous cysts in 25 including: MCNs (n=9) and IPMNs (n=16). Cyst fluid CEA (p=0.19) and amylase (p=0.64) between all IPMNs and MCNs were similar. Between branched duct IPMNs and MCNs alone, cyst fluid CEA (p=0.34) and amylase (p=0.92) were also similar.

CONCLUSION

In this single center study, pancreatic cyst fluid amylase and CEA levels appeared to be of limited value to influence the differential of mucinous pancreatic cysts. Larger studies are recommended to evaluate this role further.

Endoscopic ultrasonography-guided fine-needle aspiration of pancreatic cystic lesions: a practical approach to diagnosis and management

The diagnosis and management of pancreatic cystic lesions remains a challenging area in gastroenterology. Differentiating benign from premalignant or premalignant from malignant cysts is complicated by the large overlap in morphologic, chemical, and clinical characteristics. Imaging alone is insufficient to accurately characterize these lesions. Cyst aspiration and fluid analysis has therefore become a major research focus through which our ability to characterize pancreatic cystic lesions has improved, although accuracy is often still lacking. Future work with molecular analysis of cyst fluid, direct cystoscopy, and confocal laser endomicroscopy will likely further enhance the diagnostic accuracy of these lesions.

Epidemiology, diagnosis, and management of cystic lesions of the pancreas

Although little is known on the true prevalence of pancreatic cysts, physicians are currently more frequently confronted with pancreatic cysts because of the increasing use of sophisticated cross-sectional abdominal imaging. Cystic lesions of the pancreas comprise of a heterogeneous group of diagnostic entities, some of which are benign such as inflammatory pseudocysts or serous cystadenomas and do not require resection when asymptomatic. Others like mucinous cysts or intraductal papillary mucinous neoplasms (IPMN) have a malignant potential and in these cases surgical resection is often indicated. For this reason an adequate distinction between the various cysts is crucial to optimize management strategy. Different diagnostic methods that could be of value in the differentiation include radiologic imaging techniques such as CT, MR, and endosonography. In addition, fluid aspiration for cytopathology, tumormarkers or molecular analysis is widely used. Different guidelines are available but so far no optimal diagnostic algorithm exists. We summarize the epidemiology, classification, clinical presentation, diagnostics, management, and future perspectives.

New trends in diffusion-weighted magnetic resonance imaging as a tool in differentiation of serous cystadenoma and mucinous cystic tumor: a prospective study

BACKGROUND/AIMS

Pancreatic cystic lesions are increasingly being recognized. Magnetic resonance imaging (MRI) is the method that brings the greatest amount of information about the morphologic features of pancreatic cystic lesions. To establish if diffusion-weighted MRI (DW-MRI) can be used as a tool to differentiate mucinous from nonmucinous lesions.

METHODS

Fifty-six patients with pancreatic cystic lesions (benign, n = 46; malignant, n = 10) were prospectively evaluated with DW-MRI in order to differentiate mucinous from nonmucinous lesions. Final diagnosis was obtained by follow-up (n = 31), surgery (n = 16) or endoscopic ultrasound-guided fine needle aspiration (n = 9). Serous cystadenoma was identified in 32 (57%) patients.

RESULTS

The threshold value established for the differentiation of mucinous from nonmucinous lesions was 2,230.06 s/mm(2) for ADC of 700. DWI-MRI behavior between mucinous and nonmucinous groups revealed sensitivity, specificity, positive predictive value, negative predictive value and accuracy to be 80, 98, 92, 93 and 93%, respectively (p < 0.01, power of sample = 1.0). In the comparison of the diffusion behavior between mucinous (n = 13) and serous (n = 32) lesions, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 100, 97, 92, 100 and 98%, respectively (p < 0.01, power of sample = 1.0). The results of endoscopic ultrasound-guided fine needle aspiration were similar to those of DW-MRI.

CONCLUSIONS

DW-MRI can be included as part of the array of tools to differentiate mucinous from nonmucinous lesions and can help in the management of pancreatic cystic lesions. and IAP.

Cystic precursors to invasive pancreatic cancer

Improvements in the sensitivity and quality of cross-sectional imaging have led to increasing numbers of patients being diagnosed with cystic lesions of the pancreas. In parallel, clinical, radiological, pathological and molecular studies have improved the systems for classifying these cysts. Patients with asymptomatic serous cystic neoplasms can be managed conservatively with regular monitoring; however, the clinical management of patients with intraductal papillary mucinous neoplasms and mucinous cystic neoplasms is far more challenging, as it is difficult to determine whether these lesions will progress to malignancy. Fortunately, prospective studies have helped to establish that proposed clinical and radiological criteria (the Sendai guidelines) can be used to guide the care of patients with cystic lesions of the pancreas. Despite this progress in imaging and clinical guidelines, sensitive and specific tests have not yet been developed that can reliably predict the histology and biological properties of a cystic lesion. Such biomarkers are urgently needed, as noninvasive precursors of pancreatic cancer are curable, while the vast majority of invasive pancreatic adenocarcinomas are not.

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.

Pancreatic cyst aspiration analysis for cystic neoplasms: mucin or carcinoembryonic antigen--which is better?

BACKGROUND

Differentiation between the various pathologies presenting as a cystic pancreatic lesion is clinically important but often challenging. We have previously advocated the performance of endoscopic ultrasound (EUS) with aspiration and determination of mucin and carcinoembryonic antigen (CEA) content. We sought to report the results of this ongoing protocol and determine the relative importance of cyst fluid mucin and CEA for the diagnostic process.

METHODS

The institutions prospectively maintained pancreatic cyst database was accessed to identify patients who had undergone pancreatic EUS and cyst aspiration as part of their evaluation. Only those patients who had subsequently undergone resection were selected, with histopathology being the gold standard for comparison.

RESULTS

From January 2000 to July 2009, 174 patients with pancreatic cystic disease underwent surgery, 121 of whom had an EUS with aspiration attempted at our institution with specimens sent for mucin and CEA. Based on histopathology, 86 mucinous lesions were identified, including 44 cystadenomas, 34 intraductal papillary mucinous neoplasms, 7 mucinous adenocarcinomas, and 1 intraductal oncocytic papillary neoplasm; 42 were nonmucinous lesions. The median cyst CEA levels were significantly higher in the mucinous lesions group at 850 versus 2 ng/mL (P = .001). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive diagnostic likelihood ratio, and negative diagnostic likelihood ratio (NDLR) were calculated respectively for mucin alone (0.80, 0.40, 0.61, 0.63, 1.33, 0.68); CEA alone (0.93, 0.43, 0.51, 0.91, 1.63, 0.16); cytology alone (0.38, 0.9, 0.92, 0.31, 3.67, 0.69); mucin or CEA (0.83, 0.65, 0.87, 0.57, 2.51, 0.26); mucin or CEA or cytology (0.92, 0.52, 0.86, 0.68, 1.91, 0.15); mucin plus CEA (0.96, 0.34, 0.25, 0.97, 1.45, 0.12); mucin plus cytology (0.25, 0.97, 0.96, 0.29,7.25, 0.78); CEA plus cytology (0.12, 1.00, 1.00, 0.26, ∞, 0.88); and mucin plus CEA plus cytology (0.08, 1.00, 1.00, 0.25, ∞, 0.92).

CONCLUSION

Assessment of cyst mucin and CEA are complementary, with the best profile obtained when both markers are determined along with cytology. This combination provides a good sensitivity, PPV, and NDLR, as well as reasonable PPV and PDNR.

The management of intraductal papillary mucinous neoplasms of the pancreas

Intraductal papillary mucinous neoplasms (IPMN) are mucinous cystic tumors of the pancreas, which were first classified into a unified diagnosis by the World Health Organization in 1996. These lesions originate from the cells of the pancreatic ductal system and may grossly or microscopically involve the pancreatic ducts in a diffuse or multifocal fashion. As experience with IPMN increases, it is becoming more evident that this process presents as a spectrum of neoplasia with significant variation regarding the clinical and radiologic presentation, malignant potential, and disease-specific outcome. IPMN encompasses a spectrum of precursor lesions, from adenoma to intraductal carcinoma to invasive cancer, with molecular data supporting the premise that this dysplastic process has the potential to progress from low-grade dysplasia to invasive carcinoma. Controversy over the management of IPMN exists because of the difficulty in obtaining a preoperative histologic diagnosis, the broad spectrum of neoplasia, the lack of understanding as to the frequency and time to malignant progression. This article describes the radiologic and histopathologic classification system of IPMN; the biologic behavior of these lesions, and the diagnostic testing most commonly used, and discusses the current treatment controversies.

[Clinical approach to incidental pancreatic cystic lesions]

Cystic lesions of the pancreas are being incidentally recognized with increasing frequency and become a common finding in clinical practice. Despite of recent remarkable advances of radiological and endoscopic assessment and a better understanding of natural history of certain subgroups of cystic lesions, differentiating among lesions and making an optimal management plan is still challenging. A multimodal approach should be performed to evaluate incidentally detected cystic lesions. Emerging evidence supports selective nonoperative management for the majority of patients with cystic lesions, but, for those in whom a suspicion of malignancy remains, surgery is indicated. Concerning long-term follow-up, there is limited data to support the ideal modality, intensity, and duration. Therefore, evidence-based guidelines for the diagnosis, management, and follow-up of cystic lesions of the pancreas should be established.

Pancreatic cyst fluid protein expression profiling for discriminating between serous cystadenoma and intraductal papillary mucinous neoplasm

BACKGROUND

Many patients with benign serous cystadenoma (SCA) of the pancreas will undergo resection because of the inability to reliably discriminate between SCA and premalignant mucinous cysts (intraductal papillary mucinous neoplasm [IPMN], mucinous cystic neoplasm [MCN]).

METHODS

Cyst fluid from patients with SCA (n = 15), non main-duct and noninvasive IPMN (n = 32), and noninvasive MCN (n = 12) was aspirated at the time of operative resection and analyzed. Commercially available and custom designed multiplex assays (Luminex) were performed using a biomarker panel developed for pancreatic cancer. Differential protein expression (fluorescence intensity, FI) was compared between the 3 groups for each protein (Wilcoxon rank sum test). Unsupervised sample clustering (hierarchical clustering) and supervised sample classification (prediction analysis for microarrays [PAM]) was then performed.

RESULTS

Differential protein expression (P < 0.05) was identified between SCA and IPMN (34/51 proteins, 67%) and between SCA and MCN (13/51 proteins, 25%). The majority of proteins were down-regulated in IPMN and MCN compared with SCA. The only proteins significantly overexpressed in the cyst fluid of patients with mucinous cysts were CEA (median FI: IPMN 11.4, MCN 13.0, SCA 5.3; P < 0.001, IPMN vs. SCA) and CA72.4 (median FI: IPMN 10.4, MCN 10.5, SCA 9.9; P = 0.003, IPMN vs. SCA). Unsupervised cluster analysis demonstrated distinct clustering of SCA and IPMN with some cross-over between MCN. Supervised sample classification with 14 proteins had an overall accuracy rate of 92% between SCA and IPMN.

CONCLUSIONS

In this study differential cyst fluid protein expression was observed between SCA and IPMN for the majority of proteins assessed and multimarker sample classification accurately discriminated between SCA and IPMN in 92% of patients.

Preoperative tissue diagnosis for tumours of the pancreas

BACKGROUND

Preoperative biopsy of pancreatic lesions suspected of malignancy is controversial.

METHODS

A systematic Medline literature search was carried out. Diagnostic studies reporting quantitative preoperative pancreatic biopsy data were evaluated.

RESULTS

The analysis included 53 studies, mostly of a retrospective nature. Despite acceptable rates for sensitivity and specificity, the negative predictive value of percutaneous and endoscopic ultrasonography-guided biopsies was 60-70 per cent. Biopsy results were considered to be essential for directing non-surgical therapy in advanced disease. However, they were of limited value in planning the treatment of resectable solid or cystic tumours, or focal lesions in the setting of chronic pancreatitis.

CONCLUSIONS

Biopsy of suspected pancreatic malignancies with systemic spread or local irresectability is indicated for planning palliative or neoadjuvant therapy. Preoperative biopsy of potentially resectable pancreatic tumours is not generally advisable, as malignancy cannot be ruled out with adequate reliability.

Cystic neoplasms of the pancreas: A diagnostic challenge

Cystic neoplasms of the pancreas are increasingly recognized due to the expanding use and improved sensitivity of cross-sectional abdominal imaging. Major advances in the last decade have led to an improved understanding of the various types of cystic lesions and their biologic behavior. Despite significant improvements in imaging technology and the advent of endoscopic-ultrasound (EUS)-guided fine-needle aspiration, the diagnosis and management of pancreatic cystic lesions remains a significant clinical challenge. The first diagnostic step is to differentiate between pancreatic pseudocyst and cystic neoplasm. If a pseudocyst has been effectively excluded, the cornerstone issue is then to determine the malignant potential of the pancreatic cystic neoplasm. In the majority of cases, the correct diagnosis and successful management is based not on a single test but on incorporating data from various sources including patient history, radiologic studies, endoscopic evaluation, and cyst fluid analysis. This review will focus on describing the various types of cystic neoplasms of the pancreas, their malignant potential, and will provide the clinician with a comprehensive diagnostic approach.

Accuracy of CT in predicting malignant potential of cystic pancreatic neoplasms

BACKGROUND

Cystic lesions of the pancreas are being identified more frequently. Deciding which asymptomatic lesions can be safely followed with serial imaging and which require resection due to malignant potential is an increasingly common question. Current clinical practice is to rely on characteristics of the lesions on CT scan, and additional information from endoscopic ultrasound with fine-needle aspiration (EUS-FNA) and cyst fluid analysis or endoscopic retrograde pancreatography (ERCP) to assess malignant potential.

HYPOTHESIS

The malignant potential of pancreatic cystic lesions cannot be accurately predicted by CT scan.

METHODS

CT scans from 48 patients with cystic lesions of the pancreas were stripped of patient identifiers and retrospectively presented to two expert radiologists. The radiologists recorded specific characteristics of the lesions thought to be important in the differential diagnosis and their opinion of the likely diagnosis. Diagnostic accuracy was assessed by comparing the radiologists' diagnoses to the final pathologic diagnosis after resection. To determine if clinical history, EUS-FNA or ERCP findings improved diagnostic accuracy, medical records were retrospectively reviewed and scored as either supporting or not supporting malignant potential of the lesion.

RESULTS

Specific diagnoses based on CT findings alone were correct in an average of 39% of the cases. Even when diagnoses were dichotomized as benign (43%) or potentially malignant (57%, papillary mucinous neoplasms, mucinous cystic neoplasms, cancer), determinations based on CT alone were accurate in an average of 61% of cases. Accuracy rates were 60.4 and 62.5% for the two radiologists, although there was only fair agreement between them (Kappa=0.28, 95% CI=(0.01-0.55), p=0.05). When all clinical information available was considered together as a single dichotomous indicator of malignant potential, the indicator was accurate in 90% of the cases (Kappa=0.73, 95% CI=(0.51-0.95, p<0.0001)).

CONCLUSION

Specific preoperative diagnosis of pancreatic cystic neoplasms by CT alone is substantially inaccurate. Complementary tests such as EUS-FNA with fluid analysis and ERCP should be recommended to improve diagnosis especially if nonoperative treatment is planned.

[Importance of endoscopy and endosonography for chronic pancreatitis and benign pancreas tumors]

Endoscopic retrograde pancreatography (ERP) and endoscopic ultrasound (EUS) are superior to cross-sectional imaging procedures for detection of low-grade pancreatitis, but detection of duct alterations is more reliable by middle and high-grade chronic pancreatitis than by low-grade. In addition to assessment of alterations in the pancreatic duct, EUS also allows detection of parenchymatous alterations. Because of the risk of post-ERP pancreatitis, ERP has been mostly eliminated from diagnostic procedures. In contrast, endoscopic retrograde cholangiopancreatography (ERCP) allows an unrivalled access to interventional treatment of inflammatory alterations of the biliopancreatic duct system, by retrograde, non-penetrable papillae even in the rendezvous procedure with EUS-assisted probing of the Ductus Wirsungianus. Despite the technical success of endoscopic procedures, surgical duct decompression has proven to be superior for relief from pancreatitic pain. Biliary drainage is also more likely to be successful on a permanent basis using surgical procedures than by repeat multi-stenting, at least by calcifying pancreatitis. Peroral transgastral transmural therapy of postpancreatitic necroses opens up further options over surgical removal of necroses.

Management of suspected pancreatic cystic neoplasms based on cyst size

BACKGROUND

Evaluation and management of cystic pancreatic neoplasms remain problematic. International consensus guidelines have advised resection for lesions greater than 3 cm.

METHODS

We reviewed our prospective pancreatic cystic neoplasm database for outcomes based on a cyst size of 3 cm.

RESULTS

Five hundred patients have been managed from 1999 to 2006. There were 349 patients (70%) with cysts less than or equal to 3 cm: 293 (84%) were not operated, including 243 nonmucinous cysts: 2 failed observation (0.8%, mean follow-up of 24 months). Fifty-six patients with cysts less than or equal to 3 cm were initially operated (16%), including 23 asymptomatic patients. Histopathology showed intraductal papillary mucinous neoplasm (IPMN) in 20, mucinous cystic neoplasm (MCN) in 18, and serous cystadenoma in 5. Twelve had carcinoma (21%). A total of 151 patients (30%) had cysts greater than cm: 87 (50%) were not operated, including 68 that were nonmucinous: 2 failed observation (2.9%, mean follow-up of 47 months). Sixty-four patients with cysts greater than 3 cm (42%) were initially operated, and final pathology showed MCN in 27, serous cystadenoma in 11, IPMN in 7, and pseudocyst in 7. Twelve had carcinoma (19%). Patients with cysts less than or equal to 3 cm were less likely to be operated (16 vs 42%; P < .001), less often symptomatic (39 vs 50%; P = .017), while older (mean age, 65 vs 61 years; P = .03). Had patients been managed by size alone, up to 20% would have received inappropriate treatment. Management based on aspiration was significantly better in predicting mucinous neoplasms compared with size (75% vs 57%; P < .001), including asymptomatic patients less than or equal to 3 cm (78% vs 65%; P = .003).

CONCLUSION

Size of pancreatic cystic lesions alone is not a reasonable basis for determining management.

Predictors of malignant potential of cystic lesions of the pancreas

BACKGROUND

Cystic lesions of the pancreas (CLP) are a diagnostic dilemma, the correct characterisation of which determines surgical management.

METHODS

From 1995 to 2005, radiology and pathology records were reviewed for the presence of CLP. CLP were divided into three groups; Group 1: Benign, Group 2: Pre-malignant, and Group 3: Malignant.

RESULTS

Seventy-nine of 121 patients were included [Group 1: n=46, Group 2: n=10, Group 3: n=23], with a median age at diagnosis of 68 (31-92) years. The median follow-up period was 24 (14-84) months. On univariate analysis, female gender (p=0.04), jaundice (p<0.01), raised serum ALT concentration (p=0.03), cyst size (> or = 2.5 cm) (p<0.01), and biliary duct dilatation (p<0.01) were associated with malignant potential. Benign cysts were more likely to present incidentally (p<0.01). On multi-variate analysis, cyst size (> or =2.5 cm) was an independent predictor of malignant potential. Sub-group analysis revealed that cysts <2.5 cm in the head of the pancreas with evidence of biliary obstruction (either abnormal liver function; raised ALT [p=0.01], ALP [p=0.01], total bilirubin [p=0.02], and/or biliary duct dilatation [p<0.01]) were associated with malignant potential.

CONCLUSION

Cyst size > or =2.5 cm on computer tomography imaging was an independent predictor of pre-malignant and malignant pancreatic cysts. Cyst size and the presence of biliary obstruction predict potentially malignant cysts of the head of the pancreas, which require surgical management.

Benign pancreatic tumors

The goal of this article is to describe the different types of benign pancreatic neoplasms, methods to distinguish between them, and treatment options. Pancreatic adenocarcinoma is associated with specific neoplastic lesions that are similar in radiographic appearance to some benign lesions. The correct differentiation of these malignant and premalignant lesions from their benign counterpart is paramount to their proper management.

18-fluorodeoxyglucose positron emission tomography enhances computed tomography diagnosis of malignant intraductal papillary mucinous neoplasms of the pancreas

OBJECTIVE

To assess the reliability of 18-fluorodeoxyglucose positron emission tomography (18-FDG PET) in distinguishing benign from malignant intraductal papillary mucinous neoplasms (IPMNs) of the pancreas and its contribution to surgical decision making.

SUMMARY BACKGROUND DATA

Pancreatic IPMNs are increasingly recognized, often as incidental findings, especially in people over age 70 and 80. Computed tomography (CT) and magnetic resonance (MR) are unreliable in discriminating a benign from a malignant neoplasm. 18-FDG PET as imaging procedure based on the increased glucose uptake by tumor cells has been suggested for diagnosis and staging of pancreatic cancer.

METHODS

From January 1998 to December 2005, 64 patients with suspected IPMNs were prospectively investigated with 18-FDG PET in addition to conventional imaging techniques [helical-CT in all and MR and magnetic resonance cholangiopancreatography (MRCP) in 60]. 18-FDG PET was analyzed visually and semiquantitatively using the standard uptake value (SUV). The validation of the diagnosis was made by a surgical procedure (n = 44), a percutaneous biopsy (n = 2), main duct cytology (n = 1), or follow-up (n = 17). Mean and median follow-up times were 25 and 27.5 months, respectively (range, 12-90 months).

RESULTS

Twenty-seven patients (42%) were asymptomatic. Forty-two patients underwent pancreatic resection, 2 palliative surgery, and 20 did not undergo surgery. An adenoma was diagnosed in 13 patients, a borderline tumor in 8, a carcinoma in situ in 5, and an invasive cancer in 21; in 17 patients a tumor sampling was not performed and therefore the histology remained undetermined. Positive criteria of increased uptake on 18-FDG PET was absent in 13 of 13 adenomas and 7 of 8 borderline IPMNs, but was present in 4 of 5 carcinoma in situ (80%) and in 20 of 21 invasive cancers (95%). Conventional imaging technique was strongly suggestive of malignancy in 2 of 5 carcinomas in situ and in 13 of 21 invasive carcinomas (62%). Furthermore, conventional imaging had findings that would be considered falsely positive in 1 of 13 adenomas (8%) and in 3 of 8 borderline neoplasms (37.5%). Therefore, positive 18-FDG PET influenced surgical decision making in 10 patients with malignant IPMN. Furthermore, negative findings on 18-FDG PET prompted us to use a more limited resection in 15 patients, and offered a follow-up strategy in 18 patients (3 positive at CT scan) for the future development of a malignancy.

CONCLUSIONS

18-FDG PET is more accurate than conventional imaging techniques (CT and MR) in distinguishing benign from malignant (invasive and noninvasive) IPMNs. 18-FDG PET seems to be much better than conventional imaging techniques in selecting IPMNs patients, especially when old and asymptomatic, for surgical treatment or follow-up.

The management of cystic lesions of the pancreas

The number of patients being identified as having asymptomatic small cysts of the pancreas is increasing. Most cystic neoplasms are SCAs, IPMNs, or MCNs. SCAs should be considered benign and in the absence of symptoms can be safely followed radiographically. Currently, most patients who present with mucinous cysts should undergo resection, because many of these patients have in situ or invasive carcinoma. The presence of a solid component seems to be associated with malignancy in patients who have mucinous cysts, and cyst size seems to be associated with malignancy in patients who have MCNs and branch duct IPMNs. Many institutions now are reporting a selective approach to resection in patients who have cystic lesions of the pancreas. Routine resection of all pancreatic cysts currently is impractical; given the large numbers of patients being identified with lesions smaller than 2 cm, this approach would result in a mortality rate that is much higher than the rate of malignancy. Most studies that have advocated a selective approach have reported the radiographic characteristics of a solid component, cyst size, and symptoms to be associated with treatment recommendations. The authors believe that radiographic follow-up is warranted in any patient for whom the assumed risk of malignancy is less than the risk of mortality from resection (no solid component, < 3 cm, asymptomatic). Most patients who have incidentally discovered cysts smaller than 3 cm in diameter and without a solid component can be safely followed radiographically. In the young patient who has a small mucinous tumor, additional factors to be considered are the likelihood of progression to malignancy and patient anxiety about radiographic follow-up. No data are available for the former. Efforts should be made to improve the ability to distinguish histopathologic subtypes without resection. The current challenges are to improve the sensitivity and specificity for the identification of mucinous subtype, to characterize better the progression of IPMN and mucinous cystic tumors, and to develop better methods for identifying the presence of in situ or invasive disease in these patients. Continued improvements in cross-sectional imaging and endoscopic techniques and further investigation into markers in the serum and cyst fluid should allow better identification of mucinous subtypes.

Utility of endoscopic ultrasound, cytology and fluid carcinoembryonic antigen and CA 19-9 levels in pancreatic cystic lesions

AIM: To assess the diagnostic accuracy of endoscopic ultrasound (EUS), fluid tumor markers and cytology in distinguishing benign from (pre)malignant pancreatic cystic lesions.

METHODS: 46 consecutive patients, referred to a gastroenterologist and surgeon for a symptomatic or incidental pancreatic cyst, were reviewed. EUS, cytology, and carcinoembryonic antigen (CEA) and carbohydrate antigen (CA 19-9) levels were compared with the final diagnosis, based on surgical pathology and/or imaging follow-up of at least 12 mo. Cysts were classified as benign (pseudocyst, serous cystadenoma) or malignant/pre-malignant (mucinous cystic neoplasm). Receiver-operator characteristics (ROC) curve analysis was performed.

RESULTS: The mean age was 56 years; 29% were male and median cyst diameter was 3 cm. Final outcome was obtained in 41 (89%) patients. Twenty-three (56%) of these 41 had surgical pathology. Twenty-three (56%) had benign lesions and 18 (44%) had malignant/pre-malignant lesions. Sensitivity, specificity and positive and negative predictive value of EUS alone to distinguish benign from malignant/premalignant pancreatic cystic lesions were 50%, 56%, 36% and 54% and for cytology were 71%, 96%, 92% and 85%, respectively. The corresponding values for the ROC-derived ideal cutoffs were 75%, 90%, 75%, 90% for CA 19-9 (> 37 U/mL) and 70%, 85%, 79% and 78% for CEA (> 3.1 ng/mL). Subgroup analysis of those with surgical pathology yielded almost identical performance and cutoffs.

CONCLUSION: Cytology and cyst fluid tumor marker analysis is a very useful tool in distinguishing benign from (pre)malignant pancreatic cystic lesions.

Pancreatic cysts: a proposed management algorithm based on current evidence

BACKGROUND

Currently, the management strategy of pancreatic cyst (PC) remains controversial because of the inability to diagnose this type of cyst accurately and the limited knowledge of its natural history. Previously, many clinicians have advocated an aggressive resectional policy. This approach is no longer appropriate, and the number of PCs detected incidentally has increased. This study reviews the present literature and attempts to provide a management algorithm of pancreatic cysts based on currently available evidence.

METHODS

A Medline search was conducted to identify studies investigating PC, with particular emphasis placed on studies addressing its diagnosis and management. Additional articles were obtained from the reference lists of key articles and recent reviews.

COMMENTS

Based on current evidence, the optimal management of PC remains an art and should be individualized based on the risk-benefit ratio of surgery, which is influenced by multiple factors, such as the patient's potential life expectancy, surgical risk; and malignant potential of the cyst. Our proposed management algorithm is based on an individual's predicted risk-benefit ratio of surgery. Prospective evaluation of the algorithm is needed to determine its integrity.

An aggressive surgical approach is warranted in the management of cystic pancreatic neoplasms

BACKGROUND

Cystic pancreatic neoplasms encompass a range of benign to malignant disease. Recommendations for surgical management vary.

METHODS

Records of patients with cystic pancreatic neoplasms from January 1996 through December 2005 were retrospectively reviewed.

RESULTS

Sixty resections were performed for 16 serous cystic neoplasms, 7 mucinous cystic neoplasms (MCNs), and 37 intraductal papillary mucinous neoplasms (IPMNs). Twenty-five percent (15/60) of neoplasms contained invasive cancer. Patients with MCN or IPMN invasive neoplasms experienced significantly diminished overall 5-year survival compared to patients with IPMN carcinoma in situ neoplasms and to patients with MCN or IPMN adenoma/borderline neoplasms (22% vs. 73% vs. 94%, P = .004).

CONCLUSIONS

Given the poor long-term survival of patients with cystic pancreatic neoplasms containing invasive cancer and the current difficulty to preoperatively distinguish among the various types of lesions in a reliable manner, our data support an aggressive surgical approach to the management of cystic pancreatic neoplasms.

A selective approach to the resection of cystic lesions of the pancreas: results from 539 consecutive patients

OBJECTIVE

To define a group of patients with pancreatic cysts who do not require resection.

SUMMARY BACKGROUND DATA

The increased use of cross-sectional imaging has resulted in an increased identification of small, asymptomatic pancreatic cysts. Data have not been available to determine which lesions should be resected.

METHODS

All patients evaluated at our institution between January 1995 and January 2005 for the ICD-9 diagnosis of pancreatic cyst were reviewed. Analysis was performed to identify associations between patient and cyst characteristics, and selection of operative or nonoperative management.

RESULTS

Pancreatic cysts were evaluated in 539 patients. Initial management was operative in 170 patients (32%), and nonoperative (radiographic follow-up) in 369 patients (68%). Factors associated with initial operative management included presence of a solid component (45% vs. 6%, P < 0.001), larger size of the lesion (mean 4.8 cm vs. 2.4 cm, P = 0.001), and presence of symptoms (44% vs. 16%, P = 0.001). Malignancy was present in 18% (32 of 170) of patients initially resected. Mucinous tumors (n = 18) were the most common malignant histologic subtype. None of the invasive cancers arising from mucinous cysts was <3 cm. Median radiographic follow-up in patients initially managed nonoperatively was 24 months (range, 1-172 months). In 29 patients (8%), changes developed within the cyst that resulted in resection; malignancy was present in 11 of 39 (38%), representing 3% (11 of 369) of all patients being followed radiographically.

CONCLUSIONS

Selected patients with cystic lesions <3 cm in diameter and without a solid component may be followed radiographically with a malignancy risk (3% this study) that approximates the risk of mortality from resection. Malignancy within mucinous tumors is associated with size, and small mucinous tumors are very unlikely to be malignant.

Cyst fluid analysis obtained by EUS-guided FNA in the evaluation of discrete cystic neoplasms of the pancreas: a prospective single-center experience

BACKGROUND

Accurate assessment of pancreatic cystic neoplasms is imperative before selecting available treatment options, such as surgical resection, drainage, or conservative therapy. Available modalities, CT and magnetic resonance imaging, have been inconsistent in diagnosis. Reports involving EUS and cyst fluid analysis have been encouraging, including studies of EUS features and/or cyst fluid analysis, which may differentiate pancreatic cystic neoplasms.

OBJECTIVE

To retrospectively determine cyst fluid characteristics that differentiate cystic neoplasms.

DESIGN

Patient evaluation included (1) EUS features (reported elsewhere) and (2) cyst fluid analysis (carcinoembryonic antigen [CEA], carbohydrate antigen 19-9 [CA 19-9], amylase and lipase, viscosity [VIS], mucin stain, and cytology). Exclusion criteria included the following: intraductal papillary mucinous tumor lesions, bloody cyst aspirate, neuroendocrine tumors, and patients without surgical histopathology.

SETTING

Pancreatic Biliary Center, St Luke's Medical Center, Milwaukee, Wisconsin.

PATIENTS

A total of 102 patients (60 women, 42 men; age, 23-76 years) presented for evaluation of pancreatic cystic neoplasm; 71 underwent surgical resection.

RESULTS

Seventy-one of 102 patients who underwent surgery presented the following histopathologic correlates: 23 pseudocysts (PC), 13 serous cystadenoma (SCyA), 21 mucinous cystadenoma (MCyA), and 14 mucinous cystadenocarcinoma (MCyA-CA). Cyst fluid analysis of these patients showed the following: VIS was lower in PC (mean, 1.3) and SCyA (1.27) when compared with MCyA (1.84) and MCyA-CA (1.9). All mucinous neoplasms had VIS >1.6, whereas only 2 mucinous cystic neoplasms (MCN) had VIS = 1.6 (both PC). The CEA level was significantly higher in MCyA (adenoma [878 ng/mL], carcinoma [27,581 ng/mL]) vs PC (189 ng/mL), and SCyA (121 ng/mL). Amylase levels were higher in PC (7210 U/L) compared with cystic neoplasm (SCyA, 679 U/L; MCyA, 1605 U/L; MCyA-CA, 569 U/L).

CONCLUSIONS

Differential diagnosis of pancreatic cystic neoplasm is significantly enhanced by cyst fluid analysis. Elevated CEA (> or =480 ng/mL) and VIS (>1.6) accurately predict MCN from SCyA and PC. Malignant from benign MCN can be differentiated by CEA levels > or =6000 ng/mL.

Innovations in Treating the Elderly Who Have Biliary and Pancreatic Disease

Many diseases of the biliary tract and pancreas preferentially effect the elderly. Recent innovations in the evaluation and management of these disorders have directly impacted the lives of many seniors. Improved outcomes of pancreatic surgery is a good example of a positive impact in quality of life, especially when these surgeries are performed in centers of excellence. Evaluation and treatment strategies are presented for complicated calculous biliary disease, pancreatic carcinoma, and pancreatic cystic neoplasms.

Pancreatic cysts 3 cm or smaller: how aggressive should treatment be?

PURPOSE

To retrospectively determine the frequency of malignancy in small (< or =3 cm) pancreatic cysts, to evaluate whether cyst morphologic features can help predict the presence of malignancy, and to determine the natural history of small pancreatic cysts at follow-up imaging.

MATERIALS AND METHODS

Institutional review board approval was obtained; informed patient consent was not required. By means of a computerized search, 510 patients with pancreatic cysts that had been detected at computed tomography (CT) or magnetic resonance (MR) imaging were identified. Cysts that were 3 cm or smaller at surgery or endoscopic ultrasonography (US)-guided cyst fluid aspiration and biopsy were included. Eighty-six patients-31 men and 55 women aged 24-89 years-fulfilled the criteria. Patients underwent surgery or were monitored with endoscopic US-guided cyst fluid analysis, cytologic analysis, and follow-up imaging. Imaging findings were compared with surgical and pathology records and with endoscopic US features. Positive predictive values (PPVs) for benignity and malignancy were calculated on the basis of cyst size and absence or presence of septa in the cysts.

RESULTS

Forty-eight patients underwent surgery, and 38 were treated nonsurgically. Seventy-five patients had benign cysts; eight, borderline (malignant) neoplasms; and three, carcinoma in situ lesions. The PPV of small pancreatic cysts for prediction of benignity was 87% (75 of 86 patients). Thirty-six patients had unilocular cysts (35 with benign lesions, one with borderline neoplasm). The PPV of unilocular cysts for prediction of benignity was 97% (35 of 36 patients). Fifty patients had septated cysts; seven of these patients had borderline neoplasms, and three had carcinoma in situ lesions. For prediction of malignancy in small cysts, the PPV of septa was 20% (10 of 50 patients), which was significantly higher than the 3% (one of 36 patients) PPV of unilocular cysts (P = .042). No significant changes in cyst morphologic features were seen in patients who were followed up with imaging for a mean period of 21.8 months.

CONCLUSION

The majority (n = 75) of small pancreatic cysts were benign. Thirty-six cysts were unilocular, and virtually all of these (n = 35) were benign. The presence of septa was associated with borderline or in situ malignancy in 20% (10 of 50) of cases.

Natural history of indeterminate pancreatic cysts

BACKGROUND

The optimal treatment for incidental asymptomatic pancreatic cysts is not known. The purpose of this study was to determine whether nonmucinous cysts by cyst-aspiration analysis can be observed safely.

METHODS

A prospective protocol was initiated in September of 1999 for all suspected cystic neoplasms. Asymptomatic patients with negative cyst aspirates (no extracellular mucin, and concentration of carcinoembryonic antigen in the cyst fluid <200 ng/mL) were followed-up clinically and radiographically.

RESULTS

Through December 2004, 221 patients have been evaluated, and 80 (36%) initially were operated. There were 141 (64%) patients with indeterminate cysts, 98 have been followed-up for more than 12 months. Compared with resected patients, observed patients were older (62 vs 56 y, P < .006), and had smaller cysts (2.4 vs 4.0, P = .001). At a mean follow-up period of 24 months, 4 patients (4%) were resected. The indication, time to resection, and pathology were as follows: 2 patients for symptoms (abdominal pain and obstructive jaundice) at 24 and 72 months, respectively: mucinous and serous cystadenomas; 1 patient for an increase in size (6.6 to 7.8 cm) at 18 months: lymphoepithelial cyst; and 1 patient for abdominal pain and increase in size (2.0 to 3.7 cm) at 41 months: pseudocyst. The only patient resected for a mucinous neoplasm had a cyst fluid carcinoembryonic antigen level of 896 ng/mL. In the remaining observed patients, 20 (23%) showed a decrease in cyst size, and 16 (19%) showed an increase in size (mean diameter change, 21%).

CONCLUSIONS

Initial follow-up evaluation indicates that asymptomatic patients without evidence of a mucinous neoplasm by cyst aspiration can be followed clinically and with interval imaging.

The differentiation between pancreatic neoplastic cysts and pancreatic pseudocyst

The number of small and often asymptomatic cystic lesions detected in pancreas has increased during the last decade. Historically the vast majority of the pancreatic cystic lesions were considered pseudocysts, but in recent series the incidence of various neoplastic cysts, such as intraductal papillary mucinous neoplasm, serous cystadenomas and cystic endocrine tumours, has increased. The possible malignant potential in these cystic neoplasms warrants careful diagnostic workup to choose the optimal treatment for each patient. Patient's age, symptoms and a possible history of acute or chronic pancreatitis with known aetiology together with high quality imaging studies are important in the differential diagnosis between pseudocysts and neoplastic cysts. Endoscopic ultrasound, cyst fluid analysis and positron emission tomography may be used in selected patients, but the accuracy of these methods needs further investigation.