The incidental pancreatic cyst

Integrated spatial transcriptomics and lipidomics of precursor lesions of pancreatic cancer identifies enrichment of long chain sulfatide biosynthesis as an early metabolic alteration

Background

The development of diverse spatial profiling technologies has provided an unprecedented insight into molecular mechanisms driving cancer pathogenesis. Here, we conducted the first integrated cross-species assessment of spatial transcriptomics and spatial metabolomics alterations associated with progression of intraductal papillary mucinous neoplasms (IPMN), bona fide cystic precursors of pancreatic ductal adenocarcinoma (PDAC).

Methods

Matrix Assisted Laster Desorption/Ionization (MALDI) mass spectrometry (MS)-based spatial imaging and Visium spatial transcriptomics (ST) (10X Genomics) was performed on human resected IPMN tissues (N= 23) as well as pancreata from a mutant Kras;Gnas mouse model of IPMN. Findings were further compared with lipidomic analyses of cystic fluid from 89 patients with histologically confirmed IPMNs, as well as single-cell and bulk transcriptomic data of PDAC and normal tissues.

Results

MALDI-MS analyses of IPMN tissues revealed long-chain hydroxylated sulfatides, particularly the C24:0(OH) and C24:1(OH) species, to be selectively enriched in the IPMN and PDAC neoplastic epithelium. Integrated ST analyses confirmed that the cognate transcripts engaged in sulfatide biosynthesis, including UGT8, Gal3St1 , and FA2H , were co-localized with areas of sulfatide enrichment. Lipidomic analyses of cystic fluid identified several sulfatide species, including the C24:0(OH) and C24:1(OH) species, to be significantly elevated in patients with IPMN/PDAC compared to those with low-grade IPMN. Targeting of sulfatide metabolism via the selective galactosylceramide synthase inhibitor, UGT8-IN-1, resulted in ceramide-induced lethal mitophagy and subsequent cancer cell death in vitro , and attenuated tumor growth of mutant Kras;Gnas allografts. Transcript levels of UGT8 and FA2H were also selectively enriched in PDAC transcriptomic datasets compared to non-cancerous areas, and elevated tumoral UGT8 was prognostic for poor overall survival.

Conclusion

Enhanced sulfatide metabolism is an early metabolic alteration in cystic pre-cancerous lesions of the pancreas that persists through invasive neoplasia. Targeting sulfatide biosynthesis might represent an actionable vulnerability for cancer interception.

Machine learning in endoscopic ultrasonography and the pancreas: The new frontier?

Pancreatic diseases have a substantial burden on society which is predicted to increase further over the next decades. Endoscopic ultrasonography (EUS) remains the best available diagnostic method to assess the pancreas, however, there remains room for improvement. Artificial intelligence (AI) approaches have been adopted to assess pancreatic diseases for over a decade, but this methodology has recently reached a new era with the innovative machine learning algorithms which can process, recognize, and label endosonographic images. Our review provides a targeted summary of AI in EUS for pancreatic diseases. Included studies cover a wide spectrum of pancreatic diseases from pancreatic cystic lesions to pancreatic masses and diagnosis of pancreatic cancer, chronic pancreatitis, and autoimmune pancreatitis. For these, AI models seemed highly successful, although the results should be evaluated carefully as the tasks, datasets and models were greatly heterogenous. In addition to use in diagnostics, AI was also tested as a procedural real-time assistant for EUS-guided biopsy as well as recognition of standard pancreatic stations and labeling anatomical landmarks during routine examination. Studies thus far have suggested that the adoption of AI in pancreatic EUS is highly promising and further opportunities should be explored in the field.

Updates in diagnosis and management of pancreatic cysts

Incidental pancreatic cysts are commonly encountered with some cysts having malignant potential. The most common pancreatic cystic neoplasms include serous cystadenoma, mucinous cystic neoplasm and intraductal papillary mucinous neoplasm. Risk stratifying pancreatic cysts is important in deciding whether patients may benefit from endoscopic ultrasound (EUS) or surgical resection. Surgery should be reserved for patients with malignant cysts or cysts at high risk for developing malignancy as suggested by various risk features including solid mass, nodule and dilated main pancreatic duct. EUS may supplement magnetic resonance imaging findings for cysts that remain indeterminate or have concerning features on imaging. Various cyst fluid markers including carcinoembryonic antigen, glucose, amylase, cytology, and DNA markers help distinguish mucinous from nonmucinous cysts. This review will guide the practicing gastroenterologist in how to evaluate incidental pancreatic cysts and when to consider referral for EUS or surgery. For presumed low risk cysts, surveillance strategies will be discussed. Managing pancreatic cysts requires an individualized approach that is directed by the various guidelines.

Thermal Liquid Biopsy (TLB) Focused on Benign and Premalignant Pancreatic Cyst Diagnosis

Background: Current efforts in the identification of new biomarkers are directed towards an accurate differentiation between benign and premalignant cysts. Thermal Liquid Biopsy (TLB) has been previously applied to inflammatory and tumor diseases and could offer an interesting point of view in this type of pathology. Methods: In this work, twenty patients (12 males and 8 females, average ages 62) diagnosed with a pancreatic cyst benign (10) and premalignant (10) cyst lesions were recruited, and biological samples were obtained during the endoscopic ultrasonography procedure. Results: Proteomic content of cyst liquid samples was studied and several common proteins in the different groups were identified. TLB cyst liquid profiles reflected protein content. Also, TLB serum score was able to discriminate between healthy and cysts patients (71% sensitivity and 98% specificity) and between benign and premalignant cysts (75% sensitivity and 67% specificity). Conclusions: TLB analysis of plasmatic serum sample, a quick, simple and non-invasive technique that can be easily implemented, reports valuable information on the observed pancreatic lesion. These preliminary results set the basis for a larger study to refine TLB serum score and move closer to the clinical application of TLB providing useful information to the gastroenterologist during patient diagnosis.

Effect of a region-wide incorporation of an algorithm based on the 2012 international consensus guideline on the practice pattern for the management of pancreatic cystic neoplasms in an integrated health system

AIM

To examine the practice pattern in Kaiser Permanente Southern California (KPSC), i.e., gastroenterology (GI)/surgery referrals and endoscopic ultrasound (EUS), for pancreatic cystic neoplasms (PCNs) after the region-wide dissemination of the PCN management algorithm.

METHODS

Retrospective review was performed; patients with PCN diagnosis given between April 2012 and April 2015 (18 mo before and after the publication of the algorithm) in KPSC (integrated health system with 15 hospitals and 202 medical offices in Southern California) were identified.

RESULTS

2558 (1157 pre- and 1401 post-algorithm) received a new diagnosis of PCN in the study period. There was no difference in the mean cyst size (pre- 19.1 mm vs post- 18.5 mm, P = 0.119). A smaller percentage of PCNs resulted in EUS after the implementation of the algorithm (pre- 45.5% vs post- 34.8%, P < 0.001). A smaller proportion of patients were referred for GI (pre- 65.2% vs post- 53.3%, P < 0.001) and surgery consultations (pre- 24.8% vs post- 16%, P < 0.001) for PCN after the implementation. There was no significant change in operations for PCNs. Cost of diagnostic care was reduced after the implementation by 24%, 18%, and 36% for EUS, GI, and surgery consultations, respectively, with total cost saving of 24%.

CONCLUSION

In the current healthcare climate, there is increased need to optimize resource utilization. Dissemination of an algorithm for PCN management in an integrated health system resulted in fewer EUS and GI/surgery referrals, likely by aiding the physicians ordering imaging studies in the decision making for the management of PCNs. This translated to cost saving of 24%, 18%, and 36% for EUS, GI, and surgical consultations, respectively, with total diagnostic cost saving of 24%.

Incidence and reasons of pancreatic resection in patients with asymptomatic serous cystadenoma

BACKGROUND/OBJECTIVES

Despite diagnostic refinements, pancreatic resection (PR) is eventually performed in some patients with asymptomatic serous cystadenoma (A-SCA). The aim of this study was to define incidence and reasons of PR in A-SCA.

METHODS

A retrospective analysis of a prospectively maintained database was performed for all the patients referred for pancreatic cystic lesions (PCL) between January 2005 and March 2016.

RESULTS

Overall, there were 1488 patients with PCL, including 1271 (85.4%) with incidental PCL (I-PCL). During the study period referral of I-PCL increased 8.5-fold. Surgery was immediately advised in 94 I-PCL (7.3%) and became necessary later on in 11 additional patients (0.9%), because of the development of symptoms. Overall, PR was performed in 105/1271 patients presenting with I-PCL (8.2%), including 27 with A-SCA (2.1%). All patients with A-SCA underwent ultrasonography and contrast-enhanced computed tomography. Magnetic resonance imaging was performed in 21 patients (77.8%), 18 F-FDG positron emission tomography in 8 (29.6%), endoscopic ultrasonography (EUS) in 2 (7.4%), and EUS-guided fine needle aspiration (EUS-FNA) in 1 (3.7%). These studies demonstrated a combination of atypical features such as solid tumor (3; 11.1%), oligo-/macrocystic tumor (24; 88.8%), mural nodules (14; 51.8%), enhancing cyst walls (17; 62.9%), dilation of the main pancreatic duct (3; 11.1%), and upstream pancreatic atrophy (1; 3.7%). Additionally, 14/27 patients (51.8%) were females with oligo-/macrocystic tumors located in the body-tail of the pancreas.

CONCLUSIONS

Management of patients with A-SCA entails a small risk of PR especially when these tumors demonstrate atypical radiologic features associated with confounding anatomic and demographic characteristics.

Linc-ing Circulating Long Non-coding RNAs to the Diagnosis and Malignant Prediction of Intraductal Papillary Mucinous Neoplasms of the Pancreas

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease that lacks effective biomarkers for early detection. We hypothesized that circulating long non-coding RNAs (lncRNAs) may act as diagnostic markers of incidentally-detected cystic PDAC precursors known as intraductal papillary mucinous neoplasms (IPMNs) and predictors of their pathology/histological classification. Using NanoString nCounter® technology, we measured the abundance of 28 candidate lncRNAs in pre-operative plasma from a cohort of pathologically-confirmed IPMN cases of various grades of severity and non-diseased controls. Results showed that two lncRNAs (GAS5 and SRA) aided in differentiating IPMNs from controls. An 8-lncRNA signature (including ADARB2-AS1, ANRIL, GLIS3-AS1, LINC00472, MEG3, PANDA, PVT1, and UCA1) had greater accuracy than standard clinical and radiologic features in distinguishing 'aggressive/malignant' IPMNs that warrant surgical removal from 'indolent/benign' IPMNs that can be observed. When the 8-lncRNA signature was combined with plasma miRNA data and quantitative 'radiomic' imaging features, the accuracy of predicting IPMN pathological classification improved. Our findings provide novel information on the ability to detect lncRNAs in plasma from patients with IPMNs and suggest that an lncRNA-based blood test may have utility as a diagnostic adjunct for identifying IPMNs and their pathology, especially when incorporated with biomarkers such as miRNAs, quantitative imaging features, and clinical data.

Discrimination of serous cystadenoma from mucinous cystadenoma in the pancreas with contrast-enhanced ultrasonography: a prospective study in 61 patients

Objectives

The preoperative diagnosis between serous cystadenomas (SCAs) and mucinous cystadenomas (MCAs) in pancreas is significant due to their completely different biological behaviors. The purpose of our study was to examine and compare detailed contrast-enhanced ultrasonography (CEUS) images of SCAs and MCAs and to determine whether there are significant findings that can contribute to the discrimination between these two diseases.

Methods

From April 2015 to June 2016, 61 patients (35 patients with SCAs and 26 patients with MCAs) were enrolled in this study. Forty-three cases were confirmed by surgical pathology and 18 by comprehensive clinical diagnoses. All of the CEUS characteristics of these lesions were recorded: size, location, echogenicity, shape, wall characteristics, septa characteristics, and the presence of a honeycomb pattern or nodules. CEUS examinations were performed by two ultrasound physicians.

Results

Location (P=0.003), shape (P=0.000), thickness of the wall (P=0.005), the number of septa (P=0.001), and the honeycomb pattern (P=0.001) were statistically significantly different. A head–neck location, a lobulated shape, an inner regular honeycomb pattern, and a thin wall (<3 mm thick) were significant in diagnosing patients with SCAs. When two of these four findings were combined, we could achieve a sensitivity of 71.4% and a specificity of 80.8% to diagnose SCA; when three of these four findings were combined, the specificity was 100%. A body–tail location, a round/oval shape, 0–2 septa, and a thick wall (≥3 mm thick) were most often detected in patients with MCAs. When two of these four findings were combined, we could achieve a sensitivity of 88.5% and a specificity of 65.7% to diagnose MCA; when three of these four findings were combined, the area under the curve (Az) was highest at 0.832, with a sensitivity of 80.8% and a specificity of 85.7%.

Conclusions

The characteristics of tumor location, shape, thickness of the wall, the number of septa, and the honeycomb pattern by CEUS play an important role in the diagnosis of SCAs and MCAs. A combination of these findings can provide better diagnostic performance in the discrimination of SCAs from MCAs.

A pilot study of radiologic measures of abdominal adiposity: weighty contributors to early pancreatic carcinogenesis worth evaluating?

Objective:

Intra-abdominal fat is a risk factor for pancreatic cancer (PC), but little is known about its contribution to PC precursors known as intraductal papillary mucinous neoplasms (IPMNs). Our goal was to evaluate quantitative radiologic measures of abdominal/visceral obesity as possible diagnostic markers of IPMN severity/pathology.

Methods:

In a cohort of 34 surgically-resected, pathologically-confirmed IPMNs (17 benign; 17 malignant) with preoperative abdominal computed tomography (CT) images, we calculated body mass index (BMI) and four radiologic measures of obesity: total abdominal fat (TAF) area, visceral fat area (VFA), subcutaneous fat area (SFA), and visceral to subcutaneous fat ratio (V/S). Measures were compared between groups using Wilcoxon two-sample exact tests and other metrics.

Results:

Mean BMI for individuals with malignant IPMNs (28.9 kg/m²) was higher than mean BMI for those with benign IPMNs (25.8 kg/m²) (P=0.045). Mean VFA was higher for patients with malignant IPMNs (199.3 cm²) compared to benign IPMNs (120.4 cm²),P=0.092. V/S was significantly higher (P=0.013) for patients with malignant versus benign IPMNs (1.25vs. 0.69 cm²), especially among females. The accuracy, sensitivity, specificity, and positive and negative predictive value of V/S in predicting malignant IPMN pathology were 74%, 71%, 76%, 75%, and 72%, respectively.

Conclusions:

Preliminary findings suggest measures of visceral fat from routine medical images may help predict IPMN pathology, acting as potential noninvasive diagnostic adjuncts for management and targets for intervention that may be more biologically-relevant than BMI. Further investigation of gender-specific associations in larger, prospective IPMN cohorts is warranted to validate and expand upon these observations.

Clinical approach to incidental pancreatic cysts

The approach to incidentally noted pancreatic cysts is constantly evolving. While surgical resection is indicated for malignant or higher risk cysts, correctly identifying these highest risk pancreatic cystic lesions remains difficult. Using parameters including cyst size, presence of solid components, and pancreatic duct involvement, the 2012 International Association of Pancreatology (IAP) and the 2015 American Gastroenterological Association (AGA) guidelines have sought to identify the higher risk patients who would benefit from further evaluation using endoscopic ultrasound (EUS). Not only can EUS help further assess the presence of solid component and nodules, but also fine needle aspiration of cyst fluid aids in diagnosis by obtaining cellular, molecular, and genetic data. The impact of new endoscopic innovations with novel methods of direct visualization including confocal endomicroscopy require further validation. This review also highlights the differences between the 2012 IAP and 2015 AGA guidelines, which include the thresholds for sending patients for EUS and surgery and methods, interval, and duration of surveillance for unresected cysts.

Role of endoscopic ultrasound-guided fine-needle aspiration cytology, viscosity, and carcinoembryonic antigen in pancreatic cyst fluid

Due to the advances and increased utility of abdominal cross-sectional imaging, the diagnosis of pancreatic cysts continues to increase. Many endosonographers, pancreatologists, and surgeons consider endoscopic ultrasound (EUS) to be an essential tool in the management of pancreatic cystic lesions (PCLs). EUS can help distinguish between mucinous and nonmucinous lesions and may identify the specific cyst type. EUS achieves these goals by delineating the cyst morphology, identifying high risk stigmata and worrisome features, and through image-guided fine-needle aspiration (FNA) and cyst fluid analysis. However, recent consensus statements have called to question the utility and diminished the role of EUS in this setting. The aim of this review is to assess the role and advances of EUS-FNA in pancreatic cyst fluid analysis, specifically in terms of fluid cytology, viscosity, and carcinoembryonic antigen (CEA) analysis.

Diagnostic approach to pancreatic cysts

PURPOSE OF REVIEW

Diagnosis of pancreatic cysts remains challenging due to limitations of currently available radiologic and endoscopic tools. The diagnostic approach should focus on identifying mucinous and malignant cysts. Mucinous cysts require further differentiation to allow appropriate management.

RECENT FINDINGS

Although the overall rate of malignant pancreatic cysts is low, it remains higher than the general population. MRI with magnetic resonance cholangiopancreatography is the preferred imaging modality for pancreatic cysts. Attempts to improve diagnostic yield of endoscopic ultrasound-guided fine needle aspiration include performing cyst wall cytology and DNA analysis. The 2012 international consensus guidelines for mucinous cystic neoplasm and intraductal papillary mucinous neoplasm are superior to the original 2006 guidelines, although issues include the relatively poor ability to diagnose malignant cysts leading to unnecessary surgeries and the de-emphasis of cyst size. Cyst size remains an important predictor of malignancy. Translational research involving genomics, microRNA, proteomics, and metabolomics holds promise for improved biomarkers. Endoscopic innovations may safely aid in cyst diagnosis.

SUMMARY

Incremental improvements in pancreatic cyst diagnosis have occurred with new biomarkers and endoscopic tools requiring validation in large-scale studies.

Incidental Cystic Lesions in the Pancreas: Resect? EUS? Follow?

Pancreatic cysts challenge clinicians due to their increased incidental identification on radiology imaging, the limitations of currently available diagnostic tools, and potential for malignancy. Following initial identification of an incidental pancreatic cyst, a dedicated pancreatic protocol abdominal CT scan or MRI pancreas with MRCP should be performed. Surgical resection is recommended for all surgical candidates with MD-IPMN, mixed or combined type IPMN, mucinous cystic neoplasm, and solid pseudopapillary neoplasm. Serous cystadenoma may be followed with serial imaging unless the patient develops symptoms, the cyst is larger than 4 cm or rapidly growing, or diagnostic uncertainty remains despite thorough evaluation. Surveillance is also recommended for BD-IPMN without the following features concerning malignancy: obstructive jaundice with a cyst in the head of the pancreas; solid component; nodule; main pancreatic duct ≥10 mm; or cytology suspected or positive for malignancy. BD-IPMN ≥3 cm without concerning features may also be followed carefully, although surgical resection should be considered in surgically fit patients. EUS-FNA for cyst wall cytology, CEA, amylase, and occasionally k-ras mutation are also likely aids in the diagnosis of pancreatic cysts beyond radiologic imaging. This author typically recommends EUS-FNA to further evaluate cysts larger than 1 cm without definitive indication for resection. EUS is also appropriate in patients with solid component, nodule, or size ≥3 cm to aid in decision making, especially in older patients who may be less suitable surgical candidates. A multidisciplinary approach with a team of dedicated gastrointestinal radiologists, pancreatic surgeons, gastrointestinal pathologists, and gastroenterologists is essential for managing patients with pancreatic cysts.

Characterization of pancreatic serous cystadenoma on dual-phase multidetector computed tomography

OBJECTIVE

The objective of the study was to characterize pancreatic serous cystadenomas on dual-phase multidetector computed tomography in a surgical series.

MATERIALS AND METHODS

This is a retrospective review of preoperative dual-phase multidetector computed tomographic scans from 68 patients with surgically resected and pathologically confirmed pancreatic serous cystadenomas.

RESULTS

Pancreatic serous cystadenomas were most commonly found in the tail (39%). The mean (SD) axial dimension was 4.5 (2.7) cm. A total of 36% contained internal calcifications. Dilatation of the main pancreatic duct (14%) and pancreatic parenchymal atrophy (11%) were uncommon. The mean (SD) attenuation of components with the highest attenuation was 49.1 (35.0) Hounsfield units on the arterial phase and 48.5 (33.4) Hounsfield units on the portal venous phase. Only 20% of neoplasms demonstrated "classic" morphology, as defined by multiple thin nonenhancing septations, calcifications, as well as the absence of main pancreatic duct dilatation and vascular involvement.

CONCLUSIONS

Only 20% of surgically resected serous cystadenomas fulfilled classic morphology. Attenuation was helpful in differentiating serous cystadenomas from insulinomas and other cystic pancreatic masses, but it was not helpful in differentiation from pancreatic adenocarcinomas. Morphologic features were more helpful in differentiating serous cystadenomas from malignant masses.

Primary solid pancreatic tumors: recent imaging findings updates with pathology correlation

The imaging findings of primary solid pancreatic tumors have long been studied and are generally well-established. However, interestingly enough, a wealth of new information has recently appeared in the literature, including the imaging findings of novel or previously seldom-addressed pathological entities as well as atypical imaging findings of common tumors, both of which are well-correlated with the pathology findings. 5 %-14 % of pancreatic ductal adenocarcinomas have been reported on dynamic contrast-enhanced computed tomography to be isoattenuating, and thus making the imaging diagnosis challenging. The imaging-pathology correlation in such isoattenuating tumors is presented along with a discussion regarding the early imaging detection of pancreatic cancers. Colloid (or mucinous non-cystic) pancreatic cancer may resemble a less harmful cystic lesion due to its abundant extracellular mucin, and thus requiring caution in the image interpretation. Serotonin-producing neuroendocrine tumors have recently been recognized as a separate entity from usual neuroendocrine tumors. Exuberant fibrosis caused by serotonin metabolites and scarce tumor cells creates a unique pattern of pancreatic ductal obstruction seen on imaging. Small solid pseudopapillary tumors appear as unencapsulated, completely solid lesions with gradually increasing enhancement after contrast administration, unlike typical solid pseudopapillary neoplasms that present as a large mixed solid and degenerated cystic or hemorrhagic mass encapsulated by a thick capsule and which, therefore, tend to be misdiagnosed on imaging. Solid serous adenoma is a rare, solid variant of serous cystadenoma and appears on imaging as a hypervascular, solid nodule due to its genuinely microscopic cystic, alveolar, and ectatic tubular tumor architecture.

Interdisciplinary management of cystic neoplasms of the pancreas

Cystic neoplasms of the pancreas are increasingly recognized due to the frequent use of abdominal imaging. It is reported that up to 20% of abdominal cross-sectional scans identify incidental asymptomatic pancreatic cysts. Proper characterization of pancreatic cystic neoplasms is important not only to recognize premalignant lesions that will require surgical resection, but also to allow nonoperative management of many cystic lesions that will not require resection with its inherent morbidity. Though reliable biomarkers are lacking, a wide spectrum of diagnostic modalities are available to evaluate pancreatic cystic neoplasms, including radiologic, endoscopic, laboratory, and pathologic analysis. An interdisciplinary approach to management of these lesions which incorporates recent, specialty-specific advances in the medical literature is herein suggested.

851 resected cystic tumors of the pancreas: a 33-year experience at the Massachusetts General Hospital

BACKGROUND

The objective of this study was to identify trends in the diagnosis and treatment of cystic neoplasms of the pancreas using a retrospective review of patients from a surgical database at an academic referral center during a 33-year period.

METHODS

Patient characteristics, including demographics, pathology, and survival, were analyzed over 5 time periods between 1978 and 2011.

RESULTS

A total of 851 consecutive patients underwent resection for a cystic neoplasm of the pancreas during a 33-year period. Sixty-five percent of patients were female, and mean age was 60 years. The most common pathologic diagnoses were intraductal papillary mucinous neoplasm (38%), mucinous cystic neoplasm (23%), serous cystadenoma (16%), and cystic neuroendocrine neoplasm (7%). There was a stepwise increase in the number of resections across time periods (67 between 1978 and 1989; 376 between 2005 and 2011), with a parallel increase in the proportion of incidentally discovered lesions (22% to 50%). Diagnosis of intraductal papillary mucinous neoplasm was very uncommon in the first 2 time periods (before the first recognition of intraductal papillary mucinous neoplasm as a distinct entity) but predominated in the last 2 (41% and 49%), and cystic neuroendocrine neoplasms, which constituted 3% of the cystic neoplasms in the first time-period, now comprise more than 8% of pancreatic cystic neoplasms. The proportion of malignant neoplasms decreased over time (41% between 1978 and 1989; 12% between 2005 and 2011), reflecting probably the earlier diagnosis and treatment of premalignant neoplasms. Although operative mortality was minimal (4/849, 0.5%), the postoperative complication rate was 38%. Overall 5-year survival for all mucinous lesions was 87%.

CONCLUSION

Cystic neoplasms of the pancreas are being diagnosed and treated with increasing frequency. At present, most are incidentally discovered intraductal papillary mucinous neoplasms.