Natural history of intraductal papillary mucinous neoplasms (IPMN): current evidence and implications for management

Risk Factors for the Development of High-risk Stigmata in Branch-duct Intraductal Papillary Mucinous Neoplasms

Objective Strict follow-up is recommended for branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) to avoid missing the development of high-risk stigmata (HRS) at a premalignant stage. This study explored the risk factors associated with the development of HRS during follow-up. Methods We performed a retrospective analysis of 283 patients with BD-IPMN, treated at Okayama University Hospital in Japan between January 2009 and December 2016. Only patients with imaging studies indicative of classical features of BD-IPMN without HRS and followed for over one year were included in the study. We performed radiological follow-up every six months and collected patients' demographic data, cyst characteristics, and clinical outcomes and used univariate logistic regression models to determine the odds of developing HRS. Results Ten patients (3.5%) developed HRS after a median surveillance period of 55.8 months. The main pancreatic duct (MPD) size (5-9 mm) and cyst growth rate (>2.5 mm/year) were both suggested to be possible risk factors for the development of HRS [odds ratio, 14.2; 95% confidence interval (CI), 3.1-65.2, p=0.0006, and odds ratio, 6.1; 95% CI 1.5-25.5, p=0.014]. Regarding the number of worrisome features (WFs), the rate of HRS development was 2.0% (4/199) in cases with no WF, 1.6% (1/62) in cases with single WF and 22.7% (5/22) in cases with multiple WFs, respectively. The rate of HRS development was significantly higher in cases with multiple WFs than in the other cases (p<0.0001). Conclusion MPD dilation, rapid cyst growth, and multiple WFs were significant risk factors for the development of HRS. In the presence of such features, it is necessary to closely follow the development of HRS and avoid missing the best opportunity to perform surgical intervention.

Natural history and optimal treatment strategy of intraductal papillary mucinous neoplasm of the pancreas: Analysis using a nomogram and Markov decision model

BACKGROUND/PURPOSE

With the increase in detection of intraductal papillary mucinous neoplasms (IPMN), a tailored approach is needed. This study was aimed at exploring the natural history of IPMN and suggest optimal treatment based on malignancy risk using a nomogram and Markov decision model.

METHODS

Patients with IPMN who underwent surveillance or surgery were included. Changes in worrisome features/high-risk stigmata and malignancy conversion rate were assessed. Life expectancy and quality-adjusted life year (QALY) were compared using a nomogram predicting malignancy.

RESULTS

Overall, 2006 patients with histologically confirmed or radiologically typical IPMN were enrolled. Of these, 1773 (88.4%), 81 (4.0%), and 152 (7.6%), respectively, had branch duct (BD)-, main duct-, and mixed-type IPMN at initial diagnosis. The cumulative risk of developing worrisome feature or high-risk stigmata was 19.0% and 35.0% at 5- and 10-year follow-up, respectively. The progression of malignancy rate at 10-year follow-up was 79.9% for main and mixed IPMNs and 5.9% for BD-IPMN. Nomogram-based malignancy risk prediction is well correlated with natural history based on pathologic biopsy and shows good stratification of survival. The decision model recommends surgery to maximize survival and QALY especially in those with >35% malignancy risk.

CONCLUSIONS

Compared with main duct- and mixed-type IPMN, which have a high risk of malignancy (79.9%), BD-IPMN is very indolent (5.9%). The nomogram-based decision model suggests surgery rather than surveillance for patients with a high malignancy risk. The optimal treatment strategy between surgery and surveillance should consider patients' health status, malignancy risk, and centers' experience.

Validation of Indications for Surgery of European Evidence-Based Guidelines for Patients with Pancreatic Intraductal Papillary Mucinous Neoplasms

BACKGROUND

Which patients with pancreatic intraductal papillary mucinous neoplasms (IPMNs) should undergo surgical intervention remains a controversial issue. The aim of this retrospective study was to validate the new European evidence-based guidelines on pancreatic cystic neoplasms (EEBGPCN) for the management of IPMNs.

METHODS

One hundred fifty-eight patients with resected IPMNs at National Taiwan University Hospital between January 1994 and December 2016 were enrolled. Clinical information, including new-onset diabetes mellitus (DM) and preoperative CA 19-9 levels, were collected. All patients were stratified into three groups-absolute, relative indications, and conservative approach-according to EEBGPCN. The performance characteristics of EEBGPCN for high-grade dysplasia (HGD)/invasive carcinoma (IC) of IPMNs were calculated.

RESULTS

One hundred seven (67.7%) patients with low-grade dysplasia and 51 patients with HGD/IC, including 10 HGD and 41 IC, were analyzed. The missed rate for HGD/IC by EEBGPCN was 1.9% (3/158). The sensitivity, specificity, positive and negative predictive values, and accuracy of the absolute or relative indications for resecting IPMN according to EEBGPCN were 94.1%, 28.0%, 38.4%, 90.9%, and 49.4%. Jaundice, enhancing mural nodule < 5 mm, cyst diameter > 40 mm, increased levels of serum CA 19-9, new-onset DM, and main pancreatic duct dilation were associated with HGD/IC.

CONCLUSIONS

The missed rate for HGD/IC is low by EEBGPCN. Increased serum CA 19-9 and new-onset DM in EEBGPCN were verified as the indications for the surgical resection of IPMNs.

Marker Identification of the Grade of Dysplasia of Intraductal Papillary Mucinous Neoplasm in Pancreatic Cyst Fluid by Quantitative Proteomic Profiling

The incidence of patients with pancreatic cystic lesions, particularly intraductal papillary mucinous neoplasm (IPMN), is increasing. Current guidelines, which primarily consider radiological features and laboratory data, have had limited success in predicting malignant IPMN. The lack of a definitive diagnostic method has led to low-risk IPMN patients undergoing unnecessary surgeries. To address this issue, we discovered IPMN marker candidates by analyzing pancreatic cystic fluid by mass spectrometry. A total of 30 cyst fluid samples, comprising IPMN dysplasia and other cystic lesions, were evaluated. Mucus was removed by brief sonication, and the resulting supernatant was subjected to filter-aided sample preparation and high-pH peptide fractionation. Subsequently, the samples were analyzed by LC-MS/MS. Using several bioinformatics tools, such as gene ontology and ingenuity pathway analysis, we detailed IPMNs at the molecular level. Among the 5834 proteins identified in our dataset, 364 proteins were differentially expressed between IPMN dysplasia. The 19 final candidates consistently increased or decreased with greater IPMN malignancy. CD55 was validated in an independent cohort by ELISA, Western blot, and IHC, and the results were consistent with the MS data. In summary, we have determined the characteristics of pancreatic cyst fluid proteins and discovered potential biomarkers for IPMN dysplasia.

Evaluating the malignant potential of intraductal papillary mucinous neoplasms of the pancreas: added value of non-enhanced endoscopic ultrasound to supplement non-enhanced magnetic resonance imaging

Purpose

To evaluate the diagnostic performance of combining non-enhanced magnetic resonance imaging (MRI) and non-enhanced endoscopic ultrasonography (EUS) for assessing the malignant potential of lesions in patients with intraductal papillary mucinous neoplasms of the pancreas (IPMNs).

Material and methods

Data from 38 patients histopathologically diagnosed with IPMN adenomas or IPMN adenocarcinomas were retrospectively analysed. Preliminary univariate and multivariate analyses were conducted to identify statistically significant associations. Three blinded radiologists evaluated the image sets to assess the diagnostic performance of combined use of non-enhanced MRI and EUS as opposed to non-enhanced MRI alone in distinguishing malignant from benign lesions. Observer performance and interobserver variability were determined using receiver-operating-characteristic curve analysis and weighted κ statistics.

Results

Multivariate analyses identified a significant difference between the abrupt change in the main pancreatic duct (MPD) calibre with distal pancreatic atrophy and the signal intensity of lesion-to-spinal cord ratio on MRI; a significant difference was observed in MPD size on EUS. Diagnostic performance assessments of the image sets did not differ significantly between the blinded radiologists.

Conclusions

The clinical utility of non-enhanced EUS may be attributive in evaluating IPMN that has already been evaluated by non-enhanced MRI.

Branch Duct-type Intraductal Papillary Mucinous Neoplasm Presenting as Paraneoplastic Small Plaque Para-psoriasis

To present and discuss a novel association between branch duct-type intraductal papillary mucinous neoplasm and paraneoplastic parapsoriasis. We present the case of a middle-aged male presenting with skin lesions that were suggestive of parapsoriasis, resistant to treatment, and in whom a diagnosis of branch-type intraductal papillary mucinous neoplasm of the pancreas was eventually made. A curative Whipple's surgery led to complete resolution of the skin lesions within 3 weeks. Paraneoplastic parapsoriasis in association with intraductal papillary mucinous pancreatic neoplasm has never been reported before.

Progression of Pancreatic Branch Duct Intraductal Papillary Mucinous Neoplasm Associates With Cyst Size

BACKGROUNDS & AIMS

Most guidelines for management of patients with intraductal papillary mucinous neoplasms (IPMN) vary in proposed surveillance intervals and durations-these are usually determined based on expert opinions rather than substantial evidence. The progression of and optimal surveillance intervals for branch-duct IPMNs (BD-IPMN) has not been widely studied. We evaluated the progression of BD-IPMN under surveillance at a single center, and determined optimal follow-up intervals and duration.

METHODS

We performed a retrospective analysis of 1369 patients with BD-IPMN seen at Seoul National University Hospital in Korea from January 2001 through December 2016. We included only patients whose imaging studies showed classical features of BD-IPMN, and collected data from each patient over time periods of at least 3 years. We reviewed radiologic and pathologic findings, and performed linear and binary logistic regressions to estimate cyst growth.

RESULTS

The median annual growth rate of the cyst was 0.8 mm over a median follow-up time of 61 months. During surveillance, 46 patients (3.4%) underwent surgery because of disease progression after a median follow-up time (in this group) of 62 months. Worrisome features were observed in 209 patients (15.3%) during surveillance, including cyst size of 3 cm or more (n = 109, 8.0%), cyst wall thickening (n = 51, 3.7%), main pancreatic duct dilatation (n = 77, 5.6%), and mural nodule (n = 43, 3.1%). Along with annual rate of cyst growth, incidences of main pancreatic duct dilatation and mural nodules associated with the sizes of cysts at detection (P < .001).

CONCLUSIONS

In a retrospective analysis of patients with BD-IPMN followed for more than 5 years, we found most cysts to be indolent, but some rapidly grew and progressed. Surveillance protocols should therefore be individualized based on initial cyst size and rate of growth.

Prevalence of incidental pancreatic cyst on upper endoscopic ultrasound

Background:

This study aimed to determine the prevalence of incidental pancreatic cysts in patients undergoing upper endoscopic ultrasound without a known pancreatic abnormality.

Methods:

This prospective study was conducted in two hospitals in Spain and enrolled consecutive patients referred for upper endoscopic ultrasound for a condition unrelated to the pancreas. Patients with a previous pancreatic anomaly, history of acute or chronic pancreatitis, evidence of acute pancreatitis, previous upper gastrointestinal surgery, or chronic abdominal pain suggestive of pancreatic origin were excluded. Univariate logistic regression was performed to evaluate individual covariates and the incidental pancreatic cyst risk.

Results:

A total of 298 patients were included, of whom 64 had pancreatic cysts (21.5%; 16.9-26.6%). The mean size of the cysts was 6.3±3.7 (range 3-25) mm. Six cysts (2%) were >10 mm and 16 (5.4%) were compatible with branch duct intraductal papillary mucinous neoplasm. The pancreatic cyst prevalence was similar in the two hospitals and increased significantly with age.

Conclusion:

The prevalence of incidental pancreatic cysts during endoscopic ultrasound was very high in our study population.

Cross-sectional prevalence of pancreatic cystic lesions in patients with acromegaly, a single-center experience

PURPOSE

Acromegaly is a disease associated with an increased risk for several kinds of neoplasms including colon and thyroid cancer. Although the association between acromegaly and pancreatic neoplasms has not been elucidated, it has recently been reported that GNAS gene mutations were found in 58% of intraductal papillary mucinous neoplasms (IPMNs), which are representative pancreatic cystic lesions, suggesting a link between IPMNs and acromegaly. To assess the prevalence of pancreatic cystic lesions in patients with acromegaly, we performed a retrospective cross-sectional single institute study.

METHODS

Thirty consecutive acromegalic patients (20 females and 10 males; mean age, 60.9 ± 11.9 years) who underwent abdominal contrast-enhanced computed tomography or magnetic resonance imaging between 2007 and 2015 at Kobe University Hospital were recruited. We also analyzed the relationship between presence of pancreatic cystic lesions and somatic GNAS mutations in pituitary tumors.

RESULTS

Seventeen of 30 (56.7%) patients studied had pancreatic cystic lesions. Nine of 17 patients (52.9%) were diagnosed with IPMNs based on imaging findings. These results suggest that the prevalence of IPMNs may be higher in acromegalic patients in acromegalic patients than historically observed in control patients (up to 13.5%). In patients with pancreatic cystic lesions, the mean patient age was higher and the duration of disease was longer than in those without pancreatic cystic lesions (67.0 ± 2.3 vs. 53.0 ± 2.7 years, p < 0.001, 15.5 ± 2.4 vs. 7.3 ± 2.8 years, p = 0.04). There were no differences in serum growth hormone levels or insulin-like growth factor standard deviation scores between these two groups (21.3 ± 6.4 vs. 23.0 ± 7.4 ng/ml, p = 0.86, 6.6 ± 0.5 vs. 8.0 ± 0.6, p = 0.70). Neither the presence of somatic GNAS mutation in a pituitary tumor nor low signal intensity of the tumor in T2 weighted magnetic resonance imaging was associated with the presence of pancreatic cystic lesions.

CONCLUSIONS

These data demonstrate that old or long-suffering patients with acromegaly have a higher prevalence of pancreatic cystic lesions. Moreover, the prevalence of pancreatic cystic lesions may be increased in acromegalic patients.

Digital next-generation sequencing identifies low-abundance mutations in pancreatic juice samples collected from the duodenum of patients with pancreatic cancer and intraductal papillary mucinous neoplasms

OBJECTIVE

Secretin-stimulated pancreatic juice contains DNA shed from cells lining the pancreatic ducts. Genetic analysis of this fluid may form a test to detect pancreatic ductal neoplasia.

DESIGN

We employed digital next-generation sequencing ('digital NGS') to detect low-abundance mutations in secretin-stimulated juice samples collected from the duodenum of subjects enrolled in Cancer of the Pancreas Screening studies at Johns Hopkins Hospital. For each juice sample, digital NGS necessitated 96 NGS reactions sequencing nine genes. The study population included 115 subjects (53 discovery, 62 validation) (1) with pancreatic ductal adenocarcinoma (PDAC), (2) intraductal papillary mucinous neoplasm (IPMN), (3) controls with non-suspicious pancreata.

RESULTS

Cases with PDAC and IPMN were more likely to have mutant DNA detected in pancreatic juice than controls (both p<0.0001); mutant DNA concentrations were higher in patients with PDAC than IPMN (p=0.003) or controls (p<0.001). TP53 and/or SMAD4 mutations were commonly detected in juice samples from patients with PDAC and were not detected in controls (p<0.0001); mutant TP53/SMAD4 concentrations could distinguish PDAC from IPMN cases with 32.4% sensitivity, 100% specificity (area under the curve, AUC 0.73, p=0.0002) and controls (AUC 0.82, p<0.0001). Two of four patients who developed pancreatic cancer despite close surveillance had SMAD4/TP53 mutations from their cancer detected in juice samples collected over 1 year prior to their pancreatic cancer diagnosis when no suspicious pancreatic lesions were detected by imaging.

CONCLUSIONS

The detection in pancreatic juice of mutations important for the progression of low-grade dysplasia to high-grade dysplasia and invasive pancreatic cancer may improve the management of patients undergoing pancreatic screening and surveillance.

Intraductal papillary mucinous neoplasm of the pancreas - epidemiology, risk factors, diagnosis, and management

Intraductal papillary mucinous neoplasm (IPMN) is one of the most common cystic neoplasms of the pancreas. It is a heterogeneous disease and can be divided into ductal types and morphological subtypes. The incidence of IPMN is increasing, likely due to the widespread use of cross-sectional imaging and a growing elderly population. IPMN poses an increasing demand on the health care system. Current guidelines provide indications for surgery and recommendations for surveillance, but management of IPMN is still challenging in routine clinical practice. In this article, we review current knowledge about IPMN and provide future directions for improving diagnosis and management.

Determining the natural history of pancreatic cystic neoplasms: a Manitoban cohort study

BACKGROUND

Most pancreatic cystic neoplasms (PCN) are thought to harbor a low malignant potential. This historical cohort study attempts to describe the natural history of these lesions in a provincial cohort, to assess the safety of non-surgical management. Pathological diagnosis of malignancy was the primary outcome measure of interest.

METHODS

All adult patients (age 18+) with PCN seen between 2000 and 2012 by the two main institutions in Manitoba were included in this study. PCN were graded as high and low risk, which dictated initial treatment plan (surgery or observation). Predictors of initial surgical treatment, delayed surgery in the observation group and the clinical/radiological predictors of malignancy were determined.

RESULTS

497 patients were included in this study. 43 (8.7%) high-risk lesions underwent initial surgery, with 13 (30.2%) cases of malignancy discovered. 450 (90.5%) low-risk cysts were observed for a median of 17.3 months (range: 0.00-142.3). 29 (6.4%) cases of delayed surgery occurred, with malignancy discovered in five (17.2%).

CONCLUSIONS

This study supports current selection criteria for management of PCNs. Due to the low incidence of malignancy in low-risk PCN, it appears that long-term observation is safe and should be the treatment modality of choice in the absence of high-risk features.

Sub-branch and mixed-type intraductal papillary mucinous neoplasms of the pancreas: 2 case reports

Intraductal papillary mucinous neoplasia (IPMN) is one of the cystic neoplasias of the pancreas. The imaging findings provide that these tumors are differentiated from the other cystic lesions of the pancreas, especially from the chronic pancreatitis, where the treatment protocol is completely different. Therefore, the correct diagnosis and classification of the IPMN ensures that the patient receives the correct approach and the appropriate surgery, if necessary. The purpose of this study is to emphasize the imaging findings of the different types of the IPMN and the changes in the management protocol of the patients according to these radiological findings.

Pathologic Evaluation and Reporting of Intraductal Papillary Mucinous Neoplasms of the Pancreas and Other Tumoral Intraepithelial Neoplasms of Pancreatobiliary Tract: Recommendations of Verona Consensus Meeting

BACKGROUND

There are no established guidelines for pathologic diagnosis/reporting of intraductal papillary mucinous neoplasms (IPMNs).

DESIGN

An international multidisciplinary group, brought together by the Verona Pancreas Group in Italy-2013, was tasked to devise recommendations.

RESULTS

(1) Crucial to rule out invasive carcinoma with extensive (if not complete) sampling. (2) Invasive component is to be documented in a full synoptic report including its size, type, grade, and stage. (3) The term "minimally invasive" should be avoided; instead, invasion size with stage and substaging of T1 (1a, b, c; ≤ 0.5, > 0.5-≤ 1, > 1 cm) is to be documented. (4) Largest diameter of the invasion, not the distance from the nearest duct, is to be used. (5) A category of "indeterminate/(suspicious) for invasion" is acceptable for rare cases. (6) The term "malignant" IPMN should be avoided. (7) The highest grade of dysplasia in the non-invasive component is to be documented separately. (8) Lesion size is to be correlated with imaging findings in cysts with rupture. (9) The main duct diameter and, if possible, its involvement are to be documented; however, it is not required to provide main versus branch duct classification in the resected tumor. (10) Subtyping as gastric/intestinal/pancreatobiliary/oncocytic/mixed is of value. (11) Frozen section is to be performed highly selectively, with appreciation of its shortcomings. (12) These principles also apply to other similar tumoral intraepithelial neoplasms (mucinous cystic neoplasms, intra-ampullary, and intra-biliary/cholecystic).

CONCLUSIONS

These recommendations will ensure proper communication of salient tumor characteristics to the management teams, accurate comparison of data between analyses, and development of more effective management algorithms.

Intraductal Papillary Mucinous Neoplasms and the Risk of Diabetes Mellitus in Patients Undergoing Resection Versus Observation

OBJECTIVE

The aim of this study is to determine the prevalence of diabetes mellitus (DM) in patients with intraductal papillary mucinous neoplasm of the pancreas (IPMN) and compare rates of new/progressive DM between IPMN patients undergoing pancreatectomy versus observation.

METHODS

Patients diagnosed with IPMN were identified from institutional databases, divided into two groups based on treatment type, pancreatectomy versus clinical observation, and subsequently evaluated. Standard demographic and clinicopathologic variables, fasting glucose, diabetic status, and pancreatic volume data, were obtained and compared between groups.

RESULTS

One hundred thirty-four IPMN patients were identified; 103 (77 %) underwent pancreatectomy and 31 (23 %) were observed. Baseline DM rate was 18 % (24/134). This was not different between groups [17 % (17/103) resected vs. 23 % (7/31) observed, p = 0.51]. Median follow-up was 53 months and new/progressive DM occurred in 37 (28 %) patients with no difference between groups [29 (28 %) resected vs. 8 (26 %) observed, p = 0.74]. Among resected patients, degree of dysplasia was associated with increase risk of new/progressive DM [moderate dysplasia OR 5.76 (1.24-26.79) and severe dysplasia OR 9.43 (1.54-57.74), p = 0.04], while procedure type and remnant volume were not.

CONCLUSIONS

The incidence and prevalence of DM among patients with IPMN was high and did not differ between resected and observed groups. Degree of dysplasia, not the amount of resected pancreas, was associated with increased risk of DM, suggesting that the presence or development of DM may be a marker of malignant progression. Confirmatory studies are required.

Demographic features and natural history of intermediate-risk multifocal versus unifocal intraductal papillary mucinous neoplasms

OBJECTIVES

This study compares the progression of multifocal (MF) intraductal papillary mucinous neoplasms (IPMNs) to unifocal (UF) lesions.

METHODS

We performed a retrospective review of demographics, risk factors, and cyst characteristics of a prospectively maintained database of 999 patients with pancreatic cysts. Patients included had IPMN under surveillance for 12 months or more. Those with high-risk stigmata were excluded. Cyst size progression and development of worrisome features were compared between MF and UF cohorts. We evaluated whether the dominant cyst in MF-IPMN had more significant growth than did the other cysts.

RESULTS

Seventy-seven patients with MF-IPMN and 54 patients with UF-IPMN, with mean follow-up of 27 and 34 months, met the criteria. There were no significant differences between demographics, risk factors, or initial cyst sizes. Fifty-seven percent of MF dominant cysts and 48% of UF cysts increased in size (P = 0.31). Progression in MF was more likely in the dominant cyst (P < 0.05). There were no significant differences in the development of mural nodules or increase in cyst size to more than 3 cm.

CONCLUSIONS

Demographics of both cohorts were similar, as was the overall incidence of worrisome features. Because meaningful size progression primarily occurred in the dominant cyst, our findings support surveillance based on the dominant cyst in MF disease.

Branch-duct intraductal papillary mucinous neoplasm and embolic stroke of unknown cause

BACKGROUND

In many embolic strokes, the specific embolic source might be uncertain. When we found asymptomatic branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) in patients with ischemic stroke of unknown cause, most of gastroenterologists might undervalue it as a potential thromboembolic sources.

METHODS

We report 4 patients with embolic stroke of unknown cause and incidental BD-IPMNs.

RESULTS

Magnetic resonance imaging revealed multiple embolic infarctions. Recommended cardiac examinations, such as 24-hour Holter monitoring and transthoracic and transesophageal echocardiography, were normal. Other cancer markers and molecular markers of hypercoagulopathy were normal. On abdominal computed tomography scan, performed to detect hidden malignancy, a low attenuated lesion with a diameter of less than 3 cm was observed in the pancreas.

CONCLUSION

Although BD-IPMNs are associated with a lower rate of malignancy than main-duct IPMNs, the BD-IPMNs had some malignant potential and frequently coexist with extrapancreatic or intrapancreatic cancers. Therefore, we suggest that, in some cases, the BD-IPMNs might be considered as a thromboembolic source.

Pancreatic intraductal papillary mucinous neoplasm in a patient with Lynch syndrome

Intraductal papillary mucinous neoplasm (IPMN) is a mucin-producing epithelial neoplasm that carries a risk of progression to invasive pancreatic ductal adenocarcinoma. Lynch syndrome is an autosomal dominant condition caused by germline mutations in mismatch repair genes such as MSH2 that lead to microsatellite instability and increased risk of tumor formation. Although families with Lynch syndrome have an increased risk of pancreatic cancer, a clear connection between Lynch syndrome and IPMN has not been drawn. We present a report of a 58 year-old Caucasian woman with multiple cancers and a germline mutation of MSH2 consistent with Lynch syndrome. A screening abdominal computed tomography scan revealed a dilated main pancreatic duct and cystic ductular structure in the uncinate process that were consistent with IPMN of the main pancreatic duct on excision. Immunohistochemistry and polymerase chain reaction of the patient’s pancreas specimen did not reveal microsatellite instability or mismatch repair gene loss of expression or function. Our findings may be explained by the fact that loss of mismatch repair function and microsatellite instability is a late event in neoplastic transformation. Given the relative rarity of main duct IPMN, its appearance in the setting of somatic MSH2 mutation suggests that IPMN may fit into the constellation of Lynch syndrome related malignancies.

Outcomes of nonresected main-duct intraductal papillary mucinous neoplasms of the pancreas

AIM: To compare characteristics and outcomes of resected and nonresected main-duct and mixed intraductal papillary mucinous neoplasms of the pancreas (IPMN).

METHODS: Over a 14-year period, 50 patients who did not undergo surgery for resectable main-duct or mixed IPMN, for reasons of precluding comorbidities, age and/or refusal, were compared with 74 patients who underwent resection to assess differences in rates of survival, recurrence/occurrence of malignancy, and prognostic factors. All study participants had dilatation of the main pancreatic duct by ≥ 5 mm, with or without dilatation of the branch ducts. Some of the nonsurgical patients showed evidence of mucus upon perendoscopic retrograde cholangiopancreatography or endoscopic ultrasound and/or after fine needle aspiration. For the surgical patients, pathologic analysis of resected specimens confirmed a diagnosis of IPMN with involvement of the main pancreatic duct or of both branch ducts as well as the main pancreatic duct. Clinical and biologic follow-ups were conducted for all patients at least annually, through hospitalization or consultation every six months during the first year of follow-up, together with abdominal imaging analysis (magnetic resonance cholangiopancreatography or computed tomography) and, if necessary, endoscopic ultrasound with or without fine needle aspiration.

RESULTS: The overall five-year survival rate of patients who underwent resection was significantly greater than that for the nonsurgical patients (74% vs 58%; P = 0.019). The parameters of age (< 70 years) and absence of a nodule were associated with better survival (P < 0.05); however, the parameters of main pancreatic duct diameter > 10 mm, branch duct diameter > 30 mm, or presence of extra pancreatic cancers did not significantly influence the prognosis. In the nonsurgical patients, pancreatic malignancy occurred in 36% of cases within a mean time of 33 mo (median: 29 mo; range: 8-141 mo). Comparison of the nonsurgical patients who experienced disease progression with those who did not progress showed no significant differences in age, sex, symptoms, subtype of IPMN, or follow-up period; only the size of the main pancreatic duct was significantly different between these two sub-groups, with the nonsurgical patients who experienced progression showing a greater diameter at the time of diagnosis (> 10 mm).

CONCLUSION: Patients unfit for surgery have a 36% greater risk of developing pancreatic malignancy of the main-duct or mixed IPMN within a median of 2.5 years.

Navigation surgery using an augmented reality for pancreatectomy

AIM

The aim of this study was to evaluate the utility of navigation surgery using augmented reality technology (AR-based NS) for pancreatectomy.

METHODS

The 3D reconstructed images from CT were created by segmentation. The initial registration was performed by using the optical location sensor. The reconstructed images were superimposed onto the real organs in the monitor display. Of the 19 patients who had undergone hepatobiliary and pancreatic surgery using AR-based NS, the accuracy, visualization ability, and utility of our system were assessed in five cases with pancreatectomy.

RESULTS

The position of each organ in the surface-rendering image corresponded almost to that of the actual organ. Reference to the display image allowed for safe dissection while preserving the adjacent vessels or organs. The locations of the lesions and resection line on the targeted organ were overlaid on the operating field. The initial mean registration error was improved to approximately 5 mm by our refinements. However, several problems such as registration accuracy, portability and cost still remain.

CONCLUSION

AR-based NS contributed to accurate and effective surgical resection in pancreatectomy. The pancreas appears to be a suitable organ for further investigations. This technology is promising to improve surgical quality, training, and education.

Current recommendations for surveillance and surgery of intraductal papillary mucinous neoplasms may overlook some patients with cancer

BACKGROUND

The 2012 Sendai Criteria recommend that patients with 3 cm or larger branch duct intraductal papillary mucinous neoplasms (BD-IPMN) without any additional "worrisome features" or "high-risk stigmata" may undergo close observation. Furthermore, endoscopic ultrasound (EUS) is not recommended for BD-IPMN <2 cm. These changes have generated concern among physicians treating patients with pancreatic diseases. The purposes of this study were to (i) apply the new Sendai guidelines to our institution's surgically resected BD-IPMN and (ii) reevaluate cyst size cutoffs in identifying patients with lesions harboring high-grade dysplasia or invasive cancer.

METHODS

We retrospectively reviewed 150 patients at a university medical center with preoperatively diagnosed and pathologically confirmed IPMNs. Sixty-six patients had BD-IPMN. Pathologic grade was dichotomized into low-grade (low or intermediate grade dysplasia) or high-grade/invasive (high-grade dysplasia or invasive cancers). Fisher's exact test, chi-square test, student's t test, linear regression, and receiver operating characteristic (ROC) analyses were performed.

RESULTS

The median BD-IPMN size on imaging was 2.4 cm (interquartile range 1.5-3.0). Fifty-one (77 %) low-grade and 15 (23 %) high-grade/invasive BD-IPMN were identified. ROC analysis demonstrated that cyst size on preoperative imaging is a reasonable predictor of grade with an area under the curve of 0.691. Two-thirds of high-grade/invasive BD-IPMN were <3 cm (n = 10). Compared to a cutoff of 3, 2 cm was associated with higher sensitivity (73.3 vs. 33.3 %) and negative predictive value (83.3 vs. 80 %, NPV) for high-grade/invasive BD-IPMN. Mural nodules on endoscopic ultrasound (EUS) or atypical cells on endoscopic ultrasound-fine needle aspiration (EUS-FNA) were identified in all cysts <2 and only 50 % of those <3 cm. Forty percent of cysts >3 cm were removed based on size alone.

DISCUSSION/CONCLUSIONS

Our results suggest that "larger" size on noninvasive imaging can indicate high-grade/invasive cysts, and EUS-FNA may help identify "smaller" cysts with high-grade/invasive pathology.

Surgical treatment and prognosis of 96 cases of intraductal papillary mucinous neoplasms of the pancreas: a retrospective cohort study

INTRODUCTION

The indications, the extent and type of surgery for intraductal papillary mucinous neoplasm (IPMN) are still controversial. This study aimed to investigate clinical manifestation, individualized surgical treatment, and prognosis of IPMN of pancreas.

METHODS

The clinical data of 96 IPMN cases treated in our hospital between January 2006 and December 2013 were retrospectively analyzed. Among the 96 patients (58 male and 38 female), 46 were main-duct type, 29 were branch-duct type, 21 were mixed type. Pancreatectomy was performed on 78 cases, including pancreaticoduodenectomy on 43 patients, distal pancreatectomy on 25, segmental pancreatectomy on 6, and total pancreatectomy on 4. A regular follow-up without surgical treatment was performed on 18 cases with asymptomatic side branch IPMN less than 3 cm in diameter.

RESULTS

The overall postoperative morbidity rate was 33.3%, and there was no perioperative mortality. 46 cases were non-invasive IPMN, 32 cases were invasive IPMN including 14 cases with lymph node metastasis. The five-year survival rate for patients with non-invasive and invasive carcinomas was 96.2% and 35.2%, respectively. The prognosis of invasive cases with lymph node metastasis was significantly worse than those without lymph node metastasis. No progression was found during the follow-up in 18 asymptomatic small branch duct type IPMN patients.

CONCLUSION

IPMN has a relative good prognosis. Main duct type and mixed type IPMN have a higher malignant potential, and should receive surgical treatment. Patients of branch duct type IPMN with lesion <3 cm in diameter and without clinical manifestations can be managed with close follow-up.

Intraductal papillary mucinous neoplasms of the pancreas: evaluation of malignant potential and surgical resectability by using MR imaging with MR cholangiography

PURPOSE

To evaluate the diagnostic performance of magnetic resonance (MR) imaging with MR cholangiopancreatography (MRCP) in determining the malignant potential and surgical resectability of pancreas intraductal papillary mucinous neoplasms (IPMNs).

MATERIALS AND METHODS

Institutional review board approval was obtained, and the requirement for informed consent was waived. Ninety-eight patients with pathologically proved pancreas IPMNs who underwent MR imaging with MRCP comprised the study population. MR images were analyzed for findings suggestive of high-risk stigmata or worrisome features, as proposed by the international consensus guidelines 2012. Interobserver agreement between two experienced observers (observers 1 and 2) and one inexperienced observer (observer 3) was assessed. Diagnostic performance of MR imaging in the evaluation of the malignant potential and surgical resectability of IPMNs was analyzed in these three observers by using receiver operating curve analysis.

RESULTS

MR imaging with MRCP showed sensitivity of 83% (35/42), 79% (33/42), and 90% (38/42); specificity of 80% (41/51), 51% (26/51), and 24% (12/51); and accuracy of 82% (76/93), 63% (59/93), and 54% (50/93) for observers 1, 2, and 3, respectively, in the evaluation of the malignant potential of pancreas IPMNs when at least one worrisome feature was present. Interobserver agreement in the detection of intramural nodules (κ = 0.349-0.574), enhanced solid components (κ = 0.318-0.574), and measurement of main pancreatic duct diameter (intraclass correlation coefficient = 0.9477) was fair to high. The respective sensitivity, specificity, and accuracy in determination of surgical resectability were 95% (81/85), 99% (84/85), and 88% (75/85); 69% (9/13), 69% (9/13), and 54% (7/13); and 92% (90/98), 95% (93/98), and 84% (82/98) for observers 1, 2, and 3.

CONCLUSION

MR imaging with MRCP is a useful modality in the evaluation of the malignant potential and resectability of IPMNs, with high sensitivity and moderate specificity in the experienced radiologists but relatively low specificity in the inexperienced radiology trainee.

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

BACKGROUND

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

OBJECTIVE

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

DESIGN

Single-center retrospective study of prospectively collected data.

SETTINGS

Tertiary referral center.

PATIENTS AND INTERVENTIONS

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

MAIN OUTCOME MEASUREMENTS

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

RESULTS

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

LIMITATIONS

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

CONCLUSION

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

Imaging features to distinguish malignant and benign branch-duct type intraductal papillary mucinous neoplasms of the pancreas: a meta-analysis

OBJECTIVE

To systematically determine the imaging findings for distinguishing malignant and benign branch-duct type intraductal papillary mucinous neoplasms (BD-IPMNs), including mixed type, and their diagnostic value through meta-analysis of published studies.

BACKGROUND

Management of BD-IPMNs, including mixed type, largely relies on imaging findings. The current knowledge on imaging findings to distinguish malignant and benign BD-IPMNs has weak evidence and is mostly from scattered individual retrospective studies.

METHODS

Thorough literature search in Ovid-MEDLINE and EMBASE databases was conducted to identify studies where findings of computed tomography, magnetic resonance imaging, and endoscopic ultrasonography of BD-IPMNs with or without main pancreatic duct (MPD) dilatation were correlated with surgical/pathological findings. Review of 1128 article candidates, including full-text review of 102 articles, identified 23 eligible articles with a total of 1373 patients for meta-analysis. Dichotomous data regarding distinction between malignant and benign BD-IPMNs were pooled using random effects model to obtain the diagnostic odds ratios (DORs) and their 95% confidence intervals (CIs) of various individual imaging findings for diagnosing malignant BD-IPMN.

RESULTS

Presence of mural nodules revealed the highest pooled DOR (95% CI) of 6.0 (4.1-8.8) followed by MPD dilatation [3.4 (2.3-5.2)], thick septum/wall [unadjusted, 3.3 (1.5-6.9); publication bias-adjusted, 2.3 (0.9-5.5)], and cyst size greater than 3 cm [2.3 (1.5-3.5)]. Multilocularity and multiplicity of the cystic lesions did not reveal statistically significant association with malignancy.

CONCLUSIONS

Presence of mural nodules should be regarded highly suspicious for malignancy warranting a surgical excision whereas cyst size greater than 3 cm, MPD dilatation (5-9 mm), or thick septum/wall may better be managed by careful observation and/or further evaluation.

[Duodenum-preserving total pancreatic head resection : an organ-sparing operation technique for cystic neoplasms and non-invasive malignant tumors]

Cystic neoplasms of the pancreas are being detected and surgically treated increasingly more frequently. Intraductal papillary mucinous neoplasms (IPMN) and mucinous cystic neoplasms (MCN) are primary benign lesions; however, the 5-year risk for malignant transformation has been estimated to be 63 % and 15 %, respectively. Surgical extirpation of a benign cystic tumor of the pancreas is a cancer preventive measure. The duodenum-preserving total pancreatic head resection technique (DPPHRt) is being used more frequently for cystic neoplasms of the pancreatic head. The complete resection of the pancreatic head can be applied as a duodenum-preserving technique or with segmental resection of the peripapillary duodenum. Borderline lesions, carcinoma in situ or T1N0 cancer of the papilla and the peripapillary common bile duct are also considered to be indications for segmental resection of the peripapillary duodenum. A literature search for cystic neoplastic lesions and DPPHRt revealed the most frequent indications to be IPMN, MCN and SCA lesions and 28 % suffered from a cystic neoplasm with carcinoma in situ or a peripapillary malignoma. The hospital mortality rate was 0.52 %. Compared to the Whipple type resection the DPPHRt exhibits significant benefits with respect to a low risk for early postoperative complications and a low hospital mortality rate of < 1 %. Exocrine and endocrine pancreatic functions after DPPHR are not impaired compared to the Whipple type resection.

Pancreatic cyst prevalence and the risk of mucin-producing adenocarcinoma in US adults

OBJECTIVES

The presence of a pancreatic cyst often prompts concern, although the rate of malignant transformation to mucin-producing adenocarcinoma is not known. We aimed to determine the prevalence rate of mucin-producing adenocarcinoma in US adults with pancreatic cysts.

METHODS

This retrospective, population-based cross-sectional study calculated the annual number of mucin-producing adenocarcinomas using the Surveillance Epidemiology and End Results (SEER 18) database and the 2010 US census. The overall prevalence rate of cysts in the population was found using data from large cross-sectional imaging studies of incidental cyst prevalence. Prevalence rates were then calculated by dividing the annual number of mucin-producing adenocarcinomas by the cyst prevalence rate.

RESULTS

Between 2005 and 2009, 1,137 mucin-producing adenocarcinomas were estimated to be found annually in a US adult population of 137,154,960. The total number of pancreas cysts, given a cyst prevalence rate of 2.5%, was 3,428,874. Therefore, the prevalence rate of mucin-producing adenocarcinoma arising in patients with pancreatic cysts was 33.2 per 100,000 (95% confidence interval (CI): 21.9-44.5). The prevalence rate was 32.8 per 100,000 (95% CI: 21.6-44.0) in women and 33.5 per 100,000 (95% CI: 22.2-44.8) in men. As expected, the rate of malignant transformation increased linearly with advancing age (highest 38.6 per 100,000 in 80- to 84-year-old men).

CONCLUSIONS

Malignant transformation of pancreatic cysts into mucin-producing adenocarcinoma in US adults is a very rare event. Current clinical guidelines and resource allocation for pancreatic cyst disease should be reconsidered given these findings.

Dysplasia at the surgical margin is associated with recurrence after resection of non-invasive intraductal papillary mucinous neoplasms

BACKGROUND

The significance of a positive margin in resected non-invasive pancreatic intraductal papillary mucinous neoplasms (IPMN) remains controversial. The aim of this study was to determine recurrence rates when dysplasia was present at the final surgical margin.

METHODS

A prospectively maintained database identified 192 patients undergoing resection of non-invasive IPMN. Pathological, peri-operative and recurrence data were analysed.

RESULTS

Ductal dysplasia was identified at the final surgical margin in 86 patients (45%) and defined as IPMN or Pancreatic Intraepithelial Neoplasia PanIN in 38 (20%) and 54 (28%) patients, respectively. At a median follow-up of 46 months, 40 (21%) patients recurred with 31 developing radiographical evidence of new cysts, 6 re-resected for IPMN and 3 diagnosed with pancreatic cancer within the remnant. Of those with margin dysplasia, 31% developed recurrent disease compared with 13% in those without dysplasia (P = 0.002). On multivariate analysis, margin dysplasia was associated with a three-fold increased risk of recurrence (P = 0.02). No relationship between dysplasia and development of pancreatic cancer was found.

DISCUSSION

In this study, dysplasia at the margin after a pancreatectomy for non-invasive IPMN was associated with recurrence in the remnant gland, but not at the resection margin. While this finding may warrant closer follow-up, it does not identify a gland at higher risk for the subsequent development of invasive disease.

Carcinogenesis of pancreatic adenocarcinoma: precursor lesions

Pancreatic adenocarcinoma displays a variety of molecular changes that evolve exponentially with time and lead cancer cells not only to survive, but also to invade the surrounding tissues and metastasise to distant sites. These changes include: genetic alterations in oncogenes and cancer suppressor genes; changes in the cell cycle and pathways leading to apoptosis; and also changes in epithelial to mesenchymal transition. The most common alterations involve the epidermal growth factor receptor (EGFR) gene, the HER2 gene, and the K-ras gene. In particular, the loss of function of tumor-suppressor genes has been documented in this tumor, especially in CDKN2a, p53, DPC4 and BRCA2 genes. However, other molecular events involved in pancreatic adenocarcinoma pathogenesis contribute to its development and maintenance, specifically epigenetic events. In fact, key tumor suppressors that are well established to play a role in pancreatic adenocarcinoma may be altered through hypermethylation, and oncogenes can be upregulated secondary to permissive histone modifications. Indeed, factors involved in tumor invasiveness can be aberrantly expressed through dysregulated microRNAs. This review summarizes current knowledge of pancreatic carcinogenesis from its initiation within a normal cell until the time that it has disseminated to distant organs. In this scenario, highlighting these molecular alterations could provide new clinical tools for early diagnosis and new effective therapies for this malignancy.

IPMN: surgical treatment

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Outcomes of intraductal papillary mucinous neoplasm with "Sendai-positive" criteria for resection undergoing non-operative management

BACKGROUND

There are few data on the outcome of patients with intraductal papillary mucinous neoplasms of the pancreas meeting criteria for resection (Sendai-positive), and not operated.

AIM

To evaluate outcome of patients with a resectable, Sendai-positive intraductal papillary mucinous neoplasm, and not operated.

METHODS

Multicentre, retrospective analysis of prospectively enrolled patients, with resectable Sendai-positive, not-operated intraductal papillary mucinous neoplasm. Overall-survival and disease-specific survival were the primary end-point, and progression-free survival secondary.

RESULTS

Thirty-five patients (60% male, median age 77) enrolled: 40% main-duct, 60% branch-duct intraductal papillary mucinous neoplasms. In 19 patients surgery was ruled out due to comorbidities, in 7 because aged > 80, 9 refused surgery. Twelve (34.3%) patients died after a mean of 32.5 months, 8 due to disease progression, 4 due to comorbidities. The median overall, disease-specific and progression-free survival were 52, 55, and 44 months respectively. Main duct involvement and age at diagnosis were associated with worse overall and progression-free survival, only main duct involvement with worse disease-specific survival (52 months main duct vs. 64 branch duct; P = 0.04).

CONCLUSION

These results suggest that in elderly and comorbid patients with Sendai-positive intraductal papillary mucinous neoplasms, especially of the branch duct, a conservative approach could be reasonable, as associated with a relatively good outcome, and should be carefully discussed with the patients.

Recurrence of non-invasive intraductal papillary municious neoplasm seven years following total pancreatectomy

INTRODUCTION

Intraductal papillary mucinous neoplasm is an increasingly recognized disease with varying premalignant potential and unclear incidence, characterized by a mucin-producing epithelium and dilation of the pancreatic duct.

PRESENTATION OF CASE

We present the first documented case of distant intestinal intraductal papillary mucinous neoplasm recurrence following total pancreatectomy for side-branch non-invasive borderline malignant intraductal papillary mucinous neoplasm.

DISCUSSION

We review the current literature in order to try and answer important questions regarding our ability to predict intraductal papillary mucinous neoplasm recurrence, our understanding of the potential for recurrence and what follow-up should be recommended to properly monitor recurrence after a benign, albeit borderline malignant, side-branch lesion resection.

CONCLUSION

Our case report confirms that the low risk classification of an intraductal papillary mucinous neoplasm lesion even after total pancreatectomy does not always predict recurrence and that definitive prognostic factors of recurrence in the setting of non-invasive disease have yet to be identified. A vigilant long-term approach to follow-up may thus be required even in low risk cases.

Natural history of asymptomatic pancreatic cystic neoplasms

BACKGROUND

The management of asymptomatic pancreatic cysts is controversial and indications for excision are based on pathology and natural history.

OBJECTIVES

This study aimed to examine outcomes of asymptomatic lesions using a protocol based on size and cyst fluid analysis.

METHODS

Asymptomatic cysts were identified from a prospectively maintained database. Sequential cross-sectional imaging studies were assessed, and results of endoscopic ultrasound-guided aspiration were co-analysed.

RESULTS

A total of 338 asymptomatic patients underwent evaluation. Overall, 84 cysts were <1.5 cm and 254 were ≥1.5 cm in diameter. Median patient follow-up was 5.1 years [interquartile range (IQR): 4.1-6.9 years]. In the group in which cysts measured <1.5 cm in diameter, median cyst size was 1.0 cm (IQR: 0.6-1.2 cm) at presentation and increased to 1.2 cm (IQR: 0.7-1.6 cm) during follow-up. Five (6.0%) patients underwent resection, all within 2 months of presentation. In the group in which cysts measured ≥1.5 cm in diameter, median cyst size was 2.5 cm (IQR: 2.0-3.4 cm) at presentation and increased to 2.7 cm (IQR: 3.0-4.2 cm). A total of 63 (24.8%) patients underwent resection. Surgery was performed with 2 months in 53 (84.1%) patients, within 12 months in four (6.3%) patients and at >12 months post-presentation in six (9.5%) patients. A total of 70.6% of resected specimens were identified as malignancies or mucinous lesions.

CONCLUSIONS

Asymptomatic cysts of <1.5 cm in diameter can safely be followed by imaging and are expected to undergo little change. A quarter of all asymptomatic cysts measuring ≥1.5 cm are appropriately resected based on imaging and cyst fluid analysis.

High-grade dysplasia and adenocarcinoma are frequent in side-branch intraductal papillary mucinous neoplasm measuring less than 3 cm on endoscopic ultrasound

BACKGROUND

Surgical resection for intraductal papillary mucinous neoplasm (IPMN) of the pancreas has increased over the last decade. While IPMN with main duct communication are generally recommended for resection, indications for resection of side-branch IPMN (SDIPMN) have been less clear. We reviewed our single institutional experience with SDIPMN and indications for resection.

METHODS

Patients who underwent resection for IPMN were identified from a prospectively maintained IRB-approved database. Patients with main pancreatic duct communication were excluded. Outcome, clinical and pathologic characteristics were correlated with endoscopic ultrasound (EUS) findings.

RESULTS

From 2000 to 2010, 105 patients who underwent preoperative EUS evaluation and resection for SDIPMN were identified. The mean age was within the sixth decade of life, and there was a slight female predominance (55 vs. 45 %). The most common presenting symptom was abdominal pain (N = 47, 45 %), followed by jaundice (N = 24, 23 %) and weight loss (N = 24, 23 %). Only ten patients (10 %) were asymptomatic at presentation; seven (70 %) had suspicious features on EUS. Of the total cohort, few patients had intracystic septations (N = 27, 26 %) or presence of mural nodules (N = 2, 2 %) on EUS. Of 39 patients who had invasive pancreatic ductal adenocarcinoma (PDAC) on final pathology, EUS-fine needle aspiration (EUS-FNA) demonstrated malignancy in only 21 (54 %). An additional seven (18 %) had EUS-FNA findings of atypia or concern for mucinous neoplasm. EUS evaluation of cyst size was correlated with final pathology. Of 70 patients with EUS cyst size <3 cm, 12 (17 %) had a preoperative EUS diagnosis of malignancy. Final pathology revealed 24 (34 %) to have PDAC: 1 of 7 (14 %) patients with cyst size <1 cm, 2 of 19 (11 %) with cyst size 1-2 cm, and 21of 44 (48 %) with cyst size 2-3 cm. Fifteen of 35 (43 %) patients with cyst size >3 cm had PDAC on final pathology. Of the patients with cyst size <3 cm, 16 (23 %) had high-grade dysplasia on final pathology: 3 of 7 (43 %) with cyst size <1 cm, 3 of 19 (16 %) with cyst size 1-2 cm, and 10 of 44 (23 %) with cyst size 2-3 cm. Seven of 35 (20 %) patients with cyst size >3 cm had high-grade dysplasia on final pathology. Although overall survival (OS) at 48 months stratified by EUS cyst size did not significantly differ between groups, patients with PDAC on final pathology had significantly worse OS compared to noninvasive pathology. A total of eight patients (8 %) developed recurrent disease, all of whom had PDAC on final pathology.

CONCLUSION

EUS is a helpful modality for the diagnostic evaluation of SDIPMN. Considering the high incidence of malignancy as well as high-grade dysplasia in SDIPMN greater than 2 cm, EUS features should be used in conjunction with other clinical criteria to guide management decisions. Patients with SDIPMN greater than 2 cm that do not undergo surgical resection may benefit from more intensive surveillance.

Intraductal papillary mucinous neoplasm of the pancreas: an update

Intraductal papillary mucinous neoplasm (IPMN) is a cystic tumor of the pancreas. The etiology is unknown, but increasing evidence suggests the involvement of several tumorigenesis pathways, including an association with hereditary syndromes. IPMN occurs more commonly in men, with the mean age at diagnosis between 64 and 67 years old. At the time of diagnosis, it may be benign, with or without dysplasia, or frankly malignant with an invasive carcinoma. Tumors arising from the main pancreatic duct are termed main-duct IPMNs, those involving the branch ducts, branch-duct IPMNs. In general, small branch-duct IPMNs are benign, particularly in asymptomatic patients, and can be safely followed. In contrast, main-duct tumors should be surgically resected and examined carefully for an invasive component. In the absence of invasion, patient's survival is excellent, from 94 to 100%. For patients with an IPMN-associated invasive carcinoma, the prognosis overall is better than those with a de novo pancreatic ductal adenocarcinoma, with a 5-year survival of 40% to 60% in some series. However, no survival advantage can be demonstrated if the invasive component in an IPMN patient is that of the conventional tubular type (versus mucinous carcinoma). Several histomorphologic variants are recognized, although the clinical significance of this "subtyping" is not well defined.

Duodenum-preserving total pancreatic head resection for benign cystic neoplastic lesions

BACKGROUND

Cystic neoplasms of the pancreas are diagnosed frequently due to early use of abdominal imaging techniques. Intraductal papillary mucinous neoplasm, mucinous cystic neoplasm, and serous pseudopapillary neoplasia are considered pre-cancerous lesions because of frequent transformation to cancer. Complete surgical resection of the benign lesion is a pancreatic cancer preventive treatment.

OBJECTIVES

The application for a limited surgical resection for the benign lesions is increasingly used to reduce the surgical trauma with a short- and long-term benefit compared to major surgical procedures. Duodenum-preserving total pancreatic head resection introduced for inflammatory tumors in the pancreatic head transfers to the patient with a benign cystic lesion located in the pancreatic head, the advantages of a minimalized surgical treatment.

PATIENTS

Based on the experience of 17 patients treated for cystic neoplastic lesions with duodenum-preserving total pancreatic head resection, the surgical technique of total pancreatic head resection for adenoma, borderline tumors, and carcinoma in situ of cystic neoplasm is presented. A segmental resection of the peripapillary duodenum is recommended in case of suspected tissue ischemia of the peripapillary duodenum. In 305 patients, collected from the literature by PubMed search, in about 40% of the patients a segmental resection of the duodenum and 60% a duodenum and common bile duct-preserving total pancreatic head resection has been performed.

RESULTS

Hospital mortality of the 17 patients was 0%. In 305 patients collected, the hospital mortality was 0.65%, 13.2% experienced a delay of gastric emptying and a pancreatic fistula in 18.2%. Recurrence of the disease was 1.5%. Thirty-two of 175 patients had carcinoma in situ.

CONCLUSION

Duodenum-preserving total pancreatic head resection for benign cystic neoplastic lesions is a safe surgical procedure with low post-operative morbidity and mortality.

Protein-protein interaction and SNP analysis in intraductal papillary mucinous neoplasm

Intraductal papillary mucinous neoplasm (IPMN) is a type of tumor that grows within the pancreatic ducts. It is a progress from hyperplasia to intraductal adenoma (IPMA), to noninvasive carcinoma, and ultimately to invasive carcinoma (IPMC). The objective of this study was to explore the molecular mechanism of the progression from IPMA to IPMC. By using the GSE19650 affymetrix microarray data accessible from Gene Expression Omnibus (GEO) database, we first identified the differentially expressed genes (DEGs) between IPMA and IPMC, followed by the protein-protein interaction and single-nucleotide polymorphism (SNP) analysis of the DEGs. Our study identified thousands of DEGs which involved regulation of cell cycle and apoptosis in this progression from IPMA to IPMC. Protein-protein interaction network construction found that MYC, IL6ST, NR3C1, CREBBP, GATA1 and LRP1 might play an important role in the progression. Furthermore, the SNP analysis confirmed the association between BRAC1 and pancreas cancer. In conclusion, our data provide a comprehensive bioinformatics analysis of genes and pathways which may be involved in the progression of IPMN from IPMA to IPMC.

The clinical relevance of the increasing incidence of intraductal papillary mucinous neoplasm

BACKGROUND & AIMS

The incidence of intraductal papillary mucinous neoplasm (IPMN) is believed to be increasing; we investigated whether this is the result of increasing burden of disease or more diagnostic scrutiny.

METHODS

In a retrospective cohort study, we calculated a trend in reported incidence of IPMN using data collected from Olmsted County, Minnesota, from 1985 to 2005. Total IPMN cases from the Olmsted database were identified through a keyword and International Classification of Diseases, 9th revision, search using a database from the Rochester Epidemiology Project, with all cases verified by subsequent chart review. The subsequent rate of IPMN-related carcinoma was calculated using data from the national Surveillance Epidemiology and End Results-9 database, reflecting trends from 1982 to 2007. Cases of IPMN-related carcinoma were identified in the Surveillance Epidemiology and End Results-9 database by limiting the search to histology codes for noninvasive and invasive IPMN.

RESULTS

Between 1985 and 2005, there was a 14-fold increase in the age- and sex-adjusted incidence of IPMN, from 0.31 to 4.35 per 100,000 persons. From 2000 to 2001, the rate of reported carcinoma increased from 0.008 to 0.032 per 100,000 persons, but stabilized afterward, with a rate of 0.06 per 100,000 persons in 2007. Mortality from all causes of pancreatic cancer was stable between 1975 and 2007 (approximately 11 deaths per 100,000 individuals).

CONCLUSIONS

The incidence of IPMN has increased in the absence of an increase in IPMN-related or overall pancreatic cancer-related mortality, so it likely results from an increase in diagnostic scrutiny, rather than greater numbers of patients with clinically relevant disease.

Outcomes of primary surveillance for intraductal papillary mucinous neoplasm

BACKGROUND

Limited data are available regarding the natural history of patients undergoing primary surveillance for intraductal papillary mucinous neoplasm (IPMN). We hypothesize that symptoms, radiologic characteristics, and cytopathology will predict cancer risk during surveillance.

METHODS

Between March 2002 and March 2010, 522 patients were diagnosed with IPMN at a single, high-volume institution. Low versus high oncologic risk was stratified prospectively. Patients with under 3 months of surveillance were excluded.

RESULTS

Two hundred ninety-two patients underwent primary surveillance for IPMN. Two hundred forty-four (84%) were classified as low-risk IPMN. Mean surveillance duration was 35 (4-99) months. Thirty (12%) patients initially stratified as low-risk developed a new indication for pancreatic resection. Only 28 underwent resection, and pathologic tissue analysis revealed 27 (96%) low-grade IPMN and one (4%) high-grade dysplastic IPMN. Overall, two (1%) patients initially determined to be low-risk developed invasive cancer. Forty-eight (16%) patients stratified as high-risk IPMN were initially managed nonoperatively. Of the 13 (27%) high-risk patients that died during follow-up, two (15%) died from pancreatic cancer.

CONCLUSIONS

Progression to pancreatic cancer during surveillance for low-risk IPMN was rare. Current indications for resection did not forecast malignancy. Poor operative candidates with high-risk IPMN progressed to invasive cancer more commonly, though a substantial portion succumbed to non-IPMN-related death.

Frequency of subtypes of biliary intraductal papillary mucinous neoplasm and their MUC1, MUC2, and DPC4 expression patterns differ from pancreatic intraductal papillary mucinous neoplasm

BACKGROUND

Biliary intraductal papillary mucinous neoplasm (B-IPMN) has been proposed as a unique clinicopathologic disease with distinct histopathologic features, although wide acceptance remains controversial. A recent consensus conference classified pancreatic IPMN (P-IPMN) into 4 subtypes (ie, gastric, intestinal, pancreatobiliary, oncocytic) based on morphologic appearance and mucin (MUC) staining properties. The aim of this study was to determine whether B-IPMN has similar histopathologic and immunologic subtypes to P-IPMN.

STUDY DESIGN

Specific immunostaining for MUC1, MUC2, and deleted for pancreas cancer, locus 4 were performed on specimens from 19 patients with a histopathologic diagnosis of B-IPMN. Immunostaining patterns of B-IPMN were correlated with histopathology.

RESULTS

Based on histopathology, the following subtypes of B-IPMN were identified: pancreatobiliary n = 9 (47%), intestinal n = 8 (42%), oncocytic n = 2 (11%), and gastric n = 0 (0%). Pancreatobiliary and oncocytic subtypes of B-IPMN were positive for MUC1 and negative for MUC2, and intestinal subtypes were positive for MUC2 and negative for MUC1. Thirteen of the 19 B-IPMN were associated with invasive carcinoma; loss of deleted for pancreas cancer, locus 4 was found in 6 of 13 invasive components and in 3 of 19 noninvasive components of B-IPMN. Five-year survival for patients with resected B-IPMN and invasive carcinoma was 38%, which is similar to that for resected P-IPMN with invasive carcinoma.

CONCLUSIONS

Histopathologic subtypes and type-specific MUC expression patterns of B-IPMN resemble those of P-IPMN. MUC1 expression and/or absence of MUC2 expression, which correlate with aggressive features of P-IPMN, were found in B-IPMN and correlate with invasive B-IPMN. Loss of deleted for pancreas cancer, locus 4 parallels the findings observed in P-IPMN. These findings provide additional support that B-IPMN is a unique entity with similarities to main duct P-IPMN.

Intraductal papillary mucinous neoplasia (IPMN) of the pancreas: its diagnosis, treatment, and prognosis

BACKGROUND

The many varieties of cystic pancreatic tumor, and especially intraductal papillary mucinous neoplasia (IPMN), have attracted increased attention recently. Their incidence may be rising, and their histopathological evaluation and classification have become more precise than before.

METHODS

We discuss the current diagnostic evaluation of IPMN, along with treatment and prognostication, on the basis of the current international guideline as well as pertinent literature retrieved by a selective PubMed search.

RESULTS

The preoperative diagnostic evaluation of IPMN is often problematic. In particular, it may not be possible to differentiate main-duct disease from branch-duct disease (MD-IPMN vs. BD-IPMN) before surgery--a distinction with implications for prognosis and treatment, as MD-IPMN is more often malignant. An IPMN adenoma can develop into invasive pancreatic cancer. Because firm diagnostic criteria are still lacking, it is recommended that all MD-IPMN lesions and all large BD-IPMN lesions should be resected. Partial pancreatectomy with clean margins is the treatment of choice.

CONCLUSION

As IPMN seems to be a slow-growing precursor of pancreatic cancer, it is possible that its early detection and surgical treatment can lead to a cure. No conclusion about the efficacy of surveillance and follow-up programs can be drawn from the available evidence. A better understanding of the natural course of IPMN and the biology of pancreatic cancer is needed to enable further improvements in diagnosis and treatment.

Branch-type intraductal papillary mucinous neoplasms: an update

BACKGROUND/AIMS

Branch-type intraductal papillary mucinous neoplasms (BT-IPMNs) are a subset of non-inflammatory mucinous lesions of the pancreas. Selected BT-IPMNs can be managed conservatively by surveillance because of their lower malignant potential. This review aims to update the reader on advances in our knowledge of BT-IPMNs since the consensus guidelines published in 2006.

METHODS

A Pubmed search for BT-IPMNs was undertaken and relevant papers were reviewed.

RESULTS

Due to the relative scarcity of this condition, still little is known about the natural history, the best method of surveillance or the surgical and non-surgical options.

CONCLUSION

A national database of BT-IPMNs would enable a large enough cohort of patients to be followed up and valid conclusions drawn regarding the best method of treatment or surveillance. and IAP.

Natural history of branch duct intraductal papillary mucinous neoplasms of the pancreas: a multicenter study in Japan

OBJECTIVE

The aim of this study was to evaluate the long-term follow-up results of patients with branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) without mural nodules (MNs) at 10 representative institutions in Japan.

METHODS

We analyzed 349 follow-up BD-IPMN patients who had no MNs on endoscopic ultrasonography at initial diagnosis.

RESULTS

Observation periods ranged from 1 to 16.3 years (median, 3.7 years). Sixty-two (17.8%) patients exhibited disease progression during follow-up. Twenty-two underwent surgery, leading to a pathological diagnosis of carcinoma in 9 and adenoma in 13. Although the remaining 287 (82.2%) showed no changes, 7 underwent surgery because of symptoms (n = 2), choice (n = 2), or development of pancreatic ductal adenocarcinoma (n = 3); all of them were diagnosed pathologically as adenomas. Of the 29 patients undergoing surgery, all 9 with carcinoma exhibited signs of progression, such as increased main pancreatic duct diameter and/or appearance of MNs. Pancreatic ductal adenocarcinomas and additional BD-IPMNs developed in 7 (2.0%) and 13 (3.7%), respectively. Overall, 320 (91.7%) patients were followed without surgery.

CONCLUSIONS

Most BD-IPMN patients who had no MNs on endoscopic ultrasonography could be managed without surgery. However, careful attention should be paid to disease progression and the development of pancreatic ductal adenocarcinomas during follow-up.

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.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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