A natural course of main duct intraductal papillary mucinous neoplasm of the pancreas with lower likelihood of malignancy

Predictors of malignancy in main duct intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND AND AIMS

The International Consensus Guidelines updated in 2017 recommended surgery to all main duct intraductal papillary mucinous neoplasms (MD-IPMNs) with the main pancreatic duct (MPD) of 10 mm or more and those with mural nodules regardless of size. The aim of the present study was to identify predictors of malignancy in MD-IPMN among preoperative factors including MPD and mural nodule size.

METHODS

Twenty-six benign MD-IPMNs (7 resected and 19 nonresected) and 32 malignant MD-IPMNs (31 resected and 1 nonresected) were included in the study. MRCP, CT, EUS, and cytology were performed using pancreatic juice collected by endoscopic retrograde pancrestography (ERP). Resected IPMNs were classified as benign or malignant by histologic examination and nonresected MD-IPMNs by imaging, cytology, and observation. Cutoff values of candidate parameters were determined by receiver operating characteristic curves. Univariate and multivariate analyses by regression model were performed.

RESULTS

MPD and mural nodule size and cytology results differed significantly between benign and malignant groups. Cutoff values of MPD and mural nodule sizes were 15 mm and 10 mm with areas under the curve of .66 and .86, respectively. Mural nodules of 10 mm or more (odds ratio, 8.32; 95% confidence interval, 1.13-61.2; P = .038) and positive cytology (odds ratio, 42.5; 95% confidence interval, 4.10-439; P = .002) were shown to be independent predictors of malignancy by multivariate analysis. When MD-IPMNs with either predictor were diagnosed to be malignant, sensitivities, specificities, and overall accuracy for malignancy were 94%, 85%, and 90%, respectively.

CONCLUSIONS

Mural nodules of 10 mm or more and positive cytology were independent predictors of malignancy in MD-IPMN.

Risk of the Watch-and-Wait Concept in Surgical Treatment of Intraductal Papillary Mucinous Neoplasm

Importance

The natural history of intraductal papillary mucinous neoplasms (IPMNs) remains uncertain. The inconsistencies among published guidelines preclude accurate decision-making. The outcomes and potential risks of a conservative watch-and-wait approach vs a surgical approach must be compared.

Objective

To provide an overview of the surgical management of IPMNs, focusing on the time of resection.

Design, Setting, and Participants

This cohort study was conducted in a single referral center; all patients with pathologically proven IPMN who received a pancreatic resection at the institution between October 2001 and December 2019 were analyzed. Preoperatively obtained images and the medical history were scrutinized for signs of progression and/or malignant features. The timeliness of resection was stratified into too early (adenoma and low-grade dysplasia), timely (intermediate-grade dysplasia and in situ carcinoma), and too late (invasive cancer). The perioperative characteristics and outcomes were compared between these groups.

Exposures

Timeliness of resection according to the final pathological findings.

Main Outcomes and Measures

The risk of malignant transformation at the final pathology.

Results

Of 1439 patients, 438 (30.4%) were assigned to the too early group, 504 (35.1%) to the timely group, and 497 (34.5%) to the too late group. Radiological criteria for malignant conditions were detected in 53 of 382 patients (13.9%), 149 of 432 patients (34.5%), and 341 of 385 patients (88.6%) in the too early, timely, and too late groups, respectively (P < .001). Patients in the too early group underwent more parenchyma-sparing resections (too early group, 123 of 438 [28.1%]; timely group, 40 of 504 [7.9%]; too late group, 5 of 497 [1.0%]; P < .001), while morbidity (too early group, 112 of 438 [25.6%]; timely group, 117 of 504 [23.2%]; too late group, 158 of 497 [31.8%]; P = .002) and mortality (too early group, 4 patients [0.9%]; timely, 4 [0.8%]; too late, 13 [2.6%]; P = .03) were highest in the too late group. Of the 497 patients in the too late group, 124 (24.9%) had a previous history of watch-and-wait care.

Conclusions and Relevance

Until the biology and progression patterns of IPMN are clarified and accurate guidelines established, a watch-and-wait policy should be applied with caution, especially in IPMN bearing a main-duct component. One-third of IPMNs reach the cancer stage before resection. At specialized referral centers, the risks of surgical morbidity and mortality are justifiable.

Clinical outcome of conservatively managed pancreatic intraductal papillary mucinous neoplasms with mural nodules and main duct dilation

BACKGROUND

Surgical resection of intraductal papillary mucinous neoplasm (IPMN) is strongly recommended for patients exhibiting high-risk stigmata (HRS). However, determining surgical indications for elderly patients with comorbidities is challenging, as clinical outcomes are not well characterized. This multicenter observational study elucidated the clinical outcomes of patients with IPMN exhibiting HRS who did not undergo surgery.

METHODS

This study enrolled 101 IPMN patients exhibiting HRS with follow-up observations at 11 hospitals in Japan (2011-2016). The median observation period was 37 months (maximum: 86 months). Primary outcomes were estimated 5-year overall survival (OS) and disease-specific survival (DSS). Survival was also stratified based on HRS features.

RESULTS

Of 101 patients, 32 (31.7%) had the main pancreatic duct (MPD) measuring ≥ 10 mm and 80 (79.2%) had mural nodules measuring ≥ 5 mm. The estimated 5-year OS and DSS were 74% and 91%, respectively. In the stratified analysis, the co-presence of MPD ≥ 10 mm and mural nodules ≥ 5 mm or mural nodule ≥ 10 mm were related to worse 5-year DSS (MPD ≥ 10 mm and mural nodules ≥ 5 mm vs other characteristics: 60% vs 95%, log-rank test: p = 0.049; mural nodules ≥ 10 mm vs < 10 mm: 77% vs 95%, log-rank test: p = 0.003).

CONCLUSIONS

The estimated 5-year DSS of conservatively managed IPMN patients with mural nodules and main duct dilation was 91%. Only IPMN patients with plural HRS or large nodule formation might have an increased mortality risk. This is an important insight that can help facilitate appropriate clinical decision-making, especially in the elderly or high-surgical risk IPMN patients.

Long-term follow-up of Branch-Duct Intraductal Papillary Mucinous Neoplasms with negative Sendai Criteria: the therapeutic challenge of patients who convert to positive Sendai Criteria

BACKGROUND

The management of Branch-Duct Intraductal Papillary Mucinous Neoplasm (BD-IPMN) is still controversial. Our objective was to assess the long-term follow-up (FU) of patients with "low-risk" BD-IPMN according to the Sendai-International Consensus Guidelines (ICG-I).

METHODS

We retrospectively analyzed a cohort of patients with BD-IPMN and Negative Sendai-Criteria (NSC) from January 2004 to October 2019. A univariate analysis was performed to determine factors associated with conversion to Positive Sendai-Criteria (PSC) and malignancy. Positive Predictive Value (PPV) and Negative Predictive Value (NPV) of the IGC-I were assessed for the development of malignancy.

RESULTS

A total of 219 patients were selected and underwent a median 58-month FU. Thirty-seven (17%) patients developed PSC during FU including 12 (5.5%) with malignant lesions. Conversely, 182 patients (83%) did not develop malignancy. The NPV and PPV of ICG-I for malignancy were 100% and 32.4%, respectively. Among patients who developed PSC, those with cancer were >65years (OR = 3.57;p = 0.015) and had significantly higher serum CA-19-9 levels (OR = 5.27;p = 0.007).

CONCLUSION

The ICG-I is a safe strategy for FU of patients with BD-IPMN. The absence of PSC exclude malignancy. Among patients who develops PSC, the risk of cancer remains low and surgery should be decided according to their surgical risk and life expectancy.

The Role of Positron Emission Tomography in Clinical Management of Intraductal Papillary Mucinous Neoplasms of the Pancreas

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas represent a heterogeneous group of tumors, increasingly diagnosed in clinical practice. An early differential diagnosis between malignant and benign lesions is crucial to patient management and the choice of surgery or observation. The therapeutic approach is currently based on a patient’s clinical, biochemical, and morphological characteristics. The latest published International Consensus Guidelines (ICG) make no mention of the role of metabolic assessments of IPMNs. The aim of this study was to review the current literature, examining the role of 18-fluorodeoxyglucose (FDG) positron emission tomography (PET) in IPMN management. An extensive literature review was conducted according to the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and 10 articles were analyzed in detail, focusing on the value of PET as opposed to other standard imaging criteria. Data were retrieved on 419 patients. The 18-FDG-PET proved more sensitive, specific, and accurate than the ICG criteria in detecting malignant IPMNs (reaching 80%, 95%, and 87% vs. 67%, 58%, and 63%, respectively). Metabolic assessments may be used as an additional tool for the appropriate management of patients with doubtful imaging findings.

The role of pancreatic juice cytology in the diagnosis of pancreatic intraductal papillary mucinous neoplasm

BACKGROUND AND AIM

pancreatic juice cytology (PJC) is an important predictor of malignant intraductal papillary mucinous neoplasm (IPMN). This study aimed to determine the role of PJC for the prediction of malignant IPMN (intraductal papillary mucinous cancer [IPMC]).

METHODS

medical records of IPMN patients who underwent surgery between 2012 and 2016 at the Nagasaki University Hospital were reviewed. Patients who underwent preoperative PJC were classified as high risk stigmata (HRS), worrisome features (WF) and no-criteria, based on imaging criteria. PJC class III or higher was considered as positive and only invasive IPMN was defined as IPMC. PJC was validated in each group with regard to sensitivity, specificity, accuracy with the corresponding 95% confidence intervals (95% CI) and area under receiver operating curve (AUROC) analysis. A p-value of < 0.05 was considered as statistically significant.

RESULTS

preoperative pancreatic juice was obtained in 33/52 IPMN patients; only patients with adequate aspirate for cytology (n = 29) were included. In the HRS group (n = 9), 4/6 non-IPMC had a negative PJC and 3/3 IPMC had a positive PJC. In the WF group (n = 17), 9/11 non-IPMC had a negative PJC and 3/6 IPMC had a positive PJC. Adding PJC to imaging results improved the AUROCs of HRS and WF from 0.63 and 0.62 to 0.83 and 0.66, respectively. PJC was negative in all no-criteria cases (n = 3; one IPMC and two non-IPMC). In all 29 patients, PJC sensitivity was 60% (95% CI: 26%-88%), specificity was 79% (95% CI: 54%-94%), accuracy was 72% (95% CI: 63%-89%) and the AUROC was 0.69 (p = 0.03).

CONCLUSION

PJC is a statistically significant IPMC predictor that can improve the validity of imaging for IPMC prediction.

Surgical management of intraductal papillary mucinous neoplasm with main duct involvement: an international expert survey and case-vignette study

BACKGROUND

The risk of invasive cancer in resected intraductal papillary mucinous neoplasm with main pancreatic duct involvement is 33%-60%. Most guidelines, therefore, advise resection of main duct intraductal papillary mucinous neoplasm and mixed type intraductal papillary mucinous neoplasm in surgically fit patients, although advice on the surgical strategy (partial or total pancreatectomy) differs. We performed a survey amongst international experts to guide the design of future studies and help to prepare for a single international set of guidelines.

METHODS

An online survey including case vignettes was sent to 221 international experts who had published on main duct/mixed type intraductal papillary mucinous neoplasm in the previous decade and to all surgeon and gastroenterologist members of the pancreatic cyst guideline committees of the European Study Group and the International Association of Pancreatology.

RESULTS

Overall, 97 experts (67 surgeons, 30 gastroenterologists) from 19 countries replied (44% response rate). Most (93%) worked in an academic hospital, with a median of 15 years' experience with intraductal papillary mucinous neoplasm treatment. In main duct/mixed type intraductal papillary mucinous neoplasm patients with pancreatic duct dilation (>5 mm) in the entire pancreas, 41% (n = 37) advised nonoperative surveillance every 3-6 months, whereas 59% (n = 54) advised operative intervention. Of those who advised operative intervention, 46% (n = 25) would perform a total pancreatectomy and 31% (n = 17) pancreatoduodenectomy with follow-up. No structural differences in advice were seen between surgeons and gastroenterologists, between continents where the respondents lived, and based on years of experience.

CONCLUSION

This international survey identified a clinically relevant lack of consensus in the treatment strategy in main duct/mixed type intraductal papillary mucinous neoplasm among experts. Studies with long-term follow-up including quality of life after partial and total pancreatectomy for main duct/mixed type intraductal papillary mucinous neoplasm are required.

Meta-analysis of mortality in patients with high-risk intraductal papillary mucinous neoplasms under observation

BACKGROUND

Although consensus guidelines suggest that patients with high-risk intraductal papillary mucinous neoplasms (IPMNs) should have surgery, a non-operative strategy is often selected in patients who are poor surgical candidates. The aim was to determine the risk of disease-related death from IPMN in patients with worrisome features or high-risk stigmata who were kept under observation.

METHODS

A PubMed literature search was undertaken of articles published from August 1992 to June 2016 (updated October 2017). The methodology was developed from PRISMA and MOOSE checklists. Incidence proportions and rates of overall and IPMN-related deaths were calculated, with subgroup analyses for main-duct/mixed-type and branch-duct IPMNs. Quality of the studies, publication bias and heterogeneity were explored.

RESULTS

Six studies reported data on overall mortality and eight described disease-specific mortality for 556 patients during follow-up ranging from 24·9 to 60·0 months. Pooled rates of overall and IPMN-related mortality were 30·9 (95 per cent c.i. 19·6 to 45·1) and 11·6 (6·0 to 21·2) per cent respectively. The pooled incidence rate for overall mortality was substantially higher than that for IPMN-related mortality: 78 (95 per cent c.i. 44 to 111) and 23 (9 to 37) per 1000 patient-years respectively. The pooled incidence rate for disease-specific mortality was considerably lower for branch-duct than for main-duct or mixed-type IPMNs: 5 (0 to 10) and 32 (12 to 52) per 1000 patient-years respectively.

CONCLUSION

In patients unfit for surgery, IPMN-related mortality among patients with worrisome features and high-risk stigmata is low, and the risk of death from other causes much higher.

Progression of Unresected Intraductal Papillary Mucinous Neoplasms of the Pancreas to Cancer: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

It is not clear how best to manage patients with low-risk intraductal papillary mucinous neoplasms (IPMNs) of the pancreas because little is known about IPMN progression to cancer. We sought to determine the cumulative incidence of development of pancreatic cancer in persons with unresected IPMNs (particularly low-risk IPMNs).

METHODS

We performed a systematic search of the MEDLINE and Embase databases through November 30, 2016 for studies reporting the cumulative incidence of pancreatic cancer in patients with unresected IPMNs or studies that provided data in sufficient detail for us to calculate cumulative incidence values. We categorized patient series as studies on low-risk IPMNs (lesions without main pancreatic duct involvement or mural nodules) or non-low-risk IPMNs. We calculated meta-analytic cumulative incidence values for pancreatic cancer at 1, 3, 5, and 10 years of follow-up by using the inverse variance method and random-effects model.

RESULTS

Among 1514 articles screened, we identified 10 studies of low-risk IPMNs (n = 2411) and 9 studies of non-low-risk IPMNs (n = 825). In studies of low-risk IPMNs, the meta-analytic cumulative incidence values for pancreatic cancer were 0.02% at 1 year (95% confidence interval [CI], 0.0%-0.23%; I²= 0.0%), 1.40% at 3 years (95% CI, 0.58%-2.48%; I² = 58.5%), 3.12% at 5 years (95% CI, 1.12%-5.90%; I² = 88.0%), and 7.77% at 10 years (95% CI, 4.09%-12.39%; I² = 79.8%). These values were much higher in studies of non-low-risk IPMNs; cumulative incidence values for pancreatic cancer were 1.95% at 1 year (95% CI, 0.0%-5.99%; I² = 84.2%), 5.69% at 3 years (95% CI, 1.10%-12.77%; I² = 89.9%), 9.77% at 5 years (95% CI, 3.04%-19.27%; I² = 92.0%), and 24.68% at 10 years (95% CI, 14.87%-35.90%; I² = 74.3%). The pooled cumulative incidence steadily increased linearly as the follow-up duration increased.

CONCLUSIONS

In a systematic review and meta-analysis, we found that low-risk IPMNs have almost 8% chance of progressing to pancreatic cancer within 10 years, and higher-risk IPMNs have almost 25% chance of progressing to cancer in 10 years; incidence values increase linearly with time. Continued long-term surveillance is therefore vital for patients with low-risk IPMNs.

Duodenum and ventral pancreas preserving subtotal pancreatectomy for low-grade malignant neoplasms of the pancreas: An alternative procedure to total pancreatectomy for low-grade pancreatic neoplasms

AIM

To describe the indications, technique and outcomes of the novel surgical procedure of duodenum and ventral pancreas preserving subtotal pancreatectomy (DVPPSP).

METHODS

Data collected retrospectively from 43 patients who underwent DVPPSP and TP between 2009 and 2015 in our single centre were analysed. For enrolment, only patients with low-grade pancreatic neoplasms, such as pancreatic neuroendocrine tumors, intraductal papillary mucinous neoplasms (IPMNs), and solid pseudo-papillary tumors, were included. Ten DVPPSP (group 1) and 13 TP (group 2) patients were selected in this study.

RESULTS

There were no significant differences in age, gender, comorbidities, preoperative symptoms, American Society of Anesthesiologists score or indications for surgery between the two groups. The most common indication was IPMN for DVPPSP and TP (60% vs 85%, P = 0.411). Compared with the TP group, the DVPPSP group had comparable postoperative morbidities (P = 0.405) and mortalities (both nil), but significantly shorter operative time (232 ± 19.6 min vs 335 ± 32.3 min, P < 0.001). DVPPSP preserved better long-term pancreatic function with less supplementary therapy (P < 0.001) and better quality of life (QoL) after surgery, including better scores in social (P = 0.042) and global health (P = 0.047) on functional scales and less appetite loss (P = 0.049) on the symptom scale.

CONCLUSION

DVPPSP is a feasible and safe procedure that could be an alternative to TP for low-grade neoplasms arising from the body and tail region but across the neck region of the pancreas; DVPPSP had better metabolic function and QoL after surgery.

Natural History of Pancreatic Cysts

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

Comparing 3 guidelines on the management of surgically removed pancreatic cysts with regard to pathological outcome

BACKGROUND AND AIMS

Currently, 3 guidelines are available for the management of pancreatic cysts. These guidelines vary in their indication for resection of high-risk cysts. We retrospectively compared the final pathologic outcome of surgically removed pancreatic cysts with the indications for resection according to 3 different guidelines.

METHODS

Patients who underwent pancreatic resection were extracted from our prospective pancreatic cyst database (2006-present). The final histopathologic diagnosis was compared with the initial indication for surgery stated by the guidelines of the International Association of Pancreatology (IAP), European Study Group on Cystic tumors of the Pancreas and American Gastroenterological Association (AGA). We considered surgery in retrospect justified for malignancy, high-grade dysplasia, solid pseudopapillary neoplasms, neuroendocrine tumors or symptom improvement. Furthermore, we evaluated the patients with suspected intraductal papillary mucinous neoplasm (IPMN) separately.

RESULTS

Overall, 115 patients underwent pancreatic resection. The preoperative diagnosis was correct in 83 of 115 patients (72%) and differentiation between benign and premalignant in 99 of 115 patients (86%). In retrospect, surgery was justified according to the aforementioned criteria in 52 of 115 patients (45%). For patients with suspected IPMN (n = 75) resection was justified in 36 of 67 (54%), 36 of 68 (53%), and 32 of 54 (59%) of patients who would have had surgery based on the IAP, European, or AGA guidelines, respectively. The AGA guideline would have avoided resection in 21 of 75 (28%) patients, versus 8 of 75 (11%) and 7 of 75 (9%) when the IAP or European guideline would have been applied strictly. Nevertheless, 4 of 33 patients (12%) with high-grade dysplasia or malignancy would have been missed with the AGA guidelines, compared with none with the IAP or European guidelines.

CONCLUSION

Although fewer patients undergo unnecessary surgery based on the AGA guidelines, the risk of missing malignancy or high-grade dysplasia with this guideline seems considerably high.

Low progression of intraductal papillary mucinous neoplasms with worrisome features and high-risk stigmata undergoing non-operative management: a mid-term follow-up analysis

OBJECTIVE

To evaluate mid-term outcomes and predictors of survival in non-operated patients with pancreatic intraductal papillary mucinous neoplasms (IPMNs) with worrisome features or high-risk stigmata as defined by International Consensus Guidelines for IPMN. Reasons for non-surgical options were physicians' recommendation, patient personal choice or comorbidities precluding surgery.

METHODS

In this retrospective, multicentre analysis, IPMNs were classified as branch duct (BD) and main duct (MD), the latter including mixed IPMNs. Univariate and multivariate analysis for overall survival (OS) and disease-specific survival (DSS) were obtained.

RESULTS

Of 281 patients identified, 159 (57%) had BD-IPMNs and 122 (43%) had MD-IPMNs; 50 (18%) had high-risk stigmata and 231 (82%) had worrisome features. Median follow-up was 51 months. The 5-year OS and DSS for the entire cohort were 81% and 89.9%. An invasive pancreatic malignancy developed in 34 patients (12%); 31 had invasive IPMNs (11%) and 3 had IPMN-distinct pancreatic ductal adenocarcinoma (1%). Independent predictors of poor DSS in the entire cohort were age >70 years, atypical/malignant cyst fluid cytology, jaundice and MD >15 mm. Compared with MD-IPMNs, BD-IPMNs had significantly better 5-year OS (86% vs 74.1%, p=0.002) and DSS (97% vs 81.2%, p<0.0001). Patients with worrisome features had better 5-year DSS compared with those with high-risk stigmata (96.2% vs 60.2%, p<0.0001).

CONCLUSIONS

In elderly patients with IPMNs that have worrisome features, the 5-year DSS is 96%, suggesting that conservative management is appropriate. By contrast, presence of high-risk stigmata is associated with a 40% risk of IPMN-related death, reinforcing that surgical resection should be offered to fit patients.

Cystic pancreatic lesions: From increased diagnosis rate to new dilemmas

Cystic pancreatic lesions vary from benign to malignant entities and are increasingly detected on cross-sectional imaging. Knowledge of the imaging appearances of cystic pancreatic lesions may help radiologists in their diagnostic reporting and management. In this review, we discuss the morphologic classification of these lesions based on a diagnostic algorithm as well as the management of these lesions.

Risk Factors for Progression or Malignancy in Main-Duct and Mixed-Type Intraductal Papillary Mucinous Neoplasm of the Pancreas

OBJECTIVES

The 2012 international guidelines state that surgery should be considered for all surgically fit patients with pancreatic main-duct (MD)/mixed intraductal papillary mucinous neoplasms (IPMNs). This study evaluated the follow-up results of MD/mixed IPMNs and risk factors for progression or malignancy.

METHODS

Patients with MD/mixed IPMNs were retrospectively enrolled and divided into surgical and nonsurgical groups. These 2 groups were compared and further categorized as progression/malignancy or not. In the nonsurgical group, disease progression was defined as radiologic tumor growth or adjacent organ invasion.

RESULTS

Data from 101 patients (73 males; mean [SD] age, 66.3 [9.1] years), including 27 and 74 in the nonsurgical and surgical groups, respectively, were analyzed. Mural nodules were more frequently detected in the surgical group (7.4% vs 31.1%, P = 0.018), whereas more multifocal cysts were observed in the nonsurgical group (40.7% vs 20.3%, P = 0.037). Forty-one patients (40.6%) showed progression or malignancy. Multivariate analysis showed that main pancreatic duct of 10 mm or greater (odds ratio, 4.368; P = 0.024) and pre-existing diabetes (odds ratio, 3.077; P = 0.046) were independent risk factors for progression or malignancy.

CONCLUSIONS

A watchful waiting strategy could be feasible for some patients with MD/mixed IPMNs, particularly those with a main pancreatic duct of less than 10 mm and without diabetes.

Pancreatic juice cytology as sensitive test for detecting pancreatic malignancy in intraductal papillary mucinous neoplasm of the pancreas without mural nodule

OBJECTIVE

Recent studies reported that mural nodule (MN) was the most associated with malignant intraductal papillary mucinous neoplasms (IPMNs). However, IPMNs without MN cannot be diagnosed as malignant if only MN is determined to be indicator of malignancy. This study aimed to investigate role of pancreatic juice cytology for IPMNs without MN.

METHODS

Medical records of 50 patients with histologically proven malignant IPMNs were reviewed. Exclusively for non-invasive cancer, extent of high-grade dysplasia along the main pancreatic duct (MPD) was determined microscopically.

RESULTS

Thirty-six percent IPMNs had no MN. Cyst and main MPD diameter were significantly smaller in IPMN without MN compared to those in IPMN with MN (23 ± 14.1 vs 35 ± 13.2 mm, p = 0.010; 6.6 ± 4.3 vs 10.9 ± 6.1 mm, p = 0.006). Sensitivity of pancreatic juice cytology was higher in IPMN without MN compared to that in IPMN with MN (94% vs 53%, p = 0.004) although it could be affected by selection bias of study patients. Absence of MN was determined to be an independent factor associated with true positive cytology (OR = 24.3, p = 0.005). Extent of high-grade dysplasia was significantly longer in IPMN with true positive cytology compared to that in IPMN with false negative cytology (46.8 ± 20.5 vs 26.4 ± 11.0 mm, p = 0.005), and tended to be longer in IPMN without MN compared to that in IPMN with MN (47.0 ± 19.0 vs 36.0 ± 20.1 mm, p = 0.16).

CONCLUSIONS

Sensitivity of pancreatic juice cytology was excellent in IPMN without MN. Pancreatic juice cytology may be a sensitive test for detection of pancreatic malignancy in IPMN without MN compared to high-risk imaging features.

Validation of the 2012 International Consensus Guidelines Using Computed Tomography and Magnetic Resonance Imaging: Branch Duct and Main Duct Intraductal Papillary Mucinous Neoplasms of the Pancreas

OBJECTIVE

To validate the 2012 guidelines for intraductal papillary mucinous neoplasm (IPMN) of the pancreas and to compare diagnostic performances of computed tomography (CT) and magnetic resonance imaging (MRI) for differentiating malignant from benign IPMN.

BACKGROUND

As IPMN has variable risks of malignancy and management of this entity is closely related to its malignant potential, it is important to predict risks of IPMN malignancy.

METHODS

This retrospective study included 158 patients with surgically confirmed IPMN of the pancreas who underwent both preoperative CT and MRI. Two radiologists evaluated the "high-risk stigmata" and "worrisome features" of the 2012 guidelines for branch duct (BD)-IPMN and main duct (MD)-IPMN. Univariate and multivariable analyses were used to identify significant predictors of malignancy in IPMN. The diagnostic performance was compared between CT and MRI.

RESULTS

Malignant IPMN was seen in 8 of 60 patients (13.3%) with BD-IPMN and 44 of 98 patients (44.9%) with MD-IPMN. Presence of mural nodule was the most important predictor in BD-IPMN and MD-IPMN (odds ratios, 9.2 and 7.6, respectively, P = 0.01 on CT; and odds ratios, 5.7 and 13.3, respectively, P ≤ 0.04 on MRI), whereas mural nodule size and lymphadenopathy were significant only in MD-IPMN (P < 0.05). The diagnostic performance of CT and MRI for significant findings was not statistically different in both types of IPMN (P > 0.34).

CONCLUSIONS

The presence of mural nodule was the most important predictor of malignancy in both types of IPMN. Mural nodule size and lymphadenopathy were also significant predictors in MD-IPMN. Computed tomography and MRI showed similar diagnostic performances for differentiating malignant from benign IPMN.

Mural nodule of 10 mm or larger as predictor of malignancy for intraductal papillary mucinous neoplasm of the pancreas: Pathological and radiological evaluations

BACKGROUND

We had previously reported that mural nodule (MN) ≥10 mm was optimal predictor of malignancy for intraductal papillary mucinous neoplasm (IPMN). However, little is known about its microscopic findings and imaging detectability.

METHODS

Medical records and resected specimens of consecutive patients with IPMNs harboring MN ≥ 10 mm were reviewed. Imaging detectability was determined on reports basis. Malignant IPMNs (noninvasive + invasive carcinomas) were microscopically classified according to localization of high-grade dysplasia (HGD) within MN.

RESULTS

Thirty-six patients were included. Imaging detectability of MN ≥ 10 mm in CT, MRI, US and EUS were 64%, 68%, 89%, and 97%, respectively. Thirty-three (92%) IPMNs were histologically diagnosed as malignant. Thirty percent of malignant IPMNs were classified into "diffuse HGD within MN", 40% into "focal HGD within MN", and 30% into "HGD outside MN", in which HGD was not located within MN but in low papillary epithelia around MN. Overall sensitivity of pancreatic juice cytology was calculated as 58%, and for "diffuse HGD within MN", "focal HGD within MN", and "HGD outside MN" as 80%, 62%, and 30%, respectively (p = 0.0237). Univariate-analysis showed localization of HGD within MN was associated with true positive cytology (OR = 5.33, p = 0.043).

CONCLUSIONS

Detectability of MN ≥ 10 mm is excellent in US and EUS. Although HGD is observed within MN in 70% of malignant IPMNs, HGD is located only in low papillary epithelia around MN in the remaining 30%, in which sensitivity of pancreatic juice cytology is shown to be inadequate.

Intraductal papillary mucinous neoplasms

PURPOSE OF REVIEW

Our understanding of intraductal papillary mucinous neoplasm (IPMN) of the pancreas has remarkably grown within the last decade; nonetheless there is still an ongoing controversy if the majority of these potentially malignant neoplasms need to be resected or if observation in a subset is well tolerated.

RECENT FINDINGS

Novel cyst fluid biomarkers, like Gnas mutations or mab DAS-1, could play a pivotal role in the distinction of IPMN vs. other cystic lesions, in the sub-classification of IPMN and in the detection of IPMN with high-grade dysplasia or invasive cancer. Other recent studies focused on natural history of minimal- and extensive-mixed IPMN and the safety of the 2012 AIP guidelines. Small series also described that observation can be an option in selected frail patients with MD-IPMN. Further, data from a large European multicenter study analysis indicated that patients with IPMN do not have an increased frequency of extrapancreatic malignancies.

SUMMARY

Increasing knowledge about the nature of IPMN and their subtypes has resulted in an individualized approach in diagnosis and treatment. Owing to the availability of accurate diagnostic instruments, timing and indication for pancreatic resection have become more selective, sparing patients with harmless IPMN from major surgery.

Imaging morphological changes of intraductal papillary mucinous neoplasm of the pancreas was associated with its malignant transformation but not with development of pancreatic ductal adenocarcinoma

BACKGROUND/OBJECTIVE

A considerable number of branch duct intraductal papillary mucinous neoplasm (BD-IPMN) developed not infrequently pancreatic malignancy, either as part of IPMN (malignant IPMN) or as concomitant pancreatic ductal adenocarcinoma (PDAC). To date, imaging morphological changes predicting occurrence of malignancy in BD-IPMN are not well-investigated. This study aimed to evaluate the relationships between occurrence of malignancy in BD-IPMN and imaging morphological changes of the tumors observed during follow-up.

METHODS

515 BD-IPMN patients with mural nodule <10 mm and negative cytology were included. 19 patients developed malignant IPMN and 8 patients developed concomitant PDAC during mean follow-up of 4.7 years. The following imaging morphological features were assessed: cyst/main pancreatic duct (MPD) diameter, occurrence of additional cyst/mural nodule.

RESULTS

Growth rate of cyst/MPD diameter were significantly larger in patients who developed malignant IPMN compared to those in patients whose IPMN remained benign (p = 0.013, p = 0.01). Occurrence of additional cyst/mural nodule were more frequently observed in patients who developed malignant IPMN (p = 0.009, p = 0.04). In contrast, none of the factors associated with imaging morphological changes of IPMN were shown to be significantly different between patients who developed concomitant PDAC and patients whose IPMN remained benign. Growth rate of MPD diameter and occurrence of additional cyst were independent factors associated with development of malignant IPMN (odds ratio 21.5, and 5.62, respectively).

CONCLUSIONS

Imaging morphological changes of IPMN, such as growth rate of MPD diameter and occurrence of additional cyst, could be indicators for development of malignant IPMN, but not for development of concomitant PDAC.

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.

The natural history of main duct-involved, mixed-type intraductal papillary mucinous neoplasm: parameters predictive of progression

OBJECTIVE

As such, the natural history of MPD-involved IPMN is poorly understood.

BACKGROUND

The high-risk of malignancy associated with main pancreatic duct (MPD)-involved intraductal papillary mucinous neoplasm (IPMN) has been established by surgical series. The International Consensus Guidelines recommend surgical resection of MPD-involved IPMN in fit patients.

METHODS

A review of a prospectively collected database (1992-2012) of patients with IPMN undergoing primary surveillance was performed. Invasive progression was defined as invasive carcinoma on pathology and/or positive cytopathology. Analyses included univariate, logistic regression, and receiver operating characteristic curve analyses.

RESULTS

A total of 503 patients with IPMN underwent primary surveillance, 70 for MPD-involved, mixed-type IPMN. Indications for intensive surveillance of these 70 high-risk patients were comorbidities, patient choice, and early/borderline MPD dilation (42%, 51%, and 7%, respectively). Mean follow-up was 4.7 years. Nine patients (13%) progressed at a mean of 3.5 (range, 1-9) years during follow-up. Univariate analyses yielded weight loss, interval (from isolated branch-duct IPMN) to MPD involvement, diffuse MPD dilation, increase of MPD diameter, absence of extra pancreatic cysts, elevated serum CA19-9 levels, and elevated serum alkaline phosphatase levels as significant. Maximum MPD and/or branch-duct diameter were not significant. In logistic regression, diffuse MPD dilation, serum CA19-9 and serum alkaline phosphatase levels, and absence of extra pancreatic cysts were predictors of invasiveness. The receiver operating characteristic curve indicated that the combination of these 4 factors achieved an accuracy of 98% in predicting progression.

CONCLUSIONS

Primary surveillance of mixed-type IPMN may be a reasonable strategy in select patients. Diffuse MPD dilation, serum CA19-9, serum alkaline phosphatase, and absence of extrapancreatic cysts predict patients likely to progress during primary surveillance.

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

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

Nonoperative management of main pancreatic duct-involved intraductal papillary mucinous neoplasm might be indicated in select patients

BACKGROUND

Although the natural history of intraductal papillary mucinous neoplasm (IPMN) remains unclear, large surgical series have reported malignancy in 40% to 90% of main pancreatic duct (MPD)-involved IPMN. Accordingly, the 2012 International Consensus Guidelines recommend surgical resection in patients with suspected MPD involvement. We hypothesized that nonoperative management of select patients with suspected MPD-involved IPMN might be indicated.

STUDY DESIGN

From 1992 to 2012, 362 patients underwent surgical resection for pathologically confirmed IPMN at a single academic center. A retrospective review of prospectively collected data was performed. Main pancreatic duct involvement was suspected with an MPD diameter ≥5 mm on preoperative imaging. A multivariate analysis was conducted to assess predictors of malignancy.

RESULTS

Of 362 patients, 334 had complete data for analysis. Main pancreatic duct involvement was suspected preoperatively in 171 patients. Final pathology revealed 20% high-grade dysplastic and 27% invasive IPMN (47% malignant). Preoperative cytopathology and serum carbohydrate antigen 19-9 independently predicted malignancy (p = 0.003 and p = 0.002, respectively) and invasiveness (p < 0.0001 and p = 0.001, respectively). Patients with both negative preoperative cytopathology and normal serum carbohydrate antigen 19-9 (ie, double negatives) had a lower rate of malignancy and invasiveness (28% and 8% vs 58% and 38%; p < 0.0001). The MPD diameter did not predict malignancy or invasiveness (p = 0.36 and p = 0.46, respectively).

CONCLUSIONS

Patients with suspected MPD-involved IPMN have a highly variable rate of malignancy. Despite recent International Consensus Guidelines recommendations, these data suggest that MPD diameter is not an optimal gauge of malignant risk. Nonoperative management of suspected MPD-involved IPMN in select patients, particularly double negatives, might be indicated. Depending on age and comorbidity, operative risk might outweigh the risk of malignant progression in these patients.

Evaluation of the Sendai and 2012 International Consensus Guidelines based on cross-sectional imaging findings performed for the initial triage of mucinous cystic lesions of the pancreas: a single institution experience with 114 surgically treated patients

BACKGROUND

The Sendai Consensus Guidelines (SCG) were formulated in 2006 to guide the management of mucinous cystic lesions of the pancreas (CLPs) and were updated in 2012 (International Consensus Guidelines, ICG 2012). This study aims to evaluate the clinical utility of the ICG 2012 with the SCG based on initial cross-sectional imaging findings.

METHODS

One hundred fourteen patients with mucinous CLPs were reviewed and classified according to the ICG 2012 as high risk (HR(ICG2012)), worrisome (W(ICG2012)), and low risk (LR(ICG2012)), and according to the SCG as high risk (HR(SCG)) and low risk (LR(SCG)).

RESULTS

On univariate analysis, the presence of symptoms, obstructive jaundice, elevated serum carcinoembryonic antigen (CEA)/carbohydrate antigen (CA)19-9, solid component, main pancreatic duct ≥ 10 mm, and main pancreatic duct ≥ 5 mm was associated with high grade dysplasia/invasive carcinoma in all mucinous CLPs. Increasing number of HR(SCG) or HR(ICG2012) features was associated with a significantly increased likelihood of malignancy. The positive predictive value of HR(SCG) and HR(ICG2012) for high grade dysplasia/invasive carcinoma was 46% and 62.5% respectively. The negative predictive value of both LR(SCG) and LR(ICG2012) was 100%.

CONCLUSION

Both the guidelines were useful in the initial cross-sectional imaging evaluation of mucinous CLPs. The ICG 2012 guidelines were superior to the SCG guidelines.

Potential predictors of disease progression for main-duct intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND AND AIM

The evidence for main pancreatic duct intraductal papillary mucinous neoplasms (MPD-IPMN) malignancy is based predominantly on investigation of resected cases, and the natural history is still unclear. The aim of the present study is to investigate the natural history of MPD-IPMN and examine potential predictors of disease progression in MPD-IPMN patients who conformed to "high-risk stigmata" criteria.

METHODS

This study included consecutive 20 follow-up patients and 19 surgical patients with "high-risk stigmata" MPD-IPMN, in whom the diameter of the MPD was > 10 mm, branch duct was < 5 mm, and who underwent clinical follow up for ≥ 2 years.

RESULTS

Among surgical patients, mural nodules and MPD diameter of invasive patients were significantly different compared with non-invasive patients. On the other hand, among follow-up patients, univariate analysis revealed the following potential predictors for disease progression: diameter of MPD ≥ 15 mm (hazard ratio [HR], 20.9; 95% confidence interval [CI], 2.59-173.4; P < 0.01); and diffuse lesions of MPD-IPMN (HR, 4.46; 95% CI, 1.10-18.0; P = 0.04). On the other hand, multivariate analysis identified only diameter of MPD ≥ 15 mm (HR, 19.2; 95% CI, 1.87-198.5; P = 0.01) as a potential predictor of disease progression.

CONCLUSION

If MPD-IPMN patients have other severe complications or reasons for not undergoing surgical treatment, MPD diameter < 15 mm, negative cytology, and no mural nodules, conservative clinical follow up for several years may be an option.

Quality of life in patients after total pancreatectomy is comparable with quality of life in patients who undergo a partial pancreatic resection

BACKGROUND

Quality of life after total pancreatectomy (TP) is perceived to be poor secondary to insulin-dependent diabetes and pancreatic insufficiency. As a result, surgeons may be reluctant to offer TP for benign and premalignant pancreatic diseases.

METHODS

We retrospectively reviewed presenting features, operative characteristics, and postoperative outcomes of all patients who underwent TP at our institution. Quality of life was assessed using institutional questionnaires and validated general, pancreatic disease-related, and diabetes-related instruments (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire [EORTC QLQ-C30 and module EORTC-PAN26], Audit of Diabetes Dependent Quality of Life), and compared with frequency-matched controls, patients after a pancreaticoduodenectomy (PD). Continuous variables were compared using Student t-test or analysis of variance. Categorical variables were compared using χ(2) or Fisher exact test.

RESULTS

Between 1994 and 2011, 77 TPs were performed. Overall morbidity was 49%, but only 15.8% patients experienced a major complication. Perioperative mortality was 2.6%. Comparing 17 TP and 14 PD patients who returned surveys, there were no statistically significant differences in quality of life in global health, functional status, or symptom domains of EORTC QLQ-C30 or in pancreatic disease-specific EORTC-PAN26. TP patients had slightly but not significantly higher incidence of hypoglycemic events as compared with PD patients with postoperative diabetes. A negative impact of diabetes assessed by Audit of Diabetes Dependent Quality of Life did not differ between TP and PD. Life domains most negatively impacted by diabetes involved travel and physical activity, whereas self-confidence, friendships and personal relationships, motivation, and feelings about the future remained unaffected.

CONCLUSIONS

Although TP-induced diabetes negatively impacts select activities and functions, overall quality of life is comparable with that of patients who undergo a partial pancreatic resection.

Invasive carcinoma derived from branch duct-type IPMN may be a more aggressive neoplasm than that derived from main duct-type IPMN

The present study aimed to evaluate the long-term follow-up results of patients with intraductal papillary mucinous neoplasm (IPMN) and to estimate the degree of IPMN malignancy based on pathological and molecular features of resected specimens. The detection rate of IPMN has increased over the last decade; however, the management of this neoplasm remains controversial. This is particularly so for branch duct-type IPMN, which carries a high potential for malignancy and risk of recurrence. We retrospectively reviewed a single institution’s prospective pancreatic resection database to identify IPMN patients who underwent pancreatectomy with curative intent. The clinicopathological variables of 100 patients resected for IPMN were analyzed with a detailed review of histopathological results (borderline lesions, non-invasive carcinoma and invasive carcinoma) to determine the grade of IPMN malignancy based on transforming growth factor (TGF)-β/SMAD4 signaling. The incidence of malignant change was significantly higher in patients with main duct-type IPMN (69.7%) compared with branch duct-type IPMN cases (17.9%). However, patients with an invasive carcinoma had a significantly worse outcome if it was derived from branch duct-type IPMN compared with those derived from main duct-type IPMN, and TGF-β mRNA expression was significantly increased in the former patient group. Immunohistochemistry also showed higher numbers of SMAD4-positive cells in patients with carcinoma derived from branch duct-type IPMN. Our results demonstrated that invasive carcinoma derived from branch duct-type IPMN is more aggressive than that derived from main duct-type IPMN, once invasive morphological change takes place. Determining TGF-β and/or SMAD4 status at initial diagnosis may be useful for stratifying IPMN patients into treatment regimens.

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.

Gene expression changes associated with the progression of intraductal papillary mucinous neoplasms

OBJECTIVES

The diagnosis of high-grade intraductal papillary mucinous neoplasm (IPMN) is difficult to distinguish from low-grade IPMN. The aim of this study was to identify potential markers for the discrimination of high-grade and invasive (HgInv) IPMN from low- and moderate-grade dysplasia IPMN.

METHODS

Laser capture microdissection was used to isolate distinct foci of low-grade, moderate-grade, high-grade, and invasive IPMN from paraffin-embedded archival tissue from 14 patients who underwent resection for IPMN. Most samples included multiple grades in the same specimen. Affymetrix Human Exon microarrays were used to compare low- and moderate-grade dysplasia IPMN with HgInv IPMN.

RESULTS

Sixty-two genes were identified as showing significant changes in expression (P ≤ 0.05 and a 2-fold cutoff), including up-regulation of 41 in HgInv IPMN. Changes in gene expression are associated with biological processes related to malignant behavior including cell motion, cell proliferation, response to hypoxia, and epithelial-to-mesenchymal transition. In addition, altered signaling in several transforming growth factor β-related pathways was exhibited in the progression of IPMN to malignancy.

CONCLUSIONS

This study identifies a set of genes associated with the progression of IPMN to malignancy. These genes are potential markers that could be used to identify IPMN requiring surgical resection.

Long-term clinical and imaging follow-up of nonoperated branch duct form of intraductal papillary mucinous neoplasms of the pancreas

OBJECTIVES

The aim of our study was to perform a 10-year imaging and clinical prospective follow-up of patients with nonoperated branch duct (BD) intraductal papillary mucinous neoplasms (IPMNs) of the pancreas.

METHODS

Forty-nine patients with BD-IPMN who displayed a low probability for malignancy were followed up including a clinical component and a series of imaging techniques such as computed tomography, magnetic resonance cholangiopancreatography, and endoscopic ultrasonography.

RESULTS

After a mean follow-up period of 77 months, 77.5% of patients remained free of symptoms. An increase in the size and number of BD cysts without mural nodules and with no significant increase of main duct size occurred in 18 patients at an average interval of 47 months. Five patients were operated on owing to recurrent pancreatitis and/or an increase in the size of either cysts or the main duct (mean time delay after diagnosis: 20 months). Pathologically, they were diagnosed as benign adenoma (n = 1) or borderline (n = 4).

CONCLUSIONS

Our long-term clinical and imaging follow-up indicated that none of the patients with BD-IPMNs developed malignancy. Therefore, BD-IPMNs with no signs of malignancy should be managed conservatively. We propose that following a 2-year patient follow-up, biannual imaging follow-ups could be sufficient.

Comparison of International Consensus Guidelines versus 18-FDG PET in detecting malignancy of intraductal papillary mucinous neoplasms of the pancreas

OBJECTIVE

To assess the reliability of the International Consensus Guidelines (ICG) and 18-fluorodeoxyglucose positron emission tomography (PET) in distinguishing benign from malignant intraductal papillary mucinous neoplasms (IPMNs) of the pancreas.

BACKGROUND

Since 2006 the ICG have been used to choose immediate surgery or surveillance for IPMN patients, but their low specificity increases the number of benign IPMNs that undergo resective surgery. PET has proved highly sensitive and specific in detecting malignancy in cystic neoplasms of the pancreas, including IPMNs.

METHODS

Patients suspected with IPMNs of the pancreas seen at our Department from January 1989 to July 2010 were identified and classified as cases of main duct, mixed type and branch type IPMN. The indication for resection or surveillance was verified a posteriori for all patients according to the ICG. PET was considered positive for a Standardized Uptake Value ≥2.5. Surveillance included clinical examination, laboratory tests, CA 19-9 serum levels, and computed tomography and/or magnetic resonance and magnetic resonance cholangiopancreatography every 6 months for 2 years and yearly thereafter. Endoscopic ultrasound was rarely performed. PET was repeated in clinically or radiologically suspect cases, or if tumor markers increased.

RESULTS

Sixty-one main duct or mixed type and 101-branch type IPMNs were included in the study. A histological diagnosis was available for 81 of 162 patients, missing for 1 locally advanced IPMN, whereas 62 patients are under surveillance and it proved impossible to contact 18. Conservative surgery was performed in 16 of 68 patients with benign IPMNs. The sensitivity, specificity, positive and negative predictive value, and accuracy of the ICG in detecting malignancy were 93.2, 22.2, 59.4, 72.7, and 61.2, whereas for PET they were 83.3, 100, 100, 84.6, and 91.3.

CONCLUSIONS

PET is more accurate than the ICG in distinguishing benign from malignant (invasive and noninvasive) IPMNs. Prophylactic IPMN resection in young patients fit for surgery should be guided by the ICG, whereas PET should be performed in older patients, cases at increased surgical risk, or when the feasibility of parenchyma-sparing surgery demands a reliable preoperative exclusion of malignancy.