Extrapancreatic malignancies and intraductal papillary mucinous neoplasms of the pancreas

The Distribution and Predictive Factor of Extra-Pancreatic Malignancy Occurrence in Patients with Pancreatic Intraductal Papillary Mucinous Neoplasm-A Ten-Year Follow-Up Case-Control Study in Taiwan

BACKGROUND AND AIMS

A higher incidence of extra-pancreatic malignancies (EPMs) in patients with pancreatic intraductal papillary mucinous neoplasm (IPMN) than in the general population has been shown in several studies. We suppose that EPMs also occur after IPMN has been diagnosed, but few reports have discussed the risk factors that have been identified, except for old age, which was only noted in one study. Our study aims to recognize the distribution of EPMs in Taiwanese patients with a longer duration of follow-up and investigate the risk factors to predict EPMs in IPMN patients.

METHODS

We retrospectively analyzed 114 patients with pancreatic IPMN from 1 January 2010 to 31 December 2014 in Chang Gung Memorial Hospital. The characteristics of the patients were all recorded. Different EPMs are demonstrated as occurring before, concurrently with, or after IPMN diagnosis. The risk factors were compared between patients with or without an EPM.

RESULTS

After an average follow-up duration of 10.45 years, 47 EPMs occurred in 42 patients (36.8%), and over half were found after IPMN was diagnosed (55.3%). The most common EPMs were colon cancer and lung cancer (21.3%). Moreover, cyst size progression was highly associated with EPM occurrence (p = 0.004) and predictive of EPM occurrence after IPMN (p = 0.002), with a cut-off value of 1 cm (accuracy: 79%; sensitivity: 88%; specificity: 58%).

CONCLUSIONS

Colon cancer and lung cancer account for the majority EPMs in Taiwan. EPMs were also frequently found after IPMN diagnosis when the follow-up duration was prolonged up to 10.45 years. Cyst size progression is a risk factor of EPM after IPMN diagnosis and we suggest a cut-off value of 1 cm for clinical utility.

Gastrointestinal cancer precursor risk and mortality in pancreatic intraductal papillary mucinous neoplasms: a nationwide cohort study

BACKGROUND AND AIMS

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a precursor of pancreatic cancer. While earlier research has shown a high prevalence of synchronous/metachronous extrapancreatic tumors in IPMN patients, these studies have often been small with retrospective data collection. The aim of the study was to examine absolute and relative risks of non-pancreatic gastrointestinal (GI) cancer precursors and mortality in histologically confirmed IPMN.

METHODS

Through the nationwide ESPRESSO histopathology cohort, we retrieved data on IPMN between 1965 and 2016. Each index case was matched to ≤5 general population controls. Through Cox regression, we estimated hazard ratios (HRs) for future GI cancer precursors and death.

RESULTS

A total of 117 patients with IPMN and 539 age- and sex-matched controls were included. Over a median of 2.1 years of follow up, we confirmed two (1.7%) incident GI cancer precursors in IPMN vs. four (0.7%) in controls, corresponding to an HR of 1.89 (95%CI = 0.34-10.55). By contrast, IPMN patients were at increased risk of death (HR 3.61 (95%CI = 1.79-7.27)). The most common cause of death in IPMN was pancreatic cancer (n = 14; 45.2% of all deaths).

CONCLUSIONS

We found no association between IPMN and other GI cancer precursors. This argues against comprehensive routine surveillance for other GI cancer precursors in IPMN patients. Mortality was increased in IPMN with pancreatic cancer being the most common cause of death, indicating the need for lifelong follow up in all resected and non-resected patients with IPMN. However, results should be confirmed in larger cohorts.

Synchronous manifestation of colorectal cancer and intraductal papillary mucinous neoplasms

High rates of extrapancreatic malignancies, in particular colorectal cancer (CRC), have been detected in patients with intraductal papillary mucinous neoplasm (IPMN). So far, there is no distinct explanation in the literature for the development of secondary or synchronous malignancies in patients with IPMN. In the past few years, some data related to common genetic alterations in IPMN and other affiliated cancers have been published. This review elucidated the association between IPMN and CRC, shedding light on the most relevant genetic alterations that may explain the possible relationship between these entities. In keeping with our findings, we suggested that once the diagnosis of IPMN is made, special consideration of CRC should be undertaken. Presently, there are no specific guidelines regarding colorectal screening programs for patients with IPMN. We recommend that patients with IPMNs are at high-risk for CRC, and a more rigorous colorectal surveillance program should be implemented.

A meta-analysis: incidental intraductal papillary mucinous neoplasm and extra-pancreatic malignancy

INTRODUCTION

Meta-analysis aimed to quantify the relationship between intraductal papillary mucinous neoplasm (IPMN) and increased incidence of extra-pancreatic malignancy (EPM) previously reported in qualitative observational cohort studies.

METHODS

Study protocol was registered with PROSPERO (CRD42020169614) and conducted to the Meta-analysis Of Observational Studies in Epidemiology and systematic review reported with Preferred Reporting Items for Systematic Reviews and Meta-Analyses, Assessing the Methodological Quality of Systematic Reviews guidelines.

RESULTS

Sixteen studies (total of 8240 patients) were included in the pooled, and 7399 patients in the subgroup meta-analyses. The odds ratio (OR) for any EPM in the presence of IPMN was 57.9 (95% confidence interval 40.5-82.7), fixed effects, I² = 59% (p < 0.0014). Subgroup analysis for any gastrointestinal EPM (i.e. oesophagus, stomach, colon and rectum) in the presence of an IPMN estimated an overall OR of 12.9 (95% confidence interval 8.8-19.0), fixed effects, I² = 64% (p < 0.0004).

CONCLUSION

Patients with an IPMN are categorically at increased risk for a higher incidence of EPM and particularly the odds of a gastrointestinal malignancy are also increased in comparison with the general population. We advocate that patients presenting with an IPMN should be considered for gastrointestinal screening including colonoscopy, upper gastrointestinal endoscopy or computed tomography.

Pancreatic cancer secondary to intraductal papillary mucinous neoplasm with collision between gastric cancer and B-cell lymphoma: A case report

BACKGROUND

Patients with intraductal papillary mucinous neoplasm (IPMN) have an increased risk of pancreatic and extrapancreatic malignancies. Lymphomas are rare extrapancreatic malignancies, and in situ collisions of early gastric cancer and diffuse large B-cell lymphoma (DLBCL) are even rarer. Here, we report the first case of pancreatic cancer comorbid with in situ collision of extrapancreatic malignancies (early gastric cancer and DLBCL) in a follow-up IPMN patient. Furthermore, we have made innovations in the treatment of such cases.

CASE SUMMARY

An 81-year-old Japanese female diagnosed with IPMN developed elevated carbohydrate antigen (CA) 19-9 levels during follow-up. Because her CA19-9 levels continued to rise, endoscopic ultrasound (EUS) was performed and revealed a suspicious lesion at the pancreatic tail. However, lesions in the pancreas were not found by computed tomography, magnetic resonance imaging, or endoscopic retrograde cholangiopancreatography. To make an exact patho-logical diagnosis, EUS-guided fine needle aspiration was performed. To our supprise, early gastric cancer was found in preoperative gastroscopy. The gastric cancer was completely resected through endoscopic submucosal dissection before postoperative pathology identified early adenocarcinoma collided with DLBCL. Subsequent EUS-guided fine needle aspiration provided pathological support for the pancreatic cancer diagnosis, and then laparoscopic distal pancreatectomy and splenectomy were performed. CA19-9 levels returned to normal postoperatively.

CONCLUSION

Endoscopic submucosal dissection is appropriate for submucosal lymphomas in patients intoleratant of chemotherapy. EUS can detect small IPMN-related pancreatic tumors.

Timing and Clinical Features of Spontaneous Decrease in Size of Small Pancreatic Cystic Lesions without High-Risk Stigmata

Background/Aims

The natural history of spontaneous decrease in the size of pancreatic cystic lesions (PCLs) without high-risk stigmata is under investigation. This study aimed to investigate the timing of spontaneous decrease in the size of PCLs without high-risk stigmata and to identify the characteristics associated with their complete resolution.

Methods

From 2000 to 2016, patients with spontaneous decreases in PCL size on computed tomography (CT) and/or magnetic resonance imaging (MRI) who had at least 1 year of follow-up were evaluated retrospectively.

Results

A total of 78 patients underwent follow-up for an average of 55.7 months. Most patients were asymptomatic, and 35 (37.2%) showed complete resolution. The initial mean PCL size was 1.6±0.9 cm (range, 0.5 to 5.6 cm). The average time to initial decrease in size and complete resolution of PCLs were 32.1 and 41.5 months, respectively. Compared with PCLs that completely resolved, presence of underlying malignancy was associated with partial resolution of PCLs in multivariable analysis (hazard ratio, 0.51; 95% confidence interval, 0.32 to 0.81; p=0.005). Endoscopic ultrasound (EUS) identified detailed findings, especially the presence of septum (p<0.001), calcification (p=0.015) and lobulation (p=0.001) that were not found on CT/MRI.

Conclusions

Asymptomatic small PCLs without high-risk stigmata can naturally decrease in size at approximately 3 years, and complete resolution can be expected in the absence of underlying malignancy. Regular follow-up of approximately 3 years with EUS may be a reasonable and safe alternative when planning the initial treatment of small PCLs without high-risk stigmata.

Prevalence of Germline Mutations Associated With Cancer Risk in Patients With Intraductal Papillary Mucinous Neoplasms

BACKGROUND & AIMS

Many patients with pancreatic adenocarcinoma carry germline mutations associated with increased risk of cancer. It is not clear whether patients with intraductal papillary mucinous neoplasms (IPMNs), which are precursors to some pancreatic cancers, also carry these mutations. We assessed the prevalence of germline mutations associated with cancer risk in patients with histologically confirmed IPMN.

METHODS

We obtained nontumor tissue samples from 315 patients with surgically resected IPMNs from 1997 through 2017, and we sequenced 94 genes with variants associated with cancer risk. Mutations associated with increased risk of cancer were identified and compared with individuals from the Exome Aggregation Consortium.

RESULTS

We identified 23 patients with a germline mutation associated with cancer risk (7.3%; 95% confidence interval, 4.9-10.8). Nine patients had a germline mutation associated with pancreatic cancer susceptibility (2.9%; 95% confidence interval, 1.4-5.4). More patients with IPMNs carried germline mutations in ATM (P < .0001), PTCH1 (P < .0001), and SUFU (P < .0001) compared with controls. Patients with IPMNs and germline mutations associated with pancreatic cancer were more like to have concurrent invasive pancreatic carcinoma compared with patients with IPMNs without these mutations (P < .0320).

CONCLUSIONS

In sequence analyses of 315 patients with surgically resected IPMNs, we found that almost 3% to carry mutations associated with pancreatic cancer risk. More patients with IPMNs and germline mutations associated with pancreatic cancer had concurrent invasive pancreatic carcinoma compared with patients with IPMNs without these mutations. Genetic analysis of patients with IPMNs might identify those at greatest risk for cancer.

Selecting optimal surgical procedures for intraductal papillary mucinous neoplasm (IPMN): An analysis based on the Surveillance, Epidemiology, and End Result registry database

INTRODUCTION

Intraductal papillary mucinous neoplasm (IPMN) is a field defect disease of pancreas that has malignant potential. Many studies have recommended surgery as the preferred treatment. We investigated whether a total pancreatectomy (TP) can improve patient prognosis compared to a pancreatoduodenectomy (PD) and the indications for each approach.

PATIENTS AND METHODS

We obtained data of 548 malignant IPMN patients who underwent either a TP or a PD from SEER database. The survival rates were analyzed using the Kaplan-Meier method and a Cox regression model. Cases were subdivided to investigate the advantages of each procedure.

RESULTS

The surgical procedures (PD and TP) did not significantly affect either cancer-specific survival (CSS) times or overall survival (OS) times in both Kaplan-Meier analysis and Cox regression (Kaplan-Meier: PCSS = 0.919, POS = 0.996; Cox: PCSS = 0.735, POS = 0.820). In the subgroup analyses, patients in stage T4 and AJCC stage III in the TP group had a longer survival time than did those in the PD group (33 months vs 14 months), but not significant (T4: PCSS = 0.124, AJCC III: PCSS = 0.102). In addition, PD had the trend to be better for poorly differentiated patients (Pos = 0.055) and older patients.

CONCLUSION

TP did not offer any significant OS and CSS benefits as compared to PD. However, for patients in stage T4 and AJCC stage III, TP may extend survival time in some degree. In older or histologically poorly differentiated patients, PD may be preferable to TP. The results are rational, but still warrant further verification due to limited sample volumes of specific subgroups.

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.

Increased incidence of extrapancreatic neoplasms in patients with IPMN: Fact or fiction? A critical systematic review

BACKGROUND

To identify potential associations between intraductal papillary mucinous neoplasm of the pancreas (IPMN) and extrapancreatic neoplasms (EPN), a systematic review of the literature has been performed.

METHODS

A systematic search of Medline/Pubmed was performed according to the PRISMA guidelines for reporting systematic reviews and meta-analysis for the following search terms: "extrapancreatic", "non pancreatic", "additional pancreatic", "additional primary" and alternatively matched with "neoplasms/tumours/cancers/malignancies/lesions". The results obtained specifically for IPMN were examined one by one by two independent investigators for further data selection and extraction.

RESULTS

Fifteen studies were identified to be suitable and included for systematic review. Fourteen reported an elevated risk for extrapancreatic malignancy, particularly gastric and colon cancer, while the largest and only prospective study did not find any association. Most studies were retrospective with a weak level of evidence that was not substantially enhanced even by a recent multicentre case series.

CONCLUSIONS

The available data on this clinically relevant question remain inconclusive. Due to lacking evidence on extrapancreatic neoplasms in IPMN patients, only a standard surveillance can be advised.

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.

Extent of Surgery and Implications of Transection Margin Status after Resection of IPMNs

Appropriate surgical strategies for management of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are a matter of debate. Preoperative and intraoperative evaluation of malignant potential of IPMN and of patient's comorbidities is of paramount importance to balance potential complications of surgery with tumors' risk of being or becoming malignant; the decision about the extent of pancreatic resection and the eventual total pancreatectomy needs to be determined on individual basis. The analysis of frozen-section margin of pancreas during operation is mandatory. The goal should be the complete resection of IPMN reaching negative margin, although there is still no agreed definition of “negative margin.” Of note, the presence of deepithelization is often wrongly interpreted as absence of neoplasia. Management of resection margin status and stratification of surveillance of the remnant pancreas, based on characteristics of primary tumour, are of crucial importance in the management of IPMNs in order to decrease the risk of tumor recurrence after resection. Although risk of local and distant recurrence for invasive IPMNs is increased even in case of total pancreatectomy, also local recurrence after complete resection of noninvasive IPMNs is not negligible. Therefore, a long-term/life-time follow-up monitoring is of paramount importance to detect eventual recurrences.

Classification, morphology and molecular pathology of premalignant lesions of the pancreas

Over the past few years there have been substantial advances in our knowledge of premalignant lesions of the pancreas. Given the dismal prognosis of untreated pancreatic cancer, and the small proportion of patients who are operative candidates, an understanding of these premalignant lesions is essential for the development of strategies for early diagnosis and prevention. The 2010 WHO classification has added new entities, including intraductal tubular papillary neoplasms (ITPNs), and clarified the nomenclature and grading of previously recognised precursor lesions of pancreatic adenocarcinoma, such as intraductal papillary mucinous neoplasms (IPMNs), mucinous cystic neoplasms (MCNs) and pancreatic intraepithelial neoplasia (PanIN). In particular, there has been an upsurge of interest in the natural history of IPMN, driven partly by improvements in imaging modalities and the consequent apparent increase in their incidence, and partly by recognition that subtypes based on location or histological appearance define groups with significantly different behaviours. In mid 2012 revised international guidelines for the classification and management of IPMNs and MCNs were published, although in several respects these guidelines represent a consensus view rather than being evidence-based. In recent years major advances in molecular technologies, including whole-exome sequencing, have significantly enhanced our knowledge of pancreatic premalignancy and have identified potentially highly specific diagnostic biomarkers such as mutations in GNAS and RNF43 that could be used to pre-operatively assess pancreatic cysts.

Management of pancreatic intraductal papillary mucinous neoplasm in an academic hospital (2005-2010): what follow-up for unoperated patients?

OBJECTIVES

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are diagnosed frequently in asymptomatic patients. It is still not clear what follow-up is indicated for patients not undergoing surgical resection.

METHODS

Review of all reports of magnetic resonance cholangiopancreatography (MRCP) from June 2005 to June 2010, identifying all patients diagnosed with IPMN; subsequent reconstruction of the initial therapeutic decision, indications for and adherence to scheduled follow-up, and IPMN evolution by morphology and by biology.

RESULTS

Overall, 4943 MRCP reports were analyzed, identifying 234 patients with IPMN. Although 143 (61.1%) of these were comprised in Sendai criteria for resection, surgical resection was considered in only 42 (17.9%) patients. Of the remainder, 52 were not subjected to any control, 58 to a single short time check, 77 to MRCP-based regular annual follow-up, and 5 were treated for associated ductal adenocarcinoma. With a median follow-up of 39.5 months (range, 12-72), 37.6% of 125 patients in follow-up had a morphological evolution, but only 2.4% has developed a malignant IPMN. No deaths were recorded, directly related to IPMN, in all 187 conservatively managed patients.

CONCLUSIONS

In the analyzed series, fewer patients than expected underwent surgical resection, and only 67.2% undergo regular follow-up, but no more than 2.4% developed malignancy.

[Strategy in intraductal papillary mucinous neoplasm of the pancreas]

Intraductal papillary mucinous neoplasm (IPMN) is a premalignant pancreatic entity characterized by papillary growth of the ductal epithelium with rich mucin production and cystic dilatation of the main pancreatic duct and/or its branches. These neoplasms are often multifocal. Preoperative distinction between benign and malignant lesions is important to select the most appropriate treatment and to improve prognosis. Early surgical resection is the treatment of choice to avoid malignant transformation when predictive factors for malignancy are present. These factors include localization, cyst greater than 3cm, nodules in the cystic wall, atypias in the cyst fluid and the presence of symptoms. The extent of resection required for adequate treatment of IPMN of the pancreas is still controversial. Patients who retain a portion of their pancreas following resection of an IPMN need to be followed up with periodic imaging to detect recurrences, signs indicating a risk of malignant transformation, and metachronous lesions. The existence of possible synchronous or metachronous lesions in other organs should also be investigated.

International consensus guidelines 2012 for the management of IPMN and MCN of the pancreas

The international consensus guidelines for management of intraductal papillary mucinous neoplasm and mucinous cystic neoplasm of the pancreas established in 2006 have increased awareness and improved the management of these entities. During the subsequent 5 years, a considerable amount of information has been added to the literature. Based on a consensus symposium held during the 14th meeting of the International Association of Pancreatology in Fukuoka, Japan, in 2010, the working group has generated new guidelines. Since the levels of evidence for all items addressed in these guidelines are low, being 4 or 5, we still have to designate them "consensus", rather than "evidence-based", guidelines. To simplify the entire guidelines, we have adopted a statement format that differs from the 2006 guidelines, although the headings are similar to the previous guidelines, i.e., classification, investigation, indications for and methods of resection and other treatments, histological aspects, and methods of follow-up. The present guidelines include recent information and recommendations based on our current understanding, and highlight issues that remain controversial and areas where further research is required.

Intraductal papillary mucinous neoplasm

Intraductal papillary mucinous neoplasm (IPMN) is a grossly visible (≥1 cm), mucin-producing neoplasm that arises in the main pancreatic duct and/or its branches. Patients with intraductal papillary mucinous neoplasm can present with symptoms caused by obstruction of the pancreatic duct system, or they can be asymptomatic. There are 3 clinical subtypes of intraductal papillary mucinous neoplasm: main duct, branch duct, and mixed. Five histologic types of intraductal papillary mucinous neoplasm are recognized: gastric foveolar type, intestinal type, pancreatobiliary type, intraductal oncocytic papillary neoplasm, and intraductal tubulopapillary neoplasm. Noninvasive intraductal papillary mucinous neoplasms are classified into 3 grades based on the degree of cytoarchitectural atypia: low-, intermediate-, and high-grade dysplasia. The most important prognosticator, however, is the presence or absence of an associated invasive carcinoma. Some main duct-intraductal papillary mucinous neoplasms progress into invasive carcinoma, mainly tubular adenocarcinoma (conventional pancreatic ductal adenocarcinoma) and colloid carcinoma. Branch duct-intraductal papillary mucinous neoplasms have a low risk for malignant transformation. Preoperative prediction of the malignant potential of an intraductal papillary mucinous neoplasm is of growing importance because pancreatic surgery has its complications, and many small intraductal papillary mucinous neoplasms, especially branch duct-intraductal papillary mucinous neoplasms, have an extremely low risk of progressing to an invasive cancer. Although most clinical decision making relies on imaging, a better understanding of the molecular genetics of intraductal papillary mucinous neoplasm could help identify molecular markers of high-risk lesions. When surgery is performed, intraoperative frozen section assessment of the pancreatic resection margin can guide the extent of resection. Intraductal papillary mucinous neoplasms are often multifocal, and surgically resected patients should be followed for metachronous disease.

Intraductal papillary mucinous neoplasm: Coming of age

Intraductal papillary mucinous neoplasm (IPMN) is a disease in evolution. Since its first description almost 30 years ago, a better understanding of the disease has steadily accrued. Yet, there are numerous challenges still for clinicians who treat this fascinating disease. A group of leading content experts on IPMN was assembled and charged with presenting cutting-edge knowledge on various topics for which they have considerable experience. This manuscript provides an historical perspective of both clinical and biological quandaries that have been resolved to date. Furthermore, it poses new avenues for investigation while highlighting the contributions of the various authors to this collective review.