Invasive carcinoma derived from the nonintestinal type intraductal papillary mucinous neoplasm of the pancreas has a poorer prognosis than that derived from the intestinal type. Surgery. 2010;147:812-817. [PMID: 20060146 DOI: 10.1016/j.surg.2009.11.011]

International evidence-based Kyoto guidelines for the management of intraductal papillary mucinous neoplasm of the pancreas

This study group aimed to revise the 2017 international consensus guidelines for the management of intraductal papillary mucinous neoplasm (IPMN) of the pancreas, and mainly focused on five topics; the revision of high-risk stigmata (HRS) and worrisome features (WF), surveillance of non-resected IPMN, surveillance after resection of IPMN, revision of pathological aspects, and investigation of molecular markers in cyst fluid. A new development from the prior guidelines is that systematic reviews were performed for each one of these topics, and published separately to provide evidence-based recommendations. One of the highlights of these new "evidence-based guidelines" is to propose a new management algorithm, and one major revision is to include into the assessment of HRS and WF the imaging findings from endoscopic ultrasound (EUS) and the results of cytological analysis from EUS-guided fine needle aspiration technique, when this is performed. Another key element of the current guidelines is to clarify whether lifetime surveillance for small IPMNs is required, and recommends two options, "stop surveillance" or "continue surveillance for possible development of concomitant pancreatic ductal adenocarcinoma", for small unchanged BD-IPMN after 5 years surveillance. Several other points are also discussed, including identifying high-risk features for recurrence in patients who underwent resection of non-invasive IPMN with negative surgical margin, summaries of the recent observations in the pathology of IPMN. In addition, the emerging role of cyst fluid markers that can aid in distinguishing IPMN from other pancreatic cysts and identify those IPMNs that harbor high-grade dysplasia or invasive carcinoma is discussed.

The Dual Role of Necroptosis in Pancreatic Ductal Adenocarcinoma

Pancreatic cancer (PC) is the seventh leading cause of cancer-related death. PC incidence has continued to increase by about 1% each year in both men and women. Although the 5-year relative survival rate of PC has increased from 3% to 12%, it is still the lowest among cancers. Hence, novel therapeutic strategies are urgently needed. Challenges in PC-targeted therapeutic strategies stem from the high PC heterogeneity and from the poorly understood interplay between cancer cells and the surrounding microenvironment. Signaling pathways that drive PC cell growth have been the subject of intense scrutiny and interest has been attracted by necroptosis, a distinct type of programmed cell death. In this review, we provide a historical background on necroptosis and a detailed analysis of the ongoing debate on the role of necroptosis in PC malignant progression.

Clinical and Molecular Attributes and Evaluation of Pancreatic Cystic Neoplasm

Intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs) are all considered "Pancreatic cystic neoplasms (PCNs)" and show a varying risk of developing into pancreatic ductal adenocarcinoma (PDAC). These lesions display different molecular characteristics, mutations, and clinical manifestations. A lack of detailed understanding of PCN subtype characteristics and their molecular mechanisms limits the development of efficient diagnostic tools and therapeutic strategies for these lesions. Proper in vivo mouse models that mimic human PCNs are also needed to study the molecular mechanisms and for therapeutic testing. A comprehensive understanding of the current status of PCN biology, mechanisms, current diagnostic methods, and therapies will help in the early detection and proper management of patients with these lesions and PDAC. This review aims to describe all these aspects of PCNs, specifically IPMNs, by describing the future perspectives.

Pancreatic ductal adenocarcinoma and invasive intraductal papillary mucinous tumor: Different prognostic factors for different overall survival

BACKGROUND

It is unclear whether invasive intraductal papillary mucinous neoplasm (IPMN) has different clinical and prognostic characteristics, beyond histological factors, when compared to pancreatic ductal adenocarcinoma (PDAC).

AIMS

compare prognostic features of resected PDAC and invasive IPMN METHODS: A retrospective study of patients resected for PDAC or invasive IPMN realized at Humanitas Cancer Center's Pancreatic Surgery Unit, Milan, Italy, between 2010 and 2016. Data recorded included patient demographics, onset symptoms, preoperative health status, tumor features, histology and surgical characteristics. Overall survival was estimated using Kaplan-Meier and prognostic factors for survival were assessed by multivariate Cox regression.

RESULTS

A total of 332 patients were included (PDAC, n = 289; invasive IPMN, n = 43). Patients with invasive IPMN had better overall survival than PDAC patients (median: 76.6 versus 25.6 months; 5-year OS rate: 65.4% vs. 14.2%; p < 0.001). PDAC histology was associated with a significantly higher risk of death than IPMN (hazard ratio 1.815, 95% CI: 1.02, 3.24; p = 0.044). Survival was also worse with PDAC in early-stage disease (IA-IB-IIA, N0). In multivariate analysis, independent predictors of worse survival included perineural invasion, preoperative ASA physical status ≥3 and pain at diagnosis.

CONCLUSIONS

Patients with IPMN had a better prognosis than PDAC patients, regardless of disease stage.

Intraductal Papillary Mucinous Carcinoma Versus Conventional Pancreatic Ductal Adenocarcinoma: A Comprehensive Review of Clinical-Pathological Features, Outcomes, and Molecular Insights

Intraductal papillary mucinous neoplasms (IPMN) are common and one of the main precursor lesions of pancreatic ductal adenocarcinoma (PDAC). PDAC derived from an IPMN is called intraductal papillary mucinous carcinoma (IPMC) and defines a subgroup of patients with ill-defined specificities. As compared to conventional PDAC, IPMCs have been associated to clinical particularities and favorable pathological features, as well as debated outcomes. However, IPMNs and IPMCs include distinct subtypes of precursor (gastric, pancreato-biliary, intestinal) and invasive (tubular, colloid) lesions, also associated to specific characteristics. Notably, consistent data have shown intestinal IPMNs and associated colloid carcinomas, defining the “intestinal pathway”, to be associated with less aggressive features. Genomic specificities have also been uncovered, such as mutations of the GNAS gene, and recent data provide more insights into the mechanisms involved in IPMCs carcinogenesis. This review synthetizes available data on clinical-pathological features and outcomes associated with IPMCs and their subtypes. We also describe known genomic hallmarks of these lesions and summarize the latest data about molecular processes involved in IPMNs initiation and progression to IPMCs. Finally, potential implications for clinical practice and future research strategies are discussed.

Intraductal Pancreatic Mucinous Neoplasms: A Tumor-Biology Based Approach for Risk Stratification

Pancreatic ductal adenocarcinoma is one of the most lethal human cancers. Its precursor lesions include pancreatic intra-epithelial neoplasia, mucinous cystic neoplasm, and intraductal papillary mucinous neoplasm (IPMN). IPMNs usually present as an incidental finding at imaging in 2.6% of the population and, according to the degree of dysplasia, they are classified as low- or high-grade lesions. Since the risk of malignant transformation is not accurately predictable, the management of these lesions is based on morphological and clinical parameters, such as presence of mural nodule, main pancreatic duct dilation, presence of symptoms, or high-grade dysplasia. Although the main genetic alterations associated to IPMNs have been elucidated, they are still not helpful for disease risk stratification. The growing body of genomic and epigenomic studies along with the more recent development of organotypic cultures provide the opportunity to improve our understanding of the malignant transformation process, which will likely deliver biomarkers to help discriminate between low- and high-risk lesions. Recent insights on the topic are herein summarized.

Current Status of Needles in the Optimization of Endoscopic Ultrasound-Guided Procedures

Endoscopic ultrasound (EUS) is among the most important tools for the evaluation of gastrointestinal tumors and affected areas around the gastrointestinal tract. It enables the acquisition of material from abnormal lesions via the gastrointestinal wall for tissue confirmation via endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). EUS-FNA has played a vital role in oncological care and has become the standard method for tissue sampling. The choice of needle type is an important factor determining tissue acquisition and has been evaluated by many researchers. New needles are introduced into the market almost every year, and opinions vary regarding proper needle selection. While there are diverse opinions but no definitive recommendations about the use of one particular device, fine-needle biopsy needles may provide detailed information on a tissue’s architecture based on greater sample yields. This permits additional analyses, including genetic sequencing and phenotyping, thereby enabling the provision of more personalized treatment plans. Furthermore, other EUS-guided procedures have been developed, including interventional EUS and through-the-needle devices. Given the continued attempts to improve the diagnostic ability and therapeutic techniques, we review in detail the available types of puncture needles to provide guidance on the selection of the appropriate needle types.

Intraductal papillary mucinous carcinoma versus pancreatic ductal adenocarcinoma: A systematic review and meta-analysis

BACKGROUND

Previous studies have indicated that there may be a difference in tumor biology between intraductal papillary mucinous carcinoma (IPMC) and pancreatic ductal adenocarcinoma (PDAC). However, the data are still controversial. The aim of this systematic review and meta-analysis was to summarize and compare the outcome of IPMC and PDAC after surgical resection.

METHODS

Studies comparing IPMC and PDAC were identified using Medline and Embase search engines. Primary outcomes of interest were survival and recurrence. Secondary outcomes were clinicopathological characteristics. Meta-analysis of data was conducted using a random-effects model.

RESULTS

A total of 14 studies were included. Pooled analysis revealed an improved 5-year overall survival (OS) for IPMC compared to PDAC (OR 0.23, 95% CI 0.09-0.56). Both colloid and tubular IPMC showed improved 5-year OS compared to PDAC (OR 0.12, 95% CI 0.05-0.25 and OR 0.38, 95% CI 0.26-0.54, respectively). Median survival time ranged from 21 to 58 months in the IPMC group compared to 12-23 months in the PDAC group. No meta-analysis could be performed on recurrence or on time-to-event data. Descriptive data showed no survival difference for higher TNM stages. IPMC was more often found at a TNM-stage of 1 (OR 4.40, 95% CI 2.71-7.15) and had lower rates of lymph node spread (OR 0.43, 95% CI 0.32-0.57).

CONCLUSION

Available data suggest that IPMC has a more indolent course with a better 5-year OS compared to PDAC. The histopathological features are less aggressive in IPMC. The reason may be earlier detection. However, for IPMC with higher TNM stages the survival seems to be similar to that of PDAC.

Pancreatic Intraductal Papillary Mucinous Neoplasm With Elevated Pre-Operative Cystic Carcinoembryonic Antigen Level: A Histopathologic Correlation

Background

To study the relationship between carcinoembryonic antigen (CEA) level, intraductal papillary mucinous neoplasm (IPMN) subtype, and the presence of invasive carcinoma.

Methods

Cystic CEA level and the following pathologic variables: subtypes of IPMN, size of cystic lesion, presence of dysplasia or carcinoma, and main or branch duct involvement from 45 IPMN cases were analyzed.

Results

There was a significant correlation between pre-operative cystic fluid CEA level and the intensity of luminal CEA staining. However, there was no correlation between CEA level and cystic mucinous secretions or mucinous epithelial cytoplasm CEA staining, mucin glycoprotein expression, size of lesion, grade of dysplasia or presence of invasive carcinoma. CEA level was neither sensitive nor specific for the presence of invasive carcinoma.

Conclusions

Cystic CEA level may not be a reliable determinant of the presence or absence of invasive carcinoma in IPMNs, and its use to assess risk of malignancy may be limited.

Adjuvant chemotherapy is associated with improved postoperative survival in specific subtypes of invasive intraductal papillary mucinous neoplasms (IPMN) of the pancreas: it is time for randomized controlled data

BACKGROUND

Very little is known about adjuvant chemotherapy for invasive Intraductal Papillary Mucinous Neoplasms (IPMNs) of the pancreas. The aim was to assess whether adjuvant chemotherapy affects survival.

METHODS

Retrospective evaluation of invasive IPMNs. Patients treated with surgery alone or followed by adjuvant chemotherapy were compared in terms of survival.

RESULTS

A total of 102 invasive IPMNs were analyzed. Median follow-up was 72 (5-318) months and 18.6% received adjuvant chemotherapy. Overall, recurrence rate was 40.2%, while 5-year overall survival and disease specific survival (DSS) were 65.3% and 69.4%, respectively. N1 disease (HR5.58, CI95% 2.49-12.51, p < 0.01), tubular type (HR2.35, CI95% 1.71-4.82, p = 0.05) and G3 tumors (HR4.54, CI95% 2.12-15.49, <0.01) were predictors of reduced DSS. Overall, there was no difference in the 5-year DSS comparing patients treated with adjuvant chemotherapy to surgery alone (61.8 vs. 69.4%, p = 0.8). Adjuvant chemotherapy significantly improved DSS only in N1 (5-years-DSS 76 vs. 35.8%, p = 0.01) and tubular carcinomas (5-years-DSS 88.9 vs. 53%, p = 0.03).

CONCLUSIONS

Adjuvant therapy improves survival only in invasive IPMNs with nodal disease or tubular differentiation. Future trials are needed to improve the level of evidence about adjuvant chemotherapy.

Clinical assessment of the GNAS mutation status in patients with intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is characterized by cystic dilation of the pancreatic duct, caused by mucin hypersecretion, with slow progression via the adenoma-carcinoma sequence mechanism. Mutation of GNAS at codon 201 is found exclusively in IPMNs, occurring at a rate of 41-75%. Recent advances in molecular biological techniques have demonstrated that GNAS mutation might play a role in the transformation of IPMNs after the appearance of neoplastic cells, rather than in the tumorigenesis of IPMNs. GNAS mutation is observed frequently in the intestinal subtype of IPMNs with MUC2 expression, and less frequently in IPMNs with concomitant pancreatic ductal adenocarcinoma (PDAC). Research has focused on assessing GNAS mutation status in clinical practice using various samples. In this review, we discuss the clinical application of GNAS mutation assessment to differentiate invasive IPMNs from concomitant PDAC, examine the clonality of recurrent IPMNs in the remnant pancreas using resected specimens, and differentiate pancreatic cystic lesions using cystic fluid collected by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA), duodenal fluid, and serum liquid biopsy samples.

Histo-molecular oncogenesis of pancreatic cancer: From precancerous lesions to invasive ductal adenocarcinoma

Pancreatic cancer is a lethal malignancy, whose precursor lesions are pancreatic intraepithelial neoplasm, intraductal papillary mucinous neoplasm, intraductal tubulopapillary neoplasm, and mucinous cystic neoplasm. To better understand the biology of pancreatic cancer, it is fundamental to know its precursors and to study the mechanisms of carcinogenesis. Each of these precursors displays peculiar histological features, as well as specific molecular alterations. Starting from such pre-invasive lesions, this review aims at summarizing the most important aspects of carcinogenesis of pancreatic cancer, with a specific focus on the recent advances and the future perspectives of the research on this lethal tumor type.

Diagnosis of intraductal papillary mucinous neoplasm using endoscopic ultrasound guided microbiopsies: A case report

Pancreatic cysts are increasingly diagnosed due to expanding use of cross-sectional imaging, but current diagnostic modalities have limited diagnostic accuracy. Recently, a novel through-the-needle microbiopsy forceps has become available, offering the possibility of obtaining cyst-wall biopsies. We present a case of 41-year-old male with chronic pancreatitis and a 2-cm pancreatic cyst, initially considered a pseudocyst. Subsequently, endoscopic ultrasound guided microbiopsies were successfully obtained, which surprisingly revealed an intraductal papillary mucinous neoplasm of mixed subtype with low grade dysplasia. In conclusion, obtaining biopsies from the wall of the pancreatic cystic lesions with this novel instrument is feasible and, as demonstrated in this case, can possibly alter the clinical outcome. Microbiopsies offered enough cellular material, allowing supplemental gene mutation analysis, which combined with other modalities could lead to a more individual approach when treating pancreatic cysts. However, prospective studies are warranted before routine clinical implementation.

Intraductal papillary mucinous neoplasms of the pancreas: Clinical association with KRAS

Intraductal papillary mucinous neoplasms of the pancreas (IPMN) are among the most important precancerous lesions in the pancreas. V‑Ki‑ras 2 Kirsten rat sarcoma viral oncogene homolog (KRAS) is one of the most important genes involved in pancreatic neoplasms, and exhibits a high mutation rate in pancreatic ductal adenocarcinomas and pancreatic intraepithelial neoplasia. The present study aimed to further elucidate the associations among IPMN subtypes (gastric, intestinal, pancreatobiliary and oncocytic), pathological classifications [low‑grade, intermediate‑grade, and high‑grade IPMN, and associated minimally invasive carcinoma (invasive depth ≤0.5 cm) and advanced invasive carcinoma (invasive depth >0.5 cm)]. A total of 56 cases of IPMN were studied using scorpion amplified refractory mutation system analysis of KRAS mutations, pathological features and prognosis. KRAS mutations were identified in 50% (28/56 cases). The frequency was 60% (9/15 cases) in gastric‑type, 52.6% (10/19 cases) in intestinal‑type, 47.3% (9/19 cases) in pancreatobiliary‑type and zero (0/3 cases) in oncocytic‑type IPMN. Except for oncocytic type IPMN, the frequencies of KRAS mutations in IPMN with low, intermediate and high grade, and IPMN‑associated carcinoma were 58.3% (7/12 cases), 27.3% (3/11 cases), 80% (4/5 cases) and 56% (14/25 cases), respectively. With more advanced dysplasia and invasion, the prevalence of KRAS mutations in intestinal‑type IPMN increased (P=0.012). The Kaplan‑Meier survival curve demonstrated that survival rate was not associated with KRAS mutation (log‑rank test; P=0.308). The prevalence of KRAS mutations was lowest in intestinal‑type IPMN, and was in proportion to the degree of dysplasia and invasion. Therefore, KRAS mutation in IPMN does not correlate with histological subtype, dysplasia grade, depth of invasion or survival.

Signet-ring Cell Carcinoma Derived from a Main Duct-type Intraductal Papillary Mucinous Neoplasm of the Pancreas: A Case Report with Long-term Follow-up

We herein report the case of a 74-year-old man who underwent surgery 9 years after his initial visit and who was pathologically diagnosed with signet-ring cell carcinoma (SRCC) derived from a main-duct-type intraductal papillary mucinous neoplasm (MD-IPMN). At the first imaging examination, only a small pancreatic cyst with mild dilation of the main pancreatic duct (MPD) was detected in the pancreatic head. Eventually, MD-IPMN with mural nodules and MPD dilation (30 mm) developed in the pancreatic body, while the pancreatic head cyst remained unchanged. Total pancreatectomy was performed and the MD-IPMN was pathologically diagnosed as SRCC derived from an intestinal-type MD-IPMN.

Initial experience with EUS-guided microbiopsy forceps in diagnosing pancreatic cystic lesions: A multicenter feasibility study (with video)

Background and Objectives

Cystic lesions of the pancreas represent a diagnostic dilemma. Recently, a through-the-needle microbiopsy forceps has become available, enabling procurement of EUS-guided histological specimens from the pancreatic cyst wall. The aim of this study was to evaluate the use of this novel instrument in a multicenter clinical setting.

Patients and Methods

Patients referred for EUS evaluation of pancreatic cysts and attempted EUS-guided microbiopsy was included retrospectively from six international tertiary centers. Patient's demographics, EUS findings, technical and clinical success, and histopathological results were recorded.

Results

: A total of 28 patients were identified. We report a technical success rate of 85.7% (n = 24). Biopsies were generally of good quality and contributed to the diagnosis in 20 patients (clinical success of 71.4%). Three adverse events were recorded (10.7%).

Conclusions

The use of the microbiopsy forceps is feasible with acceptable rates of technical and clinical success. Prospective studies are warranted to determine the diagnostic potential compared to the other modalities. However, the results from this preliminary study are promising.

Surveillance of patients with intraductal papillary mucinous neoplasm with and without pancreatectomy with special reference to the incidence of concomitant pancreatic ductal adenocarcinoma

BACKGROUND

The presence of an intraductal papillary mucinous neoplasm is important in the detection of concomitant pancreatic ductal adenocarcinoma. The aim of this study was to elucidate the incidence and timing of development of concomitant pancreatic ductal adenocarcinoma in patients with and without pancreatectomy for intraductal papillary mucinous neoplasm.

METHODS

We reviewed retrospectively the surveillance data for 22 patients who underwent pancreatectomy for pancreatic ductal adenocarcinoma concomitant with intraductal papillary mucinous neoplasm (pancreatic ductal adenocarcinoma-resection group), 180 who underwent pancreatectomy for intraductal papillary mucinous neoplasm (intraductal papillary mucinous neoplasm-resection group), and 263 whose intraductal papillary mucinous neoplasms were left untreated (nonresection group). The incidence and timing of the development of a concomitant pancreatic ductal adenocarcinoma during the surveillance of patients with and without partial pancreatectomy for intraductal papillary mucinous neoplasm were investigated using the Kaplan-Meier method.

RESULTS

During a median surveillance period of 40 months (range 6-262 months), 5 patients in the pancreatic ductal adenocarcinoma-resection group, 6 in the intraductal papillary mucinous neoplasm-resection group, and 8 in the nonresection group developed concomitant pancreatic ductal adenocarcinoma. The estimated 5-year (17%) and 10-year (56%) cumulative incidences of secondary pancreatic ductal adenocarcinoma in the pancreatic ductal adenocarcinoma-resection group were significantly greater than those in the other two groups (P < .01). Conversely, the difference in the estimated cumulative incidence of concomitant pancreatic ductal adenocarcinoma between the intraductal papillary mucinous neoplasm-resection and nonresection groups was not significant (5-year, 5.0% vs 2.2%; 10-year, 5.0% vs 8.7%; P = .87).

CONCLUSION

Long-term (≥5-year) surveillance in patients with intraductal papillary mucinous neoplasm is necessary and important because of the potential for development of concomitant pancreatic ductal adenocarcinoma. Those with a history of resection of concomitant pancreatic ductal adenocarcinoma at the time of the initial operation are at quite high risk for the development of secondary pancreatic ductal adenocarcinoma.

Diabetes mellitus in intraductal papillary mucinous neoplasm of the pancreas is associated with high-grade dysplasia and invasive carcinoma

BACKGROUND

While the association between Diabetes Mellitus (DM) and pancreatic ductal adenocarcinoma is well recognized, its importance in intraductal papillary mucinous neoplasm of the pancreas (IPMN) is not well-defined. We sought to examine the associations of DM with degree of dysplasia and morphological subtypes in IPMN.

METHODS

In 454 patients with resected IPMN, we evaluated associations of DM with high-grade dysplasia (HGD), invasive carcinoma, precursor epithelial subtype (gastric, intestinal, oncocytic, pancreatobiliary), and histological type of invasive carcinomas (tubular, colloid, oncocytic) using logistic regression. We performed multivariate analyses adjusting for worrisome features and high-risk stigmata of malignancy in a subset of 289 patients with annotated radiological characteristics.

RESULTS

The prevalence of DM in our study was 34%. DM was significantly associated with HGD (OR 2.02, 95% CI 1.02-4.01, P = 0.045) and invasive carcinoma (OR 2.05, 95% CI 1.08-3.87, P = 0.027) after adjusting for worrisome features. Compared to patients without DM, those with recent-onset DM (≤5 years before surgery) had 6.9-fold (95% CI 2.38-19.92, P < 0.001) higher risk of invasive carcinoma. DM was associated with increased likelihood of intestinal-type precursor epithelium (OR 1.63, 95% CI 1.07-2.47, P = 0.022) and colloid carcinomas (OR 2.46, 95% CI 1.01-5.99, P = 0.047) CONCLUSION: Preoperative DM was associated with significantly higher risk of HGD and invasive carcinoma in resected IPMN, and risk of invasive carcinoma was highest in patients with recent-onset DM. Patients with DM were more likely to harbor intestinal-type IPMN and colloid carcinomas. Our findings suggest that a diagnosis of DM in patients with IPMN may warrant more aggressive surveillance.

Revisions of international consensus Fukuoka guidelines for the management of IPMN of the pancreas

The management of intraductal papillary mucinous neoplasm (IPMN) continues to evolve. In particular, the indications for resection of branch duct IPMN have changed from early resection to more deliberate observation as proposed by the international consensus guidelines of 2006 and 2012. Another guideline proposed by the American Gastroenterological Association in 2015 restricted indications for surgery more stringently and recommended physicians to stop surveillance if no significant change had occurred in a pancreatic cyst after five years of surveillance, or if a patient underwent resection and a non-malignant IPMN was found. Whether or not it is safe to do so, as well as the method and interval of surveillance, has generated substantial debate. Based on a consensus symposium held during the meeting of the International Association of Pancreatology in Sendai, Japan, in 2016, the working group has revised the guidelines regarding prediction of invasive carcinoma and high-grade dysplasia, surveillance, and postoperative follow-up of IPMN. As the working group did not recognize the need for major revisions of the guidelines, we made only minor revisions and added most recent articles where appropriate. The present guidelines include updated information and recommendations based on our current understanding, and highlight issues that remain controversial or where further research is required.

Comparison of guidelines for intraductal papillary mucinous neoplasm: What is the next step beyond the current guidelines?

Management of intraductal papillary mucinous neoplasm is controversial, and several guidelines have aimed to establish an adequate strategy for surgical resection and surveillance. We compared various intraductal papillary mucinous neoplasm guidelines and considered new matters that are pivotal for improved treatment of intraductal papillary mucinous neoplasm. We identified and compared 11 published guidelines, three of which were major guidelines that mainly referred to the diagnosis and treatment of intraductal papillary mucinous neoplasm (International Association of Pancreatology 2012 guidelines, European Study Group on Cystic Tumours of the Pancreas 2013 guidelines, and American Gastroenterological Association 2015 guidelines). The main concerns of these three guidelines were indication for surgery and follow up of non-resected lesions. Among the differences between the three guidelines, the period of surveillance recommended was the most controversial matter. Meanwhile, several nomograms have been proposed to improve the diagnosis of intraductal papillary mucinous neoplasm from the level of experts' experiences to that of rational systems. We discuss the adequate strategy of surveillance for intraductal papillary mucinous neoplasm with and without pancreatectomy and nomograms aiming to predict the risk of malignancy in patients with intraductal papillary mucinous neoplasm.

Prognostic value of histological subtype in intraductal papillary mucinous neoplasm of the pancreas: A retrospective analysis of outcome from one single center

We sought to retrospectively analyze the outcomes of patients with intraductal papillary mucinous neoplasm (IPMN) at our pancreatic surgery center, and to evaluate the prognostic value of histological subtype.The clinical data of 121 IPMNs treated in our center between 2005 and 2014 were retrospectively analyzed. Pathological slides were thoroughly reviewed by 2 specialized pathologists.Of the 121 patients, 48, 57, and 16 had main-duct, branch-duct, and mixed type IPMNs, respectively. Forty-one patients had invasive IPMNs. Histological subtypes consisted of 35 intestinal (28.9%), 56 gastric (46.3%), 29 pancreatobiliary (24.0%), and 1 oncocytic type (0.8%). Histological subtype was associated with radiological type, T stage, and degree of dysplasia (P < .05). No significant difference in overall survival was observed among the 4 histological subtypes, regardless of whether we considered all IPMNs (P = .106), or invasive IPMNs only (P = .828). However, the overall survival was associated with radiological type, T stage, degree of dysplasia, lymph-node status, and nerve invasion. For invasive IPMNs, the overall survival was associated with nerve invasion and lymph-node status; however, the association between nerve invasion and overall survival lost statistical significance after multivariate analysis.Histological subtype had limited prognostic value in patients with IPMNs, and the main prognostic factor for patients with invasive IPMNs was the lymph-node status.

Spectrum and Classification of Cystic Neoplasms of the Pancreas

As patients are living longer and axial imaging is more widespread, increasing numbers of cystic neoplasms of the pancreas are found. Intraductal papillary mucinous neoplasms and mucinous cystic neoplasms are the most common. The revised Sendai guidelines provide a safe algorithm for expectant management of certain cystic neoplasms; however, studies are ongoing to identify further subgroups that can be treated nonoperatively. For those patients with high-risk clinical features or symptoms, surgical resection can be performed safely at high-volume pancreatic centers. Accurate diagnosis is critical for accurate decision making.

Pathology of Pancreatic Cancer Precursor Lesions

To better understand pancreatic ductal adenocarcinoma (PDAC) and improve its prognosis, it is essential to understand its origins. This article describes the pathology of the 3 well-established pancreatic cancer precursor lesions: pancreatic intraepithelial neoplasia, intraductal papillary mucinous neoplasm, and mucinous cystic neoplasm. Each of these precursor lesions has unique clinical findings, gross and microscopic features, and molecular aberrations. This article focuses on histopathologic diagnostic criteria and reporting guidelines. The genetics of these lesions are briefly discussed. Early detection and adequate treatment of pancreatic cancer precursor lesions has the potential to prevent pancreatic cancer and improve the prognosis of PDAC.

Intraductal Papillary Mucinous Neoplasm of the Pancreas: Current Perspectives

In this article, we aimed to review the literature on the clinics and management of intraductal papillary mucinous neoplasm (IPMN). Intraductal papillary mucinous neoplasm of the pancreas is a mucin-producing cystic mass originating from the pancreatic ductal system. Approximately 25% of the pancreatic neoplasms resected surgically and 50% of pancreatic cysts detected incidentally are IPMNs. They can be benign or malignant in character, while malignant transformation of benign forms can be encountered. It is important to determine IPMNs in the early stages, implementation of appropriate treatment approaches, and follow-up to provide better prognosis. We reviewed the studies published in the English medical literature through PubMed and summarized the clinical features and current approaches to the treatment and follow-up of the IPMN. Due to the recent advances and widespread implementation of radiological imaging techniques, the incidental detection rate of IPMNs has increased significantly. The effective treatment of the disease is possible via the detailed diagnosis of the disease, determination of the prognostic factors, and a multidisciplinary approach. Recent literature also emphasized the molecular profile determination approaches for assessment of prognosis of patients with IPMN. Current knowledge on IPMN, a clinically important epidemiologic problem, shows that the treatment should be personalized considering the prognostic features and life expectancy of the patient.

Prevalence, Diagnosis and Management of Pancreatic Cystic Neoplasms: Current Status and Future Directions

Cystic neoplasms of the pancreas are found with increasing prevalence, especially in elderly asymptomatic individuals. Although the overall risk of malignancy is very low, the presence of these pancreatic cysts is associated with a large degree of anxiety and further medical investigation due to concerns about malignancy. This review discusses the different cystic neoplasms of the pancreas and reports diagnostic strategies based on clinical features and imaging data. Surgical and nonsurgical management of the most common cystic neoplasms, based on the recently revised Sendai guidelines, is also discussed, with special reference to intraductal papillary mucinous neoplasm (IPMN; particularly the branch duct variant), which is the lesion most frequently identified incidentally. IPMN pathology, its risk for development into pancreatic ductal adenocarcinoma, the pros and cons of current guidelines for management, and the potential role of endoscopic ultrasound in determining cancer risk are discussed. Finally, surgical treatment, strategies for surveillance of pancreatic cysts, and possible future directions are discussed.

Intraductal Papillary Mucinous Neoplasms Often Contain Epithelium From Multiple Subtypes and/or Are Unclassifiable

Pancreatic intraductal papillary mucinous neoplasms (IPMNs) are subclassified into gastric, intestinal, pancreatobiliary, and oncocytic subtypes based on histologic features. The WHO classification scheme suggests use of immunohistochemical stains to help subtype IPMNs with ambiguous histology. Seventy-two pancreatic IPMN resections between 2008 and 2014 were retrospectively evaluated. Immunohistochemistry for CDX2, MUC2, and MUC5AC was performed on cases where the histologic subtype could not be determined on routine hematoxylin and eosin (H&E) sections. There were 41 gastric (57%), 8 intestinal (11%), 4 pancreatobiliary (6%), and 1 oncocytic (1%) IPMNs. Eighteen (25%) IPMNs were either unclassifiable due ambiguous morphology or contained distinct epithelium from >1 subtype (i.e., "mixed"). Two IPMNs initially unclassifiable strictly by H&E morphology were definitively classified as intestinal after positive immunohistochemical staining with CDX2, MUC2, and MUC5AC. Immunohistochemistry for another 7 IPMNs unclassifiable by H&E did not indicate a clear subtype and often contained discordant results (e.g., discordant CDX2 and MUC2 staining). In our experience, a considerable number of IPMNs are either unclassifiable or contain epithelium from >1 subtype. Furthermore, among those IPMNs initially unclassifiable by H&E morphology, application of immunohistochemical stains to aid in subtyping allow for definite classification in only a small subset of cases. These data, when taken in context with the significant ranges in the reported prevalence of specific histologic subtypes, suggest that accurate IPMN subtyping is poorly reproducible in up to 25% of cases, and in these problematic cases, immunohistochemistry adds little value.

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.

Thirty years of experience with intraductal papillary mucinous neoplasm of the pancreas: from discovery to international consensus

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is characterized by intraductal papillary proliferation of mucin-producing epithelial cells that exhibit various degrees of dysplasia. IPMN is classified as the main duct type (MD-IPMN) and the branch duct type (BD-IPMN) according to the location of involvement, and into four histological subtypes (gastric, intestinal, pancreatobiliary, and oncocytic) according to the histomorphological and immunohistochemical characteristics. Mucin core protein expression correlates with the biological behavior and prognosis of the tumor. DNA analysis has shown that IPMN is associated with a number of gene mutations, but the roles of many of these mutations require further investigation. Most patients with MD-IPMN undergo tumor resection. Patients with BD-IPMN who do not undergo resection may develop malignant change, and concomitant separate pancreatic cancer occurs in 2-10% of patients with IPMN. Patients with a strong family history may develop multiple BD-IPMNs as well as concomitant pancreatic cancer. Malignant changes are relatively easy to detect, especially by endoscopic ultrasonography (EUS), but the optimal surveillance protocol is currently unclear.

KEY MESSAGES

The 2012 guidelines for the management of IPMN recommend that patients with 'high-risk stigmata' (obstructive jaundice, enhanced solid component, and main pancreatic duct size ≥10 mm) should undergo resection. Patients with 'worrisome features' (cyst size ≥3 cm, thickened enhanced cyst walls, non-enhanced mural nodules, main pancreatic duct size 5-9 mm, abrupt change in main pancreatic duct caliber with distal pancreatic atrophy, lymphadenopathy, and clinical acute pancreatitis) should be evaluated by EUS. EUS is a more sensitive test than computed tomography or magnetic resonance imaging for the early detection of malignancy.

CONCLUSIONS

Most patients with MD-IPMN should undergo tumor resection. Patients with BD-IPMN who do not undergo resection should undergo careful surveillance including EUS for the early detection of malignant change and separate pancreatic cancer.

Intraductal Papillary Mucinous Adenocarcinoma of the Pancreas: Clinical Outcomes, Prognostic Factors, and the Role of Adjuvant Therapy

BACKGROUND

Intraductal papillary mucinous adenocarcinoma (IPMCs) occur more frequently in main-duct intraductal papillary mucinous neoplasms.

METHODS

Review of the literature.

RESULTS

The prognosis of IPMCs depends on its histopathological subtype: colloid IPMCs have superior survival rates mainly secondary to more favorable pathological features, whereas tubular IPMCs have survival outcomes similar to that of conventional pancreatic adenocarcinomas. The epithelial background plays an equally important role in defining the biology of IPMCs: gastric IPMC subtypes demonstrate an overall worse survival outcome when compared to intestinal, pancreatobiliary, and oncocytic subtypes. Lymph node involvement is one of the strongest predictors of survival in IPMC, with a decreasing overall survival as the lymph node ratio increases. There is little evidence to support adjuvant chemoradiation in patients with IPMC.

CONCLUSION

Our current understanding of IPMC biology based on histopathological and epithelial background subtypes as well as clinicopathological predictors should influence patient counseling and selection for adjuvant therapy.

Intraductal Papillary Mucinous Neoplasm of Pancreas

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are neoplasms that are characterized by ductal dilation, intraductal papillary growth, and thick mucus secretion. This relatively recently defined pathology is evolving in terms of its etiopathogenesis, clinical features, diagnosis, management, and treatment guidelines. A PubMed database search was performed. All the relevant abstracts in English language were reviewed and the articles in which cases of IPMN could be identified were further scrutinized. Information of IPMN was derived, and duplication of information in several articles and those with areas of persisting uncertainties were excluded. The recent consensus guidelines were examined. The reported incidence of malignancy varies from 57% to 92% in the main duct-IPMN (MD-IPMN) and from 6% to 46% in the branch duct-IPMN (BD-IPMN). The features of high-risk malignant lesions that raise concern include obstructive jaundice in a patient with a cystic lesion in the pancreatic head, the findings on radiological imaging of a mass lesion of >30 mm, enhanced solid component, and the main pancreatic duct (MPD) of size ≥10 mm; while duct size 5-9 mm and cyst size <3 mm are considered as “worrisome features.” Magnetic resonance imaging (MRI) and endoscopic ultrasound (EUS) are primary investigations in diagnosing and following up on these patients. The role of pancreatoscopy and the analysis of aspirated cystic fluid for cytology and DNA analysis is still to be established. In general, resection is recommended for most MD-IPMN, mixed variant, and symptomatic BD-IPMN. The 5-year survival of patients after surgical resection for noninvasive IPMN is reported to be at 77-100%, while for those with invasive carcinoma, it is significantly lower at 27-60%. The follow-up of these patients could vary from 6 months to 1 year and would depend on the risk stratification for invasive malignancy and the pathology of the resected specimen. The understanding of IPMN has evolved over the years. The recent guidelines have played a role in this regard.

A vascular endothelial growth factor gene polymorphism predicts malignant potential in intraductal papillary mucinous neoplasm

OBJECTIVES

The aim of this study was to evaluate the clinical relevance of vascular endothelial growth factor (VEGF) single nucleotide polymorphisms (SNPs) in intraductal papillary mucinous neoplasms (IPMNs).

METHODS

A total of 169 IPMN and 108 pancreatic ductal adenocarcinoma patients who underwent curative resection were enrolled, and VEGF +405G/C and -460C/T SNPs were investigated.

RESULTS

Vascular endothelial growth factor +405C/C was found more frequently in malignant IPMNs compared with +405G/G (odds ratio [OR], 2.7; P = 0.04), and +405C allele was associated with malignant IPMNs compared with +405G (P = 0.055). In branch duct IPMNs, VEGF +405C/C was significantly associated with malignant transformation (CC vs GG: OR, 4.0; P = 0.03; CC vs CG + GG: OR, 3.3; P = 0.04), and there was a trend of VEGF +405C/C associated with malignant transformation of gastric-type IPMNs (CC vs GG: OR, 3.0; P = 0.07). When the survival outcomes were analyzed based on VEGF +405G/C SNPs, however, there was no relationship between VEGF SNPs and overall survival in patients with both IPMNs and pancreatic ductal adenocarcinomas.

CONCLUSIONS

Vascular endothelial growth factor +405G/C SNP was significantly associated with malignant transformation in IPMNs, especially branch duct and gastric-type IPMNs. Vascular endothelial growth factor +405G/C SNP might be helpful in predicting clinical course in pancreatic disease with potential for malignant transformation.

Current roles of endoscopy in the management of intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is characterized by intraductal papillary proliferation of mucin-producing epithelial cells that exhibit various degrees of dysplasia. IPMN is classified into four histological subtypes (gastric, intestinal, pancreatobiliary, and oncocytic) according to its histomorphological and immunohistochemical characteristics. Endoscopic retrograde cholangiopancreatography plays a crucial role in the evaluation of these features of IPMN. Endoscopic ultrasonography (EUS) has proven to be more sensitive than computed tomography or magnetic resonance imaging for early detection of malignancy. The present review addresses the current roles of endoscopy and related techniques in the management of IPMN. The particular focus is on diagnosing IPMN and malignancy within IPMN, detecting pancreatic cancer concomitant with IPMN, differentiating the epithelial subtypes of IPMN, determining the optimal strategy for the management of branch duct IPMN, and discussing innovative endoscopic technology related to IPMN. The disadvantages of endoscopic examinations of IPMN and different attitudes toward EUS-guided fine-needle aspiration for IPMN between Japan (negative) and other countries (active) are also discussed.

Oncocytic-type intraductal papillary mucinous neoplasms: a unique malignant pancreatic tumor with good long-term prognosis

BACKGROUND

The different epithelial phenotypes of intraductal papillary mucinous neoplasms (IPMNs) are predictors of tumor biology and post-surgical outcomes. Oncocytic-type IPMN (O-IPMN) seems to have a unique natural history, but not much information is available because of its rarity. We sought to describe the characteristics of a cohort of patients resected for O-IPMNs, focusing on their long-term outcomes after surgery.

STUDY DESIGN

We conducted a retrospective review of the demographics, clinical presentation, pathology, and survival of a cohort of patients resected for IPMN between 1990 and 2013, comparing O-IPMN with other IPMN subtypes.

RESULTS

Eighteen of 400 patients (4.5%) who underwent resection for IPMN had the oncocytic subtype. Compared with other IPMN patients, those with O-IPMNs were more likely to be male (72% vs 45%; p = 0.02) and to have main pancreatic duct involvement (72% vs 42%; p = 0.01). Oncocytic IPMNs occurred in asymptomatic individuals in 67% of cases. They had either invasive carcinoma (61%) or high-grade dysplasia (39%), and the proportions in other epithelial subtypes were 19% and 21%, respectively (p < 0.001). After resection, the 10-year recurrence rate for O-IPMNs was 46%. Recurrences occurred up to 11 years after the initial resection and a completion total pancreatectomy was performed in 4 patients. At a median follow-up of 7 years, no patients with O-IPMN had died from the disease.

CONCLUSIONS

Oncocytic IPMN is a unique tumor subtype that occurs mostly in the main pancreatic duct and is malignant. Recurrences after resection are not uncommon and can occur more than 10 years after the initial resection. Reoperations for recurrent O-IPMN are often feasible and have excellent results in terms of survival.

Systematic review and meta-analysis of the spectrum and outcomes of different histologic subtypes of noninvasive and invasive intraductal papillary mucinous neoplasms

BACKGROUND

Our aim was to review the available evidence to determine the clinical importance of the histologic subtypes of noninvasive and invasive intraductal papillary mucinous neoplasms (IPMNs) on disease characteristics and overall survival.

METHODS

We reviewed systematically 14 comparative studies that reported clinicopathologic characteristics and survival of 1,617 patients with IPMN (900 noninvasive and 717 invasive).

RESULTS

The pancreatobiliary subtype was associated with the greatest likelihood of tumor invasion (67.9%; odds ratio [OR], 2.87; 95% CI, 1.90-4.35), harboring an associated mural nodule (56.6%; OR, 2.92; 95% CI, 1.21-7.04), demonstrating tumor recurrence (46.3%; OR, 3.28; 95% CI, 1.41-7.66) and transformation to tubular adenocarcinoma (81.8%; OR, 92.96; 95% CI, 20.76-416.28) among all subtypes. The gastric subtype was associated with the least likelihood of tumor invasion (10.2%; OR, 0.18; 95% CI, 0.13-0.26), association with main duct IPMN (19.2%; OR, 0.12; 95% CI, 0.06-0.26), and tumor recurrence (9.4%; OR, 0.47; 95% CI, 0.26-0.83) among all subtypes. The intestinal subtype had the greatest likelihood of progressing to colloid carcinoma among all subtypes. Tubular adenocarcinoma was associated with an increased risk of vascular invasion (32.9%; OR, 4.86; 95% CI, 1.96-12.01), perineural invasion (54.5%; OR, 2.30; 95% CI, 1.22-4.34), nodal metastasis (52.4%; OR, 3.31; 95% CI, 1.79-6.14), and a positive margin status (17.3%; OR, 8.45; 95% CI, 1.52-46.83). Tubular adenocarcinoma (hazard ratio [HR], 1.90; 95% CI, 1.36-2.67) had a poorer 5-year overall survival compared with colloid carcinoma and was similar to the survival observed in pancreatic ductal adenocarcinoma (HR, 2.00; 95% CI, 1.59-2.52).

CONCLUSION

The prognosis of IPMN depends on its pathologic subtype. Subtype identification should be considered an essential component in future guidelines for the management of IPMN.

"High-risk stigmata" of the 2012 international consensus guidelines correlate with the malignant grade of branch duct intraductal papillary mucinous neoplasms of the pancreas

OBJECTIVES

The 2012 international consensus guidelines for the management of intraductal papillary mucinous neoplasm (IPMN) of the pancreas stratified patients into 2 clinical categories, "high-risk stigmata" and "worrisome features," and recommended different therapeutic strategies for these groups. The aim of this study was to elucidate the significance of these categories in terms of predicting malignant IPMNs.

METHODS

The medical records of 100 consecutive patients who underwent pancreatectomy for IPMNs were retrospectively reviewed. Seventy patients with branch duct IPMNs (BD-IPMNs) were stratified into 3 groups. The relationships between the number of predictive factors and histopathologic grade were investigated.

RESULTS

The prevalence rates of malignant IPMN, invasive carcinoma, and lymph node metastasis in the high-risk group were 80%, 55%, and 20%, respectively, with these percentages significantly increasing in a stepwise manner according to the number of predictive factors. In contrast, there was no significant correlation between the number of worrisome features and grade of malignancy in patients stratified as having worrisome BD-IPMNs.

CONCLUSIONS

The number of high-risk stigmata correlated significantly with the grade of malignancy of BD-IPMNs. The presence of at least 1 high-risk stigma in patients with BD-IPMNs indicates a need for pancreatectomy with lymphadenectomy.

Systematic review and meta-analysis comparing the surgical outcomes of invasive intraductal papillary mucinous neoplasms and conventional pancreatic ductal adenocarcinoma

OBJECTIVE

The aim of this study was to summarize the current literature comparing the surgical outcomes of invasive intraductal papillary mucinous neoplasms (IPMN(INV)) and conventional pancreatic ductal adenocarcinomas (PDAC) in order to determine the differences in disease characteristics and prognosis.

METHODS

Systematic review of the literature yielded 12 comparative studies reporting the clinicopathological characteristics and overall survival (OS) of 1,450 patients with IPMN(INV) with 19,304 patients with conventional PDAC.

RESULTS

IPMN(INV) had a significantly lower likelihood of tumors extending beyond the pancreas [27.6 vs. 94.3 %; T4 vs. T1: odds ratio (OR) 0.111, 95 % confidence intervals (CI) 0.057-0.214], nodal metastasis (45.4 vs. 62.9 %: OR 0.507, 95 % CI 0.347-0.741), positive margin (14.2 vs. 28.3 %; OR 0.438, 95 % CI 0.322-0.596), perineural invasion (49.2 vs. 76.5 %; OR 0.304, 95 % CI 0.106-0.877) and vascular invasion (25.2 vs. 45.7 % OR 0.417, 95 % CI 0.177-0.980) when compared with PDAC. The 5-year OS of IPMN(INV) was significantly better than PDAC [31.4 vs. 12.4 %: hazard ratio (HR) 0.659, 95 % CI 0.574-0.756]. The tubular subtype had a poorer 5-year OS and demonstrated significantly more aggressive features such as nodal metastases, vascular invasion, and perineural invasion compared with the colloid subtype.

CONCLUSION

IPMN(INV) were significantly more likely to present at an earlier stage and were less likely to demonstrate nodal involvement, perineural invasion and vascular invasion. When controlled for stage, IPMN(INV) had an improved OS when compared with PDAC in the early stages.

Elevated expression level of microRNA-196a is predictive of intestinal-type intraductal papillary mucinous neoplasm of the pancreas

OBJECTIVES

Aberrant expression of several microRNAs (miRs) has been reported in various neoplasms including intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. MicroRNA-196a (miR-196a) is up-regulated in Barrett esophagus (characterized by intestinal metaplasia) and in colorectal cancer; this relationship between intestinal characteristics and miR-196a might also be applicable to intestinal-type IPMNs. The aim of this study was to evaluate whether intestinal-type IPMNs can be discriminated from non-intestinal-type IPMNs by the expression level of miR-196a in tissue and pancreatic juice samples.

METHODS

Thirty-seven formalin-fixed paraffin-embedded tissue samples (including 3 of normal pancreatic ducts) and 36 pancreatic juice samples were obtained. The expression level of miR-196a measured by quantitative reverse transcription-polymerase chain reaction assays was compared between intestinal-type and non-intestinal-type IPMNs.

RESULTS

MicroRNA-196a expression in intestinal-type IPMN tissue samples (n = 18) was significantly higher than that of non-intestinal-type IPMNs (n = 16) (P < 0.001). Similarly, miR-196a expression in pancreatic juice samples of intestinal-type IPMNs (n = 6) was significantly higher than that of non-intestinal-type IPMNs (n = 30) (P = 0.008), and the sensitivity and specificity for prediction of intestinal-type IPMNs using pancreatic juice samples were both 83%.

CONCLUSIONS

Elevated expression of miR-196a in pancreatic juice samples is predictive of intestinal-type IPMNs.

Precursor lesions for sporadic pancreatic cancer: PanIN, IPMN, and MCN

Pancreatic cancer is still a dismal disease. The high mortality rate is mainly caused by the lack of highly sensitive and specific diagnostic tools, and most of the patients are diagnosed in an advanced and incurable stage. Knowledge about precursor lesions for pancreatic cancer has grown significantly over the last decade, and nowadays we know that mainly three lesions (PanIN, and IPMN, MCN) are responsible for the development of pancreatic cancer. The early detection of these lesions is still challenging but provides the chance to cure patients before they might get an invasive pancreatic carcinoma. This paper focuses on PanIN, IPMN, and MCN lesions and reviews the current level of knowledge and clinical measures.

Treatment strategy for main duct intraductal papillary mucinous neoplasms of the pancreas based on the assessment of recurrence in the remnant pancreas after resection: a retrospective review

OBJECTIVES

To clarify the recurrence pattern after resection of main duct intraductal papillary mucinous neoplasms (MD-IPMNs) using molecular analyses and determine the most adequate treatment strategy.

BACKGROUND

The most appropriate resection line for MD-IPMNs remains an unresolved issue.

METHODS

Medical records of 56 patients with pancreatectomy were retrospectively reviewed. Histological subtypes and Kras/GNAS mutations were assessed in patients with recurrence in the remnant pancreas.

RESULTS

Forty-nine patients underwent partial pancreatectomy and 7 underwent total pancreatectomy. Thirty-six patients (64%) had malignant MD-IPMNs. Recurrence was observed in 7 of 49 patients (14%), including 6 with malignant IPMNs and 1 with pancreatic ductal adenocarcinoma, all of whom underwent remnant pancreatectomy. The cumulative disease-specific survival rate of patients with pancreatic recurrence was greater than that of patients with extrapancreatic recurrence (P < 0.001). Although the pancreatic margin status at the initial operation did not affect the pancreatic recurrence rate, all 4 recurrent IPMNs examined had histological subtypes and Kras/GNAS mutations identical to those of the initial lesions. Four patients experienced recurrence in the remnant pancreas or systemic recurrence after resection of high-grade dysplasia of MD-IPMN. Three of the 56 patients had concomitant pancreatic ductal adenocarcinomas and MD-IPMNs.

CONCLUSIONS

One-step total pancreatectomy can be avoided, and remnant total pancreatectomy would lead to favorable outcomes even in patients with pancreatic recurrence, some cases of which seem to involve residual lesions. Postoperative surveillance of high-grade dysplasia should be performed as if malignant, and close attention should be paid to the occurrence of concomitant pancreatic ductal adenocarcinomas in patients with MD-IPMNs.

Disease spectrum of intraductal papillary mucinous neoplasm with an associated invasive carcinoma invasive IPMN versus pancreatic ductal adenocarcinoma-associated IPMN

OBJECTIVES

Current version of World Health Organization classification introduced the concept of ‘‘intraductal papillary mucinous neoplasm(IPMN) with an associated invasive carcinoma.’’ The authors investigated the clinicopathologic characteristics and prognosis of this disease category according to tumor morphology and percentage of invasive component.

METHODS

Fifty-nine patients who underwent surgical resection of IPMN with an associated invasive carcinoma at Seoul National University Hospital were subgrouped according to the invasive component of less than 5% (minimally invasive [MI] intraductal papillary mucinous carcinoma [IPMC] [MI-IPMC]), 5%- 50% (invasive IPMC [IPMC-I]),and 50% or greater (pancreatic ductal adenocarcinoma [PDAC]-associated IPMN [PDAC-IPMN]). Prognosis was compared with 219 curatively resected conventional PDAC.

RESULTS

Eleven MI-IPMCs (18.6%), 24 IPMC-Is (40.7%), and 24PDAC-IPMNs (40.7%) were identified. With the transition from MIIPMC to IPMC-I and PDAC-IPMN, percentage of advanced T (P G0.001) or N stage (P = 0.001), expression of S100A4 (P = 0.004), p53(P = 0.028), and CD24 (P = 0.009) increased; and SMAD4 expression decreased (P G 0.001). The overall 5-year survival rates for MIIPMC,IPMC-I, and PDAC-IPMN were 80.8%, 59.0%, and 29.3%,respectively (P G 0.001). Pancreatic ductal adenocarcinoma-associated IPMN had poor prognosis compared with MI-IPMC (P = 0.011) or IPMC-I (P = 0.026) but had comparable prognosis with conventional PDAC (P = 0.138).

CONCLUSIONS

Pancreatic ductal adenocarcinoma-associated IPMN has different clinicopathological characteristics compared with the IPMC-I.Intraductal papillary mucinous neoplasm with an associated invasive carcinoma is composed of a wide spectrum of disease.

Pathohistological subtype predicts survival in patients with intraductal papillary mucinous neoplasm (IPMN) of the pancreas

OBJECTIVE

To investigate different subtypes of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas and their prognostic value.

BACKGROUND

IPMNs of the pancreas are estimated to have a better prognosis than pancreatic ductal adenocarcinomas (PDACs). In addition to the different growth types (ie, main duct vs. branch duct types), the histological subtypes of IPMNs (ie, intestinal, pancreatobiliary, gastric, and oncocytic type) are prognostically relevant. These subtypes can be characterized by different mucin (MUC) expression patterns. In this study, we analyzed the IPMNs from 2 pancreatic cancer referral centers by correlating the MUC expression, histological subtype, and clinical outcome.

METHODS

We re-evaluated all resections due to a pancreatic tumor over a period of 15 years. Cases with IPMNs were identified, and the subtypes were distinguished using histopathological analysis, including the immunohistochemical analysis of MUC (ie, MUC1, MUC2, and MUC5AC) expression. Furthermore, we determined clinical characteristics and patient outcome.

RESULTS

A total of 103 IPMNs were identified. On the basis of the MUC profile, histopathological subtypes were classified into the following categories: intestinal type [n = 45 (44%)], pancreatobiliary type [n = 41 (40%)], gastric type [n = 13 (12%)], and oncocytic type [n = 4 (4%)]. The following types of resections were performed: pancreatic head resections [n = 77 (75%)], tail resections [n = 16 (15%)], total pancreatectomies [n = 5 (5%)], and segment resections [n = 5 (5%)]. The 5-year survival of patients with intestinal IPMNs was significantly better than pancreatobiliary IPMNs (86.6% vs. 35.6%; P < 0.001). The pancreatobiliary subtype was strongly associated with malignancy [odds ratio (OR): 6.76], recurrence (P < 0.001), and long-term survival comparable with that of PDAC patients.

CONCLUSIONS

Evaluation of IPMN subtypes supports postoperative patient prognosis prediction. Therefore, subtype differentiation could lead to improvements in clinical management. Potentially identifying subgroups with the need for adjuvant therapy may be possible.

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.

Intraductal papillary mucinous neoplasms of the pancreas with distinct pancreatic ductal adenocarcinomas are frequently of gastric subtype

OBJECTIVE

To identify a high-risk group of patients with pancreatic ductal adenocarcinoma (PDAC), independently arising in the pancreas with intraductal papillary mucinous neoplasm (IPMN), using histopathologic subtypes.

BACKGROUND

Pathologic features of IPMN with distinct PDAC, including histopathologic subtypes of IPMN and PDAC phenotypes, have not been well characterized. Mucin expression patterns and the mutational status of GNAS and KRAS are useful to explore the relationship between these 2 lesion types.

METHODS

Clinicopathologic data of 179 resected IPMNs and 180 resected PDACs without IPMNs as a control group were reviewed. IPMNs were classified into 4 grades (low-grade, intermediate-grade, high-grade dysplasia, and an associated invasive carcinoma) and 4 subtypes (gastric, intestinal, pancreatobiliary, and oncocytic). The expression of MUC1, MUC2, MUC5AC, MUC6, and CDX2 was investigated by immunohistochemistry in IPMNs and PDACs with and without IPMNs. The mutational status of GNAS and KRAS was evaluated by cycle sequencing in PDACs and pre-/coexisting IPMNs.

RESULTS

Twenty-six synchronous or metachronous PDACs were identified in 20 patients (11.2%) with IPMNs. Occurrence of concomitant PDACs was more frequently observed in gastric-type IPMNs (18/110, 16.4%) compared with intestinal (1/49, 2.0%), pancreatobiliary (1/17, 5.9%), or oncocytic-type (0/3, 0%) (P = 0.047). Both PDACs with and without IPMNs were frequently positive for MUC1, MUC5AC, and MUC6 expression, as assessed by immunohistochemistry, but were negative for MUC2 and CDX2. The mucin-staining patterns were similar to those of invasive tubular adenocarcinoma arising from gastric-type IPMNs. Mutation of GNAS within codon 201 was not detected in PDACs and gastric-type IPMNs, whereas most of these exhibited KRAS mutations. However, the R201H GNAS mutation was detected in 1 intestinal-type IPMN with distinct PDAC.

CONCLUSIONS

Mucin expression patterns demonstrate that PDAC without GNAS mutations of an aggressive phenotype frequently arise in the pancreas with benign gastric-type IPMN in the absence of GNAS mutations.

Evaluation of clinical meaning of histological subtypes of intraductal papillary mucinous neoplasm of the pancreas

OBJECTIVES

Prognostic value of histological subtypes of pancreatic intraductal papillary mucinous neoplasm (IPMN) has been reported to have conflicting results. The authors investigated the clinicopathological characteristics and prognostic significance of the histological subtypes of IPMNs with various degrees of dysplasia.

METHODS

Two hundred thirteen patients with surgically treated pancreatic IPMN at a single tertiary care referral center were included. Pathological slides were thoroughly reviewed by a specialized pathologist.

RESULTS

Of the 213 patients, 38 low-grade, 97 intermediate-grade, and 18 high-grade dysplasia and 59 IPMNs with an associated invasive carcinoma (invasive IPMN) were identified. Histological subtypes consisted of 135 gastric (63.4%), 38 intestinal (17.8%), 38 pancreatobiliary (17.8%), and 2 oncocytic types (0.9%). Histological subtypes were associated with radiological type (P < 0.001), degree of dysplasia (P < 0.001), and T stage (P < 0.001). The proportions of invasive IPMN were 14.1%, 42.1%, 57.9%, and 100% of gastric, intestinal, pancreatobiliary, and oncocytic types, respectively. Disease-specific survival was not affected by histological subtype in overall patients (P = 0.881). For invasive IPMNs, histological subtypes had a marginal significance on survival (P = 0.050), which lost statistical significance after multivariate analysis (P = 0.341).

CONCLUSIONS

Although histological subtypes are associated with the degree of dysplasia, histological subtypes have limited prognostic value for pancreatic IPMNs.

Pancreatic cystic neoplasms: management and unanswered questions

Approximately 10% of persons 70 years old or older are now diagnosed with pancreatic cysts, but it is not clear which ones require additional analysis, interventions, or follow-up. Primary care doctors rely on gastroenterologists for direction because no one wants to miss a diagnosis of pancreatic cancer, but meanwhile there is pressure to limit use of diagnostic tests and limit costs. We review the different cystic neoplasms of the pancreas and diagnostic strategies based on clinical features and imaging data. We discuss surgical and nonsurgical management of the most common cystic neoplasms, based on the recently revised Sendai guidelines. Intraductal papillary mucinous neoplasm (particularly the branch duct variant) is the lesion most frequently identified incidentally. We report what is known about its pathology, its risk of developing into pancreatic ductal adenocarcinoma, the pros and cons of current guidelines for management, and the potential role of endoscopic ultrasound in determining cancer risk. We also review surgical treatment and strategies for surveillance of pancreatic cysts.