Extent of surgical resections for intraductal papillary mucinous neoplasms

Pancreatoscopy-Guided Endotherapies for Pancreatic Diseases

Per-oral pancreatoscopy (POP) is a pancreas-preserving modality that allows for targeted pancreatic duct interventions, particularly in cases where standard techniques fail. POP specifically has an emerging role in the diagnosis, risk stratification, and disease extent determination of main duct intraductal papillary mucinous neoplasms (IPMNs). It has also been successfully used for laser ablation of IPMNs in poor surgical candidates, lithotripsy for complex stone disease, and laser stricturoplasty. As experience with POP increases beyond select referral center practices, further studies validating POP efficacy with long-term follow-up will help clarify when POP-guided intervention is most beneficial in relation to surgical intervention.

Mucin-filled CBD, difficult to manage cholangitis

Intraductal papillary mucinous neoplasms (IPMNs) are mucin-secreting cystic neoplasm of pancreas. They have a malignant potential. They are usually localised to the pancreas but occasionally can involve surrounding structures (1.9%-6.6%), like bile duct and duodenum, and are labelled as IPMN with invasion. Jaundice as a manifestation of IPMN is not common (4.5%). It can present as jaundice as a result of invasion of common bile duct (CBD) resulting in stricture formation or uncommonly as a result of fistulising to CBD with resultant obstruction of CBD by thick mucin secreted by this tumour. As only few cases (around 23) of mucin-filled CBD are reported in the literature. We are presenting our experience in dealing a rare case of obstructive jaundice caused by IPMN fistulising into CBD, highlighting the difficulties faced in managing such case, especially with regards to biliary drainage and what can be the optimum management in such cases.

Intraductal papillary mucinous neoplasms of the pancreas: a clinical challenge

The incidental detection rate of intraductal papillary mucinous neoplasms (IPMNs) has significantly increased. However, little is known about the natural history of these tumors. Their optimal management and appropriate follow-up are still unclear. We have, therefore, reviewed the available literature on IPMN focusing on their diagnosis, treatment according to the risk of malignant transformation, and follow-up. Areas covered: Bibliographical searches were performed in PubMed for the terms 'intraductal papillary mucinous neoplasm' and 'natural history' and 'diagnosis' and 'treatment' and 'surgery' and 'follow-up' and 'prognosis.' PubMed was used to search for all the relevant articles published over the last 10 years. A total of 7244 records were identified. After filtering for year range, English language, human studies, article types, and removing duplicates, 74 articles were left with the strongest level of evidence. Expert commentary: Available guidelines for IPMN management are mainly based on expert opinions and may lack strong evidence. Further studies are warranted to better predict the risk of recurrence/future malignancy and to establish standardized guidelines. IPMNs management should be based on multidisciplinary discussion and treatment should be tailored to an individual patient according to patient and tumor characteristics.

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.

Surgical Management of Pancreatic Cysts: A Shifting Paradigm Toward Selective Resection

Due to the widespread use of high-quality cross-sectional imaging, pancreatic cystic neoplasms are being diagnosed with increasing frequency. Clinicians are therefore asked to counsel a growing number of patients with pancreatic cysts diagnosed incidentally at an early, asymptomatic stage. Over the last two decades, accumulating knowledge on the biologic behavior of these neoplasms along with improved diagnostics through imaging and endoscopic cyst fluid analysis have allowed for a selective therapeutic approach toward these neoplasms. On one end of the management spectrum, observation is recommended for typically benign lesions (serous cystadenoma), and on the other end, upfront resection is recommended for likely malignant lesions (main duct IPMN, mucinous cystadenoma, solid pseudopapillary tumor, and cystic pancreatic neuroendocrine tumors). In between, management of premalignant lesions (branch duct IPMN) is dictated by the presence of high-risk features. In general, resection should be considered whenever the risk of malignancy is higher than the risk of the operation. This review aims to describe the evolution and current status of evidence guiding the selection of patients with pancreatic cystic neoplasms for surgical resection, along with a specific discussion on the type of resection required and expected outcomes.

Endoscopic ultrasonography-guided tumor ablation

Real-time guidance of needle advancement has transformed endoscopic ultrasound (EUS) from a diagnostic to an interventional procedure. EUS-guided fine-needle puncture has application in various interventional procedures (drainage of pseudocyst, biliary intervention, and injection of drugs). Celiac plexus or ganglion neurolysis for pain control is the major current EUS-guided fine-needle injection procedure. Feasibility and safety to accurately position needle devices and/or inject under real-time EUS imaging with precise delivery of interventional agent have expanded the use of EUS to ablate tumors. These include radiofrequency ablation, or delivery of fiducial markers, potential antitumor agents, or radioactive seeds, in the cancer mass. Minimally invasive EUS-guided antitumor therapy is primarily used for pancreatic cancer because of better anatomic access (vs other imaging modality) and the dismal prognosis (despite improvements in surgery and chemoradiation). Also, the response to parenteral chemotherapy in pancreatic cancer is poor because of suboptimal drug delivery resulting from hypovascularity and abundant desmoplasia. Other targets for EUS-guided tumor ablation are pancreatic neuroendocrine tumor and pancreatic cyst lesion, which are less aggressive and curable by resection. However, patients non-eligible for surgery may benefit from local EUS-guided ablation.

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.

Is It Time to Expand the Role of Total Pancreatectomy for IPMN?

Intraductal papillary mucinous neoplasms (IPMN) are cystic precursors to pancreatic cancer believed to arise within a widespread neoplastic field defect. The tendency for some patients to present with multifocal disease and/or develop additional lesions over time argues in favor of a field defect and complicates surgical management decisions. Surgery usually consists of partial pancreatic resection, which leaves behind a pancreatic remnant at risk for recurrent disease and progression to cancer. As an alternative, total pancreatectomy (TP) provides the most complete oncologic resection, but postoperative morbidity and quality of life (QoL) issues have generally limited its use to only the highest risk patients. Significant progress has been made in the management of the post-TP apancreatic state and studies now show less morbidity with acceptable QoL comparable to type 1 diabetic and post-pancreaticoduodenectomy patients. These improvements do not yet justify the routine use of TP, but they have opened the door for expansion to additional subsets of non-invasive IPMN. Here, we have identified several groups of patients that we believe would benefit from TP over partial resection based on the most current literature.

[Endoscopic Ultrasound-guided Local Therapy of Pancreatic Tumors]

The development of curvilinear EUS has enabled EUS-guided fine-needle aspiration of intra-abdominal mass lesions. With the introduction of interventional EUS, this technology has undergone several modifications in order to be applied to clinical medicine. One of the potential uses of interventional EUS is the EUS-guided local therapy of pancreatic tumors. Various treatment modalities such as fine-needle injection, radiofrequency ablation, photodynamic therapy, laser ablation, and brachytherapy have been tried under EUS guidance. Some of these modalities are being applied clinically. These methods for EUS-guided local therapy of pancreatic tumors will be reviewed in this article.

Value of diffusion-weighted MRI for differentiating malignant from benign intraductal papillary mucinous neoplasms of the pancreas

OBJECTIVE

The purpose of this study was to evaluate whether the use of diffusion-weighted MRI (DWI) increases diagnostic accuracy in the differentiation of malignant from benign intraductal papillary mucinous neoplasms (IPMNs) of the pancreas over the accuracy of contrast-enhanced MRI with MRCP.

MATERIALS AND METHODS

A total of 61 patients with surgically resected IPMNs (19 malignant, 42 benign) who underwent gadoxetic acid-enhanced MRI, DWI, and MRCP were included. Two blinded observers evaluated two image sets, that is, conventional MRI with MRCP images versus combined conventional MRI with MRCP and DW images, and scored their confidence for malignancy of IPMNs. Qualitative analyses of the IPMNs were also conducted. Diagnostic performance (ROC curve analysis), accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were evaluated. The Fisher exact test was used to compare groups.

RESULTS

The diagnostic performance (area under the ROC curve [Az]) with respect to predicting malignancy of IPMNs improved significantly for both observers after additional review of DW images (p < 0.05). The diagnostic accuracy, sensitivity, specificity, PPV, and NPV of combined conventional and DW images were higher than those of conventional MR images alone. Diffusion restriction was more often present in malignant IPMNs (78.9%) than in benign IPMNs (16.7%) (p < 0.001) with excellent interobserver agreement (ĸ = 0.965).

CONCLUSION

Compared with conventional MRI alone, adding DWI to conventional MRI improves diagnostic accuracy with increased specificity for differentiating malignant from benign IPMNs of the pancreas.

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

BACKGROUND

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

METHODS

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

RESULTS

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

DISCUSSION/CONCLUSIONS

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

Implications of imaging criteria for the management and treatment of intraductal papillary mucinous neoplasms - benign versus malignant findings

OBJECTIVES

Evaluation of computed tomography (CT) and magnetic resonance imaging (MRI) for differentiation of pancreatic intraductal papillary mucinous neoplasm (IPMN) subtypes based on objective imaging criteria.

METHODS

Fifty-eight patients with 60 histologically confirmed IPMNs were included in this retrospective study. Eighty-three imaging studies (CT,n = 42; MRI,n = 41) were analysed by three independent blinded observers (O1-O3), using established imaging criteria to assess likelihood of malignancy (-5, very likely benign; 5, very likely malignant) and histological subtype (i.e., low-grade (LGD), moderate-grade (MGD), high-grade dysplasia (HGD), early invasive carcinoma (IPMC), solid carcinoma (CA) arising from IPMN).

RESULTS

Forty-one benign (LGD IPMN,n = 20; MGD IPMN,n = 21) and 19 malignant (HGD IPMN,n = 3; IPMC,n = 6; solid CA,n = 10) IPMNs located in the main duct (n = 6), branch duct (n = 37), or both (n = 17) were evaluated. Overall accuracy of differentiation between benign and malignant IPMNs was 86/92 % (CT/MRI). Exclusion of overtly malignant cases (solid CA) resulted in overall accuracy of 83/90 % (CT/MRI). The presence of mural nodules and ductal lesion size ≥30 mm were significant indicators of malignancy (p = 0.02 and p < 0.001, respectively).

CONCLUSIONS

Invasive IPMN can be identified with high confidence and sensitivity using CT and MRI. The diagnostic problem that remains is the accurate radiological differentiation of premalignant and non-invasive subtypes.

KEY POINTS

• CT and MRI can differentiate benign from malignant forms of IPMN. • Identifying (pre)malignant histological IPMN subtypes by CT and MRI is difficult. • Overall, diagnostic performance with MRI was slightly (not significantly) superior to CT.

Inter-observer variability of clinical target volume delineation in radiotherapy treatment of pancreatic cancer: a multi-institutional contouring experience

BACKGROUND

An observational multi-institutional study has been conducted aimed to evaluate the inter-observer variability in clinical target volume (CTV) delineation among different radiation oncologists in radiotherapy treatment of pancreatic cancer.

METHODS

A multi-institutional contouring dummy-run of two different cases of pancreatic cancer treated by postoperative and preoperative radiotherapy (RT) was performed. Clinical history, diagnostics, and planning CT imaging were available on AIRO website (http://www.radioterapiaitalia.it). Participants were requested to delineate CTVs according to their skills and knowledge. Aiming to quantify interobserver variability of CTVs delineations, the total volume, craniocaudal, laterolateral, and anteroposterior diameters were calculated. Descriptive statistic was calculated. The 95% Confidence Interval (95% CI) for coefficient of variation (CV) was estimated. The Dice Similarity Index (DSI) was used to evaluate the spatial overlap accuracy of the different CTVs compared with the CTVs of a national reference Centre considered as a benchmark. The mean DSI (mDSI) was calculated and reported.

RESULTS

A total of 18 radiation oncologists from different Institutes submitted the targets. Less variability was observed for the Elective CTV rather than the Boost CTV, in both cases. The estimated CV were 28.8% (95% CI: 21.2-45.0%) and 20.0% (95% CI: 14.9-30.6%) for the Elective CTV, in adjuvant (Case 1) and neoadjuvant (Case 2) case, respectively. The mDSI value was 0.68 for the Elective CTVs in both cases (range 0.19-0.79 in postoperative vs range 0.35-0.79 in preoperative case). The mDSI was increased to 0.71 (Case 1) and 0.72 (Case 2) if the observers with a worse agreement have been excluded. On the other hand, a CV of 42.4% (95% CI: 30.1-72.4%) and 63.8% (95% CI: 43.9-119.2%) with a mDSI value of 0.44 and 0.52, were calculated for the Boost CTV in Case 1 and Case 2, respectively.

CONCLUSIONS

The CV and mDSI obtained values for Elective CTVs showed an acceptable agreement among participants either in postoperative as well in preoperative setting. Additional strategies to reduce the variability in Boost CTV delineation need to be found and promoted.

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.

Endoscopic ultrasound in the diagnosis of pancreatic intraductal papillary mucinous neoplasms

Pancreatic cystic lesions are increasingly recognised due to the widespread use of different imaging modalities. Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas represent a common, but also heterogeneous group of cystic tumors with a significant malignant potential. These neoplasms must be differentiated from other cystic tumors and properly classified into their different types, main-duct IPMNs vs branch-duct IPMNs. These types have a different malignant potential and therefore, different treatment strategies need to be implemented. Endoscopic ultrasound (EUS) offers the highest resolution of the pancreas and can aid in the differential diagnosis, classification and differentiation between benign and malignant tumors. The addition of EUS fine-needle aspiration can supply further information by obtaining fluid for cytology, measurement of tumor markers and perhaps DNA analysis. Novel techniques, such as the use of contrast and sophisticated equipment, like intraductal probes can provide information regarding malignant features and extent of these neoplasms. Thus, EUS is a valuable tool in the diagnosis and appropriate management of these tumors.

Total pancreatectomy for the treatment of pancreatic neoplasms

BACKGROUND

Total pancreatectomy (TP) is an operation that has long been associated with high morbidity and mortality, and rarely advocated for treatment of pancreatic tumours. Because of the improvements in diabetes management, there has been renewed interest in TP for treatment of pancreatic neoplasm, with a need to reassess outcomes.

METHODS

Fifteen patients (9%) underwent TP in a single Australian high-volume tertiary institution between August 2005 and January 2012. Pancreaticoduodenectomy (PD) was performed in 150 patients during the same time period. Indications and peri-operative outcomes of patients were compared.

RESULTS

TP was performed for treatment of malignancy in 13 (87%) cases, for tumours involving the pancreatic neck. Complete tumour clearance achieved. Portal vein resections were more frequently required than in the PD group (5 (33%) versus 9 (6%); P = 0.004), as were blood transfusions (11 (73%) versus 28 (19%); P < 0.001), and median operative times were longer (10.5 versus 7.0 h; P < 0.001). Overall, complications were significantly greater in the TP group compared with the PD group (13 (87%) versus 86 (57%); P = 0.029), but the difference was mainly as a result of high grade I complications, in particular symptomatic hypoglycaemia (4 (27%) versus 0 (0%): P < 0.001) that could be easily managed. The overall lengths of stay and readmission rates were similar between groups.

CONCLUSION

TP should be considered in selective cases for treatment of pancreatic neoplasm if it allows complete clearance. The procedure does not appear to be associated with significant increases in serious complications compared with PD.

IPMN: surgical treatment

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

European experts consensus statement on cystic tumours of the pancreas

Cystic lesions of the pancreas are increasingly recognized. While some lesions show benign behaviour (serous cystic neoplasm), others have an unequivocal malignant potential (mucinous cystic neoplasm, branch- and main duct intraductal papillary mucinous neoplasm and solid pseudo-papillary neoplasm). European expert pancreatologists provide updated recommendations: diagnostic computerized tomography and/or magnetic resonance imaging are indicated in all patients with cystic lesion of the pancreas. Endoscopic ultrasound with cyst fluid analysis may be used but there is no evidence to suggest this as a routine diagnostic method. The role of pancreatoscopy remains to be established. Resection should be considered in all symptomatic lesions, in mucinous cystic neoplasm, main duct intraductal papillary mucinous neoplasm and solid pseudo-papillary neoplasm as well as in branch duct intraductal papillary mucinous neoplasm with mural nodules, dilated main pancreatic duct >6mm and possibly if rapidly increasing in size. An oncological partial resection should be performed in main duct intraductal papillary mucinous neoplasm and in lesions with a suspicion of malignancy, otherwise organ preserving procedures may be considered. Frozen section of the transection margin in intraductal papillary mucinous neoplasm is suggested. Follow up after resection is recommended for intraductal papillary mucinous neoplasm, solid pseudo-papillary neoplasm and invasive cancer.

Laparoscopic distal pancreatectomy: Up-to-date and literature review

Pancreatic surgery represents one of the most challenging areas in digestive surgery. In recent years, an increasing number of laparoscopic pancreatic procedures have been performed and laparoscopic distal pancreatectomy (LDP) has gained world-wide acceptance because it does not require anastomosis or other reconstruction. To date, English literature reports more than 300 papers focusing on LDP, but only 6% included more than 30 patients. Literature review confirms that LDP is a feasible and safe procedure in patients with benign or low grade malignancies. Decreased blood loss and morbidity, early recovery and shorter hospital stay may be the main advantages. Several concerns still exist for laparoscopic pancreatic adenocarcinoma excision. The individual surgeon determines the technical conduction of LDP, with or without spleen preservation; currently robotic pancreatic surgery has gained diffusion. Additional researches are necessary to determine the best technique to improve the procedure results.

Management strategy for multifocal branch duct intraductal papillary mucinous neoplasms of the pancreas

OBJECTIVES

Branch duct intraductal papillary mucinous neoplasms of the pancreas (BD-IPMNs) often are composed of multifocal lesions. We aimed to clarify the clinicopathologic features of multifocal BD-IPMNs.

METHODS

Medical records of 211 patients with BD-IPMNs (169 solitary and 42 multifocal) were retrospectively analyzed. We compared the pathological grade of resected IPMNs and the resulting clinical course between solitary and multifocal BD-IPMNs.

RESULTS

Sixty-nine patients (54 with solitary and 15 with multifocal BD-IPMNs) underwent pancreatectomy, and of these patients, 62 exhibited at least 1 malignant predictor. There was no significant difference in the prevalence of malignancy in the resected BD-IPMNs between the 2 groups. In the remaining 142 patients who exhibited no malignant predictors, both groups demonstrated no differences in morphologic changes of BD-IPMNs. Seventeen distinct ductal carcinomas were identified in both groups, and there was no difference in the prevalence of ductal carcinoma between the 2 groups. Moreover, there was no significant difference in the disease-specific survival rate between the 2 groups.

CONCLUSIONS

In patients with multifocal BD-IPMNs, resection is only warranted for lesions that exhibit malignancy predictors; moreover, closer attention to the potential presence or development of distinct ductal carcinoma in patients with multifocal and solitary BD-IPMNs is warranted.

[Pathology and classification of intraductal papillary mucinous neoplasms of the pancreas]

Intraductal papillary mucinous neoplasms (IPMN) are precursor lesions of ductal adenocarcinoma of the pancreas and one of the most common cystic entities in this organ. Branch and main duct types are further distinguished based on the tumor localization. An additional classification is based on the predominant architecture and immunohistochemical profile with four prognostic relevant subtypes, gastric, intestinal, pancreato-biliary and oncocytic. This review provides an overview about the malignant potential of the different subtypes and the prognosis of associated invasive tumors and gives recommendations for the pathological assessment of resection specimens with IPMNs.

[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.

Focus on the intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasms (IPMNs) are rare pancreatic tumours, accounting for less of 1-2% of all neoplasms of the gland. Main characteristics of IPMNs are their favourable prognosis as these pre-malignant or frankly malignant lesions are usually slow-growing tumours and radical surgery is frequently possible. According with the localization of the lesions, three different entities are identified: the main-duct IPMN (type I), the branch-duct IPMN (type II) and the mixed type (type III, involving both the main pancreatic duct and side branches). IMPNs do not present pathognomonic signs or symptoms. Obstruction of the main pancreatic duct system may cause abdominal pain and acute pancreatitis (single or recurrent episodes). The tumour may be incidentally discovered in asymptomatic patients, particularly in those with branch-duct IPMNs. In clinical practice, any non-inflammatory cystic lesion of the pancreas should be considered as possible IPMN. Computed tomography, magnetic resonance imaging with cholangiopancreatography and endoscopic ultrasonography can localize IPMN and assess its morphology and size. The choice between non-operative and surgical management strictly depends from the risk of malignancy and of the definitively distinction between benign and malignant IPMNs. Main-duct IPMNs are at higher risk of malignant degeneration, especially in older patients; as a consequence no doubt does not exist as concerns the need of surgery for IPMN type I and III. A less aggressive surgical approach as well as the possibility of conservative management have been suggested for asymptomatic, small size (< 3-3.5 cm), branch-duct IPMN.

Outcome of the pancreatic remnant following segmental pancreatectomy for non-invasive intraductal papillary mucinous neoplasm

OBJECTIVES

Intraductual papillary mucinous neoplasms (IPMNs) are often multifocal and involve the entire pancreas. Because of the morbidity associated with total pancreatectomy, surgeons will perform segmental pancreatectomy, resecting only the most 'threatening' IPMN lesion(s). We sought to determine whether the presence of residual IPMN following segmental pancreatectomy for non-invasive IPMN increases the risk for subsequent development of invasive pancreatic cancer and decreases survival.

METHODS

Data on patients undergoing segmental resection of non-invasive IPMN during the period 1991-2010 at a high-volume academic institution were prospectively accrued.

RESULTS

Of 243 patients who underwent segmental resection for IPMN, 191 (79%) demonstrated non-invasive pathology. Of these, 153 (80%) showed the absence and 38 (20%) the presence of residual IPMN at the initial operation. Of the 38 patients with residual IPMN, eight had positive IPMN margins, 23 had radiographic evidence of IPMN, and seven had both. During a mean follow-up of 73 months, 31 (20%) of 153 patients without residual IPMN developed a new radiographic lesion consistent with IPMN and, of these, three (10%) were found to represent invasive cancer. One (3%) of 38 patients with residual IPMN developed invasive cancer. In summary, in 191 initially non-invasive cases of IPMN, four invasive cancers (2%) developed during follow-up. The mean progression-free interval in these four patients was 54 months (range: 20-99 months).

CONCLUSIONS

Compared with patients undergoing complete operative IPMN clearance, patients with residual IPMN after segmental pancreatectomy do not demonstrate increased risk for the development of invasive disease or reduced survival. In patients without residual IPMN who later develop new IPMN, the risk for invasive IPMN is increased.

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.