Intraductal papillary mucinous neoplasms of the pancreas

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.

What Is the Best Way to Identify Malignant Transformation Within Pancreatic IPMN: A Systematic Review and Meta-Analyses

OBJECTIVES

Pancreatic intraductal papillary mucinous neoplasias (IPMNs) represent 25% of all cystic neoplasms and are precursor lesions for pancreatic ductal adenocarcinoma. This study aims to identify the best imaging modality for detecting malignant transformation in IPMN, the sensitivity and specificity of risk features on imaging, and the usefulness of tumor markers in serum and cyst fluid to predict malignancy in IPMN.

METHODS

Databases were searched from November 2006 to March 2014. Pooled sensitivity and specificity of diagnostic techniques/imaging features of suspected malignancy in IPMN using a hierarchical summary receiver operator characteristic (HSROC) approach were performed.

RESULTS

A total of 467 eligible studies were identified, of which 51 studies met the inclusion criteria and 37 of these were incorporated into meta-analyses. The pooled sensitivity and specificity for risk features predictive of malignancy on computed tomography/magnetic resonance imaging were 0.809 and 0.762 respectively, and on positron emission tomography were 0.968 and 0.911. Mural nodule, cyst size, and main pancreatic duct dilation found on imaging had pooled sensitivity for prediction of malignancy of 0.690, 0.682, and 0.614, respectively, and specificity of 0.798, 0.574, and 0.687. Raised serum carbohydrate antigen 19-9 (CA19-9) levels yielded sensitivity of 0.380 and specificity of 0903. Combining parameters yielded a sensitivity of 0.743 and specificity of 0.906.

CONCLUSIONS

PET holds the most promise in identifying malignant transformation within an IPMN. Combining parameters increases sensitivity and specificity; the presence of mural nodule on imaging was the most sensitive whereas raised serum CA19-9 (>37 KU/l) was the most specific feature predictive of malignancy in IPMNs.

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

OBJECTIVE

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

INTRODUCTION

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

PRESENTATION OF CASE

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

DISCUSSION

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

CONCLUSION

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

Intraoperative pancreatoscopy with narrow band imaging: a novel method for assessment of resection margins in case of intraductal papillary mucinous neoplasm

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) is characterized by intraductal proliferation of neoplastic mucinous cells with a variable extent along the main duct or its branches. The lesion may be continuous or discontinuous. Skip lesions have been described in about 6-19% of cases. Complete resection without leaving behind any skip lesions is important, to such an extent that many groups suggest even total pancreatectomy, a major and morbid surgery.

METHODS

A 40 year-male patient with chronic pancreatitis presented with recent-onset diabetes mellitus and weight loss. Ultrasound and computed tomography (CT) scan showed a cystic lesion in the head and uncinate process of pancreas. Peroral pancreatoscopy showed villous projections with dilated tortuous vessel in the head, suspicious of IPMN. The duct beyond pancreatic head could not be visualized and remained unassessed. At pancreatoduodenectomy, pancreatoscopy with narrow band imaging (NBI) was done using flexible pancreatoscope through the cut end of the duct at the neck to assess the duct in the body and tail.

RESULTS

Pancreatoscopy with NBI showed a normal-looking resection margin and a skip lesion 1 cm beyond it. The revised resection margin confirmed the skip lesion on frozen section and also that the fresh cut margin was negative. The remaining duct in the body and tail was normal on pancreatoscopy. Total clearance of the disease could be achieved without a major procedure such as total pancreatectomy.

CONCLUSIONS

Intraoperative pancreatoscopy, especially with NBI, is a good diagnostic tool for IPMN and also helps in intraoperative decision-making of the resection margins.

Repeated pancreatectomy after pancreato-duodenectomy for a intraductal papillary mucinous tumour: advantage of pancreatico-gastrostomy with a gastric partition

BACKGROUND

  Regular follow-up and monitoring of intraductal papillary mucinous neoplasms (IPMN) is important as there is a risk of recurrence in both the non-invasive and invasive IPMN.

METHODS

  Three patients developed pancreatic remnant recurrence after a pancreatico-duodenectomy for IPMN. Pancreatico-gastrostomy anastomosis was performed in all patients. Long-term follow-up was performed with radiographical surveillance and by endoscopic gastroscopy.

RESULTS

  Magnetic resonance imaging (MRI) and endoscopic ultrasonography (EUS) revealed in one patient, 2 years after surgery, a 3-cm mass at the site of the anastomosis and dilatation of the Wirsung duct >6 mm in two other patients (2 and 3 years after surgery, respectively). The diagnosis of recurrence was confirmed endoscopically by the presence of a large amount of mucin at the anastomotic site. Cytological examination revealed moderate dysplasia. Opacification of the Wirsung duct after endoscopic retrograde cholangiopancreatography (ERCP) was only possible in one patient in whom an irregular stenosis of the duct was observed.

CONCLUSIONS

  Long-term follow-up of the pancreatic remnant after pancreato-duodenectomy for IPMN is better achieved with pancreatico-gastrostomy anastomosis.

Middle-preserving pancreatectomy for synchronous ampullary carcinoma and solid-pseudopapillary tumor of distal pancreas

INTRODUCTION

Total pancreatectomy is the treatment of choice for multicentric diseases involving the pancreas. Middle-preserving pancreatectomy is a recently reported alternative procedure when the pancreatic body is spared from disease.

PRESENTATION OF CASE

We report a 63-year old lady who underwent a combined Whipple's operation and distal splenopancreatectomy for her synchronous ampullary carcinoma and solid-pseudopapillary tumor of the distal pancreas.

DISCUSSION

For multiple tumors of the pancreas, the choice of surgery should be based on the nature of pathology and follow the principle of oncological resection.

CONCLUSION

Middle-preserving pancreatectomy is a safe and feasible option for patient with multicentric or synchronous pancreatic pathologies.

The management of intraductal papillary mucinous neoplasms of the pancreas

Intraductal papillary mucinous neoplasms (IPMN) are mucinous cystic tumors of the pancreas, which were first classified into a unified diagnosis by the World Health Organization in 1996. These lesions originate from the cells of the pancreatic ductal system and may grossly or microscopically involve the pancreatic ducts in a diffuse or multifocal fashion. As experience with IPMN increases, it is becoming more evident that this process presents as a spectrum of neoplasia with significant variation regarding the clinical and radiologic presentation, malignant potential, and disease-specific outcome. IPMN encompasses a spectrum of precursor lesions, from adenoma to intraductal carcinoma to invasive cancer, with molecular data supporting the premise that this dysplastic process has the potential to progress from low-grade dysplasia to invasive carcinoma. Controversy over the management of IPMN exists because of the difficulty in obtaining a preoperative histologic diagnosis, the broad spectrum of neoplasia, the lack of understanding as to the frequency and time to malignant progression. This article describes the radiologic and histopathologic classification system of IPMN; the biologic behavior of these lesions, and the diagnostic testing most commonly used, and discusses the current treatment controversies.

Diagnosis and management strategy for cystic neoplasm of the pancreas

OBJECTIVE

This article aimed to propose a management strategy for cystic neoplasm of the pancreas based on the available evidence in the medical literature.

METHODS

A Medline search was undertaken to identify articles from 1988 to 2008 using the keywords 'pancreatic cyst', 'pancreatic neoplasms', and 'cystic neoplasm of pancreas'. Additional papers were identified by a manual search of the references from the key articles.

COMMENTS

The optimal management of cystic neoplasms of pancreas remains controversial and should be individualized based on the balance between the risk and benefit. Multiple factors such as patient's comorbidity, performance status, life expectancy, and surgical risk, should be weighed against the malignant potential of the cyst.

Intraductal papillary mucinous neoplasms

Intraductal papillary mucinous neoplasm (IPMN) is characterized by enhanced mucus secretion. It is a benign or low-grade neoplasm associated with a dilated main pancreatic duct, patulous ampullary orifice, and abundant mucus secretion. Foci of aggressive cancer may arise and become invasive. Surgery is the only treatment that can cure IPMN, but the extent of pancreatic resection and the intraoperative margins remain areas of controversy. The risks of total pancreatectomy must be weighed against the risk for developing cancer in the residual pancreas. Risks must be factored against the natural course of the disease and the likelihood of malignancy developing over the life expectancy.

Pancreatic head resection with segmental duodenectomy: safety and long-term results

OBJECTIVE

To evaluate the usefulness and long-term results with pancreatic head resection with segmental duodenectomy (PHRSD; Nakao's technique) in patients with branch-duct type intraductal papillary mucinous neoplasms (IPMNs). A prospective study from Nagoya (Japan) and Barcelona (Spain).

SUMMARY BACKGROUND DATA

Surgery should be the first choice of treatment of IPMNs. An aggressive surgery (eg, pancreatoduodenectomy) should be questioned in patients with an indolent disease or with noninvasive tumors. Recently, organ-preserving pancreatic resections for benign and noninvasive IPMN located in the head of the pancreas have been described. We have PHRSD in which the pancreatic head can be completely resected and the major portion of the duodenum can be preserved by this procedure. There have been only 4 reports concerning PHRSD with <8 patients (each one) in the English literature.

METHODS

Thirty-five patients underwent PHRSD (20 men, 15 women), mean age 65.1 +/- 9.0 (range, 55-75). Mean maximal diameter of the cystic lesion was 26.4 +/- 5.3 mm (range, 20-33 mm) and mean diameter of the main pancreatic duct was 3.3 +/- 0.5 mm (range, 3.0-4.0 mm). Alimentary tract reconstruction was performed in 20 patients by pancreatogastrostomy, duodenoduodenostomy, and choledochoduodenostomy (type A) and 15 patients by pancreaticojejunostomy, duodenoduodenostomy and choledochojejunostomy (Roux-en-Y; type B). Surgical parameters, postoperative complications, endocrine function, exocrine function, and long-term outcomes were evaluated. To compare the perioperative factors, a matched-pairs analysis between PHRSD patients and patients with pylorus preserving pancreaticoduodenectomy (PPPD) was performed. In the latter group were included 32 patients with branch-duct type of IPMN operated during the same time period that patients with PHRSD. The mean follow-up period was 48.8 months.

RESULTS

Mean operative time after PHRSD was 365 +/- 50 and mean surgical blood loss was 615 +/- 251 mL. There was no mortality. Pancreatic fistula occurred in 10% and 13% with types (alimentary tract reconstruction) A and B, respectively. Noninvasive IPMN was found in 31 patients and invasive IPMN in 4 patients (11.4%). In the matched-pairs analysis between PHRSD and PPPD, the 2 procedures were comparable in regard to operation time and intraoperative blood loss. The overall incidence of pancreatic fistula was higher after PPPD than after PHRSD; the difference was not statistically significant. When fistulas occurred after PHRSD they were grade A (biochemical). In contrast, pancreatic fistulas after PPPD were grade A in 78% of cases and grade B in 22% (clinically relevant fistula). The incidence of delayed gastric emptying was significantly higher in the PPPD group compared with the PHRSD group (P < 0.01). Endocrine pancreatic function, measured by fasting blood glucose levels and HbA1, levels was unchanged in 94.28% of patients, in the PHRSD group, and in 87.87% in the PPPD group. Body weight was unchanged in 80% after PHRSD and in 59% after PPPD. Postoperative enzyme substitution was needed in 20% of patients after PHRSD and in 40% patients after PPPD. The 5-year survival rate was 100% in patients with benign IPMN and 42% in patients with invasive IPMN.

CONCLUSION

PHRSD is a safe and reasonable technique appropriate for selected patients with branch-duct IPMN. The major advantages of PHRSD are promising long-term results in terms of pancreatic function (exocrine and endocrine) with important consequences in elderly patients. Long-term outcome was satisfactory without tumor recurrence in noninvasive carcinoma. PHRSD should therefore be considered as an adequate operation as an organ-preserving pancreatic resection for branch-duct type of IPMN located at the head of the pancreas.

The management of cystic lesions of the pancreas

The number of patients being identified as having asymptomatic small cysts of the pancreas is increasing. Most cystic neoplasms are SCAs, IPMNs, or MCNs. SCAs should be considered benign and in the absence of symptoms can be safely followed radiographically. Currently, most patients who present with mucinous cysts should undergo resection, because many of these patients have in situ or invasive carcinoma. The presence of a solid component seems to be associated with malignancy in patients who have mucinous cysts, and cyst size seems to be associated with malignancy in patients who have MCNs and branch duct IPMNs. Many institutions now are reporting a selective approach to resection in patients who have cystic lesions of the pancreas. Routine resection of all pancreatic cysts currently is impractical; given the large numbers of patients being identified with lesions smaller than 2 cm, this approach would result in a mortality rate that is much higher than the rate of malignancy. Most studies that have advocated a selective approach have reported the radiographic characteristics of a solid component, cyst size, and symptoms to be associated with treatment recommendations. The authors believe that radiographic follow-up is warranted in any patient for whom the assumed risk of malignancy is less than the risk of mortality from resection (no solid component, < 3 cm, asymptomatic). Most patients who have incidentally discovered cysts smaller than 3 cm in diameter and without a solid component can be safely followed radiographically. In the young patient who has a small mucinous tumor, additional factors to be considered are the likelihood of progression to malignancy and patient anxiety about radiographic follow-up. No data are available for the former. Efforts should be made to improve the ability to distinguish histopathologic subtypes without resection. The current challenges are to improve the sensitivity and specificity for the identification of mucinous subtype, to characterize better the progression of IPMN and mucinous cystic tumors, and to develop better methods for identifying the presence of in situ or invasive disease in these patients. Continued improvements in cross-sectional imaging and endoscopic techniques and further investigation into markers in the serum and cyst fluid should allow better identification of mucinous subtypes.

How useful are clinical, biochemical, and cross-sectional imaging features in predicting potentially malignant or malignant cystic lesions of the pancreas? Results from a single institution experience with 220 surgically treated patients

BACKGROUND

This study aims to determine the use of preoperative clinical, biochemical, and cross-sectional imaging features for predicting malignancy in cystic lesions of the pancreas (CLP).

STUDY DESIGN

Two hundred twenty patients who underwent operations for CLP or suspected CLP were reviewed. Patients were divided into two groups, patients undergoing operations for pseudocysts and patients undergoing operations for suspected cystic neoplasms. The predictive effect of various preoperative factors on the malignant potential of CLP was evaluated.

RESULTS

Forty-four patients with a preoperative diagnosis of pseudocysts underwent operations for complications of pseudocyst. Forty-two were confirmed pathologically to have pseudocysts, but two were found, unexpectedly, to harbor malignant lesions. One hundred seventy-six patients underwent operations for suspected pancreatic cystic neoplasms. There were 70 benign, 51 potentially malignant, and 55 malignant CLP. On multivariate analysis, three factors, ie, elevated serum carcinoembryonic antigen (CEA) or carbohydrate antigen 19-9; cyst size > 3 cm; and presence of one or more of three morphologic features, such as solid component; peripheral calcification; and main duct dilation on cross-sectional imaging were independent predictors of malignancy. Presence of two or three of these factors had a positive predictive value of 88% in predicting a premalignant or malignant CLP.

CONCLUSIONS

Most pancreatic pseudocysts can be accurately diagnosed preoperatively. In patients with suspected pancreatic cystic neoplasms, elevated serum CEA or carbohydrate antigen 19-9, cyst size > 3 cm, and presence of suspicious morphologic features on imaging are predictors of potentially malignant or malignant CLP. Patients with a high likelihood of a potentially malignant or malignant lesion based on these three factors should undergo operation without additional investigations.

Pancreatic cysts: a proposed management algorithm based on current evidence

BACKGROUND

Currently, the management strategy of pancreatic cyst (PC) remains controversial because of the inability to diagnose this type of cyst accurately and the limited knowledge of its natural history. Previously, many clinicians have advocated an aggressive resectional policy. This approach is no longer appropriate, and the number of PCs detected incidentally has increased. This study reviews the present literature and attempts to provide a management algorithm of pancreatic cysts based on currently available evidence.

METHODS

A Medline search was conducted to identify studies investigating PC, with particular emphasis placed on studies addressing its diagnosis and management. Additional articles were obtained from the reference lists of key articles and recent reviews.

COMMENTS

Based on current evidence, the optimal management of PC remains an art and should be individualized based on the risk-benefit ratio of surgery, which is influenced by multiple factors, such as the patient's potential life expectancy, surgical risk; and malignant potential of the cyst. Our proposed management algorithm is based on an individual's predicted risk-benefit ratio of surgery. Prospective evaluation of the algorithm is needed to determine its integrity.

[Organ-preserving resection of the pancreaticoduodenal region in the treatment of intraductal papillary mucinous tumors]

INTRODUCTION

The standard surgical procedure for intraductal papillary mucinous neoplasms of the main duct (IPMN-M) or side branch ducts (IPMN-Br) is pancreaticoduodenectomy. IPMN-BR is a more indolent disease with a lower incidence of malignancy.

OBJECTIVE

To evaluate the usefulness of organ-preserving pancreatic resections (OPPR) including duodenum-preserving pancreatic head resection (DPHR) and pancreatic head resection with segmental duodenectomy (PHRSD) in patients with IPMN-BR.

PATIENTS AND METHOD

Surgical outcomes were evaluated in eight IPMN-Br patients: DPHR was performed in 4 patients and PHRSD was performed in 4 patients. In addition, 13 IPMN patients with Whipple resections were included in the analysis.

RESULTS

The incidence of postoperative complications was 38% after Whipple resection, 100% after DPHR and 25% after PHRSD. The mean length of hospital stay was 27 days after DPHR, 22 days after Whipple resection and 16 days after PHRSD. Invasive IPMN was found in 38% of the patients in the Whipple group, and noninvasive IPMN was found in 100% of patients who underwent organ-preserving surgery.

CONCLUSIONS

Pancreaticoduodenectomy remains the treatment of choice in patients with invasive IPMN. PHRSD appears to be a useful procedure for IPMN-Br located in the head of the pancreas.

Intraductal papillary neoplasm of the bile duct extending superficially from the intrahepatic to extrahepatic bile duct

Intraductal papillary neoplasm of the bile duct (IPNB) or liver is a recently noted rare disease, and its pathogenesis remains unclear. Here we present a case of IPNB with an interesting morphology, which was treated by resection of the right hemiliver and extrahepatic bile duct. A 79-year-old woman was found to have a high alkaline phosphatase level and slight dilatation of the right intrahepatic bile duct on imaging studies. The right intrahepatic bile duct became dilated over a 2-year period; however, no solid mass could be detected, and tumor markers were not elevated. Hepatic resection was scheduled because a mucin-producing bile duct carcinoma of the liver was suspected. A right hemihepatectomy was conducted, and the extrahepatic bile duct was also resected after malignant cells were found in the surgical stump of the right bile duct and in the bile itself. Macroscopically, diffuse dilatation of the intrahepatic bile duct was noted, but no solid component or mucin within the duct was found. Histopathological findings revealed carcinoma in situ, IPNB, in the majority of intrahepatic bile ducts, with no lymph node metastasis, and it extended continuously to the epithelium of the common bile duct. No tumor recurrence or biliary dilatation was observed at follow-up 2 years after surgery. It is important to consider malignancy in the presence of a dilated bile duct and in the absence of any cause of occlusion. Complete resection of IPNB results in a good prognosis and no recurrence.