Intraductal papillary mucinous tumor of the pancreas

Cross Validation of the Monoclonal Antibody Das-1 in Identification of High-Risk Mucinous Pancreatic Cystic Lesions

BACKGROUND & AIMS

Although pancreatic cystic lesions (PCLs) are frequently and incidentally detected, it is a challenge to determine their risk of malignancy. In immunohistochemical and enzyme-linked immunosorbent assay (ELISA) analyses of tissue and cyst fluid from pancreatic intraductal papillary mucinous neoplasms, the monoclonal antibody Das-1 identifies those at risk for malignancy with high levels of specificity and sensitivity. We aimed to validate the ability of Das-1 to identify high-risk PCLs in comparison to clinical guidelines and clinical features, using samples from a multicenter cohort.

METHODS

We obtained cyst fluid samples of 169 PCLs (90 intraductal papillary mucinous neoplasms, 43 mucinous cystic neoplasms, and 36 non-mucinous cysts) from patients undergoing surgery at 4 tertiary referral centers (January 2010 through June 2017). Histology findings from surgical samples, analyzed independently and centrally re-reviewed in a blinded manner, were used as the reference standard. High-risk PCLs were those with invasive carcinomas, high-grade dysplasia, or intestinal-type intraductal papillary mucinous neoplasms with intermediate-grade dysplasia. An ELISA with Das-1 was performed in parallel using banked cyst fluid samples. We evaluated the biomarker's performance, generated area under the curve values, and conducted multivariate logistic regression using clinical and pathology features.

RESULTS

The ELISA for Das-1 identified high-risk PCLs with 88% sensitivity, 99% specificity, and 95% accuracy, at a cutoff optical density value of 0.104. In 10-fold cross-validation analysis with 100 replications, Das-1 identified high-risk PCLs with 88% sensitivity and 98% specificity. The Sendai, Fukuoka, and American Gastroenterological Association guideline criteria identified high-risk PCLs with 46%, 52%, and 74% accuracy (P for comparison to Das-1 ELISA <.001). When we controlled for Das-1 in multivariate regression, main pancreatic duct dilation >5 mm (odds ratio, 14.98; 95% confidence interval, 2.63-108; P < .0012), main pancreatic duct dilation ≥1 cm (odds ratio, 47.9; 95% confidence interval, 6.39-490; P < .0001), and jaundice (odds ratio, 6.16; 95% confidence interval, 1.08-36.7; P = .0397) were significantly associated with high-risk PCLs.

CONCLUSIONS

We validated the ability of an ELISA with the monoclonal antibody Das-1 to detect PCLs at risk for malignancy with high levels of sensitivity and specificity. This biomarker might be used in conjunction with clinical guidelines to identify patients at risk for malignancy.

Successful management of life-threatening bleeding of intraductal papillary mucinous neoplasms in the pancreatic head

Complications associated with intraductal papillary mucinous neoplasms, such as acute pancreatitis, perforation, and fistula formation, have been documented. Intraductal papillary mucinous neoplasm with intratumoral hemorrhage is rare. To the best of our knowledge, there have been no previous reports of intraductal papillary mucinous neoplasm rupture and bleeding with intra-abdominal hemorrhage. A 74-year-old woman complained of acute upper right abdominal pain. She was under follow-up for an intraductal papillary mucinous neoplasm in the pancreatic head. Contrast-enhanced computed tomography revealed intraductal papillary mucinous neoplasm rupture and bleeding with intra-abdominal hemorrhage. The bleeding was treated with selective endovascular embolization of a branch of the gastroduodenal artery. Follow-up examinations are recommended even for intraductal papillary mucinous neoplasm patients without malignant findings because of the potential risk of rupture and bleeding with intra-abdominal hemorrhage. Clinicians should be aware of this possibility to ensure that patients are appropriately treated.

My Treatment Approach: Pancreatic Cysts

Our treatment approach for either symptomatic or incidentally found pancreatic cysts continues to improve. The true incidence of pancreatic cysts is not known, and pancreatic cystic neoplasms, especially intraductal papillary mucinous neoplasms, are currently most commonly diagnosed and resected. This is a result of increasing awareness, widespread availability of imaging, and better understanding of the nature of pancreatic cysts as well. Recent studies on molecular analysis and devices such as microbiopsy forceps help us better define and select the treatment approach to alleviate symptoms and to prevent malignant tumors while avoiding unnecessary surgery.

Management of patients with pancreatic cystic lesions: A case-based survey

BACKGROUND

Pancreatic cystic lesions (PCL), including intraductal papillary mucinous neoplasia (IPMN), harbor different malignant potential and the optimal management is often challenging. The present study aims to depict the compliance of experts with current consensus guidelines and the accuracy of treatment recommendations stratified by the medical specialty and hospital volume.

METHODS

An international survey was conducted using a set of 10 selected cases of PCL that were presented to a cohort of international experts on pancreatology. All presented cases were surgically resected between 2004 and 2015 and histopathological examination was available. Accuracy of the treatment recommendations was based on the European and international consensus guideline algorithms, and the histopathological result.

RESULTS

The response rate of the survey was 26% (46 of 177 contacted experts), consisting of 70% surgeons and 30% gastroenterologists/oncologists (GI/Onc). In the case of main-duct IPMN (MD-IPMN), surgeons preferred more often the surgical approach in comparison with the GI/Onc (55 versus 44%). The mean accuracy rate based on the European and international consensus guidelines, and the histopathological result, were 71/76/38% (surgeons), and 70/73/34% (GI/Onc), respectively. High-volume centers achieved insignificantly higher accuracy scores with regard to the histopathology. Small branch-duct IPMN with cysts <2 cm and malignant potential were not identified by the guideline algorithms.

CONCLUSION

The survey underlines the complexity of treatment decisions for patients with PCL; less than 40% of the recommendations were in line with the final histopathology in this selected case panel. Experts and consensus guidelines may fail to predict malignant potential in small PCL.

Intraductal papillary mucinous neoplasms and mucinous cystadenomas: current status and recommendations

The real prevalence of pancreatic cystic lesions remains unknown. The malignant potential of some of these lesions remains a cause for significant concern. Thus, it is mandatory to develop a strategy to clearly discriminate those cysts with a potential for malignant transformation from those that do not carry any significant risk. Intraductal papillary mucinous neoplasms and mucinous cystadenomas are mucinous cystic neoplasms with a known malignant potential that have gained greater recognition in recent years. However, despite the numerous studies that have been carried out, their differential diagnosis among other cysts subtypes and their therapeutic approach continue to be a challenge for clinicians. This review contains a critical approach of the current recommendations and management strategies regarding intraductal papillary mucinous neoplasms and mucinous cystadenomas, as well as highlighting the limitations exposed in current guidelines.

Expansion of epigenetic alterations in EFEMP1 promoter predicts malignant formation in pancreatobiliary intraductal papillary mucinous neoplasms

Purpose

Although limited understanding exists for the presence of specific genetic mutations and aberrantly methylated genes in pancreatobiliary intraductal papillary mucinous neoplasms (IPMNs), the fundamental understanding of the dynamics of methylation expansion across CpG dinucleotides in specific gene promoters during carcinogenesis remains unexplored. Expansion of DNA methylation in some gene promoter regions, such as EFEMP1, one of the fibulin family, with tumor progression has been reported in several malignancies. We hypothesized that DNA hypermethylation in EFEMP1 promoter would expand with the tumor grade of IPMN.

Methods

A sample of 65 IPMNs and 30 normal pancreatic tissues was analyzed. IPMNs were divided into the following three subsets according to pathological findings: 31 with low-grade dysplasia (low grade), 11 with high-grade dysplasia (high grade), and 23 with associated invasive carcinoma (invasive Ca). Mutations in the KRAS or GNAS genes were analyzed by Sanger sequencing, and methylation status of two discrete regions within the EFEMP1 promoter, namely region 1 and region 2, was analyzed by bisulfite sequencing and fluorescent high-sensitive assay for bisulfite DNA (Hi-SA). Expression status of EFEMP1 was investigated by immunohistochemistry (IHC).

Results

KRAS mutations were detected in 39, 55, and 70 % of low-grade, high-grade, and invasive Ca, respectively. GNAS mutations were observed in 32, 55, and 22 % of low-grade, high-grade, and invasive Ca, respectively. The methylation of individual regions (region 1 or 2) in the EFEMP1 promoter was observed in 84, 91, and 87 % of low-grade, high-grade, and invasive Ca, respectively. However, simultaneous methylation of both regions (extensive methylation) was exclusively detected in 35 % of invasive Ca (p = 0.001) and five of eight IPMNs (63 %) with extensive methylation, whereas 20 of 57 (35.1 %) tumors of unmethylation or partial methylation of the EFEMP1 promoter region showed weak staining EFEMP1 in extracellular matrix (p = 0.422). In addition, extensive EFEMP1 methylation was particularly present in malignant tumors without GNAS mutations and associated with disease-free survival of patients with IPMNs (p < 0.0001).

Conclusions

Extensive methylation of the EFEMP1 gene promoter can discriminate invasive from benign IPMNs with superior accuracy owing to their stepwise accumulation of tumor progression.

Electronic supplementary material

The online version of this article (doi:10.1007/s00432-016-2164-x) contains supplementary material, which is available to authorized users.

Comparison of the international consensus guidelines for predicting malignancy in intraductal papillary mucinous neoplasms

BACKGROUND

This study sought to evaluate the predictors of malignancy in the 2012 international consensus guidelines for intraductal papillary mucinous neoplasms (IPMNs) and validate their diagnostic value relative to the 2006 guidelines.

METHODS

Between 2002 and 2014, 177 consecutive patients who underwent curative resection of IPMN were reviewed. Based on the 2012 guidelines, high-risk stigmata (mural nodule with enhancement, main pancreatic duct [MPD] ≥ 10 mm, and obstructive jaundice) and worrisome features (cyst size ≥ 30 mm, thickened cyst wall, mural nodule without enhancement, MPD 5-9 mm, an abrupt change in MPD diameter, and lymphadenopathy) were assessed, and predictive and diagnostic values were analyzed statistically.

RESULTS

Multivariate analysis identified obstructive jaundice (odds ratio [OR], 23.9; P < .0001), abrupt change in MPD diameter (OR, 3.01; P = .017) and lymphadenopathy (OR, 5.84; P = .027) as independent predictive factors, with an accuracy of 69.8, 67.4, and 66.3%, respectively. Operative intervention was indicated in 156 patients (94.0%) using the 2006 guidelines, and in 130 (78.3%) using the 2012 guidelines. The accuracy of the 2006 guidelines was 35.5% compared with 44.8% for the 2012 guidelines. The area under the curve (AUC) for the 2006 and 2012 guidelines was 0.65 and 0.67, respectively; ΔAUC was 0.02, which was not statistically significant. When the worrisome features were combined with high-risk stigmata, the AUC increased to 0.79.

CONCLUSION

Obstructive jaundice, abrupt change in MPD diameter, and lymphadenopathy were independent predictive factors in the 2012 guidelines with high accuracy. Using the new guidelines, the number of patients with IPMN managed with observation and the predictive accuracy increased.

Malignant transformation and overall survival of morphological subtypes of intraductal papillary mucinous neoplasms of the pancreas: A network meta-analysis

BACKGROUND

Emerging evidence suggests the predictive role of morphological subtypes (gastric, intestinal, pancreatobiliary, and oncocytic) of intraductal papillary mucinous neoplasms (IPMNs) in malignant transformation and overall survival. But results of these studies are currently discordant.

METHODS

A comprehensive literature search in MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) was conducted for eligible studies. Network meta-analysis using the random-effect model was carried out to detect differences in incidences of invasive IPMNs and hazard ratios from survival curves among four morphological subtypes.

RESULTS

19 studies were included in the network comparison. The outcomes showed that pancreatobiliary-type (OR for odds ratio=25.87, 95% CI: 12.11-52.10, compared with gastric-type) and oncocytic-type (OR=18.59, 95% CI: 7.18-42.74) IPMNs had the highest risks of progressing to invasive IPMNs, followed by intestinal-type (OR=5.71, 95% CI: 2.85-10.61) and gastric-type IPMNs. With the gastric type as the baseline, pancreatobiliary-type IPMNs were found to have the worst prognosis (HR for hazard ratio=5.05, 95% CrI: 1.33-13.47) while no significant differences were found for the intestinal type (HR=1.90, 95% CrI: 0.59-4.58) and the oncocytic type (HR=3.29, 95% CrI: 0.75-9.71).

CONCLUSION

It is suggested that pancreatobiliary-type IPMNs are the most likely to become invasive and are associated with poor prognosis. In contrast, the other three subtypes have similar overall survivals even though the oncocytic- and intestinal-type IPMNs are predisposed to be more invasive than gastric-type IPMNs.

Intraductal papillary mucinous neoplasms

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Diagnosis and management of cystic lesions of the pancreas

Pancreatic cystic lesions (PCLs) are being increasingly identified in recent years. They show a wide spectrum of imaging and clinical features. The diagnosis and discrimination of these lesions are very important because of the risk for concurrent or later development of malignancy. PCLs are usually first diagnosed and characterized by conventional imaging modalities such as trans-abdominal ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI). However, their ability to differentiate the benign and malignant lesions remains limited. Endoscopic US may be more helpful for the diagnosis and differentiation of PCLs because of its high resolution and better imaging characteristics than cross-sectional imaging modalities. It also allows for fine-needle aspiration (FNA) of cystic lesions for biochemical, cytological and DNA analysis that might be further helpful for diagnosis and differentiation. The management options of PCLs are to observe, endoscopic treatment or surgical resection. However, the decision for management is sometimes hampered by limitations in current diagnostic and tissue sampling techniques. As further diagnostic and non-invasive management options become available, clinical decision-making will become much easier for these lesions.

mAb Das-1 is specific for high-risk and malignant intraductal papillary mucinous neoplasm (IPMN)

OBJECTIVE

Intraductal papillary mucinous neoplasm (IPMN) consists of four epithelial subtypes that correlate with histological grades and risks for malignant transformation. mAb Das-1 is a monoclonal antibody against a colonic epithelial phenotype that is reactive to premalignant conditions of the upper GI tract. We sought to assess the ability of mAb Das-1 to identify IPMN with high risk of malignant transformation.

DESIGN

mAb Das-1 reactivity was evaluated in 94 patients with IPMNs by immunohistochemistry. Lesional fluid from 38 separate patients with IPMN (n=27), low-grade non-mucinous cystic neoplasms (n=7) and pseudocysts (n=4) was analysed by ELISA and western blot.

RESULTS

Immunohistochemistry-Normal pancreatic ducts were non-reactive and low-grade gastric-type IPMN (IPMN-G) (1/17) and intermediate-grade IPMN-G (1/23) were minimally reactive with mAb Das-1. In contrast, mAb Das-1 reactivity was significantly higher in high-risk/malignant lesions (p<0.0001) including: intestinal-type IPMN with intermediate-grade dysplasia (9/10); high-grade dysplasia of gastric (4/7), intestinal (12/12), oncocytic (2/2) and pancreatobiliary types (2/2); and invasive tubular (8/12), colloid (7/7) and oncocytic (2/2) carcinoma. The sensitivity and specificity of mAb Das-1 for high-risk/malignant IPMNs were 85% and 95%, respectively. Lesional fluid-Samples from low- and intermediate-grade IPMN-G (n=9), and other low-grade/benign non-mucinous lesions demonstrated little reactivity with mAb Das-1. Conversely, cyst fluid from high-risk/malignant IPMNs (n=18) expressed significantly higher reactivity (p<0.0001). The sensitivity and specificity of mAbDas-1 in detecting high-risk/malignant IPMNs were 89% and 100%, respectively.

CONCLUSIONS

mAb Das-1 reacts with high specificity to tissue and cyst fluid from high-risk/malignant IPMNs and thus may help in preoperative clinical risk stratification.

Clinical implication of morphological subtypes in management of intraductal papillary mucinous neoplasm

PURPOSE

Morphological subtypes of intraductal papillary mucinous neoplasm (IPMN) have been established. Invasive IPMNs include colloid carcinoma and tubular carcinoma. Few studies have explored the association between the morphological and invasive subtypes in a large population. Clinical relevance of the morphological subtypes remains unclear.

METHODS

One hundred sixty-nine consecutive patients who underwent curative resection of IPMN were enrolled. The intraductal components were classified into four distinct epithelial subtypes: gastric, intestinal, pancreatobiliary, and oncocytic. The invasive components were classified as colloid or tubular.

RESULTS

The numbers of patients with gastric, intestinal, pancreatobiliary, and oncocytic subtypes were 123, 42, 3, and 1, respectively. Fifty-six patients had invasive cancer (tubular type, 42; colloid type, 14). The proportions of gastric type IPMN within each histological grade were 88 % among adenomas, 43 % among noninvasive carcinomas, 41 % among minimally invasive carcinomas, and 74 % among invasive carcinomas. Gastric subtype was more commonly associated with branch duct type and intestinal subtype with main duct type, and these tendencies were statistically significant (P = 0.0131). Furthermore, there was a strong correlation between gastric and tubular types and between intestinal and colloid types (P < 0.0001). The 5-year survival rate among the 56 invasive cancers was 52.7 % for gastric type and 89.7 % for intestinal type, which was statistically significant (P = 0.030).

CONCLUSIONS

Gastric type IPMN is mostly derived from branch duct IPMN and often demonstrates benign behavior, as seen with adenomas. However, once gastric type IPMN develops into invasive carcinoma, the survival rate is significantly lower than other types.

Laparoscopic pancreatic resections

PURPOSE

Pancreatic surgery is technically complex and requires considerable expertise. Laparoscopic pancreatic surgery adds the need for considerable experience with advanced laparoscopic techniques. Despite the technical difficulties, an increasing number of centers propagate the use of laparoscopy in pancreatic surgery over the last decade.

METHODS

In this review, we provide an overview of the literature regarding the advantages and disadvantages of laparoscopic pancreatic surgery. Larger prospective randomized studies have emerged in the subset of laparoscopic or retroperitoneoscopic surgery for acute pancreatitis, considerable single center experience has been reported for laparoscopic pancreatic tail resection, and laparoscopic pancreatic head resection, however, is still restricted to a few experienced centers worldwide.

RESULTS AND CONCLUSIONS

Laparoscopic pancreatic surgery is becoming more and more established, in particular for the treatment of benign and premalignant lesions of the pancreatic body and tail. It has been shown to decrease postoperative pain, narcotic use, and length of hospital stay in larger single center experience. However, prospective trials are needed in laparoscopic resective pancreatic surgery to evaluate its advantages, safety, and efficacy in the treatment of pancreatic neoplasms and in particular in malignant pancreatic tumors.

Intraductal papillary mucinous neoplasms of the pancreas: is the puzzle solved?

Intraductal papillary mucinous neoplasms (IPMN) are drawing more attention and being detected more frequently. This review focuses on current understanding of the management of IPMN, regarding morphological classification, subclassification by cell lineage features, molecular abnormalities, radiological and imaging evaluation, progression to cancer, incidence and risk factors for malignancy, risk of distinct pancreatic adenocarcinoma and extrapancreatic malignancies, treatment strategy, and types of surgical resection. In particular, missing links in solving the IPMN puzzles are described with regard to differential diagnosis, role of cyst fluid analysis, multifocal IPMN, histological evaluation of the surgical specimen, observation without resection, follow up of patients after resection, role of adjuvant therapy for invasive carcinoma, screening for other neoplasms in patients with IPMN on follow up, prognostic factors influencing long-term outcomes, and role of endoscopic therapy.

[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.

Intraductal papillary mucinous neoplasms of the pancreas complicated with intraductal hemorrhage, perforation, and fistula formation: CT and MR imaging findings with pathologic correlation

OBJECTIVE

To correlate the CT and MR images with pathologic findings on intraductal papillary mucinous neoplasms (IPMNs) complicated with intraductal hemorrhage, perforation, and fistula.

MATERIALS AND METHODS

We retrospectively evaluated the CT (n = 5), MR imaging (n = 4), and pathological features of five IPMN patients complicated with intraductal hemorrhage (n = 5), perforation (n = 1), and fistula into the duodenum and jejunum (n = 1).

RESULTS

Intraductal hemorrhage could be detected as high attenuation on non-contrast CT in two of the five cases, and as high signal intensity on fat-suppressed T1-weighted MR images in all four of the cases. Perforation and fistula could be recognized on CT images. In all IPMNs, denuded epitheliums were observed pathologically. Dissolution of the duct wall and extension of mucinous materials were seen at the area of denuded epithelium. Perforations and fistula, without evidence of cancer invasion, were recognized in the dissolved duct wall. Pathogenesis of the perforations and fistula formations appeared to be related to excessive pressure in the dilated ducts and autodigestion of enzyme-rich fluids.

CONCLUSION

Complications with IPMN could be recognized on CT and fat-suppressed T1-weighted MR images. Intraductal hemorrhage might be predictive sign of perforation and fistula formation.

Adrenal pseudocyst mimicking cystic neoplasm of pancreatic tail

Cystic neoplasms of the pancreatic tail are usually picked up as incidental findings during imaging studies. We report an unusual case of adrenal pseudocyst mimicking cystic tumor of pancreatic tail who presented with abdominal pain and weight loss. Ultrasonography and CT of the abdomen revealed a cystic mass in relation to the pancreatic tail. On exploration, a cystic mass was present in the tail of the pancreas, for which distal pancreatectomy was performed. The histopathology report surprisingly revealed an adrenal pseudocyst without a cellular lining. The normal adrenal gland was compressed in the wall. This case highlights that this rare possibility should be considered in the differential diagnosis of cystic lesions of the pancreatic tail.

Molecular characteristics and biological behaviours of the oncocytic and pancreatobiliary subtypes of intraductal papillary mucinous neoplasms

Intraductal papillary mucinous neoplasm (IPMN) consists of four epithelial subtypes. Of those, pancreatobiliary and oncocytic types are recently recognized and relatively uncommon, and usually exhibit high-grade dysplasia. The biological properties and molecular characteristics of these two types have not been well documented. The few molecular studies of the oncocytic type showed absence of KRAS mutations commonly seen in the other subtypes, raising the possibility that the oncocytic type is distinct from the other subtypes. Thus, we examined clinicopathological features and molecular alterations of the two subtypes. The study cohort consisted of 12 pancreatobiliary and 18 oncocytic IPMN cases. KRAS, BRAF, and PIK3CA mutations and TP53, SMAD4, and β-catenin expression were analysed, and the results of molecular and clinicopathological profiles were compared between the two subtypes. KRAS mutations were identified in the oncocytic type, but less frequently than the pancreatobiliary type (17% versus 58%, p = 0.048). BRAF mutation was found in a single oncocytic tumour, and no PIK3CA mutations were seen in any of the study cohort. TP53 overexpression was less frequent in the oncocytic type than in the pancreatobiliary type (11% versus 58%, p = 0.013). Invasive components were present in 50% of the oncocytic and 92% of the pancreatobiliary types, with lymph node metastasis more frequently seen in the latter, corresponding to better outcomes in the former (5-year survival rates: 93% versus 32%, p = 0.014). Our demonstration of KRAS and BRAF mutations in the oncocytic-type IPMN supports a role for the activation of the RAS-MAPK pathway in this tumour type. However, the less frequent TP53 overexpression associated with the significantly lower rates of invasion and nodal disease in the oncocytic type correlates with better outcomes compared to the pancreatobiliary type.

Pseudointraductal papillary mucinous neoplasia caused by microscopic periductal endocrine tumors of the pancreas: a report of 3 cases

Intraductal papillary mucinous neoplasms constitute histologically distinctive pancreatic tumors characterized by cystically dilated pancreatic ducts lined by papillary epithelium, often with extensive mucin production. With increasing awareness of and vigilance for these tumors, there has been a surge in the incidence of intraductal papillary mucinous neoplasms in the last few decades. However, resections of presumed intraductal papillary mucinous neoplasms sometimes reveal other types of cystic lesions. Here we describe 3 cases of small, incidentally identified pancreatic endocrine tumors that focally compressed the main pancreatic duct and presented clinically, radiologically, and grossly as intraductal papillary mucinous neoplasm. The histology of the dilated ducts in all cases lacked convincing features of intraductal papillary mucinous neoplasm, prompting more careful examination of the specimens and eventual identification of small well-differentiated endocrine neoplasms. The constellation of findings represented by pancreatic endocrine neoplasm-associated duct stricture and dilatation can mimic intraductal papillary mucinous neoplasm clinically and pathologically. Awareness of this phenomenon can potentially avoid misdiagnosis of intraductal papillary mucinous neoplasm in such cases.

Risk factors associated with the postoperative recurrence of intraductal papillary mucinous neoplasms of the pancreas

OBJECTIVES

The risk factors correlated with the post-operative recurrence of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are not well established. The aim was to determine the risk factors of recurrence.

METHODS

We reviewed retrospectively the differences of clinicopathologic features between the recurrence and nonrecurrence groups of patients with IPMN who underwent surgical resection and analyzed the recurrence-related factors.

RESULTS

A total of 103 patients were confirmed to have IPMNs. The mean postoperative follow-up was 3.2 years, and the recurrence rate was 12.6%. Recurrent cases (n=13) had the following pathologic grades: adenoma, 1; and invasive carcinoma, 12. The mean postoperative survival was 17.0 months in the recurrence group and 41.4 months in the nonrecurrence group (P<0.001). The independent risk factors of recurrence were invasive carcinoma (P=0.017, hazard ratio=71.79; 95% confidence interval (CI)=2.13-2417.05), elevated carbohydrate antigen 19-9 (P=0.007, hazard ratio=37.97, 95% CI=2.66-542.32), and main location in the pancreatic head (P=0.038, hazard ratio=0.16, 95% CI=0.03-0.90).

CONCLUSIONS

The risk factors associated with recurrence of IPMNs were invasive pathology, elevated carbohydrate antigen 19-9, and main location in the pancreatic head. A more careful follow-up is needed for such patients.

Invasive carcinomas originating from intraductal papillary mucinous neoplasms of the pancreas: conspicuity and primary sites of the solid masses on triple-phase dynamic CT imaging

OBJECTIVE

To assess the conspicuity of invasive carcinomas (solid masses) originating from pancreatic intraductal papillary mucinous neoplasms (invasive IPMNs) and the primary sites of the solid masses on thin-slice dynamic CT.

METHODS

Twenty patients with pathologically proven invasive IPMNs underwent triple-phase dynamic CT examinations (arterial, portal, and delayed phases). Qualitative and quantitative analyses of conspicuity of the solid masses were performed for all phases. The primary sites [branch duct and/or main pancreatic duct (MPD)] of the solid masses were evaluated on CT in comparison to the pathologic findings.

RESULTS

The qualitative and quantitative analyses of the conspicuity of the solid masses showed that the arterial phase images were superior to those of the portal and delayed phases. The primary sites of the solid mass were histopathologically diagnosed as branch ducts in 6 (30%) patients, MPD in 13 (65%), and both branch ducts and the MPD in one (5%). The sensitivity and specificity of the CT evaluation of the primary sites were 100% for the branch ducts, and for the MPD 93% and 100%, respectively.

CONCLUSION

Arterial phase images are useful for the diagnosis of invasive IPMNs, and attention should be paid to pancreatic parenchyma surrounding the MPD when detecting invasive carcinomas.

Evidence-based imaging of pancreatic malignancies

A high-quality pancreatic protocol computed tomography (CT) is the primary imaging modality for diagnosing and staging pancreatic malignancy. The main limitation of CT is the lack of sensitivity for early pancreatic lesions. Endoscopic ultrasound (EUS) provides an excellent complement to CT for both diagnosis and staging of pancreatic cancer, and allows easy access for needle aspiration and tissue diagnosis. Magnetic resonance (MR) can be helpful for evaluating small hepatic nodules or cystic lesions of the pancreas, but in general, the role of MR and positron emission tomography remains limited to special situations when the results of CT and EUS are equivocal.

Invasive intraductal papillary mucinous carcinomas of the pancreas: predictors of survival and the role of lymph node ratio

INTRODUCTION

Intraductal papillary mucinous neoplasms (IPMNs) are being increasingly recognized, and often harbor cancer. Lymph node metastases are an important prognostic factor for patients with invasive intraductal papillary carcinoma (I-IPMC), but the role of lymph node ratio (LNR) in predicting survival after surgery for I-IPMC is unknown.

METHODS

The combined databases from the Surgical Department of Massachusetts General Hospital of Boston and the University of Verona were queried. We retrospectively reviewed clinical and pathologic data of all patients with resected, pathologically confirmed, I-IPMC between 1990 and 2007. Univariate and multivariate analysis were performed.

RESULTS

I-IPMCs were diagnosed in 104 patients (55 males and 49 females), median age was 69 years. Recurrent disease was identified in 49 patients (47.1%) and the median 5-year disease specific survival (DSS) was 60.1%. The median number of resected/evaluated nodes was 15 (range, 5-60). There were 60 (57.7%) patients who had negative lymph nodes (N0), whereas 44 (42.3%) had lymph node metastases (N1). Patients with lymph node metastases had a shorter 5-year DSS (28.9%) compared with patients with negative lymph nodes (80.3%; P < 0.05) As the LNR increased, 5-year DSS decreased (LNR = 0, 86.5%; LNR >0 to 0.2, 34.4%; LNR >0.2, 11.1%; P < 0.05). On multivariate analysis, LNR, the presence of a family history of pancreatic cancer and a preoperative value of Ca 19.9 > 37 U/L were significant predictors of survival (P < 0.05).

CONCLUSIONS

Lymph node ratio is a strong predictor of survival after resection for invasive intraductal papillary mucinous carcinoma.

Predictors of the presence of concomitant invasive ductal carcinoma in intraductal papillary mucinous neoplasm of the pancreas

OBJECTIVE

Invasive ductal carcinoma (DC) of the pancreas arising as an independent lesion in association with intraductal papillary mucinous neoplasm (IPMN) has occasionally been reported. However, clinicopathological features related to the presence of DC in patients with IPMN remain largely unknown. The purpose of the present study was to determine the factors predicting the presence of concomitant DC in those with IPMN.

MATERIALS AND METHODS

We retrospectively reviewed the clinicopathological data of a consecutive series of 236 patients with IPMN treated by surgical resection or followed up at our institution between January 1987 and June 2008. In an attempt to identify predictors for the presence of DC, clinicopathological variables were compared between IPMN patients with concomitant DC and those without concomitant DC.

RESULTS

Of 236 patients with IPMN, concomitant DC was detected synchronously or metachronously in 22 patients (9.3%). All the 22 IPMNs were of branch duct type and histological grades of 12 resected IPMNs were adenoma(n = 8) and borderline (n = 4). Multivariate analysis revealed 2 significant predictive factors for the presence of DC in IPMN, including worsening diabetes mellitus (P < 0.001) and an abnormal serum CA 19-9 level (P = 0.024).

CONCLUSION

In view of the high prevalence of DC careful inspection of the entire pancreatic gland is necessary for early detection of DC in patients with branch duct IPMNs, especially when worsening diabetes mellitus and an abnormal serum CA 19-9 level are manifested.

Recurrence patterns of intraductal papillary mucinous neoplasms of the pancreas on enhanced computed tomography

OBJECTIVE

To characterize imaging features and findings in recurrent intraductal papillary mucinous neoplasms (IPMN); thereby reconciling the "field defect" theory with the appearance of recurrences distant from the resection margin.

METHODS

Computed tomography findings were reviewed in 89 patients who were resected with IPMN. At follow-up, the appearance of the pancreatic duct, features of recurrent masses, evidence of enhancement, calcifications, lymphadenopathy, and metastases were recorded.

RESULTS

Fourteen (16%) of the 89 patients had evidence of recurrence. Nine (64%) of the 14 patients demonstrated evidence for local recurrence. Ten recurrent lesions were noted in 9 patients. Patients with recurrence demonstrated an increase of pancreatic ductal dilatation of 3.3 mm, whereas patients without recurrence either had no dilatation or dilatation which then decreased over time.

CONCLUSIONS

Computed tomography findings suspicious for tumor recurrence include enlarging mass (either solid, cystic or both), progressive ductal dilatation, or extrapancreatic disease. There was a lack of correlation between margin status and location of recurrence within the pancreas consistent with the global field defect theory of IPMN.

Branch duct intraductal papillary mucinous neoplasms in a retrospective series of 190 patients

Background

A consensus conference has recommended close observation of branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) smaller than 30 mm, without symptoms or mural nodules. This study investigated whether these recommendations could be validated in a single-centre experience of BD-IPMNs.

Methods

Some 190 patients with radiological imaging or histological findings consistent with BD-IPMN were enrolled between 1998 and 2005. Those with less than 6 months' follow-up and no histological confirmation were excluded.

Results

BD-IPMN was diagnosed by computed tomography and pancreatography in 105 patients and pathologically in 85. Eighteen patients had adenoma, 53 borderline malignancy, five carcinoma in situ and nine invasive carcinoma. Findings associated with malignancy were the presence of radiologically suspicious features (P &lt; 0·001) and a cyst size of at least 30 mm (P = 0·001). Had consensus guidelines been applied, 54 patients would have undergone pancreatic resection, whereas only 28 of these patients actually had a resection; 12 of the latter patients had a malignancy compared with none of the 26 patients who were treated conservatively.

Conclusion

A simple increase in cyst size is not a reliable predictor of malignancy. Observation is recommended for patients with a BD-IPMN smaller than 30 mm showing no suspicious features on imaging.

Multifocal intraductal papillary mucinous neoplasm of the pancreas-A case report

Cystic neoplasms of the pancreas are relatively rare, comprising 10 percent of pancreatic cysts and only 1 percent of pancreatic cancers. Cystic neoplasms include mucinous cystic neoplasms, serous cystadenomas, papillary cystic tumors, cystic islet cell tumors and intraductal papillary mucinous neoplasms of the pancreas (IPMNs). IPMN was first described in 1982. It has been most commonly described in 60 to 70 years old males, and represents a relatively “new” but increasingly recognized disease. The improvement and widespread use of modern imaging equipments and heightened awareness of physicians contribute to the increasing incidence of IPMN. The majority of IPMNs are located in the pancreatic head (75%) while the rest involves the body/tail regions. Multifocal IPMNs have been hypothesized, but the true presence of multifocality is unknown. Here we present a 72-year-old male diagnosed with IPMN (carcinoma in situ) in the pancreatic head and a branch duct type IPMN (duct atypia) in the pancreatic body and tail. The patient underwent a Whipple intervention and a distal pancreatectomy. A three-year disease-free survival has been observed so far.

Role of endosocopic ultrasound in the diagnosis of cystic tumours of the pancreas

With the increased use of sophisticated imaging, cystic lesions in the pancreas are being recognized with greater frequency. Although imaging alone may not provide a specific diagnosis in many cases, a combination of imaging characteristics, clinical presentation, and additional procedures such as endoscopic ultrasound guided fine needle aspiration of cystic lesion, allows appropriate management. Cystic lesions in the pancreas can be divided pathologically into congenital cysts, pseudocysts and cystic neoplasm. At least four different types of cystic neoplasm have been described: mucinous neoplasms, intraductal papillary mucinous neoplasms, serous neoplasms and papillary cystic neoplasms The most important diagnosis is differentiating between mucinous and non-mucinous cystic lesion because of their different potential of malignancy. Endoscopic ultrasound provides the highest resolution of the pancreas and endoscopic ultrasound-fine needle aspiration can supply further diagnostic information on the basis of cytology, fluid viscosity, concentration of tumour glycoproteins, amylase level, molecular analysis that may contribute to the better clinical outcome of these neoplasms.

Endoscopic ultrasonography for evaluating patients with recurrent pancreatitis

Acute recurrent pancreatitis (ARP) is still a complex diagnostic and therapeutic challenge in clinical practice. In up to 30% of cases of ARP, it is not possible to establish the etiology of the disease. In the other 70%, many factors play an etiological role in ARP: microlithiasis, sphincter of Oddi dysfunction (SOD), pancreas divisum, hereditary pancreatitis, cystic fibrosis, a choledochocele, annular pancreas, an anomalous pancreatobiliary junction, pancreatic tumors or chronic pancreatitis are diagnosed. EUS should be useful in ARP as it is sensitive for diagnosing bile duct stones, gallbladder sludge, pancreatic lesions, ductal abnormalities and chronic pancreatitis. Endoscopic ultrasound (EUS) appears to be diagnostic in the majority of patients with previously unexplained pancreatitis, and offers an alternative to endoscopic retrograde cholangiopancreatography (ERCP) as the initial diagnostic test in patients with ARP.

Prospective evaluation of indeterminate ERCP findings by intraductal ultrasound

BACKGROUND AND AIM

Although the role of intraductal ultrasound (IDUS) in the evaluation of specific disease entities is well known, its utility in evaluating indeterminate findings in a heterogeneous group of patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) is unknown. This study evaluates the diagnostic accuracy of IDUS in patients with indeterminate findings at ERCP.

METHODS

This was a prospective study of all patients who underwent IDUS for evaluation of an indeterminate biliary stricture or main pancreatic duct (MPD) dilation noted at ERCP over an 8-month period. The accuracy of IDUS was established based on long-term follow-up, surgery, or further investigations.

RESULTS

Twenty-nine (5%) of 600 patients who underwent ERCP had an indeterminate finding that warranted further evaluation by IDUS: this was biliary stricture in 19 patients and MPD dilation in 10. Technical success was 100%. Mean duration of follow-up was 435 days (range 192-614 days). In patients with biliary stricture, IDUS diagnosed 11 as benign and eight as malignant. In patients with MPD dilation, IDUS diagnosed intraductal papillary mucinous tumor in six patients and chronic pancreatitis in four. Findings on IDUS supported the correct diagnosis in 27 of 29 patients (93%). In two patients with dominant hilar stricture in the setting of primary sclerosing cholangitis, IDUS was false positive in one and false negative in the other. One patient died of multiorgan failure due to post-ERCP pancreatitis.

CONCLUSIONS

A technically easy procedure, IDUS offers unique advantages in the evaluation of patients with indeterminate findings at ERCP.

Do consensus indications for resection in branch duct intraductal papillary mucinous neoplasm predict malignancy? A study of 147 patients

BACKGROUND AND AIMS

Recent consensus guidelines suggest that presence of > or =1 of the following is an indication for resection (IR) of branch duct intraductal papillary mucinous neoplasm (IPMN-Br): cyst-related symptoms, main pancreatic duct diameter > or =10 mm, cyst size > or =30 mm, intramural nodules, or cyst fluid cytology suspicious/positive for malignancy. Among a cohort of patients with IPMN-Br we determined if the consensus IR (CIR), presence of multifocal IPMN-Br, or growth of cyst size on follow-up predict malignancy.

METHODS

We identified 147 patients with IPMN-Br of whom 66 underwent surgical resection at diagnosis and 81 were followed conservatively, of whom 11 were resected during follow-up. Clinical, imaging, histological, and cyst fluid characteristics from all 147 patients with IPMN-Br were obtained from clinical records and/or by contacting the patients. In all cases, presence of CIR at baseline and during follow-up (N = 66), presence of multifocal cysts (N = 57), and increase in cyst size (N = 38) were noted.

RESULTS

Among the 77 resected IPMN-Brs, at initial evaluation 61 had at least one CIR and 16 had none. Malignancy was present in 9/61 (15%) with CIR and 0/16 without IR (P= 0.1). When presence of any one of the CIR was taken as an indicator of malignancy, the CIR had a sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 23%, 14%, and 100%, respectively. Prevalence of malignancy in those with single versus multifocal IPMN-Br was similar (13%vs 11%). No patient has developed malignancy after a median follow-up of 15 months. So far, none of the 38 patients with increase in cyst size on follow-up has developed malignancy related symptoms.

CONCLUSIONS

Suggested consensus indications for resection identify all patients with malignancy; however, their specificity is low. In the short term it would be safe to follow patients without these features.

Role of endoscopic ultrasound in the diagnosis of intraductal papillary mucinous neoplasms: correlation with surgical histopathology

BACKGROUND & AIMS

Intraductal papillary mucinous neoplasms (IPMNs) are precancerous tumors characterized by dilation of the main pancreatic duct, its side branches, or both. The purpose of this study was to evaluate the role of endoscopic ultrasound (EUS) in differentiating benign and malignant IPMNs.

METHODS

We identified all patients between July 1996-November 2005 who underwent preoperative EUS for IPMNs. Malignancy was defined as the presence of invasive carcinoma; all other neoplasms were considered benign. The results of EUS and EUS-guided fine-needle aspiration (EUS-FNA) were compared with corresponding histopathology.

RESULTS

Seventy-four patients (38 male; mean age, 65 years) with 21 (28%) malignant and 53 (72%) benign IPMNs were identified. Sixty-five (88%) underwent EUS-FNA. Compared with benign tumors, patients with malignant IPMNs were more likely to be older (P = .011), present with jaundice (P = .03) or weight loss (P = .03), and have EUS features of a dilated main pancreatic duct (P = .0001), solid lesion (P = .0001), pancreatic ductal filling defects (P = .03), or thickened septa within any cyst (P = .02). The sensitivity, specificity, and accuracy of EUS-FNA for the diagnosis of malignancy were 75% (95% confidence interval [CI], 53%-89%), 91% (95% CI, 79%-97%), and 86% (95% CI, 76%-93%), respectively. Cyst or pancreatic duct fluid carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 did not differ between groups.

CONCLUSIONS

Older age, jaundice and weight loss, and EUS features of a solid lesion, dilated main pancreatic duct, ductal filling defects, and thickened septa are predictive of malignancy in patients with IPMNs. EUS-FNA cytology is helpful, but cyst fluid CEA and CA 19-9 are of limited value to differentiate malignant from benign IPMNs.

Intraductal papillary mucinous neoplasms of the pancreas: effect of invasion and pancreatic margin status on recurrence and survival

BACKGROUND

The natural history and prognosis for patients with intraductal papillary mucinous neoplasms (IPMN) with and without invasion remain poorly defined. This study evaluated the outcome after pancreatectomy for IPMN according to the pancreatic transection margin status and the presence or absence of invasive carcinoma.

METHODS

Data from a prospective pancreatic tumor database and medical records were reviewed for all patients who underwent pancreatic resection for IPMN at our institution between July 1990 and July 2003. Surgical specimens were re-reviewed by a single pathologist.

RESULTS

IPMN was diagnosed in 35 (26%) of 137 patients who underwent pancreatic resection for cystic neoplasms. Invasive IPMN was confirmed in 13 (37%) of 35 patients. Noninvasive IPMN was found in 22 (63%) of 35 patients; pathology re-review changed the original diagnosis from invasive to noninvasive IPMN in 6 patients. Noninvasive IPMN was found at the final pancreatic margin in eight patients; none developed recurrent disease at a median follow-up of 34 months. Recurrent disease was identified in 7 (58%) of 13 patients with invasive IPMN and in none with noninvasive IPMN. The median overall survival was 22.9 and 84.9 months in patients with invasive and noninvasive IPMN, respectively (P=.0009).

CONCLUSIONS

Distinction between invasive and noninvasive IPMN is essential in estimating prognosis and determining the need for adjuvant therapy and the frequency of follow-up surveillance. Noninvasive IPMN, even if present at the pancreatic margin, was not associated with recurrent disease. In contrast, invasive IPMN was associated with early recurrence and short survival.

Multidetector CT of the pancreas

CT is the primary imaging modality of the pancreas. This article reviews the multidector CT technique and its current status in the diagnosis of various pancreatic diseases. Special emphasis is given to the impact of multidetector CT and postprocessing imaging techniques on the staging of pancreatic adenocarcinoma.

Accuracy of preoperative imaging methods in a retrospective series of 14 patients with operated intraductal papillary mucinous tumors of the pancreas

Accuracy of preoperative imaging methods for the diagnosis of intraductal papillary mucinous tumor of the pancreas (IPMT) is not well known.

AIMS

To compare diagnostic accuracy of various preoperative imaging methods with pathology data following surgical resection.

PATIENTS AND METHODS

Fourteen consecutive patients underwent pancreatic surgical resection for IPMT between January 1988 and May 2002. Imaging methods included endoscopic retrograde cholangiopancreatography and/or magnetic resonance cholangiopancreatography and/or endoscopic ultrasonography. Results of preoperative morphological examinations were compared with histopathological findings from surgical specimens.

RESULTS

IPMT was located to the pancreatic head or body in 72% of patients and involved the main pancreatic duct (MPD) in 79% of cases Carcinoma was diagnosed in 35% of the cases. Sensitivity of imaging methods varied from 64 to 80% to accurately locate the tumor and from 73 to 80% in distinguishing between types involving the MPD or the accessory ducts. Planned surgical resection based on preoperative imagery correlated with final surgery in 57% of the patients. Histological study of whole pancreas specimens revealed lesions in undilated ducts, and also dilated ducts without histological lesions.

CONCLUSION

The sensitivity of preoperative imaging methods is moderate in defining intraductal extension of IPMT. Duct dilatation is not predictive of histological involvement by tumors and ducts may be pathological without dilatation.

Precursors to invasive pancreatic cancer

Pancreatic cancer, once invasive, is almost uniformly fatal. In order to alleviate the dismal prognosis associated with this disease, it is imperative that pancreatic cancer be recognized and treated prior to invasion. Understanding the morphology and biology of precursor lesions of invasive pancreatic cancer has therefore become an issue of paramount importance. In the last decade, significant progress has been in the recognition and appropriate classification of these precursor lesions, and the current review will focus on our state-of-the-art knowledge on this topic. Mucinous cystic neoplasms (MCNs), intraductal papillary mucinous neoplasms (IPMNs), and pancreatic intraepithelial neoplasia (PanIN) encompass the three known morphologically distinct precursors to invasive pancreatic cancer. In addition to discussion of the "classic" precursor entities, this review will also address some of the recent diagnostic controversies for these lesions, in particular features that distinguish IPMNs from PanIN lesions. Finally, the potential clinical impact of recognizing these precursor lesions in the context of early detection of pancreatic cancer will be discussed.

Intraductal Papillary Mucinous Neoplasms of the Pancreas: CT Patterns of Recurrence and Multiobserver Performance in Detecting Recurrent Neoplasm After Surgical Resection

OBJECTIVE

The purposes of our study were to describe the CT appearance of recurrent intraductal papillary mucinous neoplasms of the pancreas after surgical resection and estimate the performance of CT in detecting recurrent neoplasms.

MATERIALS AND METHODS

A single unblinded reviewer characterized the presence and appearance of recurrent intraductal papillary mucinous neoplasms on 66 CT scans of 17 patients with proven recurrence, noting location and appearance of recurrent neoplasm. These results, described in this article, were summarized in tabular format and shown to three blinded observer. The observers then evaluated one postoperative CT examination from every patient at our institution who underwent surgical removal of intraductal papillary mucinous neoplasms (n = 45) for the presence or absence of local or distant recurrence.

RESULTS

The unblinded reviewer found 11 cases of local recurrence. Extrapancreatic local recurrences tend to have solid components (5/6), tend to be located adjacent to the resection margin (5/6), and may exhibit vascular invasion (2/6). Intrapancreatic neoplasms are usually cystic (4/5). Nine patients had distant metastases. Prospective sensitivity for recurrent tumor ranged from 76% (13/17) to 94% (16/17). Sensitivity for local recurrence ranged from 55% (6/11) to 82% (9/11). Specificity ranged from 79% (22/28) to 96% (27/28). Interobserver agreement for predicting recurrence was moderate to substantial (kappa = 0.51-0.65).

CONCLUSION

Locally recurrent intraductal papillary mucinous neoplasms of the pancreas tend to be either extrapancreatic and solid at the resection margin or intrapancreatic and cystic. CT can detect most recurrent intraductal papillary mucinous neoplasms of the pancreas with moderate to substantial interobserver agreement.

Autoimmune chronic pancreatitis

In recent years a peculiar type of chronic pancreatitis with underlying autoimmunity has been described. Lymphoplasmacytic infiltration and fibrosis on histology and elevated IgG levels or detected autoantibodies on laboratory data support the concept of autoimmune chronic pancreatitis (AIP). Pancreatic imaging reveals a rare association of diffuse enlargement of the pancreas and irregular narrowing of the main pancreatic duct, which is unique and specific to AIP. Although AIP is not a common disease, it is increasingly being recognized as knowledge of this entity builds up. Clinically it is very important to be aware of this disease because AIP can clinically disguise as pancreaticobiliary malignancies, ordinary chronic, or acute pancreatitis. Above all, AIP is a very attractive disease to clinicians in terms of its dramatic response to oral steroid therapy in contrast to ordinary chronic pancreatitis. This review discusses the clinical, laboratory, histologic, and imaging findings that are seen in patients with AIP, especially focusing on the diagnosis.

MUC1 and MUC2 in pancreatic neoplasia

MUCs are glycoproteins with various roles in homeostasis and carcinogenesis. Among other actions, MUC1 may inhibit cell-cell and cell-stroma interactions and function as a signal transducer, participating in cancer progression. In contrast, MUC2 is normally found only in goblet cells, where it contributes to the protective barrier function of these cells. Recently, a tumour suppressor role has been demonstrated for MUC2, and both MUC1 and MUC2 appear to have important roles in pancreatic neoplasia. MUC1 appears to be a marker of aggressive phenotype and may facilitate the vascular spread of carcinoma cells. In contrast, MUC2 is rarely detectable in aggressive pancreatic tumours, but is commonly expressed in intraductal papillary mucinous neoplasms (IPMNs), which are rare, indolent tumours, in intestinal IPMNs, and in indolent colloid carcinomas. MUC2 appears to be not only a marker of this indolent pathway, but also partly responsible for its less aggressive nature. Thus, in pancreatic neoplasia, MUC1 and MUC2 have potential diagnostic and prognostic value as markers of aggressive and indolent phenotypes, respectively, and have potential as therapeutic targets.