Intraoperative ultrasonography by high-resolution annular array transducer for intraductal papillary mucinous tumors of the pancreas

The use of intraoperative ultrasound for diagnosis and stadiation in pancreatic head neoformations

The intraoperative staging of the pancreatic cancer is important to make a proper treatment. For this reason the intraoperative echography is playing an important role in the right treatment choice. The intraoperative echography, that can be performed with an open or laparoscopic probe, is used to confirm the preoperative diagnosis and assess the pancreatic cancer resecability. The intraoperative echography (IOUS) or laparoscopic intraoperative echography (LIOUS) are useful to identify the patients with a non resecable cancer and perform a faster neoadjuvant treatment. The LIOUS can also avoid an useless laparotomy. The aim of this study is to assess, both in our experience and in the cited literature, the concordance rate between the pancreatic cancer preoperative staging, performed with TC and MRI (when it is available), and intraoperative staging, performed with intraoperative laparotomic or laparoscopic echography.

MATERIAL AND METHODS

We have analyzed the treatment management of 34 patients, who were candidate to major surgery for suspected pancreatic head cancer and who underwent to intraoperative LIOUS or IOUS staging from 2001 to 2012.

RESULTS

LIOUS and IOUS have allowed to detect cases in which preoperative diagnosis, proved by CT and MRI, was not agreeing with intraoperative diagnosis (22 patients on 34, 64% discordance rate), avoiding the execution of a demolitive and uneseful surgery in order to guarantee the surveillance and life's quality of patients.

CONCLUSION

We suggest to perform in every patients undergone to pancreatic surgery an intraoperative ultrasound exam, to detect unresecable and unpredicted lesions.

Intraductal Papillary Mucinous Neoplasm of Pancreas

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

Applications of intraoperative ultrasound in the treatment of complicated cases of acute and chronic pancreatitis and pancreatic cancer - own experience

Both acute and chronic inflammation of the pancreas often lead to complications that nowadays can be resolved using endoscopic and surgical procedures. In many cases, intraoperative ultrasound examination (IOUS) enables correct assessment of the extent of the lesion, and allows for safe surgery, while also shortening its length.

AIM OF THE RESEARCH

At the authors' clinic, intraoperative ultrasound is performed in daily practice. In this paper, we try to share our experiences in the application of this particular imaging technique.

RESEARCH SAMPLE AND METHODOLOGY

Intraoperative examination conducted by a surgeon who has assessed the patient prior to surgery, which enabled the surgeon to verify the initial diagnosis. The material presented in this paper includes 145 IOUS procedures performed during laparotomy due to lesions of the pancreas, 57 of which were carried out in cases of inflammatory process.

RESULTS AND CONCLUSIONS

IOUS is a reliable examination tool in the evaluation of acute inflammatory lesions in the pancreas, especially during the surgery of chronic, symptomatic inflammation of the organ. The procedure allows for a correct determination of the necessary scope of the planned surgery. The examination allows for the differentiation between cystic lesions and tumors of cystic nature, dictates the correct strategy for draining, as well as validates the indications for the lesion's surgical removal. IOUS also allows the estimation of place and scope of drainage procedures in cases of overpressure in the pancreatic ducts caused by calcification of the parenchyma or choledocholitiasis in chronic pancreatitis. In pancreatic cancer, IOUS provides a verification of the local extent of tumor-like lesions, allowing for the assessment of pancreatic and lymph nodes metastasis, and indicating the presence of distant and local metastases, including the liver. IOUS significantly improves the effectiveness of intraoperative BAC aspiration or drainage of fluid reservoirs.

Comparison of ERCP, EUS, and ERCP combined with EUS in diagnosing pancreatic neoplasms: a systematic review and meta-analysis

In the current study, we performed a systematic review of literature pertaining to the diagnostic value of endoscopic retrograde cholangiopancreatography (ERCP), endoscopic ultrasonography (EUS), and combined ERCP plus EUS to pancreatic cancer. We searched MEDLINE, OVID, and the Cochrane Library for studies evaluating diagnostic validity of ERCP, EUS, and ERCP plus EUS between January 1989 and May 2014. We obtained pooled estimates of sensitivity, specificity, and summary receiver operating characteristic curves (SROC). A total of 10 studies that included 669 patients who fulfilled all of the inclusion criteria were considered for inclusion in the analysis. The pooled sensitivities of EUS, ERCP, and EUS plus ERCP were 76.7, 57.9, and 79.9 %, respectively. The pooled specificities were 91.7, 90.6, and 94.2 %, respectively. The *Q index estimates were 0.828, 0.862, and 0.896, respectively. The *Q indices for EUS and EUS plus ERCP were significantly higher compared with ERCP (P = 0.010 and 0.008, respectively). Our meta-analysis showed that ERCP plus EUS was associated with a high diagnostic value for the detection of pancreatic neoplasms compared with ERCP and EUS alone.

Clinicopathologic characteristics of patients with resected multifocal intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND

Intraductal papillary mucinous neoplasms of the pancreas are defined as mucin-producing neoplasms arising in the main pancreatic duct (main duct type), its major branches (branch duct type), or in both (mixed type). Intraductal papillary mucinous neoplasms of the pancreas can occur as a single collection of cysts or as multifocal lesions. While subtypes of intraductal papillary mucinous neoplasms of the pancreas are well described in literature, little is known about the importance of multifocal intraductal papillary mucinous neoplasms of the pancreas. This study evaluated the clinicopathologic characteristics of patients with surgically resected, multifocal intraductal papillary mucinous neoplasm of the pancreas.

METHODS

Clinicopathologic features and preoperative imaging of patients resected for multifocal intraductal papillary mucinous neoplasm of the pancreas defined as intraductal papillary mucinous neoplasm of the pancreas occurring in more than just 1 area, from January 2004 to July 2010 at the Department of Surgery, University of Heidelberg were analyzed. Preoperative parameters, including number of cysts, cyst size, presence of nodules, and epidemiologic data, were assessed and compared to patients with unifocal intraductal papillary mucinous neoplasms of the pancreas.

RESULTS

Among 287 patients with resected intraductal papillary mucinous neoplasms of the pancreas, 51 patients (17.8%) with multifocal cystic pancreatic lesions were identified by preoperative imaging. The median age of patients with multifocal intraductal papillary mucinous neoplasms of the pancreas was ≥ 68 years (P = .002) compared to patients with unifocal intraductal papillary mucinous neoplasm of the pancreas (median age, 64 years). Thirty-one multifocal intraductal papillary mucinous neoplasms of the pancreas were of mixed type (60.8%), 15 of branch duct type (29.4%), and 5 of main duct type (9.8%). Histologically, 10 multifocal intraductal papillary mucinous neoplasms of the pancreas had low-grade dysplasia (19.6%), 11 had moderate dysplasia (21.6%), 6 had high-grade dysplasia (11.8%), and 24 had invasive carcinoma (47.1%).

CONCLUSION

Most multifocal intraductal papillary mucinous neoplasms of the pancreas involve the main pancreatic duct and synchronously its major side branches (mixed type). Patients with multifocal intraductal papillary mucinous neoplasm of the pancreas present at an older age compared to patients with single cystic pancreatic neoplasm. The risk of harboring malignancy-nearly 60% in the present study-seems to be increased in patients with multifocal intraductal papillary mucinous neoplasms of the pancreas compared to single lesions.

Diagnostic and radiological management of cystic pancreatic lesions: important features for radiologists

Cystic pancreatic neoplasms are often an incidental finding, the frequency of which is increasing. The understanding of such lesions has increased in recent years, but the numerous types of lesions involved can hinder differential diagnosis. They include, in particular, intraductal papillary mucinous neoplasms (IPMN), serous cystic neoplasms (SCN), and mucinous cystic neoplasms (MCN). Knowledge of their histological and radiological structure, as well as distribution in terms of localization, age, and sex, helps to differentiate such tumours from common pancreatic pseudocysts. Several types of cystic pancreatic neoplasms can undergo malignant transformation and, therefore, require differentiated radiological management. This review aims to develop a broader understanding of the pathological and radiological characteristics of cystic pancreatic neoplasms, and provide a guideline for everyday practice based on current concepts in the radiological management of the given lesions.

Intraductal papillary mucinous neoplasms of the pancreas

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are rare tumors with different characteristics than conventional ductal pancreatic adenocarcinomas. Although they are commonly classified as cystic neoplasms of the pancreas, within their own subgroup of pancreatic cystic tumors, they are unique in their presentation, histologic characteristics, treatment, and survival rates. Currently, strategies are being implemented to better characterize these tumors preoperatively. Once IPMN is diagnosed, treatment strategies are based upon multiple factors, including patient condition, symptoms, and type and extent of disease. Although these factors may determine different treatment strategies, surgery remains the mainstay of therapy due to the favorable survival rate if the disease is diagnosed and treated prior to the development of invasive carcinoma. The goal of treatment is to alleviate symptoms and to extirpate disease prior to its transition to malignancy, invasion, and metastases. Although some experts advocate a nonoperative approach to patients with suspected benign disease, the risk of progression to malignancy can present a dilemma for the treating physician and patient. Unfortunately, differentiation of benign from malignant disease can only be determined conclusively following complete review of the entire surgical specimen. To further complicate treatment strategies, IPMN is a multifocal disease, and additional lesions can develop in the remnant pancreas. This fact has compelled most physicians familiar with the disease to institute lifelong surveillance for patients with the disease. Although our understanding of IPMN has increased greatly since its initial description in 1982, the natural history of the disease is poorly defined, and there is no consensus among experts on standards of practice. Although additional long-term follow-up of greater numbers of patients and their response to various interventions are necessary to develop consensus-based practice guidelines, this review will discuss our treatment recommendations based upon a review of the literature.

Intraoperative ultrasonography of the pancreas

Intraoperative ultrasonography (US) of the pancreas is a versatile technique that provides excellent spatial and contrast resolution and real-time imaging capabilities, making it useful for diagnostic imaging as well as for guidance of laparoscopic and open operative procedures. Intraoperative US may be used for applications such as staging and localizing tumors; performing regional metastatic surveys; documenting arterial and venous patency; identifying endocrine tumors; distinguishing pancreatitis from a neoplasm; and guiding biopsy, duct cannulation, and drainage of abscesses or cysts. The scanning approach and technique vary according to the application, with many different equipment and transducer options and sterilization methods available. With increasing clinical demands for intraoperative US, it is essential that radiologists be familiar with its uses and technique. In addition, to properly perform intraoperative US and accurately interpret the images, knowledge of normal and variant pancreatic and vascular anatomy and relevant landmarks is needed. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.307105051/-/DC1.

Natural history of intraductal papillary mucinous neoplasia: How much do we really know?

Information on the natural history of intraductal papillary mucinous neoplasia (IPMN) is currently inadequate due to a lack of carefully orchestrated long-term follow-up on a large cohort of patients with asymptomatic disease. Based on the available data, one can draw the conclusions that main duct IPMN is commonly associated with malignancy and an aggressive operative stance should be taken with resection being offered to most patients who are suitable operative candidates. In contrast, the majority of branch type IPMN with a diameter of less than 3 cm can be safely followed with routine surveillance imaging provided they lack the high-risk covariates of age, symptomatology, nodularity or wall thickness.

Intraductal papillary mucinous neoplasms of the pancreas: diagnosis and management

Intraductal papillary mucinous neoplasms (IPMNs), characterized by intraductal papillary growth and thick mucin secretion, have increasingly been recognized. Despite modern preoperative evaluation, major difficulties still remain in distinguishing malignant invasive types from benign IPMNs. Following a PubMed database search, all relevant abstracts and articles on IPMN published in English and Chinese were reviewed. Main-duct and the mixed type IPMNs carry a higher risk of malignancy as compared with branch-duct type IPMNs. Treatment of branch-duct type IPMNs remains controversial. Once operation is indicated, intraoperative frozen section of margins plays an important role in the decision concerning the extent and type of surgery. Pancreatectomy, partly preserving both endocrine and exocrine pancreatic function, is advocated for most patients with IPMN, though total pancreatectomy may be necessary in some. Both for patients subjected to surgery and those only observed, IPMN patients need regular close follow-up to identify recurrence or progressive disease.

Malignant potential of intraductal papillary mucinous neoplasms of the pancreas

An intraductal papillary mucinous neoplasm (IPMN) is now a well-recognized disease entity. In general, the prognosis of IPMN is much more favorable than that of pancreatic ductal adenocarcinoma (PDAC). However, IPMN has a broad biological spectrum and it sometimes progresses, slowly showing neoplastic transformations. International consensus guidelines have been recently proposed for the management of IPMN. While they significantly contribute to appropriate management of IPMN, various issues including the natural history and malignant potential of IPMN are not fully elucidated. This review focuses on the malignant potential, including the postoperative recurrence of IPMN, coincidence of IPMN with PDAC, and extrapancreatic malignancy that may affect the long-term survival of the patients rather than IPMN itself.

Clinical presentation can predict disease course in patients with intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND

Preoperative diagnosis of malignancy within intraductal papillary mucinous neoplasm of the pancreas (IPMN) solely by clinical or radiological findings is not always possible. We sought a correlation between preoperative clinico-radiological findings and outcome.

METHODS

A prospective database of pancreatic resections for IPMN (2002-2008) and a retrospective pathological revision of all pancreatic cancer specimens (1995-2001) were analyzed. The patients were grouped into asymptomatic with preoperative diagnosis of IPMN (group 1), symptomatic with a preoperative diagnosis of IPMN (group 2), and those with a preoperative diagnosis of pancreatic cancer whose specimen revealed a background of IPMN (group 3). The groups were compared for demographics, clinical presentation, pathological findings, and outcome.

RESULTS

Of the 62 patients with IPMN, 19 were in group 1, 23 in group 2, and 20 in group 3. Their median age (range) was 65.6 (46-80), 67 (50-84), and 73.4 (57-86) years, respectively. The clinical presentation for groups 2 and 3 included abdominal pain (56% vs. 32 %), weight loss (8% vs. 52%), obstructive jaundice (4% vs. 57%), pancreatitis (22% and 5%), and new onset of diabetes (14% and 44%). Invasive cancer was found in one patient in group 1 (5.2%), two patients in group 2 (8.7%), and all patients in group 3. IPMN was present in 23 of 217 (10.6%) of all resected pancreatic cancer specimens. Five year survival for patients with invasive disease was 47% and 92% for patients with noninvasive disease (mean follow-up 37.6 months).

CONCLUSIONS

Benign IPMN can usually be differentiated from adenocarcinoma preoperatively. The clinical presentation is highly indicative of disease course.

Middle pancreatectomy: safety and long-term results

BACKGROUND

Pancreaticoduodenectomy and distal pancreatectomy for lesions of the neck or body of the pancreas sacrifice a large amount of normal pancreatic tissue. Middle pancreatectomy (MP) is a parenchyma sparing technique that reduces the risk of postoperative endocrine and exocrine insufficiency. This study aims to evaluate the perioperative and long-term results of MP and to clarify whether MP can be performed with outcomes comparable with traditional pancreatectomies.

METHOD

Twenty-six patients who underwent MP for benign or low-grade malignant tumor of the pancreas between 1991 and 2006 at the Department of Surgery II, Nagoya University Graduate School of Medicine, were identified. Their outcomes were compared with 2 separate control groups, 35 left-side pancreatectomies (LSP) and 60 right-side pancreatectomies (RSP).

RESULTS

The mean operating time of the MP group was 295 minutes, which was significantly shorter than that for RSP (P=.0001). The rate of pancreatic fistula formation was higher in the MP group than in the 2 control groups, although the differences did not reach statistical significance. After a mean follow-up of 71 months, postoperative endocrine function was equivalent to the pre-operative values in the MP group, and none of the patients developed diabetes mellitus postoperatively. Only 1 patient in the MP group required enzyme substitution postoperatively for exocrine insufficiency. The MP group was inclined to be superior to the other 2 control groups in terms of postoperative nutritional status.

CONCLUSION

Middle pancreatectomy is a reasonable technique that is indicated for selected patients with benign or low malignant tumors in the neck and body of the pancreas. Middle pancreatectomy seems to result in better preservation of exocrine and endocrine functions as well as in better nutritional status postoperatively.

Intraoperative ultrasound of the pancreas

Intraoperative ultrasound provides spatial resolution of the pancreas superior to computed tomography, magnetic resonance imaging, and transabdominal sonography. This pictorial essay will review common benign and malignant pancreatic processes including the following: pancreatic ductal adenocarcinoma, pancreatitis, endocrine tumors, mucinous cystic neoplasm, intraductal papillary mucinous neoplasm, serous cystadenoma, and solid pseudopapillary tumor. The use of intraoperative ultrasound in specific surgical situations will be discussed, which include the following: (1) identification of insulinoma(s) which are not detectable preoperatively, (2) identification of the pancreatic duct to determine dissection planes for chronic pancreatitis surgery (eg, Puestow procedure) and for tumor resection, and (3) staging purposes for malignant disease.

Management of mucin-producing cystic neoplasms of the pancreas

During the last decade small lesions of the pancreas have been increasingly recognized in clinical practice. Among these lesions, mucin-producing cystic neoplasms represent a recently described and unique entity among pancreatic tumors. In 1996, the World Health Organization distinguished two different types of mucinous cystic tumors: intraductal papillary mucinous neoplasms (IPMNs) of the pancreas, which are characterized by mucin production, cystic dilation of the pancreatic ducts, and intrapapillary growth, and mucinous cystic neoplasms (MCNs), which are defined by ovarian-like stroma and in most cases do not communicate with pancreatic ducts. Further, IPMNs can be subdivided into main-duct type, mixed-type, and branch-duct type tumors. Older data did not distinguish among different subsets of cystic neoplasms of the pancreas, and consequently many databases were inconsistent. Histopathologically, both IPMNs and MCNs demonstrate a wide spectrum of cellular atypia ranging from mild mucinous hyperplasia to invasive adenocarcinoma. Because mucinous cystic neoplasms of the pancreas show significant differences in clinical behavior from patient to patient, knowledge of the clinicopathologic characteristics and natural history of specific subtypes of IPMNs and MCNs has become crucial for physicians working in the field of gastroenterology. The present work offers an overview of current and generally accepted clinical guidelines for the diagnosis and treatment of IPMNs and MCNs.

Correlation between CT patterns and pathological classification of intraductal papillary mucinous neoplasm

OBJECTIVE

To examine CT patterns of intraductal papillary mucinous neoplasm (IPMN), analyze their correlation with pathologic classification, and discuss the value of CT in the diagnosis and differential diagnosis of IPMN.

METHODS

CT patterns of 39 IPMN patients, whose clinical data were complete and whose diagnosis was confirmed by surgery and pathology, were classified into three types: (1) simple main pancreatic duct (MPD) dilation type, (2) MPD dilation with pancreatic cystic lesion type, and (3) simple pancreatic cystic lesion type. Correlations between the three CT types and Takada pathologic classification (MPD type, furcation type and mixture type) were analyzed. The 39 IPMN cases were pathologically classified as the benign group and the malignant/borderline group. CT characteristics including the presence or absence of mural nodules, intrafocal partitions, focal size and the degree of MPD and common bile duct (CBD) dilation were analyzed statistically.

RESULTS

A correlation was found between the CT simple MPD dilation type and the pathological MPD type, between the MPD dilation with pancreatic cystic lesion type and the furcation and mixture types, and between the simple cystic lesion type and the furcation type (p<0.001). The benign rate was 92% in patients without intrafocal mural nodules, and 42% in patients with intrafocal mural nodules. The difference between the two groups was statistically significant (p=0.003). The presence or absence of intrafocal partitions was not correlated with benignancy or malignancy (p=0.793). The maximum diameter of malignant/borderline lesions was bigger than that of benign ones (p=0.016). There was no significant difference in MPD and CBD diameters between the benign and malignant/borderline groups. Regardless of pathological classification, the MPD diameter was larger than the CBD diameter in all cases (p=0.02).

CONCLUSION

The three CT types of IPMN well correlated with the pathologic classification, which is helpful for analyzing CT manifestations and improving the accuracy of diagnosis. MPD dilation is usually larger than CBD dilation in IPMN patients, which is also helpful in the diagnosis and differential diagnosis of IPMN in the context of other related findings.

Intraductal papillary mucinous neoplasms of the pancreas

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are now a well-recognized category of slowly growing tumors with a remarkably better prognosis, even when malignant, than pancreatic ductal adenocarcinoma. Their clinical and pathohistologic features have been increasingly attracting the attention of clinicians since their first description 25 years ago. Despite its burgeoning volume recently, accumulated literature devoted to IPMN still provides a low level of evidence with regard to diagnosis, treatment, and prognosis. Therefore, we performed a Medline-based systematic review of the literature aimed at clearly defining the clinicopathologic characteristics of pancreatic IPMN and determining the best currently available evidence-based principles of diagnosis and management of patients with this disease.

Collateral branches IPMTs: secretin-enhanced MRCP

Recently, the fantastic evolution of imaging modalities (especially MR, MDCT, EUS) has raised many issues regarding the correct classification of smaller and smaller lesions, their preoperative evaluations, and indications of most appropriate treatment. However, it is still debated which technique should be employed for the diagnosis and the follow-up of intraductal papillary mucinous tumours (IPMTs). Despite the superb spatial resolution of MDCT, nowadays most of the authors agree on considering MR with magnetic resonance cholangiopancreatography (MRCP) the imaging modality of choice in studying IPMTs. In particular, MRCP is rapid, non-invasive, and accurate in detecting, localizing, and correctly classifying IPMT. The diagnostic performance of MRCP is even improved after the introduction of secretin stimulation. In fact, dynamic MRCP studies after secretin administration, besides facilitating the depiction of the structural characteristics of the lesions, make easier the detection of the communicating duct of branch duct IPMTs with the main pancreatic duct, especially if the newest high resolution 3D heavily T2-weighted sequences are utilized. Secretin stimulation is also useful in the demonstration of early changes of associated chronic pancreatitis. Consequently, we believe that secretin-enhanced MRCP is the most suitable imaging modality in the diagnosis and follow-up of IPMTs of the collateral branches.

Presentation and management of pancreatic cystic neoplasms

Pancreatic cystic neoplasms are less frequent than other pancreatic tumors, but because of the wide availability and improvement of modern imaging methods, these neoplasms are being recognized with increasing frequency and it is often possible to be differentiated preoperatively not only from other cystic pancreatic disorders but also from one another. Most patients have no symptoms while clinical signs are not really useful in the clinical work up, and when they are present, they never help us to identify the type of pathology. Treatment differs with the diagnosis. Serous cystic neoplasms are uniformly benign and usually do not mandate resection unless this lesion is symptomatic. In contrast, mucinous cystic neoplasms and intraductal papillary mucinous neoplasms have a premalignant or malignant tendency, and therefore should be managed aggressively by pancreatic resection; in the absence of invasive disease, prognosis is excellent after appropriate surgery, but the presence of invasive malignancy signifies a poor prognosis. Solid pseudopapillary neoplasms have nonaggressive behavior and their management is related to the extension of the disease. The purpose of this article is to review the types of pancreatic cystic neoplasms, their diagnosis, indications for surgical treatment, and outcome.

The clinicopathologic features of intraductal papillary mucinous neoplasms of the pancreas

Since first described in 1982, intraductal papillary mucinous neoplasm (IPMN) has been the preferred term to describe the proliferation of the pancreatic ductal epithelium. It is totally different from pancreatic carcinoma in epidemiology, histology, pathology and prognosis. According to the site of involvement, IPMNs are classified into three categories, i.e. main duct type, branch duct type, and combined type. Most branch duct IPMNs are benign, whereas the other two types are often malignant. A large branch duct IPMN and marked dilation of the main pancreatic duct indicate the presence of adenoma at least. The additional existence of large mural nodules increases the possibility of malignancy in all types. The prognosis is more favorable after complete resection of benign and non-invasive malignant IPMNs. Malignant IPMNs that become more aggressive after parenchymal invasion necessitate adequate lymph node dissection. On the other hand, asymptomatic branch duct IPMNs without mural nodules can be observed without the need for resection for a considerable period of time. Our review addresses available data, current understanding, controversy, and future directions about IPMNs.

Predictive factors of malignant or invasive intraductal papillary-mucinous neoplasms of the pancreas

The aim of this study was to identify useful preoperative diagnostic findings indicative of malignant or invasive intraductal papillary-mucinous neoplasms (IPMN) of the pancreas to determine an optimal operative procedure for IPMN. Sixty-two IPMNs, which consisted of 29 adenomas, 10 borderline tumors, 11 adenocarcinomas in situ, and invasive adenocarcinomas were reviewed from 1990 to 2003. Preoperative predictive factors of malignant or invasive IPMN were analyzed among 10 factors by univariate and multivariate analysis. Diameter of the main pancreatic duct (> or =6 mm) and cytological examination of the pancreatic juice (the presence of malignant cells) were identified as independent predictive factors of malignant IPMN, and only cytological examination of the pancreatic juice (the presence of malignant cells) was identified as an independent predictor of invasive IPMN by multivariate analysis (P < 0.05). There was no recurrent disease in patients with adenoma and adenocarcinoma in situ, whereas recurrences occurred in 6 of 12 patients with invasive IPMN. Patient survival in noninvasive IPMN was significantly (P = 0.018) better than that in invasive IPMN (The overall 5-year survival rates were 87.2% and 49.2%, respectively). These results might be useful for selecting an optimal surgical procedure for IPMN.

Intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND/AIMS

Intraductal papillary mucinous neoplasms (IPMNs) are neoplasms of the pancreatic duct epithelium characterized by intraductal papillary growth and thick mucin secretion. Quantities of mucin fill the main and/or branches of pancreatic ducts and cause ductal dilatation. This review encompasses IPMNs, including symptoms, diagnosis, management, and prognosis.

METHODS

A Pubmed database search was performed. All abstracts were reviewed and all articles in which cases of IPMNs could be identified were further scrutinized. Further references were extracted by cross-referencing.

RESULTS

Only one-third of all patients are symptomatic. According to the site of involvement, IPMNs are classified into three types: main duct type, branch duct type, and combined type. Most branch type IPMNs are benign, while the other two types are frequently malignant. The presence of large mural nodules increases the possibility of malignancy in all types. Presence of a large branch type IPMN and marked dilatation of the main duct indicate the existence of adenoma at least. Synchronous or metachronous malignancies may be developed in various organs. Endoscopic retrograde cholangiopancreatography, endoscopic ultrasonography, and intraductal ultrasonography clearly demonstrate ductal dilatation and mural nodules, while magnetic resonance pancreatography best visualizes the entire outline of IPMNs.

CONCLUSIONS

Prognosis is excellent after complete resection of benign and non-invasive malignant IPMNs. The extent of pancreatic resection and the intraoperative management of resection margins remain controversial. Total pancreatectomy should be reserved for patients with resectable but extensive IPMNs involving the whole pancreas; its benefits, however, must be balanced against operative and postoperative risks. Regular monitoring for disease recurrence is important after surgery.

Ultrasonography of the pancreas. 7. Intraoperative imaging

The usefulness of intraoperative ultrasonography (IOUS) has been documented in the Literature since the Eighties and, although its main applications are in hepatobiliary and pancreatic surgery, it has been used also in neurosurgery, cardiovascular and endocrine surgery. The continuous technical developments have led to an increase in the diagnostic accuracy of IOUS from the Eighties to now. The use of IOUS has increased in time together with the technical innovations until, mainly in the midnineties, its value was recognized by many surgeons. This results have been obtained with scanners that allow to depict fine anatomical details and detect small lesions in real time with extremely high spatial resolution. IOUS is able to shows fine details, such as primary or secondary lesions not detectable with other preoperative imaging modalities or tumor extension and its relationship with vessels. Assessment of resectability by IOUS may determine important changes in therapeutic planning. The role of IOUS, however, has recently been down-sized, especially in those centers where preoperative imaging is advanced. This article will review the clinical role of pancreatic IOUS in the different pancreatic pathologies.

Cystic tumors of the pancreas

Cystic tumors of the pancreas are less frequent than solid lesions and are often detected incidentally, as many of these lesions are small and asymptomatic. However, they may be associated with pancreatitis or have malignant potential. With advancements in diagnostic imaging, cystic lesions of the pancreas are being detected with increasing frequency. Many lesions can cause a pancreatic cyst, most being non-neoplastic while approximately 10% are cystic tumors, ranging from benign to highly malignant tumors. With increasing experience it is becoming clear that the prevalence of pseudocyst among cystic lesions of the pancreas is lower than usually presumed. A presumptive diagnosis of pseudocyst based on imaging appearance alone can cause a diagnostic error, and neoplastic cysts of the pancreas are particularly susceptible to this misdiagnosis, which can result in inappropriate treatment. Cystic tumors of the pancreas are formed by serous or mucinous structures showing all stages of cellular differentiation. According to the WHO classification, they can be subdivided on the basis of their histological type and biological behavior into benign tumors, borderline tumors, and malignant tumors. Cystic pancreatic tumors can be subdivided into peripheral (serous cystadenomas, mucinous cystic tumors, solid and papillary epithelial neoplasms, cystic islet cell tumors), which do not communicate with the main pancreatic duct, and ductal tumors (mucinous tumor), according to their site of origin. On the basis of imaging criteria alone, it can be very difficult to differentiate non-tumoral cystic lesions from neoplastic ones. The management of these patients is complex, and it is important to correlate imaging findings with knowledge of the patient’s symptoms and of the natural history and predictors of malignancy in pancreatic cysts.

International consensus guidelines for management of intraductal papillary mucinous neoplasms and mucinous cystic neoplasms of the pancreas

Non-inflammatory cystic lesions of the pancreas are increasingly recognized. Two distinct entities have been defined, i.e., intraductal papillary mucinous neoplasm (IPMN) and mucinous cystic neoplasm (MCN). Ovarian-type stroma has been proposed as a requisite to distinguish MCN from IPMN. Some other distinct features to characterize IPMN and MCN have been identified, but there remain ambiguities between the two diseases. In view of the increasing frequency with which these neoplasms are being diagnosed worldwide, it would be helpful for physicians managing patients with cystic neoplasms of the pancreas to have guidelines for the diagnosis and treatment of IPMN and MCN. The proposed guidelines represent a consensus of the working group of the International Association of Pancreatology.

The potential of oncolytic virus therapy for pancreatic cancer

The objective of this paper was to review a new category of gene therapy using oncolytic viruses for the treatment of pancreatic cancer. The eligibility and feasibility of oncolytic virus therapy as a novel therapeutic agent against pancreatic cancer are discussed as well as basic research for clinical trials, including a historical perspective and the current status of these novel agents. Even combination therapy, such as surgery with radiation and chemotherapy, has not significantly improved the survival rate of pancreatic cancer. Recently, a clinical trial (phase I and II) using an oncolytic adenovirus, ONYX-015, was completed in patients with pancreatic cancer. The phase II trial yielded beneficial results (tumor reduction or stabilization) in about 50% of the patients. A phase I study of the efficacy of oncolytic herpes viruses, G207, OncoVEX GM-CSF, and 1716 against a variety of tumors has been completed, and G207 is in phase II trials for use against brain tumors. In addition, a phase I trial using the herpesvirus showed good tolerance at all dosages. We discuss the basic scientific principles and current results of the above clinical trials with respect to these oncolytic viruses, and then compare the relative advantages and disadvantages of adenoviruses and herpesviruses as oncolytic agents. We also review the published literature on newly developed oncolytic viruses. The concept of oncolytic therapy has been studied for a century. Recent technological developments have made these oncolytic viruses more tumor-specific by exploiting the tumor cell environments. In addition, these viruses have been reported to increase the immunosusceptibility of the tumor cells, and have been designed to express other genes to increase the susceptibility of tumor cells to other therapeutic agents. Oncolytic virus therapy certainly appears to be a feasible treatment for pancreatic cancer.

Clinical aspects of intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasm (IPMN) is a spectrum of neoplasia in the pancreatic duct epithelium characterized by cystic dilation of the main and/or branch pancreatic duct. According to the site of involvement IPMNs are classified into three categories, i.e., main duct type, branch duct type, and combined type. Most branch duct IPMNs are benign, whereas the other two types are often malignant. A large size of branch duct IPMN and marked dilation of the main pancreatic duct indicate the presence of adenoma at least. The additional existence of large mural nodules increases the possibility of malignancy in all types. Of recent interest is the relatively high prevalence of synchronous and/or metachronous malignancy in various organs, including the pancreas. The prognosis is favorable after complete resection of benign and noninvasive malignant IPMNs. Malignant IPMNs acquiring aggressiveness after parenchymal invasion necessitate adequate lymph node dissection. On the other hand, asymptomatic branch duct IPMNs without mural nodules can be observed without resection for a considerably long time. This review addresses available data, current understanding, controversy, and future directions.

Intraoperative ultrasound

Intraoperative ultrasound (IOUS) can provide various diagnostic information that is otherwise not available, and can guide or assist various surgical procedures in real time. With refinement of equipment, IOUS is currently used in a wide variety of surgical operations,such as hepatobiliary, pancreatic, endocrine, cardiovascular,and neurologic surgery. Our overview of IOUS, including instrumentation,techniques, indications, advantages, disadvantages,and future perspective, is described in this article. Being safe, quick, accurate, and versatile intraoperatively, IOUS is a valuable technique that surgeons are recommended to master to improve intraoperative decision making and surgical procedures.

Intraductal papillary mucinous neoplasm of the pancreas: diagnosis and treatment

Intraductal papillary mucinous neoplasm (IPMN) is characterized by cystic dilatation of the main and/or branch pancreatic duct. Only one-third of all patients are symptomatic, and others are diagnosed by chance. IPMNs are classified into 3 types: main duct, branch duct, and mixed IPMN. Most branch-type IPMNs are benign, while the other 2 types are frequently malignant. The presence of large mural nodules increases the possibility of malignancy in all types. Presence of a large branch-type IPMN and marked dilatation of the main duct indicate, at the very least, the existence of adenoma. Ultrasonography, endosonography, and intraductal ultrasonography clearly demonstrate ductal dilatation and mural nodules, and magnetic resonance pancreatography best visualizes the entire outline of IPMN. Not infrequently, synchronous or metachronous malignancy develops in various organs, including the pancreas. Prognosis is excellent after complete resection of benign and noninvasive malignant IPMNs. Asymptomatic branch-type IPMNs without mural nodules may be followed up without resection. Malignant IPMNs displaying acquired aggressiveness after parenchymal invasion require adequate lymph node dissection. Total pancreatectomy is needed for some IPMNs; its benefits, however, must be balanced against operative and postoperative risks because most IPMNs are slow growing and affect elderly people, and prognosis is favorable for IPMN patients with even malignant neoplasms.

Power Doppler ultrasonography for the assessment of vascular invasion by pancreatic cancer

AIM

To investigate the diagnostic accuracy of power Doppler ultrasonography (US) in assessing the vascular invasion by pancreatic cancer.

METHODS

A prospective study of 40 consecutive patients with pancreatic cancer (head 35, body 5) was performed. All patients underwent surgery. The relationships between tumor and each vessel were classified into four types according to the closest circumferential contact of the tumor with the vessel. A type 0 indicated no contact; type 1 indicated less than one third contact; type 2 indicated one third to 99% contact, and type 3 indicated encasement. Vascular invasion was diagnosed in types 2 and 3. The diagnostic accuracy was evaluated in the portal vein and in the splanchnic arteries (celiac artery, common hepatic artery, and superior mesenteric artery). The power Doppler US findings were confirmed by the operative findings. The results of power Doppler US were compared with those of CT scan and angiography.

RESULTS

Portal vein invasion was confirmed in resected specimens in 23 cases and by operative findings in 5 cases. For the diagnosis of portal vein invasion, sensitivity, specificity, and overall accuracy of power Doppler US were, respectively, 79.3, 90.9, and 82.5%. The respective values were 79.3, 100, and 85% for CT and 72.4, 81.8, and 75% for angiography. For the diagnosis of arterial invasion, sensitivity, specificity, and overall accuracy of power Doppler US were 80, 92, and 90%, respectively. The corresponding values were 47, 88, and 73% for CT and 47, 100, and 80% for angiography.

CONCLUSION

Power Doppler US proved to be useful for the diagnosis of vascular invasion by pancreatic cancer.