Clinicopathological features and prognosis of mucinous cystic neoplasm with ovarian-type stroma: a multi-institutional study of the Japan pancreas society

Pathology of Pancreatic Cancer Precursor Lesions

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

[Recommendations for the diagnosis, staging and treatment of pre-malignant lesions and pancreatic adenocarcinoma]

BACKGROUND AND OBJECTIVE

Clinical management of adenocarcinoma of the pancreas is complex, and requires a multidisciplinary approach. The same applies for the premalignant lesions that are increasingly being diagnosed. The current document is an update on the diagnosis and management of premalignant lesions and adenocarcinoma of the pancreas.

PATIENTS AND METHODS

A conference to establish the basis of the literature review and manuscript redaction was organized by the Grupo Español Multidisciplinar en Cáncer Digestivo. Experts in the field from different specialties (Gastroenterology, Surgery, Radiology, Pathology, Medical Oncology and Radiation Oncology) met to prepare the present document.

RESULTS

The current literature was reviewed and discussed, with subsequent deliberation on the evidence.

CONCLUSIONS

Final recommendations were established in view of all the above.

Nature and management of pancreatic mucinous cystic neoplasm (MCN): A systematic review of the literature

BACKGROUND

The current management of pancreatic mucinous cystic neoplasms (MCN) is defined by the consensus European, International Association of Pancreatology and American College of Gastroenterology guidelines. However, the criterion for surgical resection remains uncertain and differs between these guidelines. Therefore through this systematic review of the existing literature we aimed to better define the natural history and prognosis of these lesions, in order to clarify recommendations for future management.

METHODS

A systematic literature search was performed (PubMed, EMBASE, Cochrane Library) for studies published in the English language between 1970 and 2015.

RESULTS

MCNs occur almost exclusively in women (female:male 20:1) and are mainly located in the pancreatic body or tail (93-95%). They are usually found incidentally at the age of 40-60 years. Cross-sectional imaging and endoscopic ultrasound are the most frequently used diagnostic tools, but often it is impossible to differentiate MCNs from branch duct intraductal papillary mucinous neoplasms (BD-IPMN) or oligocystic serous adenomas pre-operatively. In resected MCNs, 0-34% are malignant, but in those less than 4 cm only 0.03% were associated with invasive adenocarcinoma. No surgically resected benign MCNs were associated with a synchronous lesion or recurrence; therefore further follow-up is not required after resection. Five-year survival after surgical resection of a malignant MCN is approximately 60%.

CONCLUSIONS

Compared to other pancreatic tumors, MCNs have a low aggressive behavior, with exceptionally low rates of malignant transformation when less than 4 cm in size, are asymptomatic and lack worrisome features on pre-operative imaging. This differs significantly from the natural history of small BD-IPMNs, supporting the need to differentiate mucinous cyst subtypes pre-operatively, where possible. The findings support the recommendations from the recent European Consensus Guidelines, for the more conservative management of MCNs.

The safety and benefit of pancreatic juice cytology under ERCP in IPMN patients

BACKGROUND

International consensus guidelines 2012 for intraductal papillary mucinous neoplasia (IPMN), defined two characteristics: high-risk stigmata (HRS) and worrisome features (WF). Patients with WF require detailed examination including cytology. However, routine endoscopic retrograde cholangiopancreatography (ERCP) for cytology is not recommended in the guidelines due to risk of post-ERCP pancreatitis (PEP). Our aim was to clarify what types of IPMN were susceptible for PEP and gain benefit of ERCP.

PATIENTS/METHODS

We examined 138 consecutive IPMN patients who underwent ERCP in our hospital, retrospectively. Patients were classified into HRS, WF and the others (N) based on imaging findings before ERCP. We assessed pancreatic juice cytology, PEP frequency and rate of malignant IPMN at 12 months after ERCP.

RESULTS

The rates of cytological malignancy were 0% (N), 4.8% (WF) and 19.5% (HRS). The PEP frequency was 14.5%, and these risk factors were branch duct (BD)-IPMN, body/tail cysts and brush cytology by multivariate logistic analysis. The rates of malignant IPMN were 0% (N), 16.4% (WF) and 48.8% (HRS). Furthermore, we examined patients with WF in detail. The PEP frequency/rate of malignancy were 3.6%/23.1% in patients with main pancreatic duct (MPD) dilatation (5-9 mm), and the sensitivity of cytology was 33.3%. On the other hand, the PEP frequency/rate of malignancy were 17.2%/0% in patients with BD-IPMN fulfilling only cyst size over 30 mm.

CONCLUSIONS

Routine ERCP for IPMN, especially for BD-IPMN, is not recommended. ERCP may be beneficial for WF patients with MPD dilatation based on a balance between PEP risk and presence of malignancy.

Risk of pancreatic cancer in patients with pancreatic cyst

BACKGROUND AND AIMS

Certain pancreatic cysts (mucinous cystic neoplasm and side branch intraductal papillary mucinous neoplasm [IPMN]) have malignant potential and require surveillance. However, whether patients with pancreatic cysts have a higher long-term risk of pancreatic cancer (PaCa) has still not been established.

METHODS

This was a retrospective study of Veterans Administration patients. Patients noted to have pancreatic cysts on CT/magnetic resonance imaging (n = 1050) were identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes. Patients aged <15 years (n = 425), patients with <1 year of follow-up (n = 13,259), and patients diagnosed to have PaCa within 1 year of identification of a pancreatic cyst (n = 102) or within 1 year of follow-up in the remaining patients in the database (n = 200) were excluded. Patients with pancreatic cystic lesions (group A, n = 755) and the remaining patients in the database without cysts (group B, n = 520,215) were followed from 1998 to 2007.

RESULTS

During the study period, in group A and B PaCa was diagnosed in 17 and 1206 patients, respectively, and the incidence rate of PaCa was 5.08 and .32 per 1000 patient-years, respectively. The hazard ratio of PaCa in all patients with cysts was 19.64 (95% CI, 12.12-31.82; P < .0001) when compared with the rest of the patients without cysts. In the subset of patients with cysts, without a history of acute or chronic pancreatitis (n = 241), the hazard ratio of PaCa (n = 5) was 18.80 (95% CI, 7.80-45.31; P < .0001).

CONCLUSION

Patients with pancreatic cysts have a significantly higher overall risk of PaCa. The etiologic distribution of cysts in our study patients is not available. Patients with mucinous cystic neoplasm and side branch IPMN are likely to have a higher risk of PaCa than our estimation of risk based on all etiologies.

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

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

MIB-1 labeling index, Ki-67, is an indicator of invasive intraductal papillary mucinous neoplasm

Despite strict criteria for the observation of intraductal papillary mucinous neoplasm (IPMN), it remains difficult to distinguish invasive IPMN from non-invasive IPMN. The aim of the present study was to identify an indicator of invasive IPMN. The present study retrospectively evaluated 53 patients (28 with non-invasive and 25 with invasive IPMN) who underwent resection of IPMN, and examined the usefulness of the MIB-1 labeling index as an indicator of invasive IPMN. The MIB-1 labeling indexes in patients with invasive IPMN were significantly higher compared with those with non-invasive IPMN (P<0.001). A receiver operating characteristic curve revealed that the area under the curve was 0.822. These results suggested that a cut-off level for the MIB-1 labeling index should be set to 15.5% to distinguish invasive from non-invasive IPMN. A multivariate analysis using a logistic regression model revealed the MIB-1 labeling index (hazard ratio, 18.692; 95% confidential interval, 4.171-83.760; P<0.001) and the existence of mural nodules (hazard ratio, 6.187, 95% confidential interval, 1.039-36.861; P=0.045) were predictive factors for invasive IPMN. However, no statistically significant differences were observed between patients with a lower MIB-1 labeling index and patients with a higher MIB-1 labeling index (P=0.798). The MIB-1 labeling index must be considered as a candidate for the classification of IPMN.

Tumoral Versus Flat Intraepithelial Neoplasia of Pancreatobiliary Tract, Gallbladder, and Ampulla of Vater

Context.—The identification of a precursor lesion is important to understanding the histopathologic and genetic alterations in carcinogenesis. There are a plethora of terminologies that describe precursor lesions of the pancreatobiliary tract, ampulla of Vater, and gallbladder. The current terminologies for precursor lesions may make it difficult to understand the tumor biology. Here, we propose the concept of tumoral and flat intraepithelial neoplasia to improve our understanding of precursor lesions of many epithelial organs, including the pancreatobiliary tract, ampulla of Vater, and gallbladder.

Objective.—To understand the dichotomous pattern of tumoral and flat intraepithelial neoplasia in carcinogenesis of pancreatobiliary tract, ampulla of Vater, and gallbladder.

Data Sources.—Review of relevant literatures indexed in PubMed.

Conclusions.—Tumoral intraepithelial neoplasia presents as an intraluminal or intraductal, mass-forming, polypoid lesion or a macroscopic, visible, cystic lesion without intracystic papillae. Microscopically, tumoral intraepithelial neoplasia shows various proportions of papillary and tubular architecture, often with a mixed pattern, such as papillary, tubular, and papillary-tubular. The malignant potential depends on the degree of dysplasia and the cell phenotype of the epithelium. Flat intraepithelial neoplasia presents as a flat or superficial, spreading, mucosal lesion that is frequently accompanied by an invasive carcinoma. Tumoral and flat intraepithelial neoplasias are not homogeneous entities and may exhibit histopathologic spectrum changes and different genetic profiles. Although intraepithelial neoplasia showed a dichotomous pattern in the tumoral versus flat types, they can coexist. Tumoral and flat intraepithelial neoplasia can be interpreted as part of a spectrum of changes in the carcinogenesis pathway of each organ.

[Ductal adenocarcinoma and unusual differential diagnosis]

Ductal pancreatic adenocarcinoma is by far the most common solid tumor of the pancreas. It has a very poor prognosis, especially in the more advanced stages which are no longer locally confined. Due to mostly unspecific symptoms, imaging is key in the diagnostic process. Because of the widespread use of imaging techniques, incidental findings are to a greater extent discovered in the pancreas, which subsequently entail further work-up. Ductal pancreatic adenocarcinoma can be mimicked by a large number of different lesions, such as anatomical variants, peripancreatic structures and tumors, rarer primary solid pancreatic tumors, cystic tumors, metastases or different variants of pancreatitis. Additionally, a number of precursor lesions can be differentiated. The correct classification is thus important as an early diagnosis of ductal pancreatic adenocarcinoma is relevant for the prognosis and because the possibly avoidable treatment is very invasive. All major imaging techniques are principally suitable for pancreatic imaging. In addition to sonography of the abdomen, usually the baseline diagnostic tool, computed tomography (CT) with its superior spatial resolution, magnetic resonance imaging (MRI) with its good soft tissue differentiation capabilities, possibly in combination with MR cholangiopancreatography (MRCP), endosonography with its extraordinary spatial resolution, conceivably with additional endoscopic retrograde CP or the option of direct biopsy and finally positron emission tomography CT (PET-CT) as a molecular imaging tool are all particularly useful modalities. The various techniques all have its advantages and disadvantages; depending on the individual situation they may need to be combined.

Laparoscopic distal pancreatectomy without needle aspiration before resection for giant mucinous cell neoplasms

Laparoscopic resection of large mucinous cystic neoplasms (MCN) has recently been reported. However, in most reports, needle aspiration of the cyst contents was performed before resection and can cause dissemination. Here, we report two patients with giant MCN: a 26-year-old woman with a 23-cm MCN and a 41-year-old woman with an 18-cm MCN. The MCN were successfully resected without aspiration by laparoscopic surgery. CT revealed no tumor involvement of the origins of the splenic artery and vein in either case. In case 1, we performed hand-assisted laparoscopic surgery while dissecting around the spleen, whereas case 2 underwent pure laparoscopic surgery. No postoperative complications occurred in either case, indicating that laparoscopic distal pancreatectomy for giant MCN is feasible without aspiration in patients without splenic artery and vein origin involvement.

Cystic Neoplasm of the Pancreas

Cystic neoplasms of the pancreas (CNPs) are not considered as rare entities any more. Imaging-based population studies attested an overall prevalence of 2 %, but that becomes five times higher on individuals of more than 70 year old. This family of neoplasms includes a wide spectrum of benign, borderline, and malignant lesions whose actual biological behavior has not been completely clarified yet. Moreover, the management of CNPs still represents a challenge for gastrointestinal (GI) specialists. While many CNPs have an indolent behavior that justifies surveillance, others should be resected because of the risk of progression to invasive cancer. Due to the high morbidity related to pancreatic resections, the surgeon should balance very carefully the advantages of a radical resection with the risks of an unrequested dangerous procedure. We reviewed the current issues regarding CNPs, with a particular focus on the clinical and radiological features that are integrated in the current guidelines and that drive the management of these patients.

International consensus on the management of intraductal papillary mucinous neoplasm of the pancreas

International consensus guidelines for the management of intraductal papillary mucinous neoplasm (IPMN) of the pancreas revised in 2012 (Fukuoka consensus) seem to be accepted well worldwide. Division of various factors to predict malignant transformation into two categories, i.e., "high-risk stigmata" and "worrisome features", is also accepted as practically useful for stratifying the risk factors. Our current interest resides in the development of noninvasive and/or invasive pancreatic cancer in areas of the pancreas distinct from IPMN. Invasive pancreatic cancers derived from and concomitant with IPMN should be distinguished to clarify the incidence of each entity, although some more definitive method for differentiation has to be devised in some cases where histological distinction is obscure. IPMN is a clue to early detection of pancreatic cancer. The optimal surveillance protocol for IPMN on observation should be determined in consideration of both of these different pancreatic cancers.

Morphological differentiation and follow-up of pancreatic cystic neoplasms using endoscopic ultrasound

Endoscopic ultrasound (EUS) is a key modality for the evaluation of suspected pancreatic cystic neoplasms (PCNs), as the entire pancreatic gland can be demonstrated with high spatial resolution from the stomach and duodenum. Detailed information can be acquired about the internal contents of the cyst(s) [septum, capsule, mural nodules (MNs)], its relation with the main pancreatic duct (MPD), and any parenchymal changes in the underlying gland. PCNs comprise true cysts and pseudocysts. True cysts can be neoplastic or nonneoplastic. Here, we describe serous cystic neoplasm (SCN), mucinous cystic neoplasm (MCN), and intraductal papillary mucinous neoplasm (IPMN) as prototype neoplastic cysts, along with nonneoplastic lymphoepithelial cysts (LECs).

The safety of endoscopic ultrasound-guided fine-needle aspiration of pancreatic cystic lesions

Endoscopic ultrasound (EUS) is widely used in the evaluation of various pancreatic diseases including pancreatic cystic lesions (PCLs). EUS-guided fine-needle aspiration (EUS-FNA) of PCLs provides cyst fluid, which is used for the differentiation of PCLs. EUS-FNA of PCLs is a safe procedure with a low complication rate. Contrary to the concerns expressed by some investigators, preoperative EUS-FNA of mucinous PCLs is unlikely to increase the frequency of postoperative peritoneal seeding.

Cystic Neoplasms of the Pancreas

Cystic neoplasms of the pancreas are being identified at an increasing frequency largely due to the increased use of abdominal cross-sectional imaging. These neoplasms represent a heterogeneous group of tumors with various genetic alterations, molecular features, and risks of malignancy. Despite the use of high-resolution radiographic studies, endoscopic evaluation, cyst fluid analysis, and novel molecular diagnostics, many of these lesions remain difficult to classify without operative resection. These diagnostic challenges are coupled with an improving but limited understanding of the natural history of these neoplasms. Treatment of pancreatic cystic neoplasms therefore remains controversial but consists largely of a selective tumor-specific approach to surgical resection. Future research remains necessary to better discriminate the biological behavior of these tumors in order to more appropriately select patients for operative intervention.

A combination of molecular markers and clinical features improve the classification of pancreatic cysts

BACKGROUND & AIMS

The management of pancreatic cysts poses challenges to both patients and their physicians. We investigated whether a combination of molecular markers and clinical information could improve the classification of pancreatic cysts and management of patients.

METHODS

We performed a multi-center, retrospective study of 130 patients with resected pancreatic cystic neoplasms (12 serous cystadenomas, 10 solid pseudopapillary neoplasms, 12 mucinous cystic neoplasms, and 96 intraductal papillary mucinous neoplasms). Cyst fluid was analyzed to identify subtle mutations in genes known to be mutated in pancreatic cysts (BRAF, CDKN2A, CTNNB1, GNAS, KRAS, NRAS, PIK3CA, RNF43, SMAD4, TP53, and VHL); to identify loss of heterozygozity at CDKN2A, RNF43, SMAD4, TP53, and VHL tumor suppressor loci; and to identify aneuploidy. The analyses were performed using specialized technologies for implementing and interpreting massively parallel sequencing data acquisition. An algorithm was used to select markers that could classify cyst type and grade. The accuracy of the molecular markers was compared with that of clinical markers and a combination of molecular and clinical markers.

RESULTS

We identified molecular markers and clinical features that classified cyst type with 90%-100% sensitivity and 92%-98% specificity. The molecular marker panel correctly identified 67 of the 74 patients who did not require surgery and could, therefore, reduce the number of unnecessary operations by 91%.

CONCLUSIONS

We identified a panel of molecular markers and clinical features that show promise for the accurate classification of cystic neoplasms of the pancreas and identification of cysts that require surgery.

Imaging of pancreatic neoplasms

Ductal adenocarcinoma accounts for 85% to 90% of all solid pancreatic neoplasms, is increasing in incidence, and is the fourth leading cause of cancer-related deaths. There are currently no screening tests available for the detection of ductal adenocarcinoma. The only chance for cure in pancreatic adenocarcinoma is surgery. Imaging has a crucial role in the identification of the primary tumor, vascular variants, identification of metastases, disease response assessment to treatment, and prediction of respectability. Pancreatic neuroendocrine neoplasms can have a distinctive appearance and pattern of spread, which should be recognized on imaging for appropriate management of these patients.

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.

Pancreatic adenocarcinoma pathology: changing "landscape"

Pancreatic cancer is a devastating disease. At time of diagnosis the disease is usually advanced and only a minority of patients are eligible for surgical resection. The overall 5-year survival is 6%. However, survival of patients with early stage pancreatic cancer is significantly better. To improve the prognosis of patients with pancreatic cancer, it is essential to diagnose and treat pancreatic cancer in the earliest stage. Prevention of pancreatic cancer by treating noninvasive precursor lesions just before they invade tissues can potentially lead to even better outcomes. Pancreatic carcinogenesis results from a stepwise progression in which accumulating genetic alterations drive neoplastic progression in well-defined precursor lesions, ultimately giving rise to an invasive adenocarcinoma. A thorough understanding of the genetic changes that drive pancreatic carcinogenesis can lead to identification of biomarkers for early detection and targets for therapy. Recent next-generation sequencing (NGS) studies have shed new light on our understanding of the natural history of pancreatic cancer and the precursor lesions that give rise to these cancers. Importantly, there is a significant window of opportunity for early detection and treatment between the first genetic alteration in a cell in the pancreas and development of full-blown pancreatic cancer. The current views on the pathology and genetics of pancreatic carcinogenesis that evolved from studies of pancreatic cancer and its precursor lesions are discussed in this review.

Pancreatic cancer: current understanding of molecular and genetic aetiologies

Pancreatic ductal adenocarcinoma (PDAC) is one of the few cancers where prognosis has not improved over the past few decades. However, there have been several advances in our understanding of the disease leading to earlier detection and targeted therapeutic treatment. It is now understood that specific somatic and germline mutations lead to the development of the disease, and the risk factors associated with this are clearer. Further, several precursor lesions have been identified which, with early detection and surveillance, allows treatment before the development of carcinoma. PDAC can now be diagnosed with a high sensitivity and specificity following advances in radiology, and treatment can be commenced at an earlier stage of the disease. With continued research we are hopeful that the next decade will see an improved survival rate for all patients with pancreatic cancer.

Cystic neoplasms of the pancreas; findings on magnetic resonance imaging with pathological, surgical, and clinical correlation

Pancreatic cysts are increasingly being identified by cross-sectional imaging studies. Pancreatic cystic lesions comprise a spectrum of underlying pathologies ranging from benign and pre-malignant lesions to frank malignancies. Magnetic resonance imaging with cholangiopancreatography is a non-invasive imaging modality used for the characterization of cystic pancreatic lesions. This article will review the most common pancreatic cystic neoplasms and the utility of MR imaging in the characterization of these cysts.

Diagnosis and Management of Pancreatic Cystic Neoplasms

Incidentally discovered pancreatic cystic lesions are increasingly common, affecting up to 10% to 15% of patients undergoing cross-sectional imaging. Although some pancreatic cystic neoplasms harbor invasive malignancy or the potential to progress over time, a majority are benign and can be observed safely. Accurate diagnosis is key to appropriate management. Diagnosis requires a multidisciplinary and multimodal approach. This review discusses each type of pancreatic cystic neoplasm and the current data on diagnosis and treatment.

Differential diagnosis of benign and malignant branch duct intraductal papillary mucinous neoplasm using contrast-enhanced endoscopic ultrasonography

AIM: To elucidate the role of contrast-enhanced endoscopic ultrasonography (CE-EUS) in the diagnosis of branch duct intraductal papillary mucinous neoplasm (BD-IPMN).

METHODS: A total of 50 patients diagnosed with BD-IPMN by computed tomography (CT) and endoscopic ultrasonography (EUS) at our institute were included in this study. CE-EUS was performed when mural lesions were detected by EUS. The diagnostic accuracy for identifying mural nodules (MNs) was evaluated by CT, EUS, and EUS combined with CE-EUS. In the patients who underwent resection, the accuracy of measuring MN height with each imaging modality was compared. The cut-off values to diagnose malignant BD-IPMNs based on MN height for each imaging modality were determined using receiver operating characteristic curve analysis.

RESULTS: Fifteen patients were diagnosed with BD-IPMN with MNs and underwent resection. The remaining 35 patients were diagnosed with BD-IPMN without MNs and underwent follow-up monitoring. The pathological findings revealed 14 cases with MNs and one case without. The accuracy for diagnosing MNs was 92% using CT and 72% using EUS; the diagnostic accuracy increased to 98% when EUS and CE-EUS were combined. The accuracy for measuring MN height significantly improved when using CE-EUS compared with using CT or EUS (median measurement error value, CT: 3.3 mm vs CE-EUS: 0.6 mm, P < 0.05; EUS: 2.1 mm vs CE-EUS: 0.6 mm, P < 0.01). A cut-off value of 8.8 mm for MN height as measured by CE-EUS improved the accuracy of diagnosing malignant BD-IPMN to 93%.

CONCLUSION: Using CE-EUS to measure MN height provides a highly accurate method for differentiating benign from malignant BD-IPMN.

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

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

Research gaps in pancreatic cancer research and comparative effectiveness research methodologies

Despite advances in cancer care, pancreatic adenocarcinoma remains one of the most lethal tumors. Most patients with pancreatic cancer are diagnosed with late stage disease, and approximately 6 % of patients are alive 5 years after diagnosis. Of the 10-20 % of patients who are candidates for resection and multi-modality therapy, most will succumb to the disease with 5-year survival rates only reaching approximately 25 % (Lim et al. in Annals of surgery 237(1):74-85, 2003 [1]; Trede et al. in Annals of surgery 211(4):447-458, 1990 [2]; Crist et al. in Annals of surgery 206(3):358-365, 1987 [3]). Clearly, there is a need to improve the management of this disease. To identify gaps in research and formulate strategies to address these issues, we designed a framework to encompass the scope of research for pancreatic cancer. In this chapter, we will examine each topic heading within this framework for gaps in knowledge and present research strategies focusing on diverse comparative effectiveness research (CER) methodologies to address the identified gaps.

Pancreatic cystic neoplasms: Review of current knowledge, diagnostic challenges, and management options

Pancreatic cystic lesions are being detected with increasing frequency, largely due to advances in cross-sectional imaging. The most common neoplasms include serous cystadenomas, mucinous cystic neoplasms, intraductal papillary mucinous neoplasms, solid pseudopapillary neoplasms, and cystic pancreatic endocrine neoplasms. Computed tomography (CT), magnetic resonance imaging (MRI), and endoscopic ultrasound (EUS) are currently used as imaging modalities. EUS-guided fine needle aspiration has proved to be a useful diagnostic tool, and enables an assessment of tumor markers, cytology, chemistries, and DNA analysis. Here, we review the current literature on pancreatic cystic neoplasms, including classification, diagnosis, treatment, and recommendations for surveillance. Data for this manuscript was acquired via searching the literature from inception to December 2014 on PubMed and Ovid MEDLINE.

Clinicopathologic characteristics of 29 invasive carcinomas arising in 178 pancreatic mucinous cystic neoplasms with ovarian-type stroma: implications for management and prognosis

Information on the clinicopathologic characteristics of invasive carcinomas arising from mucinous cystic neoplasms (MCNs) is limited, because in many early studies they were lumped and analyzed together with noninvasive MCNs. Even more importantly, many of the largest prior studies did not require ovarian-type stroma (OTS) for diagnosis. We analyzed 178 MCNs, all strictly defined by the presence of OTS, 98% of which occurred in perimenopausal women (mean age, 47 y) and arose in the distal pancreas. Twenty-nine (16%) patients had associated invasive carcinoma, and all were female with a mean age of 53. Invasion was far more common in tumors with grossly visible intracystic papillary nodule formation ≥1.0 cm (79.3% vs. 8.7%, P=0.000) as well as in larger tumors (mean cyst size: 9.4 vs. 5.4 cm, P=0.006); only 4/29 (14%) invasive carcinomas occurred in tumors that were <5 cm; however, none were <3 cm. Increased serum CA19-9 level (>37 U/L) was also more common in the invasive tumors (64% vs. 23%, P=0.011). Most invasive carcinomas (79%) were of tubular type, and the remainder (5 cases) were mostly undifferentiated carcinoma (2, with osteoclast-like giant cells), except for 1 with papillary features. Interestingly, there were no colloid carcinomas; 2 patients had nodal metastasis at the time of diagnosis, and both died of disease at 10 and 35 months, respectively. While noninvasive MCNs had an excellent prognosis (100% at 5 y), tumors with invasion often had an aggressive clinical course with 3- and 5-year survival rates of 44% and 26%, respectively (P=0.000). The pT2 (>2 cm) invasive tumors had a worse prognosis than pT1 (≤2 cm) tumors (P=0.000), albeit 3 patients with T1a (<0.5 cm) disease also died of disease. In conclusion, invasive carcinomas are seen in 16% of MCNs and are mostly of tubular (pancreatobiliary) type; colloid carcinoma is not seen in MCNs. Serum CA19-9 is often higher in invasive carcinomas, and invasion is typically seen in OTS-depleted areas with lower progesterone receptor expression. Invasion is not seen in small tumors (<3 cm) and those lacking intracystic papillary (mural) nodules of ≥1 cm, thus making the current branch-duct intraductal papillary mucinous neoplasm management protocols also applicable to MCNs.

Mucinous cystic neoplasm of the pancreas activated during pregnancy

The characteristic histological feature of pancreatic mucinous cystic neoplasm (MCN) is ovarian-like stroma (OS) underlying the epithelium and existence of estrogen receptors and progesterone receptors in the nucleus of OS. We experienced a case of pancreatic MCN which was activated during pregnancy and confirmed the existence of estrogen receptors and progesterone receptors. In cases with potential factors for malignancy, surgical resection of MCN may be needed during pregnancy. On the other hand, in cases without these, as female sex hormones may have an influence on the behavior of pancreatic MCN during pregnancy, the timing of surgery should be decided on a case-by-case basis, taking into consideration the status of the malignancy, the stage of the pregnancy, and the condition of the mother and fetus.

A case of mucinous cystic neoplasm of the liver: a case report

A 71-year-old woman was referred to our institution for further investigation of epigastric pain. The patient had been detected to have a multilocular cyst in the medial segment of the liver measuring 69 mm in diameter at another hospital 2 years ago, and the diameter of the cyst had increased to 90 mm. Although the cyst had gradually increased in size, there was no evidence of mural nodules. As we were concerned about the malignant potential of the lesion, a left hepatic segmentectomy was performed. Pathologically, the cyst was lined by columnar and cuboidal epithelium with low-grade atypia. The epithelium covered an ovarian-like stroma, and the diagnosis was mucinous cystic neoplasm of the liver (MCN-L) with low-grade intraepithelial neoplasia. MCN-L is a rare disease and its characteristics are still poorly understood. MCN-L occurs at a lower frequency as compared to the counterpart of MCN of the pancreas, further investigations are necessary to clarify the biological malignancy of MCN-L.

Noninvasive intraductal papillary mucinous neoplasms and mucinous cystic neoplasms: recurrence rates and postoperative imaging follow-up

BACKGROUND

Although surveillance guidelines for resected invasive mucinous neoplastic cysts are well-established, those for noninvasive cysts are not defined. We used our experience with resected noninvasive mucinous neoplastic cysts to define recurrence rates and the optimal frequency of postoperative imaging follow-up.

METHODS

We reviewed the medical records of 134 patients with resected, pathologically confirmed noninvasive mucinous neoplasms between 2002 and 2012. Demographics, comorbidities, cyst characteristics, and recurrence were evaluated. Survival analysis was used to estimate the distribution of time to recurrence and regression models were used to investigate factors associated with recurrence.

RESULTS

Eighty-seven patients with intraductal papillary mucinous neoplasms (IPMNs) were compared with 47 patients with mucinous cystic neoplasms (MCNs). Those with MCNs were more often females (P = .001), significantly younger (P = .001), more symptomatic (P = .009), and had cysts more often located in the tail (P < .001). Median follow-up was 42 months. Recurrence rates for IPMNs were 0%, 5%, and 10% versus 0% for MCNs respectively at postoperative years 1, 2, and 3 (P = .014). On multivariable analysis, size >3 cm (P = .027), higher grade dysplasia (P = .043), and positive resection margins (P < .001) were significantly associated with recurrence.

CONCLUSION

Resected noninvasive IPMNs with moderate- or high-grade dysplasia and negative resection margins require imaging follow-up every 2 years, given the 16% overall recurrence rate. Although the follow-up interval for noninvasive, low-grade, dysplastic IPMNs with negative margins could be lengthened, all noninvasive IPMNs having positive margins require yearly follow-up at the minimum. Resected noninvasive MCNs--irrespective of grade and margin status--do not require surveillance, although the development of branch duct-IPMNs in the remnant pancreas can be investigated in the long term at the discretion of the provider.

Pancreatic intraductal papillary mucinous neoplasm--where is the challenge?

Cystic lesions of the pancreas are increasingly recognized due to the widespread use of modern abdominal imaging technologies. The majority of these lesions display pseudocysts and mucinous cystic neoplasms. In contrast to pseudocysts, it is well established that mucinous cystic neoplasms of the pancreas exhibit a significant potential for malignant transformation over time. Among mucinous cystic tumors, the most frequently observed entity is pancreatic intraductal papillary mucinous neoplasm (IPMN). IPMNs are characterized by cystic dilation of pancreatic ducts and the production of mucus and by an adenoma-carcinoma sequence eventually culminating in invasive carcinoma in some patients. Due to the high risk of harboring malignancy, there is international consensus that IPMNs with involvement of the main pancreatic duct should be recommended for surgical resection. To date, the indication for surgery of branch-duct IPMNs is controversially discussed because of the overall lower risk of malignant transformation compared to main-duct IPMNs. Particularly for small and asymptomatic side-branch IPMNs, the indication for surgical resection remains challenging. In addition to the international consensus guidelines, a number of potential preoperative features predicting malignant transformation have been discussed recently. Moreover, novel surgical pancreatic parenchyma-sparing techniques such as enucleations or segmental pancreatic resections have been reported in order to treat IPMNs. The present article aims to demonstrate the current scientific knowledge in this field and to highlight the current controversy.

Mucinous Cystic Neoplasms of the Pancreas: Are we Overestimating Malignant Potential?

Surgical resection is recommended for all mucinous cystic neoplasms (MCNs) of the pancreas as a result of: 1) lack of an accurate tumor marker for invasive cancer; 2) young age at diagnosis; and 3) historical studies revealing 36 per cent incidence of malignancy in resected lesions. This study compares the clinicopathologic and prognostic features of our series of resected MCNs to recent studies using the current International Association of Pancreatology (IAP) system. Thirty-eight resected MCNs were identified. Almost all patients were female (97.4%); median age at diagnosis was 53.5 years (interquartile range [IQR], 41.3 to 61.0). The majority occurred in the body/tail of the pancreas (86.8%); median size on computed tomography/magnetic resonance imaging was 5.0 cm (IQR, 3 to 8.8). Comparison of the five high-grade (HG, 13.2%) and 33 low-grade (86.8%) MCNs revealed that 1) patients were similar in age (55.0 vs 52.0 years, respectively) and 2) HG lesions were significantly larger on preoperative imaging (9.9 vs 3.5 cm) and final pathology (10.9 vs 3.5 cm). These data, taken together with five recent studies that adhere to the 2012 IAP criteria (385 total MCNs), reveal that a cutoff of less than 3 cm without mural nodules would have only missed one (0.26%) HG lesion. Surveillance of these lesions may be appropriate for some patients.

Pancreatic ductal adenocarcinoma: Risk factors, screening, and early detection

Pancreatic cancer is the fourth most common cause of cancer-related deaths in the United States, with over 38000 deaths in 2013. The opportunity to detect pancreatic cancer while it is still curable is dependent on our ability to identify and screen high-risk populations before their symptoms arise. Risk factors for developing pancreatic cancer include multiple genetic syndromes as well as modifiable risk factors. Genetic conditions include hereditary breast and ovarian cancer syndrome, Lynch Syndrome, familial adenomatous polyposis, Peutz-Jeghers Syndrome, familial atypical multiple mole melanoma syndrome, hereditary pancreatitis, cystic fibrosis, and ataxia-telangiectasia; having a genetic predisposition can raise the risk of developing pancreatic cancer up to 132-fold over the general population. Modifiable risk factors, which include tobacco exposure, alcohol use, chronic pancreatitis, diet, obesity, diabetes mellitus, as well as certain abdominal surgeries and infections, have also been shown to increase the risk of pancreatic cancer development. Several large-volume centers have initiated such screening protocols, and consensus-based guidelines for screening high-risk groups have recently been published. The focus of this review will be both the genetic and modifiable risk factors implicated in pancreatic cancer, as well as a review of screening strategies and their diagnostic yields.

Endoscopic ultrasound and pancreatic applications: what the radiologist needs to know

As the technology has improved, endoscopic ultrasound (EUS) has taken on an important role in the diagnosis of a number of different neoplastic and non-neoplastic pancreatic diseases. EUS can provide high-resolution images with subtle anatomic detail, and has also taken on an important role in the targeted biopsy of the pancreas and adjacent structures. This review seeks to familiarize radiologists with the role of EUS in the diagnosis of chronic and autoimmune pancreatitis, solid pancreatic masses, and cystic pancreatic neoplasms.

Italian consensus guidelines for the diagnostic work-up and follow-up of cystic pancreatic neoplasms

This report contains clinically oriented guidelines for the diagnostic work-up and follow-up of cystic pancreatic neoplasms in patients fit for treatment. The statements were elaborated by working groups of experts by searching and analysing the literature, and then underwent a consensus process using a modified Delphi procedure. The statements report recommendations regarding the most appropriate use and timing of various imaging techniques and of endoscopic ultrasound, the role of circulating and intracystic markers and the pathologic evaluation for the diagnosis and follow-up of cystic pancreatic neoplasms.

Benign cystic neoplasm and endocrine tumours of the pancreas--when and how to operate--an overview

BACKGROUND

The recent evolution of limited local operative procedures for benign pancreatic lesions shifted surgical treatment options to the application of local techniques, although major resections of pancreatic head and left resection are still the standard.

OBJECTIVES

To evaluate the level of evidence of tumour enucleation (EN), pancreatic middle segment resection (PMSR) and duodenum preserving total/subtotal pancreatic head resection (DPPHRt/s), we focus based on present knowledge on indication to surgical treatment evaluating the questions, when and how to operate.

RESULTS

Tumour enucleation is recommended for all symptomatic neuro-endocrine tumours with size up to 2-3 cm and non-adherence to pancreatic main-ducts. EN has been applied predominantly in neuro-endocrine tumours and less frequently in cystic neoplasms. 20% of enucleation are performed as minimal invasive laparascopic procedure. Surgery related severe post-operative complications with the need of re-intervention are observed in about 11%, pancreatic fistula in 33%. The major advantage of EN are low procedure related early post-operative morbidity and a very low hospital mortality. PMSR is applied in two thirds for symptomatic cystic neoplasm and in one third for neuro-endocrine tumours. The high level of 33% pancreatic fistula and severe post-operative complications of 18% is related to management of proximal pancreatic stump. DPPHRt/s is used in 70% for symptomatic cystic neoplasms, for lesions with risk for malignancy and in less than 10% for neuro-endocrine tumours. DPPHRt with segment resection of peripapillary duodenum and intra-pancreatic common bile duct has been applied in one third of patients and in two thirds by complete preservation of duodenum and common bile duct. The level of evidence for EN and PMSR is low because of retrospective data evaluation and absence of RCT results. For DPPHR, 7 prospective, controlled studies underline the advantages compared to partial pancreaticoduodenectomy.

CONCLUSION

The application of tumour enucleation, pancreatic middle segment resection and duodenum preserving subtotal or total pancreatic head resection are associated with low level surgery related early post-operative complications and a very low hospital mortality. The major advantage of the limited procedures is preservation of exo- and endocrine pancreatic functions.

A systematic review of solid-pseudopapillary neoplasms: are these rare lesions?

OBJECTIVE

The aim of the study was to determine if there had been any change in the number of solid-pseudopapillary neoplasm (SPN) cases detected and their evaluation or management over time.

METHODS

A systematic review of SPN was performed of all articles published in English in PubMed and Scopus.

RESULTS

A total of 2744 patients with SPN were identified in 484 studies published between 1961 and 2012; 87.8% of the cases were reported between 2000 and 2012. A total of 2408 (87.8%) were females, and the mean age was 28.5 (SD, 13.7) years. The most common symptom was abdominal pain in 63.6% of the cases and incidentally detected in 38.1% of the cases. There were 2285 patients who underwent pancreatic resection. The mean tumor size was 8.6 (SD, 4.3) cm. Follow-up was reported for 1952 (90.5%) patients, with a mean follow-up of 36.1 (SD, 32.8) months. Disease-free survival was documented in 1866 (95.6%) patients with recurrence in 86 (4.4%) patients; the median time to recurrence was 50.5 months.

CONCLUSIONS

The number of SPNs reported in the literature has seen a 7-fold increase in the number of cases reported since 2000 compared with before. Solid-pseudopapillary neoplasms continue to be primarily found in young women and present with nonspecific symptoms. Surgery remains the mainstay of treatment with an excellent long-term prognosis.

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

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

[Duodenum-preserving total pancreatic head resection : an organ-sparing operation technique for cystic neoplasms and non-invasive malignant tumors]

Cystic neoplasms of the pancreas are being detected and surgically treated increasingly more frequently. Intraductal papillary mucinous neoplasms (IPMN) and mucinous cystic neoplasms (MCN) are primary benign lesions; however, the 5-year risk for malignant transformation has been estimated to be 63 % and 15 %, respectively. Surgical extirpation of a benign cystic tumor of the pancreas is a cancer preventive measure. The duodenum-preserving total pancreatic head resection technique (DPPHRt) is being used more frequently for cystic neoplasms of the pancreatic head. The complete resection of the pancreatic head can be applied as a duodenum-preserving technique or with segmental resection of the peripapillary duodenum. Borderline lesions, carcinoma in situ or T1N0 cancer of the papilla and the peripapillary common bile duct are also considered to be indications for segmental resection of the peripapillary duodenum. A literature search for cystic neoplastic lesions and DPPHRt revealed the most frequent indications to be IPMN, MCN and SCA lesions and 28 % suffered from a cystic neoplasm with carcinoma in situ or a peripapillary malignoma. The hospital mortality rate was 0.52 %. Compared to the Whipple type resection the DPPHRt exhibits significant benefits with respect to a low risk for early postoperative complications and a low hospital mortality rate of < 1 %. Exocrine and endocrine pancreatic functions after DPPHR are not impaired compared to the Whipple type resection.

Mucinous cystic neoplasm of the pancreas: is surgical resection recommended for all surgically fit patients?

BACKGROUND

Surgical removal of mucinous cystic neoplasms (MCNs) is usually recommended because of the risk of malignancy. However, increased experience of MCNs suggests that the incidence of invasion is lower than had been thought. This study was designed to establish more reasonable surgical indications for MCN through re-assessment using strict pathologic diagnostic criteria.

METHODS

Ninety-four patients who underwent surgical removal of MCNs at Seoul National University Hospital from 1991 to 2012 were retrospectively analyzed. Pathologic results were re-evaluated by an experienced pathologist. Medical records and radiologic images were reviewed to determine factors predicting malignancy.

RESULTS

Of the 94 patients, 4 were found to have intraductal papillary mucinous neoplasms (IPMNs). Of the 90 MCNs, 60 (66.7%) were low-grade, 21 (23.3%) were intermediate-grade, and 5 (5.5%) were high-grade dysplasias; and 4 (4.4%) were invasive carcinoma. Mural nodules on CT scan (p = 0.005) and abnormal serum CA19-9 concentration (p = 0.029) were significant predictors of malignancy. All MCNs less than 3 cm in size with normal serum tumor markers were benign and all malignant MCNs had cyst fluid CA19-9 over 10,000 units/ml. The five year disease specific survival rates were 98.8% for all patients and 75.0% for those with invasive MCNs.

CONCLUSION

MCNs had a low prevalence of malignancy. Regardless of the histological grade, long-term outcome was excellent. Therefore, in the absence of specific symptoms, surgery may not be indicated for MCNs <3 cm without mural nodules or elevated serum tumor markers. Validation by a prospective study with very careful design is needed.