Primary pancreatic cystic neoplasms revisited. Part I: serous cystic neoplasms

Diagnostics and Management of Pancreatic Cystic Lesions-New Techniques and Guidelines

Pancreatic cystic lesions (PCLs) are increasingly diagnosed owing to the wide use of cross-sectional imaging techniques. Accurate identification of PCL categories is critical for determining the indications for surgical intervention or surveillance. The classification and management of PCLs rely on a comprehensive and interdisciplinary evaluation, integrating clinical data, imaging findings, and cyst fluid markers. EUS (endoscopic ultrasound) has become the widely used diagnostic tool for the differentiation of pancreatic cystic lesions, offering detailed evaluation of even small pancreatic lesions with high sensitivity and specificity. Additionally, endoscopic ultrasound-fine-needle aspiration enhances diagnostic capabilities through cytological analysis and the assessment of fluid viscosity, tumor glycoprotein concentration, amylase levels, and molecular scrutiny. These detailed insights play a pivotal role in improving the clinical prognosis and management of pancreatic neoplasms. This review will focus mainly on the latest recommendations for the differentiation, management, and treatment of pancreatic cystic lesions, highlighting their clinical significance.

Pancreatic Cystic Neoplasms

Early detection of high-risk pancreatic cystic lesions enables potentially curative surgical resection, and early detection of lesions without worrisome features may lead to appropriate surveillance. Regrettably, differentiating premalignant and malignant cysts from nonmalignant ones remains challenging. However, emerging additional diagnostic tools, including the needle biopsy with microforceps and needle-based confocal laser endomicroscopy, are of exciting potential along with cyst fluid analysis".

Basic pancreatic lesions: Radiologic-pathologic correlation

The basic pancreatic lesions include location, size, shape, number, capsule, calcification/calculi, hemorrhage, cystic degeneration, fibrosis, pancreatic duct alterations, and microvessel. One or more basic lesions form a kind of pancreatic disease. As recognizing the characteristic imaging features of pancreatic basic lesions and their relationships with pathology aids in differentiating the variety of pancreatic diseases. The purpose of this study is to review the pathological and imaging features of the basic pancreatic lesions.

Pancreatic cystic neoplasms and post-inflammatory cysts: interobserver agreement and diagnostic performance of MRI with MRCP

PURPOSE

We aimed to answer several clinically relevant questions; (1) the interobserver agreement, (2) diagnostic performance of MRI with MRCP for (a) branch duct intraductal papillary mucinous neoplasms (BD-IPMN), mucinous cystic neoplasms (MCN) and serous cystic neoplasms (SCN), (b) distinguishing mucinous (BD-IPMN and MCN) from non-mucinous cysts, and (c) distinguishing three pancreatic cystic neoplasms (PCN) from post-inflammatory cysts (PIC).

METHODS

A retrospective analysis was performed at a tertiary referral center for pancreatic diseases on 71 patients including 44 PCNs and 27 PICs. All PCNs were confirmed by surgical pathology to be 17 BD-IPMNs, 13 MCNs, and 14 SCNs. Main duct and mixed type IPMNs were excluded. Two experienced abdominal radiologists blindly reviewed all the images.

RESULTS

Sensitivity of two radiologists for BD-IPMN, MCN and SCN was 88-94%, 62-69% and 57-64%, specificity of 67-78%, 67-78% and 67-78%, and accuracy of 77-82%, 65-75% and 63-73%, respectively. There was 80% sensitivity, 63-73% specificity, 70-76% accuracy for distinguishing mucinous from non-mucinous neoplasms, and 73-75% sensitivity, 67-78% specificity, 70-76% accuracy for distinguishing all PCNs from PICs. There was moderate-to-substantial interobserver agreement (Cohen's kappa: 0.65).

CONCLUSION

Two experienced abdominal radiologists had moderate-to-high sensitivity, specificity, and accuracy for BD-IPMN, MCN, and SCN. The interobserver agreement was moderate-to-substantial. MRI with MRCP can help workup of incidental pancreatic cysts by distinguishing PCNs from PICs, and premalignant mucinous neoplasms from cysts with no malignant potential.

Pancreatic Neuroendocrine Tumor with Benign Serous Cystadenoma: A Rare Entity

Mixed serous-neuroendocrine neoplasm constitutes pancreatic serous cystic neoplasms and pancreatic neuroendocrine tumor, two tumor components with different underlying pathologies. The differentiation of these tumors is important as the management and prognosis depend on the pancreatic neuroendocrine tumor component. We report a case of mixed serous-neuroendocrine neoplasm in a 47-year-old female who presented with epigastric pain abdomen for two years. Imaging studies, tumor markers, thorough systemic evaluation, surgical resection, histopathological examination, and timely follow-up constituted our management approach. A 4 cm × 4 cm mass in the distal pancreas with multiple cysts in the pancreatic parenchyma containing serous fluid on distal pancreatectomy and splenectomy was found. The histopathological examination revealed combined benign serous cystadenoma and neuroendocrine tumor. She did not have any recurrence or metastasis by four years of follow-up.

Focal Pancreatic Lesions: Role of Contrast-Enhanced Ultrasonography

The introduction of contrast-enhanced ultrasonography (CEUS) has led to a significant improvement in the diagnostic accuracy of ultrasound in the characterization of a pancreatic mass. CEUS, by using a blood pool contrast agent, can provide dynamic information concerning macro- and micro-circulation of focal lesions and of normal parenchyma, without the use of ionizing radiation. On the basis of personal experience and literature data, the purpose of this article is to describe and discuss CEUS imaging findings of the main solid and cystic pancreatic lesions with varying prevalence.

Pearls and pitfalls of imaging features of pancreatic cystic lesions: a case-based approach with imaging-pathologic correlation

A variety of neoplastic and non-neoplastic lesions of the pancreas can present with a predominantly cystic architecture. These lesions are increasingly being detected as incidental findings on routine cross-sectional imaging following technological advances in these techniques and their widespread use. The different histopathological behaviors show various common and uncommon imaging findings, and some cases show similar appearance in spite of different histopathology. Each lesion requires specific management because of the differing risk of progression to malignancy, and an accurate imaging diagnosis is crucial. The typical imaging characteristics that differentiate pancreatic cystic lesions have been well described and fully summarized. However, in addition to a small percentage of cases that shows uncommon imaging findings, a substantial percentage of cystic lesions shows overlapping imaging findings that can lead to radiological misdiagnosis. For appropriate diagnosis and optimal treatment strategy, it is important to know the uncommon and overlapping imaging findings of these lesions, in addition to familiarity with the typical aspects. In this article, we reconfirm the well-known characteristic imaging features of pancreatic cystic lesions and present several diagnostically challenging cases, focusing on the uncommon and overlapping imaging findings.

Clinicoradiological features of resected serous cystic neoplasms according to morphological subtype and preoperative tentative diagnosis: can radiological characteristics distinguish serous cystic neoplasms from other lesions?

Purpose

Serous cystic neoplasm (SCN) of the pancreas is considered benign in most cases. However, some SCN patients undergo surgical resection because lesions could not be differentiated preoperatively. This study evaluated causes of resection for SCN, investigated clinical and radiological features of surgically resected SCNs, and compared characteristics of SCNs diagnosed accurately and those misdiagnosed.

Methods

One hundred patients, who underwent surgery for pancreatic cystic tumors with pathological confirmation of SCN between 2000 and 2014 were retrospectively analyzed.

Results

The mean patient age was 52.9 years, 67 (67%) were female, and most lesions (72%) were located in the pancreatic body or tail. Fifty-one (51%) pathologically confirmed SCNs were preoperatively diagnosed as non-SCNs. Patients underwent surgery due to uncertain diagnosis (58%) or symptomatology (18%). According to radiological examination, most lesions were macrocystic (85%), exhibited septation (58%), or were enhancing lesions (48%). Compared with preoperatively diagnosed non-SCNs, accurately diagnosed SCNs exhibited septation (75.5% vs. 41.2%, P = 0.001) and central scar (36.7% vs. 11.8%, P = 0.003) more frequently in radiological examinations. In terms of macrocystic tumors (n = 85), most parameters did not differentiate preoperative diagnoses, although lesions accurately diagnosed as SCN exhibited septation more frequently than those preoperatively misdiagnosed as mucinous cystic neoplasm or intraductal papillary mucinous neoplasm (70.7% vs. 38.9% vs. 33.3%, respectively, P = 0.009).

Conclusion

It is difficult to accurately distinguish macrocystic SCNs from other cystic tumors using conventional radiological methods. For more accurate diagnosis, new biomarkers and/or other diagnostic modalities are needed and warrant further investigation.

Cystic Lesions of the Pancreas: Differential Diagnosis and Cytologic-Histologic Correlation

CONTEXT.—

Pancreatic cystic lesions (PCLs) are very common, and their detection is increasing with the advances in imaging techniques. Because of the major implications for management, distinguishing between neoplastic and nonneoplastic PCLs is critical. Neoplastic cysts with potential to progress into cancer include mucinous PCLs (intraductal papillary mucinous neoplasms and mucinous cystic neoplasms) and nonmucinous cysts (solid pseudopapillary tumors, serous cystic neoplasms, and neuroendocrine tumors with cystic degeneration). Nonneoplastic cysts with no risk of malignant transformation include pseudocysts, retention cysts, lymphoepithelial cysts, cystic pancreatic lymphangioma, and duplication cyst/ciliated foregut cysts. The role of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) cytology with cyst fluid analysis in the diagnosis of PCLs has evolved during the last decade; however, a definitive diagnosis on cytologic specimens is hampered by the sparse cellularity and can be challenging. EUS-FNA can play an important role to differentiate low-risk from high-risk pancreatic cysts and to distinguish between patients with cysts who need clinical follow-up versus those who require surgery.

OBJECTIVE.—

To provide an integrative approach to diagnose pancreatic cystic lesions using EUS-FNA cytology and cyst fluid analysis, along with clinical, radiologic, histologic, genetic, and molecular characteristics.

DATA SOURCES.—

The review and analysis of the latest literature describing pancreatic cystic lesions.

CONCLUSIONS.—

Accurate diagnosis of PCLs requires a multidisciplinary and multimodal team approach, including the integration of clinical findings, imaging, cytology, cyst fluid analysis, and molecular testing.

Robotic enucleations of pancreatic benign or low-grade malignant tumors: preliminary results and comparison with robotic demolitive resections

BACKGROUND

The incidental detection of benign to low-grade malignant small pancreatic neoplasms increased in the last decades. The surgical management of these patients is still under debate. The aim of this paper is to evaluate the safety and feasibility of robotic enucleations and to compare the outcomes with non-parenchymal sparing robotic resections.

METHODS

The study included a total of 25 patients. Nine of them underwent a robotic enucleation (EN Group) and 16 patients received a robotic demolitive resection (DR Group). Perioperative and medium-term outcomes were compared between the two groups.

RESULTS

Patients' baseline characteristics were similar in the two groups except for presence of symptoms and tumor size, due to the inclusion criteria. Operative time was significantly shorter and postoperative results were better for EN group, including a significant shorter hospitalization (5 vs. 8 days, p = 0.027), reduced pancreatic leaks (22% vs. 50%, p = 0.287) and a better preservation of glandular function (100% vs. 62.5%, p = 0.066). Mortality rate was zero in both groups, with all patients free from disease at a median follow-up of 18 months.

CONCLUSIONS

The risks of under/overtreatment remain still unavoidable for benign to low-grade malignant small pancreatic neoplasms. Simple enucleation should be performed whenever oncological appropriate, to achieve the best postoperative outcomes. The adoption of robotic technique might widen the indications for parenchymal sparing, minimally invasive surgery.

A prospective study on endoscopic ultrasound for the differential diagnosis of serous cystic neoplasms and mucinous cystic neoplasms

BACKGROUND

To provide criteria for the differential diagnosis of serous cystic neoplasms (SCNs) and mucinous cystic neoplasms (MCNs) by analyzing the imaging features of these two neoplasms by endoscopic ultrasound (EUS).

METHODS

From April 2015 to December 2017, a total of 69 patients were enrolled in this study. All patients were confirmed to have MCNs (31 patients) or SCNs (38 patients) by surgical pathology. All patients underwent EUS examination. The observation and recorded items were size, location, shape, cystic wall thickness, number of septa, and solid components.

RESULTS

Head/neck location, lobulated shape, thin wall and > 2 septa were the specific imaging features for the diagnosis of SCNs. When any two imaging features were combined, we achieved the highest area under the curve (Az) (0.824), as well as the appropriate sensitivity (84.2%), specificity (80.6%), positive predictive value (PPV) (84.2%), and negative predictive value (NPV) (80.6%). Body/tail location, round shape, thick wall and 0-2 septa were the specific imaging features for the diagnosis of MCNs. When any three imaging features were combined, we obtained the highest Az value (0.808), as well as the appropriate sensitivity (77.4%), specificity (84.2%), PPV (80.0%) and NPV (82.1%).

CONCLUSIONS

Pancreatic cystadenomas that meet any two of the four imaging features of head/neck location, lobulated shape, thin wall and > 2 septa could be diagnosed as SCNs, and those that meet any three of the four imaging features of body/tail location, round shape, thick wall and 0-2 septa could be considered as MCNs.

TRIAL REGISTRATION

The study was registered at the Chinese Clinical Trial Registry. The registration identification number is ChiCTR-OOC-15006118 . The date of registration is 2015-03-20.

Current indications and yield of endoscopic ultrasound and ancillary techniques in pancreatic cystic neoplasms

An increase in the diagnosis of pancreatic cystic neoplasm has been described lately. Surgical treatment or surveillance is advised depending on the type of lesion diagnosed. The most accurate diagnostic approach is needed to make the best therapeutic decision. Endoscopic ultrasound is a very valuable tool in the evaluation of pancreatic cystic neoplasm. It generates high-quality images and allows the possibility of sampling the cystic fluid for cytology, microbiological and molecular evaluation. Even with this evaluation, the sensitivity of this approach is not always adequate. New technological resources have been developed to try to improve the diagnostic accuracy of pancreatic cystic neoplasms. The two most promising techniques are needle-based confocal laser endomicroscopy and contrast-enhanced harmonic endoscopic ultrasound. Needle-based confocal laser endomicroscopy allows a microscopic evaluation of mucosal glands and vascular pattern, to differentiate mucinous from non-mucinous lesions. Contrast-enhanced harmonic endoscopic ultrasound is used for the vascular evaluation of the microcirculation of the cyst wall and mural nodule, mainly to make the difference between malignant nodules and mucus plugs. A combination of these different diagnostic techniques can improve the diagnostic accuracy of pancreatic cystic neoplasms to offer the adequate therapeutic decision.

The Use of Biomarkers in the Risk Stratification of Cystic Neoplasms

Cyst fluid biomarkers may be used to identify pancreatic cyst subtypes. Biomarkers are selected based on their ability to accurately distinguish mucinous from nonmucinous cysts and to risk stratify cysts based on malignant potential. Biomarkers of interest include but are not limited to amylase, oncogenes, DNA analysis, and epigenetic markers. The introduction of next-generation sequencing and molecular panels has aided in improved diagnostic accuracy and risk stratification. This review presents the diagnostic performance of currently available biomarkers and proposes an algorithm to incorporate their use in the diagnosis of pancreatic cysts.

Radiological Workup of Cystic Neoplasms of the Pancreas

Pancreatic cystic lesions are being detected with increasing frequency because of increased use and improved quality of cross-sectional imaging techniques. Pancreatic cystic lesions encompass non-neoplastic lesions (such as pancreatitis-related collections) and neoplastic tumors. Common cystic pancreatic neoplasms include serous cystadenomas, mucinous cystic neoplasms, intraductal papillary mucinous neoplasms, and solid pseudopapillary tumors. These cystic pancreatic neoplasms may have typical morphology, but at times show overlapping imaging features on cross-sectional examinations. This article reviews the classical and atypical imaging features of commonly encountered cystic pancreatic neoplasms and presents the limitations of current cross-sectional imaging techniques in accurately classifying pancreatic cystic lesions.

Imaging and Screening of Pancreatic Cancer

Given the low disease prevalence of both exocrine and endocrine cancers in the general population, screening is not recommended. However, in as many as 25% of cases there is a precursor lesion or an identifiable genetic predisposition. For these patients at increased risk, screening with imaging is recommended. Multidetector computed tomography, MR imaging or magnetic resonance cholangiopancreatography, and endoscopic ultrasound examination can be used as screening modalities. Recent advances in dual energy CT and total body MR imaging have increased the suitability of these noninvasive modalities as first-line imaging screening options.

My Treatment Approach: Pancreatic Cysts

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

Giant Serous Cystadenoma of the Pancreas (⩾10 cm): The Clinical Features and CT Findings

Purpose. To report the clinical features and CT manifestations of giant pancreatic serous cystadenoma (≥10 cm). Methods. We retrospectively reviewed the clinical features and CT findings of 6 cases of this entity. Results. All 6 patients were symptomatic. The tumors were 10.2 cm–16.5 cm (median value, 13.0 cm). CT imaging revealed that all 6 cases showed microcystic appearances (n = 5) or mixed microcystic and macrocystic appearances (n = 1). Five patients with tumors at the distal end of the pancreas received distal pancreatectomy. Among these 5 patients, 2 patients underwent partial transverse colon resection or omentum resection due to close adhesion. One patient whose tumor was located in the pancreatic head underwent pancreaticoduodenectomy; however, due to encasement of the portal and superior mesenteric veins, the tumor was incompletely resected. One patient had abundant draining veins on the tumor surface and suffered large blood loss (700 mL). After 6–49 months of follow-up the 6 patients showed no tumor recurrence or signs of malignant transformation. Conclusions. Giant pancreatic serous cystadenoma necessitates surgical resection due to large size, symptoms, uncertain diagnosis, and adjacent organ compression. The relationship between the tumors and the neighboring organs needs to be carefully assessed before operation on CT image.

Left-sided pancreatic incidentalomas treated with laparoscopic approach: a report of 20 cases

BACKGROUND

The diffusion of cross-sectional imaging has recently permitted the detection of an increasing number of incidentalomas localized in the distal pancreas. Currently, there are no studies in the literature exploring the laparoscopic approach as treatment for left-sided pancreatic incidentalomas.

METHODS AND RESULTS

We report a series of 20 incidentalomas localized in the body and tail of the pancreas treated with laparoscopic surgery over the period 2010-2014. The incidental masses of our series included a great variety of histotypes and a relevant proportion of malignant lesions. In two cases, the laparoscopic procedures were converted to open surgery. No postoperative death was observed. The postoperative pancreatic fistula rate was 20 %, and the new-onset diabetes rate was 25 %.

CONCLUSIONS

Left-sided pancreatic incidentalomas in patients with minor comorbidities can be safely treated with laparoscopic approach. Only clinical trials will confirm whether laparoscopic surgery is an effective treatment for malignant lesions.

Mixed serous neuroendocrine neoplasm of the pancreas: Case report and literature review

INTRODUCTION

The aim of this study was to report a new case of mixed serous neuroendocrine neoplasm (MSNN) and review the literature concerning this type of lesion, which was added to the World Health Organization classification of pancreatic tumors in 2010.

RESULTS

A 73-year-old woman presented with a pancreatic mass. The lesion was an intriguing combination of serous cystic neoplasm (SCN) and pancreatic neuroendocrine tumor (PanNET), in which the PanNET component grew into the wall of the serous oligocystic adenoma. We searched different databases for studies that had investigated MSNN. A total of 15 patients (age, 28-78), including the patient in the present study, were evaluated. We discuss these cases in detail especially regarding morphology and pathology; our case was the only one involving a collision type combination.

CONCLUSION

Although MSNN is recognized as a variant of SCN, it is quite different from SCN or PanNET. A new morphological analysis of MSNN may help in elucidating its histogenesis and prognosis.

Current perspectives on pancreatic serous cystic neoplasms: Diagnosis, management and beyond

Pancreatic cystic neoplasms have been increasingly recognized recently. Comprising about 16% of all resected pancreatic cystic neoplasms, serous cystic neoplasms are uncommon benign lesions that are usually asymptomatic and found incidentally. Despite overall low risk of malignancy, these pancreatic cysts still generate anxiety, leading to intensive medical investigations with considerable financial cost to health care systems. This review discusses the general background of serous cystic neoplasms, including epidemiology and clinical characteristics, and provides an updated overview of diagnostic approaches based on clinical features, relevant imaging studies and new findings that are being discovered pertaining to diagnostic evaluation. We also concisely discuss and propose management strategies for better quality of life.

Clinical importance of Familial Pancreatic Cancer Registry in Japan: a report from kick-off meeting at International Symposium on Pancreas Cancer 2012

Pancreatic cancer is still a highly lethal disease with a 5-year survival rate of approximately 5 %. Early detection offers one of the best hopes for improving survival. Previous cohort studies and case-control studies showed that 4-10 % of pancreatic cancers have a hereditary basis, and individuals with a family history have an increased risk of developing pancreatic and extra-pancreatic malignancies. Since individuals with a family history of pancreatic cancer and those with a known genetic syndrome that predisposes to pancreatic cancer will be the first to benefit from early detection tests as they become available, familial pancreatic cancer (FPC) registries have been established in the US and Europe, but not yet in Japan. Such registries form the basis for epidemiological studies, clinical trials, and basic research on familial pancreatic cancer. There is a need for FPC registries in Japan as cancer risk varies among different populations and discoveries made in Western populations may not translate to the Japanese population. These registries in Japan will align with ongoing international efforts and add to a better understanding of the natural history, risk factors, screening strategies, and responsible genes, for improving survival of this dismal disease.

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).

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 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.

Analysis of VEGF/PlGF heterodimer level in pancreatic cyst fluid as a biomarker for serous cystadenoma

INTRODUCTION

Pancreatic cyst fluid (PCF) analysis provides valuable information in the preoperative evaluation of pancreatic cysts. Vascular endothelial growth factors (VEGF) and other proangiogenesis factors such a placental growth factor (PlGF) are promising biomarkers for identifying serous cystadenoma (SCA). VEGF-A has recently been reported as a SCA marker. We sought to assess the value of the VEGF-A/PlGF heterodimer as a potential biomarker of SCA in PCF.

MATERIALS AND METHODS

PCF was analyzed for VEGF/PlGF and 7 additional proangiogenic markers including VEGF-A, VEGF-C, VEGF-D, TEK tyrosine kinase, endothelial (TIE-2), soluble fms-like tyrosine kinase-1 (sFlt-1), PlGF, and basic fibroblast growth factor (bFGF). True-positive or false-negative results were determined by histological confirmation of SCA and false-positive or true-negative results with confirmation of a non-SCA cyst by either cytology or histology, elevated carcinoembryonic antigen ≥192 ng/mL, elevated amylase ≥5000 U/L, or detected KRAS/GNAS mutations.

RESULTS

Forty-eight PCFs were analyzed; 1 was technically inadequate. Of the remaining 47, 3 (6%) contained measurable (>60 pg/mL) concentrations of VEGF/PlGF heterodimer: 1 pseudocyst, 1 cystic adenocarcinoma, and 1 SCA. Of 6 histologically confirmed SCAs, there was only 1 (17%) true positive. Six PCFs were not classifiable due to insufficient data, leaving 41 PCFs for performance calculations (33 true negative, 5 false negative, 1 true positive, and 2 false positive) yielding a sensitivity of 17% and specificity of 94%.

CONCLUSIONS

VEGF/PlGF heterodimer is present in low concentrations in PCF and is an insensitive biomarker for SCA. Additional study is required to determine clinical utility of heterodimeric VEGF/PlGF in combination with other proangiogenic markers.

Management of serous cystic neoplasms of the pancreas

Pancreatic serous cystadenomas are uncommon benign tumours that are often found incidentally on routine imaging examinations. Radiological imaging techniques alone have proven to be suboptimal to fully characterize cystic pancreatic lesions. Endoscopic ultrasound, with the addition of fine-needle aspiration in difficult cases, has showed greater diagnostic accuracy than conventional imaging techniques. The best management strategy of these neoplasms is still debated. Surgery should be limited only to symptomatic and highly selected cases and most of the patients should only be strictly monitored. In the current paper, we provide an updated overview on pancreatic serous cystadenomas, focusing our attention on epidemiology, clinical characteristics and diagnostic evaluation; finally, we also discuss different management strategies and areas for future research.

Endoscopic ultrasound and pancreatic cystic lesions-diagnostic and therapeutic applications

Pancreatic cystic lesions are being detected with an increasing frequency. Endoscopic ultrasound (EUS) provides both diagnostic and therapeutic means for pancreatic cystic lesions. Detailed imaging and EUS-guided fine-needle aspiration provide additional information on pancreatic cystic lesions. EUS-guided pseudocyst drainage has advantages over conventional drainage modalities. EUS-guided cyst ablation is a promising therapeutic modality.

To cease or 'de-cyst'? The evaluation and management of pancreatic cystic lesions

Due to the widespread use of cross-sectional imaging and advances in imaging technology, pancreatic cystic lesions are increasingly being detected. The diagnosis and management of such cysts remains challenging and continues to evolve. Different pancreatic cyst types have varying malignant potential. Thus, accurate cyst characterization is essential to appropriate management; the most clinically important distinction is differentiating mucinous lesions, which have malignant potential and may benefit from surgical resection, from non-mucinous cystic lesions. Endoscopic ultrasound with fine needle aspiration with cytologic, chemical,, and tumor marker analysis appears to be the best currently available method for accurately characterizing a cyst's malignant potential, and therefore impacts the most important management decision for a pancreatic cyst-continued surveillance or surgical resection.

Imaging pitfalls of pancreatic serous cystic neoplasm and its potential mimickers

The aim of this article is to clarify diagnostic pitfalls of pancreatic serous cystic neoplasm (SCN) that may result in erroneous characterization. Usual and unusual imaging findings of SCN as well as potential SCN mimickers are presented. The diagnostic key of SCN is to look for a cluster of microcysts (honeycomb pattern), which may not be always found in the center. Fibrosis in SCN may be mistaken for a mural nodule of intraductal papillary mucinous neoplasm (IPMN). The absence of cyst wall enhancement may be helpful to distinguish SCN from mucinous cystic neoplasm. However, oligocystic SCN and branch duct type IPMN may morphologically overlap. In addition, solid serous adenoma, an extremely rare variant of SCN, is difficult to distinguish from neuroendocrine tumor.

Investigating MicroRNA Expression Profiles in Pancreatic Cystic Neoplasms

OBJECTIVES:

Current diagnostic tools for pancreatic cysts fail to reliably differentiate mucinous from nonmucinous cysts. Reliable biomarkers are needed. MicroRNAs (miRNA) may offer insights into pancreatic cysts. Our aims were to (1) identify miRNAs that distinguish benign from both premalignant cysts and malignant pancreatic lesions using formalin-fixed, paraffin-embedded (FFPE) pathology specimens; (2) identify miRNAs that distinguish mucinous cystic neoplasm (MCN) from branch duct-intraductal papillary mucinous neoplasm (BD-IPMN).

METHODS:

A total of 69 FFPE pancreatic specimens were identified: (1) benign (20 serous cystadenoma (SCA)), (2) premalignant (10 MCN, 10 BD-IPMN, 10 main duct IPMN (MD-IPMN)), and (3) malignant (19 pancreatic ductal adenocarcinoma (PDAC)). Total nucleic acid extraction was performed followed by miRNA expression profiling of 378 miRNAs interrogated using TaqMan MicroRNA Arrays Pool A and verification of candidate miRNAs. Bioinformatics was used to generate classifiers.

RESULTS:

MiRNA profiling of 69 FFPE specimens yielded 35 differentially expressed miRNA candidates. Four different 4-miRNA panels differentiated among the lesions: one panel separated SCA from MCN, BD-IPMN, MD-IPMN, and PDAC with sensitivity 85% (62, 97), specificity 100% (93, 100), a second panel distinguished MCN from SCA, BD-IPMN, MD-IPMN, and PDAC with sensitivity and specificity 100% (100, 100), a third panel differentiated PDAC from IPMN with sensitivity 95% (76, 100) and specificity 85% (72, 96), and the final panel diagnosed MCN from BD-IPMN with sensitivity and specificity approaching 100%.

CONCLUSIONS:

MiRNA profiling of surgical pathology specimens differentiates serous cystadenoma from both premalignant pancreatic cystic neoplasms and PDAC and MCN from BD-IPMN.

Activated wnt signaling in stroma contributes to development of pancreatic mucinous cystic neoplasms

BACKGROUND & AIMS

Pancreatic mucinous cystic neoplasm (MCN), a cystic tumor of the pancreas that develops most frequently in women, is a potential precursor to pancreatic ductal adenocarcinoma. MCNs develop primarily in the body and tail of the pancreas and are characterized by the presence of a mucinous epithelium and ovarian-like subepithelial stroma. We investigated the involvement of Wnt signaling in KRAS-mediated pancreatic tumorigenesis and development of MCN in mice, and Wnt activation in human MCN samples.

METHODS

LSL-Kras(G12D), Ptf1a-cre mice were crossed with elastase-tva mice to allow for introduction of genes encoded by the replication-competent avian sarcoma-leukosis virus long-terminal repeat with splice acceptor viruses to pancreatic acinar cells and acinar cell progenitors, postnatally and sporadically. Repeat with splice acceptor viruses that expressed Wnt1 were delivered to the pancreatic epithelium of these mice; pancreatic lesions were analyzed by histopathology and immunohistochemical analyses. We analyzed levels of factors in Wnt signaling pathways in 19 MCN samples from patients.

RESULTS

Expression of Wnt1 in the pancreatic acinar cells and acinar cell progenitors of female mice led to development of unilocular or multilocular epithelial cysts in the pancreas body and tail, similar to MCN. The cystic lesions resembled the estrogen receptor- and progesterone receptor-positive ovarian-like stroma of MCN, but lacked the typical mucinous epithelium. Activated Wnt signaling, based on nuclear localization of β-catenin, was detected in the stroma but not cyst epithelium. Wnt signaling to β-catenin was found to be activated in MCN samples from patients, within the ovarian-like stroma, consistent with the findings in mice.

CONCLUSIONS

Based on studies of mice and pancreatic MCN samples from patients, the canonical Wnt signaling pathway becomes activated and promotes development of the ovarian-like stroma to contribute to formation of MCNs.

Rate of growth of pancreatic serous cystadenoma as an indication for resection

BACKGROUND

The purpose of this study was to examine the natural history and growth rate of pancreatic serous cystadenomas (SCAs) to determine which factors lead to resection for these benign neoplasms.

METHODS

We reviewed retrospectively a prospectively maintained database, identifying patients diagnosed with SCAs of the pancreas. The diagnosis was made via a combination of classic imaging features with or without cyst aspiration results consistent with SCA. To determine growth rates, gamma regression models were used and the average was modeled using the log function.

RESULTS

A prospectively maintained database of 1,241 pancreatic cystic neoplasms was queried from 1998 to 2010. A total of 219 patients (18%) were diagnosed with SCA, 194 in the surveillance group and 25 in the resection group. Twenty patients underwent resection after initial imaging principally for presence of symptoms and indeterminate diagnosis, and 5 underwent resection after surveillance for development of symptoms and/or rapid rate of growth. Rate of growth increased at a steady state over time, with an estimated doubling time of 12 years (95% confidence interval, 7.8-21.5).

CONCLUSION

This study shows that growth patterns are similar for SCAs of the pancreas regardless of initial size. When doubling time is faster than 12 years, resection should be considered.

Pancreatic cystic neoplasms: a review of preoperative diagnosis and management

Pancreatic cystic neoplasms (PCNs) are a diverse group of neoplasms in the pancreas, and are more increasingly encountered with widespread abdominal screening and improved imaging techniques. The most common types of PCNs are serous cystic neoplasms (SCNs), mucinous cystic neoplasms (MCNs), and intraductal papillary mucinous neoplasms (IPMNs). Clinicians frequently feel bewildered in the differential diagnosis and subsequent management among the various types of lesions in the pancreas, which may lead to overtreatment or delayed treatment. The current review provides recent developments in the understanding of the three most common types of PCNs, the latest modalities used in preoperative diagnosis and differential diagnosis, as well as the most up to date management. Suggestions for diagnosis and differential diagnosis of SCNs, MCNs, and IPMNs are also provided for young surgeons. Better understanding of these neoplasms is essential for clinicians to make accurate diagnosis and to provide the best management for patients.

Fine-needle aspirations of pancreatic serous cystadenomas: improving diagnostic yield with cell blocks and α-inhibin immunohistochemistry

BACKGROUND

The diagnosis of serous cystadenoma (SCA), a rare benign pancreatic neoplasm, can alter the management of patients with pancreatic masses. Although characteristic imaging findings and fluid chemical analysis have been described, SCAs are not always recognized preoperatively. Furthermore, scant cellular yield on fine-needle aspiration (FNA) often leads to a nondiagnostic or nonspecific benign diagnosis. α-Inhibin (AI), a sensitive marker for SCA, is infrequently required for diagnosis in surgical specimens due to their characteristic histologic appearance. The objective of the current study was to determine whether AI staining can improve SCA diagnosis on FNA specimens.

METHODS

Fifteen confirmed cases of SCA with prior FNA specimens were selected for this study. FNAs were evaluated for cellularity, cellular arrangement, and cytomorphology. Resection specimens were reviewed.

RESULTS

Of the 15 FNA cases, approximately 75% demonstrated scant cellularity (11 of 15 cases). On smears, the cells were arranged as flat sheets, corresponding to strips of cells on cell block sections. The cells were small and round to cuboidal, with clear cytoplasm; occasional plasmacytoid cells and oncocytic cells were identified. Flattened cells, corresponding to attenuated epithelial cells lining macrocysts on the resections, were also noted. Stromal fragments were present in 5 FNAs and correlated with the hyalinized stroma in the resection specimens. AI immunostaining was positive in 88% of cases (7 of 8 of cases), thereby supporting the diagnosis of SCA.

CONCLUSIONS

The results of the current study indicate that low cellularity and bland cytology are inherent to SCAs. Performing cell blocks and AI staining on FNA specimens is useful for establishing the diagnosis of SCA. An immunohistochemical panel including AI, chromogranin, and synaptophysin may enhance the diagnostic accuracy of pancreatic FNA specimens.

Incidentally discovered pancreatic intraepithelial neoplasia: what is its clinical significance?

PURPOSE

Pancreatic intraepithelial neoplasia (PanIN) is a presumed precursor of pancreatic ductal adenocarcinoma (PDAC). We assessed the relationship between incidental PanIN after resection of non-adenocarcinoma lesions and the development of metachronous PDAC in the remnant.

METHODS

We retrospectively reviewed the clinicopathologic data of patients who underwent pancreatectomy for non-PDAC from January 2000 to January 2010. Intraductal papillary mucinous lesions were excluded. All available postoperative imaging and clinical follow-up data were reviewed; the risk of developing PDAC was assessed in patients with a minimum follow-up time of 6 months and with imaging studies available for review.

RESULTS

A total of 584 patients were analyzed. Median age was 59 years (range 10-85 years), and 338 (58 %) were female. The most common lesions for which resection was performed were serous cystic neoplasms (17 %), pancreatic neuroendocrine tumors (38 %), metastatic tumors (9 %), and mucinous cystic neoplasms (7 %). PanIN was identified in 153 (26 %) patients. The majority of these patients had PanIN-1 or -2 (50 and 41 %, respectively), whereas 13 (8 %) had PanIN-3. Of the 506 (87 %) patients with adequate follow-up (median 3.7 years, range 0.5-12.6 years), 1 patient (0.2 %) with PanIN identified at the time of initial resection developed cancer in the remnant. This occurred 4.4 years after a distal pancreatectomy in the setting of PanIN-1B. No patient with PanIN-3 developed cancer during follow-up.

CONCLUSIONS

PanIN was identified in 26 % of patients who underwent resection for histopathology other than PDAC. The presence of PanIN of any grade did not result in an appreciable cancer risk in the pancreatic remnant after short-term follow-up.

Diagnosis and management of cystic pancreatic lesions

OBJECTIVE

The purpose of this review is to outline the management guidelines for the care of patients with cystic pancreatic lesions.

CONCLUSION

The guidelines are as follows: Annual imaging surveillance is generally sufficient for benign serous cystadenomas smaller than 4 cm and for asymptomatic lesions. Asymptomatic thin-walled unilocular cystic lesions smaller than 3 cm or side-branch intraductal papillary mucinous neoplasms should be followed up with CT or MRI at 6 and 12 months interval after detection. Cystic lesions with more complex features or with growth rates greater than 1 cm/year should be followed more closely or recommended for resection if the patient's condition allows surgery. Symptomatic cystic lesions, neoplasms with high malignant potential, and lesions larger than 3 cm should be referred for surgical evaluation. Endoscopic ultrasound with fine-needle aspiration (FNA) biopsy can be used preoperatively to assess the risk of malignancy.

Interdisciplinary management of cystic neoplasms of the pancreas

Cystic neoplasms of the pancreas are increasingly recognized due to the frequent use of abdominal imaging. It is reported that up to 20% of abdominal cross-sectional scans identify incidental asymptomatic pancreatic cysts. Proper characterization of pancreatic cystic neoplasms is important not only to recognize premalignant lesions that will require surgical resection, but also to allow nonoperative management of many cystic lesions that will not require resection with its inherent morbidity. Though reliable biomarkers are lacking, a wide spectrum of diagnostic modalities are available to evaluate pancreatic cystic neoplasms, including radiologic, endoscopic, laboratory, and pathologic analysis. An interdisciplinary approach to management of these lesions which incorporates recent, specialty-specific advances in the medical literature is herein suggested.

The incidental cystic pancreas mass: a practical approach

Technical advances in cross-sectional imaging have led to the discovery of incidental cystic pancreatic lesions in the oncology and non-oncology population that in the past remained undetected. These lesions have created a diagnostic and management dilemma for both clinicians and radiologists: should these lesions be ignored, watched, aspirated, or removed? In this review, recommendations concerning the assessment of the more common pancreatic cystic incidental lesions are presented.

Incidentally discovered benign pancreatic cystic neoplasms not communicating with the ductal system: MR/MRCP imaging appearance and evolution

PURPOSE

The authors sought to determine magnetic resonance/magnetic resonance cholangiopancreatography (MR/MRCP) imaging features of incidentally discovered benign, noncommunicating cystic neoplasms (BNCNs) of the pancreas to assess their evolution over time and identify MR/MRCP imaging features predictive of tumour growth.

MATERIAL AND METHODS

This was a retrospective study, so informed consent was waived. Sixty-two patients with a diagnosis of BNCN were assessed. Inclusion criteria were incidentally discovered cystic neoplasm of the pancreas with nonmeasurable walls, no mural nodules and no communication with the pancreatic ductal system and who underwent ≥ 1 MR/MRCP examination. Image analysis, performed at diagnosis and during follow-up, included macroscopic pattern (microcystic/macrocystic/mixed), number of cysts (unicystic/oligocystic/multicystic), BNCN maximum diameter and tumour growth rates.

RESULTS

A total of 64 BNCNs was detected. Macroscopic pattern was mixed in 31/64 (48%), microcystic in 28/64 (44%) and macrocystic in 5/64 (8%). BNCNs appeared multicystic in 38/64 (59%) cases, oligocystic in 22/64 (35%) and unicystic in 4/64(6%). All qualitative parameters remained unchanged during follow-up. At diagnosis, the median maximum BNCN diameter was 35.0 mm and 38.0 mm at the final examination (p<0.001). BNCNs showed a tumour growth rate of 2 mm/year.

CONCLUSIONS

Mixed and microcystic patterns were the most common, accounting for 48% and 44% of cases, respectively, and showed no change over time. MR/MRCP features predictive of lesion enlargement were a mixed/ macrocystic pattern, and lesion size was >3 cm (both p<0.001).

Pancreatic cystic lesions: How endoscopic ultrasound morphology and endoscopic ultrasound fine needle aspiration help unlock the diagnostic puzzle

Cystic lesions of the pancreas are being diagnosed with increasing frequency, covering a vast spectrum from benign to malignant and invasive lesions. Numerous investigations can be done to discriminate between benign and non-evolutive lesions from those that require surgery. At the moment, there is no single test that will allow a correct diagnosis in all cases. Endoscopic ultrasound (EUS) morphology, cyst fluid analysis and cytohistology with EUS-guided fine needle aspiration can aid in this difficult diagnosis.