Diagnosis and management of cystic neoplasms of the pancreas: an evidence-based approach. J Am Coll Surg. 2008;207:106-120. [PMID: 18589369 DOI: 10.1016/j.jamcollsurg.2007.12.048]

Towards a Simplified and Cost-Effective Diagnostic Algorithm for the Surveillance of Intraductal Papillary Mucinous Neoplasms (IPMNs): Can We Save Contrast for Later?

The increased detection of pancreatic cysts in recent years has triggered extensive diagnostic investigations to clarify their potential risk of malignancy, resulting in a large number of patients undergoing numerous imaging follow-up studies for many years. Therefore, there is a growing need for optimization of the current surveillance protocol to reduce both healthcare costs and waiting lists, while still maintaining appropriate sensibility and specificity. Imaging is an essential tool for evaluating patients with intraductal papillary mucinous neoplasms (IPMNs) since it can assess several predictors for malignancy and thus guide further management recommendations. Although contrast-enhanced magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography (MRCP) has been widely recommended by most international guidelines, recent results support the use of unenhanced abbreviated-MRI (A-MRI) protocols as a surveillance tool in patients with IPMN. In fact, A-MRI has shown high diagnostic performance in malignant detection, with high sensitivity and specificity as well as excellent interobserver agreement. The aim of this paper is, therefore, to discuss the current available evidence on whether the implementation of an abbreviated-MRI (A-MRI) protocol for cystic pancreatic lesion surveillance could improve healthcare economics and reduce waiting lists in clinical practice without significantly reducing diagnostic accuracy.

One size does not fit all for pancreatic cancers: A review on rare histologies and therapeutic approaches

Exocrine pancreatic neoplasms represent up to 95% of pancreatic cancers (PCs) and are widely recognized among the most lethal solid cancers, with a very poor 5-year survival rate of 5%-10%. The remaining < 5% of PCs are neuroendocrine tumors that are usually characterized by a better prognosis, with a median overall survival of 3.6 years. The most common type of PC is pancreatic ductal adenocarcinoma (PDAC), which accounts for roughly 85% of all exocrine PCs. However up to 10% of exocrine PCs have rare histotypes, which are still poorly understood. These subtypes can be distinguished from PDAC in terms of pathology, imaging, clinical presentation and prognosis. Additionally, due to their rarity, any knowledge regarding these specific histotypes is mostly based on case reports and a small series of retrospective analyses. Therefore, treatment strategies are generally deduced from those used for PDAC, even if these patients are often excluded or not clearly represented in clinical trials for PDAC. For these reasons, it is essential to collect as much information as possible on the management of PC, as assimilating it with PDAC may lead to the potential mistreatment of these patients. Here, we report the most significant literature regarding the epidemiology, typical presentation, possible treatment strategies, and prognosis of the most relevant histotypes among rare PCs.

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.

Diagnosis and management of pancreatic cystic neoplasms

This review outlines the current classification of pancreatic cystic lesions, with a particular emphasis on pancreatic cystic neoplasms (PCNs). It will describe the diagnostic approach to PCNs, with reference to clinicopathological features, cross-sectional radiology and endoscopic ultrasound. This review will conclude with an evidence-based discussion of the management of PCNs focused on recent clinical guidelines.

Tumor Markers in Pancreatic Cystic Fluids for Diagnosis of Malignant Cysts

Background and aim

Early diagnosis of premalignant or malignant pancreatic cysts is essential to improve prognosis. Sampling of pancreatic cyst fluid by fine-needle aspiration during endoscopic ultrasonography (EUS) enables cytopathological examination combined with biochemical analysis. This study aimed to provide an aid based on biological markers for the preoperative management of patients with pancreatic cysts.

Methods

Pancreatic fluids obtained by EUS-guided fine-needle aspiration from 115 patients with cystic lesions were assayed for amylase, lipase, carcinoembryonic antigen (CEA), CA 19-9 and CA 72-4. In addition, chromogranin A (CgA) and neuron-specific enolase (NSE) were measured in 28 fluid samples.

Results

ROC curve analysis of the different markers for diagnosis of mucinous cysts showed that CEA had the highest area under the curve (0.93, 95% CI 0.87-0.97), with a sensitivity and specificity of 89% and 93%, respectively, at the cutoff value of 317 μg/L. The CgA and NSE concentrations in 5 NET cysts (median values of 210 [63-492] and 68.5 [9-496] μg/L, respectively) were higher than in 23 other cysts (median values of 8 [7-828] and 2.7 [0.5-35.8] μg/L, respectively) (p = 0.0015 and p = 0.0045, respectively).

Conclusions

CEA is the best marker for identifying a cyst as mucinous. In case of low levels of CEA, our results suggest that CgA and NSE measurements may be helpful in the diagnosis of a neuroendocrine tumor and therefore deserve further investigation.

Surgical Management of Pancreatic Cysts: A Shifting Paradigm Toward Selective Resection

Due to the widespread use of high-quality cross-sectional imaging, pancreatic cystic neoplasms are being diagnosed with increasing frequency. Clinicians are therefore asked to counsel a growing number of patients with pancreatic cysts diagnosed incidentally at an early, asymptomatic stage. Over the last two decades, accumulating knowledge on the biologic behavior of these neoplasms along with improved diagnostics through imaging and endoscopic cyst fluid analysis have allowed for a selective therapeutic approach toward these neoplasms. On one end of the management spectrum, observation is recommended for typically benign lesions (serous cystadenoma), and on the other end, upfront resection is recommended for likely malignant lesions (main duct IPMN, mucinous cystadenoma, solid pseudopapillary tumor, and cystic pancreatic neuroendocrine tumors). In between, management of premalignant lesions (branch duct IPMN) is dictated by the presence of high-risk features. In general, resection should be considered whenever the risk of malignancy is higher than the risk of the operation. This review aims to describe the evolution and current status of evidence guiding the selection of patients with pancreatic cystic neoplasms for surgical resection, along with a specific discussion on the type of resection required and expected outcomes.

Therapeutic Approach to Cystic Neoplasms of the Pancreas

Management of cystic neoplasms of the pancreas is challenging as it relies on radiologic and cyst fluid markers to discriminate between benign and pre-cancerous lesions, however their ability to predict malignancy is limited. While asymptomatic serous cystadenomas can be managed conservatively, mucinous cystic neoplasms and intraductal papillary mucinous neoplasms are more difficult to manage. A selective approach, based on the preoperative likelihood of high-grade dysplasia or invasive disease, is the standard of care. Research is focusing on the development of pre-operative markers for identifying high risk lesions, which will spare patients with low-risk or benign lesions the risks of pancreatectomy.

Acinar cell cystadenoma of the pancreas: A retrospective analysis of ten-year experience from a single academic institution

BACKGROUND/OBJECTIVE

Acinar cell cystadenoma (ACA), also referred to as "acinar cystic transformation", is a rare and newly recognized cystic lesion of the pancreas displaying apparent acinar cell differentiation with benign outcomes. We summarized our experience with the diagnosis, clinicopathologic feature, treatment and prognosis of ACA to provide a reference for the disposal of this uncommon condition.

METHODS

We retrospectively analyzed the clinical data from eight patients with ACA treated in our hospital between March, 2005 and January, 2015.

RESULTS

Among eight patients, five of whom were female and the age at diagnosis ranged from 33 to 67 years (mean, 49.8 y). The most commonly clinical symptom was abdominal pain. Eight lesions were unifocal and either unilocular (n = 5) or multilocular (n = 3) with average size of 10.5 cm (range, 5.1-19.7 cm). All the patients were treated surgically and a definite diagnosis of ACA was obtained by the histopathological, histochemical and immunohistochemical tests. The length of stay range was from 11 to 17 days and there were no perioperative deaths. At a median follow-up of 57.3 months, all the patients were alive and there was no evidence of recurrence, distant metastasis or malignant transformation.

CONCLUSIONS

Appropriately preoperative differential diagnosis of ACA remains challenging and the final result is usually gained by the histopathology and immunohistochemistry. Although the origin of ACA is still contradictory, surgery is actively advocated as the most effective method for relieving the symptoms and preventing the tumor from local extension or malignant transformation so as to obtain an optimal long-term survival.

Which is the best current guideline for the diagnosis and management of cystic pancreatic neoplasms? An appraisal using evidence-based practice methods

BACKGROUND AND AIM

Cystic pancreatic neoplasms (CPNs) are an increasingly diagnosed entity. Their heterogeneity poses complex diagnostic and management challenges. Despite frequently encountering these entities, particularly in the context of the increased imaging of patients in modern medicine, doctors have to rely on incomplete and ambiguous published literature. The aim of this project was to review the guidelines relating to CPNs using evidence-based practice (EBP) methods.

METHODS

A search of both the primary and secondary literature was performed. Five sets of guidelines were identified which were then methodologically appraised by the AGREE II instrument, a validated and widely utilised tool for guideline development assessment.

RESULTS

The 2014 'Italian consensus guidelines for the diagnostic work-up and follow-up of cystic pancreatic neoplasms' were found to be the most methodologically sound guidelines, on the basis of both the overall score and average weighted domain score.

CONCLUSIONS

The current best guidelines were identified. The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument can be used for retrospective review of published guidelines or as a roadmap for guideline-writing groups. All guidelines found were methodologically limited. Further longitudinal/prospective studies are required to improve the level of evidence.

KEY POINTS

• Cystic pancreatic neoplasms (CPNs) are an increasingly encountered entity in modern medicine. • Clinical uncertainty remains with regard to optimal diagnostic and management strategies. • The Italian consensus guidelines for cystic pancreatic neoplasms are currently the best guidelines.

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.

Pancreatic mucinous cystadenoma with serum CA 19-9 over 1,000,000 U/mL: a case report and review of the literature

BACKGROUND

The diagnosis of pancreatic cystic neoplasms has become more accurate recently. In some cases, however, doubt remains regarding the lesion's malignant potential. CA 19-9 has long been identified as a reliable biomarker in differentiating pancreatic benign and malignant lesions, especially in non-jaundiced patients.

CASE REPORT AND DISCUSSION

We report a case of a young female who presented with a mucinous lesion in the tail of the pancreas and a serum CA 19-9 over 1,000,000 U/mL. She was taken to surgery and had a distal pancreatectomy and splenectomy. Pathology reports showed only a mucinous cystadenoma. After 1 year of follow-up, her serum CA 19-9 was normal. Following that, the work-up in these lesions, the role of the biomarker in pancreatic adenocarcinoma and in the differentiation between benign and malignant lesions is discussed.

Treatment of pancreatic cystic neoplasm: surgery or conservative?

Pancreatic cystic neoplasms (PCNs) are a heterogeneous group of tumors with distinct biological features. These neoplasms are now being recognized more frequently owing to advances in cross-sectional imaging and increasing awareness. Guidelines for treatment of the common and clinically important PCNs frequently have been revised in view of the continuing controversies and evolving clinical data. This review summarizes the management approaches of the common and clinically important PCNs based on current evidence and guidelines.

European experts consensus statement on cystic tumours of the pancreas

Cystic lesions of the pancreas are increasingly recognized. While some lesions show benign behaviour (serous cystic neoplasm), others have an unequivocal malignant potential (mucinous cystic neoplasm, branch- and main duct intraductal papillary mucinous neoplasm and solid pseudo-papillary neoplasm). European expert pancreatologists provide updated recommendations: diagnostic computerized tomography and/or magnetic resonance imaging are indicated in all patients with cystic lesion of the pancreas. Endoscopic ultrasound with cyst fluid analysis may be used but there is no evidence to suggest this as a routine diagnostic method. The role of pancreatoscopy remains to be established. Resection should be considered in all symptomatic lesions, in mucinous cystic neoplasm, main duct intraductal papillary mucinous neoplasm and solid pseudo-papillary neoplasm as well as in branch duct intraductal papillary mucinous neoplasm with mural nodules, dilated main pancreatic duct >6mm and possibly if rapidly increasing in size. An oncological partial resection should be performed in main duct intraductal papillary mucinous neoplasm and in lesions with a suspicion of malignancy, otherwise organ preserving procedures may be considered. Frozen section of the transection margin in intraductal papillary mucinous neoplasm is suggested. Follow up after resection is recommended for intraductal papillary mucinous neoplasm, solid pseudo-papillary neoplasm and invasive cancer.

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.

Mucinous cystic neoplasms of the pancreas with ovarian stroma

BACKGROUNDS

Mucinous cystic neoplasms (MCNs) of the pancreas are rare, but have recently been increasing in incidence. The aim of this retrospective clinical study was to elucidate the clinicopathological features and prognosis of MCNs with ovarian stroma at a single centre.

METHODS

Using the presence of ovarian stroma as a requisite criterion for diagnosis of MCNs, the medical records of 47 surgically treated patients with MCNs from January 2004 to April 2011 were reviewed and classified according to the new 2010 World Health Organization classification.

RESULTS

Included were 37 cases of low-grade (78.7%), 4 intermediate-grade (8.5%) and 1 high-grade dysplasia (8.5%), and 5 cases of invasive carcinomas (10.6%). Patients were exclusively women (91.5%) with a mean age of 48.5 years. Most tumours were in the pancreatic body/tail (89.4%) with a mean size of 5.24 cm. More than half were asymptomatic. Findings associated with malignancy were presence of mural nodules (P < 0.001) and cyst wall calcifications (P = 0.017). All invasive MCNs were ≥5.0 cm or had mural nodules. No lymph node metastasis was seen in 20 cases of lymph nodes dissected. None of the 42 patients with non-invasive MCNs recurred after a mean follow-up of 25 months. However, two of five patients with invasive MCNs recurred, and one died within 2 years.

CONCLUSIONS

The prognosis of the resected non-invasive MCNs was excellent. Although resection should be considered for all cases, in low-risk MCNs (<5 cm and without nodules), nonradical resections (i.e. enucleations) are appropriate.

Primary pancreatic cystic neoplasms of the pancreas revisited. Part IV: rare cystic neoplasms

Primary pancreatic cystic neoplasms are being recognized with increasing frequency due to modern imaging techniques. In addition to the more common cystic neoplasms-serous cystadenoma, primary mucinous cystic neoplasm, and intraductal papillary mucinous neoplasm-there are many other less common neoplasms that appear as cystic lesions. These cystic neoplasms include solid pseudopapillary neoplasm of the pancreas (the most common rare cystic neoplasm), cystic neuroendocrine neoplasm, cystic degeneration of otherwise solid neoplasms, and then the exceedingly rare cystic acinar cell neoplasm, intraductal tubular neoplasm, angiomatous neoplasm, lymphoepithelial cysts (not true neoplasms), and few others of mesenchymal origin. While quite rare, the pancreatic surgeon should at the least consider these unusual neoplasms in the differential diagnosis of potentially benign or malignant cystic lesions of the pancreas. Moreover, each of these unusual neoplasms has their own natural history/tumor biology and may require a different level of operative aggressiveness to obtain the optimal outcome.

MicroRNA dissects out dangerous pancreatic cysts from all the rest

Malignant transformation of pancreatic cysts occurs in only a fraction of patients. The diagnostic dilemma is identifying which cysts pose a cancerous threat. Cyst fluid has been analyzed in a variety of ways to answer this question but the microRNA (miRNA) profile of the fluid may finally hold the answer.

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).

Whole-exome sequencing of neoplastic cysts of the pancreas reveals recurrent mutations in components of ubiquitin-dependent pathways

More than 2% of adults harbor a pancreatic cyst, a subset of which progresses to invasive lesions with lethal consequences. To assess the genomic landscapes of neoplastic cysts of the pancreas, we determined the exomic sequences of DNA from the neoplastic epithelium of eight surgically resected cysts of each of the major neoplastic cyst types: serous cystadenomas (SCAs), intraductal papillary mucinous neoplasms (IPMNs), mucinous cystic neoplasms (MCNs), and solid pseudopapillary neoplasms (SPNs). SPNs are low-grade malignancies, and IPMNs and MCNs, but not SCAs, have the capacity to progress to cancer. We found that SCAs, IPMNs, MCNs, and SPNs contained 10 ± 4.6, 27 ± 12, 16 ± 7.6, and 2.9 ± 2.1 somatic mutations per tumor, respectively. Among the mutations identified, E3 ubiquitin ligase components were of particular note. Four of the eight SCAs contained mutations of the von Hippel-Lindau gene (VHL), a key component of the VHL ubiquitin ligase complex that has previously been associated with renal cell carcinomas, SCAs, and other neoplasms. Six of the eight IPMNs and three of the eight MCNs harbored mutations of RNF43, a gene coding for a protein with intrinsic E3 ubiquitin ligase activity that has not previously been found to be genetically altered in any human cancer. The preponderance of inactivating mutations in RNF43 unequivocally establish it as a suppressor of both IPMNs and MCNs. SPNs contained remarkably few genetic alterations but always contained mutations of CTNNB1, previously demonstrated to inhibit degradation of the encoded protein (β-catenin) by E3 ubiquitin ligases. These results highlight the essential role of ubiquitin ligases in these neoplasms and have important implications for the diagnosis and treatment of patients with cystic tumors.

Incidental pancreatic cysts on 3D turbo spin echo magnetic resonance cholangiopancreatography: prevalence and relation with clinical and imaging features

PURPOSE

To estimate the prevalence of incidental pancreatic cysts (IPCs) in asymptomatic patients addressed to magnetic resonance cholangiopancreatography (MRCP), and to correlate it with clinical and imaging features.

MATERIALS AND METHODS

Magnetic resonance cholangiopancreatography performed over 26-months on 152 patients with unsuspected/unknown pancreatic disease were reviewed to assess IPCs' features of presentation. Multivariate analysis was performed to evaluate the correlation of IPCs with clinical information and type of pancreaticobiliary findings at MRCP.

RESULTS

Prevalence of IPCs was 44.7%. Cysts sized 3-24 mm (mean, 6.08 mm), and were ≤4 in number in 83.8% of patients. Based on number, dimensions and relation with the main pancreatic duct, IPCs presented with intraductal-papillary-mucinous neoplasm (IPMN)-like or indeterminate patterns in 31.7% and 13.1% of patients, respectively. At follow-up on 24 patients, no evolution was found, except in one patient with proven IPMN showing increase in cysts number and dimensions (evolution rate of 4.1%). Features correlating with IPCs were age ≥60 years old, and history of autoimmune hepatobiliary disease, showing odds ratios of 5.95 (95% CI 2.77-12.79) and 0.13 (95% CI 0.04-0.44), respectively.

CONCLUSIONS

Incidental pancreatic cysts represent a frequent finding at MRCP, correlating positively with increasing age, and negatively with biliary autoimmune disease. Cysts more frequently present with IPMN-like pattern.

Recurrent GNAS mutations define an unexpected pathway for pancreatic cyst development

More than 2% of the adult U.S. population harbors a pancreatic cyst. These often pose a difficult management problem because conventional criteria cannot always distinguish cysts with malignant potential from those that are innocuous. One of the most common cystic neoplasms of the pancreas, and a bona fide precursor to invasive adenocarcinoma, is called intraductal papillary mucinous neoplasm (IPMN). To help reveal the pathogenesis of these lesions, we purified the DNA from IPMN cyst fluids from 19 patients and searched for mutations in 169 genes commonly altered in human cancers. In addition to the expected KRAS mutations, we identified recurrent mutations at codon 201 of GNAS. A larger number (113) of additional IPMNs were then analyzed to determine the prevalence of KRAS and GNAS mutations. In total, we found that GNAS mutations were present in 66% of IPMNs and that either KRAS or GNAS mutations could be identified in 96%. In eight cases, we could investigate invasive adenocarcinomas that developed in association with IPMNs containing GNAS mutations. In seven of these eight cases, the GNAS mutations present in the IPMNs were also found in the invasive lesion. GNAS mutations were not found in other types of cystic neoplasms of the pancreas or in invasive adenocarcinomas not associated with IPMNs. In addition to defining a new pathway for pancreatic neoplasia, these data suggest that GNAS mutations can inform the diagnosis and management of patients with cystic pancreatic lesions.

Pancreatic Cystic Lesions of Nonmucinous Type

Cystic lesions of nonmucinous type can arise within the pancreas or can develop from adjacent structures and appear to involve the pancreas. In addition, some typically solid masses can become cystic or can present as cystic lesions. Nonmucinous cysts can be neoplastic, inflammatory, reactive, or congenital. The vast majority of neoplastic nonmucinous cysts are benign. Because of the difficulty in determining the neoplastic potential of a pancreatic cyst preoperatively, many non-neoplastic cysts are resected. This article reviews the surgical pathology of nonmucinous cysts.

Primary pancreatic cystic neoplasms revisited. Part III. Intraductal papillary mucinous neoplasms

Intraductal papillary mucinous neoplasms (IPMNs) represent about 25% of all primary pancreatic cystic neoplasms and are increasingly recognized during the last two decades. They are characterized by intraductal proliferation of neoplastic mucinous cells forming papillary projections into the pancreatic ductal system, which is typically dilated and contains globules of mucus. IPMNs may be multifocal and have malignant potential. Modern imaging is essential in establishing preoperative diagnosis and in differentiating different subtypes of IPMNs (i.e., main-duct vs. branch-type disease). Endoscopic retrograde or magnetic resonance cholangiopancreatography accurately delineate the morphologic changes of the pancreatic ductal system. Endoscopic ultrasonography (usually used in conjunction with image-guided FNA and analysis of the aspirated material) is commonly used for differential diagnosis of IPMNs from other pancreatic cystic lesions. Surgical resection (usually anatomic pancreatectomy, depending on the location of the disease) is the treatment of choice. Total pancreatectomy may occasionally be required in selected patients, but is associated with formidable long-term morbidity. A conservative approach has recently been proposed for carefully selected patients with branch-duct IPMNs. Recurrences following surgical resection can be observed, especially in patients with multifocal disease or in the presence of underlying malignancy.

Primary pancreatic cystic neoplasms revisited: part II. Mucinous cystic neoplasms

Mucinous cystic neoplasms (MCNs) of the pancreas represent one of the most common primary pancreatic cystic neoplasms, accounting for approximately half of these cases. MCNs are observed almost exclusively in women, and most commonly are located in the body/tail of the pancreas. In contrast to SCNs, MCNs have malignant potential. Proliferative changes (hyperplasia with or without atypia, borderline changes, non-invasive or carcinomas in-situ, and invasive carcinomas) can often be observed within the same neoplasm. Several risk factors for the presence of underlying malignancy within an MCN have recently been recognized. Cross-sectional imaging is of key importance for the diagnostic evaluation of patients with a cystic pancreatic lesion. Cyst fluid examination (cytology, biochemical/genetic analysis) is possible by using fine needle aspiration of the MCN, usually under endoscopic guidance, and may provide useful information for the differential diagnosis. Since MCNs have malignant potential, surgical resection is the treatment of choice.

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

Primary pancreatic cystic neoplasms have been recognized increasingly during the two recent decades and include mainly serous cystic neoplasms, mucinous cystic neoplasms, and intraductal papillary mucinous neoplasms. Serous cystic neoplasms represent about 30% of all cystic neoplasms of the pancreas and are characterized by their microcystic appearance (on imaging, macroscopically, and microscopically) and their benign biologic behavior. Modern diagnostic methodology allows the preoperative diagnosis with an acceptable accuracy. Currently, indications for resection of serous cystic neoplasms of the pancreas include the presence of symptoms, size > 4 cm (because these 'large' neoplasms have a more rapid growth rate and probably will soon become symptomatic), and any uncertainty about the diagnosis of a serous versus a mucinous cystic neoplasm. Resection should also be considered for lesions in the body/tail of the pancreas. Conservative treatment is a reasonable option in selected patients (for example in the presence of small, asymptomatic lesions in the pancreatic head, especially in the frail or elderly patient).

Intraductal papillary mucinous neoplasms of the pancreas: diagnosis and management

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

Multidisciplinary management strategy for incidental cystic lesions of the pancreas

BACKGROUND

At our institution, incidental pancreatic cysts are frequently identified in asymptomatic patients undergoing routine imaging for staging of nonpancreatic malignancies. Management of these patients is unclear because a small but significant number of incidental pancreatic cysts are malignant.

STUDY DESIGN

Our institutional database was reviewed for patients with ICD-9 codes for pancreatic cysts from 1980 to 2005. Clinicopathologic factors, including CT and endoscopic ultrasound (EUS) characteristics and management strategies, were analyzed.

RESULTS

Over 25 years, 942 patients were identified with pancreatic cysts. Excluding those with symptoms or pseudocysts, 350 patients remained with incidental pancreatic cysts. Mean overall survival was 41.4 months (mean follow-up 32.7 months). Forty-one patients underwent resection, of whom 38 (92.7%) had premalignant or malignant pathology. Univariate analysis of variables predicting pathologic premalignant or malignant diagnosis identified pancreatic neck or body location as significant factors.

CONCLUSIONS

These data suggest that most incidental pancreatic cysts can be managed nonoperatively using a selective strategy based on detailed review of CT imaging and EUS findings.

Surgical treatment of cystic neoplasms of the pancreas

CONTEXT: Diagnosis and treatment of cystic neoplasms of the pancreas increased significantly in the last decades. There are only a few Brazilian publications on these tumors. The majority of them are limited to reports of one or few cases. OBJECTIVE: To present our experience with 27 patients with cystic neoplasms of the pancreas. METHODS: Demographic data, clinical manifestations, diagnostic exams, surgical procedures, postoperative complications, and follow-up data of 27 patients with cystic neoplasms of the pancreas were analyzed, according to the histological type of the tumor. RESULTS: There were 10 (37%) serous cystic tumors, 10 (37%) mucinous cystic tumors, 4 (15%) intraductal papillary mucinous tumors, and 3 (11%) solid pseudopapillary tumors or Frantz tumor. All serous cystic tumors, 6 (60%) mucinous tumors, 2 (50%) intraductal papillary mucinous tumors, and 2 (67%) solid pseudopapillary tumors were benign. The age of the patients varied from 31 to 82 years and all tumors were more common in female. Two patients had been treated previously as a pseudocyst. Surgical procedures depended on the location and extension of the tumor. Two patients underwent only laparotomy with tumor biopsy, one cholecystectomy with Roux-en-Y hepaticojejunostomy for jaundice treatment, 6 pancreatoduodenectomy, and 18 partial pancreatectomy. The most common postoperative complication was pancreatic fistula (n = 5; 19%). One patient died of necrotic pancreatitis. Of the 10 patients with serous cystic tumor, only 1 had tumor recurrence at the section border. The three patients with mucinous cystoadenocarcinoma in which was not possible to resect the tumor, died 6 to 24 months after laparotomy. The six patients with benign mucinous tumors did not have tumor recurrence. CONCLUSIONS: The most common cystic neoplasms of the pancreas are serous and mucinous cysts. These tumors are more frequent in female. Although almost all serous cysts are benign, 40% of mucinous cysts are malign. Misdiagnosis may delay appropriate treatment and increase mortality.

Cystic neoplasms of the pancreas

Cystic neoplasms of the pancreas are a heterogeneous group of pancreatic tumors that vary in pathophysiology, malignant potential, clinical course, and outcomes. Their management is heavily predicated on establishing an accurate diagnosis. This can be particularly challenging, but can often be achieved by a thorough history and physical examination combined with high-quality, thin-slice computed tomography, although additional diagnostic tools may be required. Once the diagnosis is established, treatment can range from simple observation to total pancreatectomy. This decision rests on a clear and complete understanding of each disease process in the context of the patient's age and comorbidities. This article reviews the most common cystic neoplasms of the pancreas, focusing on their diagnosis and management.

The Role of Endoscopy in the Management of Cystic Pancreatic Lesions

Pancreatic cystic lesions may be due to pseudocysts and related inflammatory fluid collections, simple cysts, cystic tumours such as serous cystadenoma, mucinous cystic neoplasm and intraductal papillary mucinous neoplasm, as well as solid tumours with areas of cystic degeneration. The main diagnostic challenge is to distinguish premalignant and malignant cystic lesions from benign cystic lesions. Cross-sectional imaging using computer tomography and magnetic resonance imaging/ magnetic resonance cholangiopancreatography provides the initial morphological characterization. Endoscopic ultrasound (EUS) is an important tool when diagnostic doubts persist and is crucial in the assessment of invasive malignancy. EUS-guided fine needle aspiration and cyst fluid analysis has been shown to be cost-effective for risk stratifying the malignant potential of cystic tumours and the need for surgical resection. In the management of symptomatic pseudocysts and related fluid collections, endoscopic drainage has been established as the preferred technique, with efficacy similar to surgery but lower costs and morbidity.

Clinical factors predictive of malignant and premalignant cystic neoplasms of the pancreas: a single institution experience

BACKGROUND

As cystic neoplasms of the pancreas are discovered with advanced imaging techniques, pancreatic surgeons often struggle with identifying who is at risk of having or developing pancreatic cancer. We sought to review our experience with the surgical management of cystic neoplasms of the pancreas to determine pre-operative clinical indicators of malignancy or premalignant (i.e. mucinous) lesions.

METHODS

Between 1996 and 2007, 114 consecutive patients with cystic neoplasms of the pancreas underwent a pancreatectomy. Invasive adenocarcinoma was identified in 35 whereas 79 had benign lesions. Mucinous lesions were considered premalignant and consisted of 29 intraductal papillary mucinous neoplasms (IPMN) and 17 mucinous cystic neoplasms (MCN). The remaining 33 benign lesions were serous microcystic adenomas. Descriptive statistics were calculated and multivariate logistic regression was performed. Receiver-operating characteristic (ROC) curves were constructed for continuous variables and the area under the curves compared. Likelihood ratios were calculated from the combinations of predictors.

RESULTS

Patients with pancreatic cancer arising from a cystic neoplasm were older than those with benign cysts. Mucinous lesions with or without associated cancer were more likely to be symptomatic and present with elevated serum carbohydrate antigen (CA)19-9 levels. Cancers more commonly presented in the head of the pancreas and were associated with longer hospitalizations after resection. Using multivariate logistic regression, size and elevated CA19-9 were predictors of malignancy whereas male gender and size were predictors of mucinous lesions with or without malignancy. Size, however, was not an accurate test to determine premalignant or malignant lesions using area under the ROC curve analysis whereas CA19-9 performed the best regardless of gender or lesion location.

CONCLUSIONS

Based upon our single institution experience with resection of cystic neoplasms of the pancreas, we advocate an aggressive surgical approach to any patient with a cystic neoplasm of the pancreas and associated elevated CA19-9.

Multidisciplinary approach to tumors of the pancreas and biliary tree

Tumors of the pancreas and biliary tree remain formidable challenges to patients and clinicians. These tumors elude early detection, rapidly spread locally and systemically, and frequently recur despite apparently complete resection. Cystic tumors of the pancreas, however, may represent a subset of patients who do not uniformly require aggressive resection, and a thoughtful, evidence-based approach to work-up allows for the rational application of surgical therapy. Increasing evidence supports treating patients who have pancreaticobiliary disease in a multidisciplinary setting.

Cystic pancreatic lesions: a simple imaging-based classification system for guiding management

Cystic lesions of the pancreas are increasingly being recognized due to the widespread use of cross-sectional imaging. The initial evaluation of a pancreatic cyst should be directed toward exclusion of a pseudocyst. Patients with pseudocysts generally have a history of acute or chronic pancreatitis, whereas those with cystic tumors most often lack such a history. Several types of cystic lesions are encountered in the pancreas. Because of morphologic overlap at imaging, accurate characterization of these lesions can be difficult. Computed tomography and magnetic resonance imaging are excellent modalities for both initial detection and characterization of cystic pancreatic lesions. An imaging classification system for these lesions has been proposed that is based on the morphologic features of the lesion. This system can be helpful in characterizing lesions, narrowing the differential diagnosis, and making decisions regarding the treatment of affected patients. Endoscopic ultrasonography-guided aspiration and biopsy is useful in cases that are indeterminate at cross-sectional imaging or that require observation.