Incidentally detected cystic lesions of the pancreas on CT: review of literature and management suggestions

Comparative accuracy of four guidelines to predict high-grade dysplasia or malignancy in surgically resected pancreatic intraductal papillary mucinous neoplasms: Small nuances between guidelines lead to vastly different results

Backgrounds/Aims

The guidelines regarding the management of intraductal papillary mucinous neoplasms (IPMNs) all have slightly different surgical indications for high-risk lesions. We aim to retrospectively compare the accuracy of four guidelines in recommending surgery for high-risk IPMNs, and assess the accuracy of elevated CA-19-9 levels and imaging characteristics of IPMNs considered high-risk in predicting malignancy or high-grade dysplasia (HGD).

Methods

The final histopathological diagnosis of surgically resected high-risk IPMNs during 2013-2020 were compared to preoperative surgical indications, as enumerated in four guidelines: the 2015 American Gastroenterological Association (AGA), 2017 International Consensus, 2018 European Study Group, and 2018 American College of Gastroenterology (ACG). Surgery was considered "justified" if histopathology of the surgical specimen showed HGD/malignancy, or there was postoperative symptomatic improvement.

Results

Surgery was postoperatively justified in 26/65 (40.0%) cases. All IPMNs with HGD/malignancy were detected by the 2018 ACG and the combined (absolute and relative criteria) 2018 European guidelines. The combined ("high-risk stigmata" and "worrisome features") 2017 International guideline missed 1/19 (5.3%) IPMNs with HGD/malignancy. The 2015 AGA guideline missed the most cases (11/19, 57.9%) of IPMNs with HGD/malignancy. We found the features most-associated with HGD/malignancy were pancreatic ductal dilation, and elevated CA-19-9 levels.

Conclusions

Following the 2015 AGA guideline results in the highest rate of missed HGD/malignancy, but the lowest rate of operating on IPMNs without these features; meanwhile, the 2018 ACG and the combined (absolute and relative criteria) 2018 European guidelines result in more operations for IPMNs without HGD/malignancy, but the lowest rates of missed HGD/malignancy in IPMNs.

Cinematic rendering of solid pseudopapillary tumors: Augmenting diagnostics of an increasingly encountered tumor

Pancreatic solid pseudopapillary tumors (SPTs) are a rare subset of pancreatic neoplasms, accounting for under 2 % of exocrine pancreatic tumors. The incidence of SPTs has shown a significant increase in the past two decades, attributed to heightened cross-sectional imaging utilization. These tumors often present with nonspecific clinical symptoms, making imaging a crucial tool in their detection and diagnosis. Cinematic rendering (CR) is an advanced 3D post-processing technique that generates highly photorealistic realistic images by accurately modeling the interaction of light within the imaged volume. This allows improved visualization of anatomic structures which holds potential to improve diagnostics. In this manuscript we present the first description of CR appearances of SPTs in the reported literature. Through showcasing a range of cases, we highlight the potential of CR in illustrating the diverse imaging characteristics of these unique neoplasms.

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.

Addressing the unmet clinical need for low-volume assays in early diagnosis of pancreatic cancer

The incidental detection of pancreatic cysts, an opportunity for the early detection of pancreatic cancer, is increasing, owing to an aging population and improvements in imaging technology. The classification of pancreatic cystic precursors currently relies on imaging and cyst fluid evaluations, including cytology and protein and genomic analyses. However, there are persistent limitations that obstruct the accuracy and quality of information for clinicians, including the limited volume of the complex, often acellular, and proteinaceous milieu that comprises pancreatic cyst fluid. The constraints of currently available clinical assays lead clinicians to the subjective and inconsistent application of diagnostic tools, which can contribute to unnecessary surgery and missed pancreatic cancers. Herein, we describe the pathway toward pancreatic cyst classification and diagnosis, the volume requirements for several clinically available diagnostic tools, and some analytical and diagnostic limitations for each assay. We then discuss current and future work on novel markers and methods, and how to expand the utility of clinical pancreatic cyst fluid samples. Results of ongoing studies applying SERS as a detection mode suggest that 50 μL of pancreatic cyst fluid is more than sufficient to accurately rule out non-mucinous pancreatic cysts with no malignant potential from further evaluation. This process is expected to leave sufficient fluid to analyze a follow-up, rule-in panel of markers currently in development that can stratify grades of dysplasia in mucinous pancreatic cysts and improve clinical decision-making.

Machine learning in endoscopic ultrasonography and the pancreas: The new frontier?

Pancreatic diseases have a substantial burden on society which is predicted to increase further over the next decades. Endoscopic ultrasonography (EUS) remains the best available diagnostic method to assess the pancreas, however, there remains room for improvement. Artificial intelligence (AI) approaches have been adopted to assess pancreatic diseases for over a decade, but this methodology has recently reached a new era with the innovative machine learning algorithms which can process, recognize, and label endosonographic images. Our review provides a targeted summary of AI in EUS for pancreatic diseases. Included studies cover a wide spectrum of pancreatic diseases from pancreatic cystic lesions to pancreatic masses and diagnosis of pancreatic cancer, chronic pancreatitis, and autoimmune pancreatitis. For these, AI models seemed highly successful, although the results should be evaluated carefully as the tasks, datasets and models were greatly heterogenous. In addition to use in diagnostics, AI was also tested as a procedural real-time assistant for EUS-guided biopsy as well as recognition of standard pancreatic stations and labeling anatomical landmarks during routine examination. Studies thus far have suggested that the adoption of AI in pancreatic EUS is highly promising and further opportunities should be explored in the field.

A Rare Presentation of a Solid Pseudopapillary Neoplasm of the Pancreas

Solid pseudopapillary neoplasms (SPN) are rare and represent a minority of all pancreatic cystic tumors. Symptoms, if present, are generally nonspecific and upper gastrointestinal bleeding is extremely uncommon as an initial presentation. A 31-year-old woman with no prior medical history presented with a 3-week period of epigastric pain, which she reported as persistent, exacerbated by eating, and associated with progressive asthenia, fatigue, and exertional dyspnea. One month prior, she had had experienced 2 episodes of melena. Upon physical examination her skin was pale, with no other changes. Through diagnostic investigation, an esophagogastroduodenoscopy showed a giant ulcer in the duodenal bulb and a suspect fistulous orifice localized on the posterior wall of the duodenal bulb. In addition, a bulge on the duodenal bulb, suggestive of an extrinsic compression, was noticed. An abdominal computed tomography scan and magnetic resonance imaging showed a mixed solid and cystic lesion in the head of the pancreas in direct proximity to the duodenum, which contained an image compatible with a fistula. The patient successfully underwent pancreaticoduodenectomy. The histopathology, including microscopic analysis and immunohistochemistry, was consistent with an SPN of the pancreas. This case emphasizes that the evaluation of patients presenting with upper gastrointestinal bleeding due to a giant duodenal ulcer and an extrinsic mass effect noted on the duodenum should include cross-sectional images of the abdomen. In this case, the finding of a large well-encapsulated pancreatic solid and cystic mass on abdominal images was suggestive of a pancreatic neoplasm diagnosis, including an SPN.

Prevalence, Incidence, and Risk of Progression of Asymptomatic Pancreatic Cysts in Large Sample Real-world Data

OBJECTIVES

Using large-sample, real-world administrative claims data, we evaluated the prevalence of putatively asymptomatic pancreatic cysts, the historical growth in their incident diagnosis, and their risk of malignant progression.

METHODS

Data were sourced from IBM MarketScan administrative claims databases of more than 200 million patients. Period prevalence was assessed using 700,000 individuals without conditions that predispose to pancreatic cyst. The standardized cumulative incidence was compared with the cross-sectional abdominal imaging rate from 2010-2017. The risk of progression to pancreatic cancer for 14,279 newly diagnosed patients with a cyst was estimated using Kaplan-Meier analysis.

RESULTS

Standardized prevalence increased exponentially with age and was 1.84% (95% confidence interval, 1.80%-1.87%) for patients older than 45. Standardized incidence nearly doubled from 2010-2017 (6.3 to 11.4 per 10,000), whereas the imaging rate changed from only 8.0% to 9.4%. The cumulative risk of pancreatic cancer at 7 years was 3.0% (95% confidence interval, 2.4%-3.5%), increasing linearly (R2 = 0.991) with an annual progression risk of 0.47%.

CONCLUSIONS

Using large-sample data, we show a significant burden of asymptomatic pancreatic cysts, with an annual risk of progression to cancer of 0.47% for 7 years. Rapid growth in cyst diagnosis over the last decade far outpaced increases in the imaging rate.

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.

Preliminary evaluation of 18F-FDG-PET/MRI for differentiation of serous from nonserous pancreatic cystic neoplasms: a pilot study

OBJECTIVES

The aim of the study was to evaluate preliminary feasibility of 18F-FDG-PET/MRI in differentiation of pancreatic serous cystic neoplasms (SCNs) from non-SCNs.

METHODS

From August 2017 to June 2019, 10 patients (3 men, 7 women; mean age, 63 years) previously diagnosed with pancreatic cystic neoplasm underwent simultaneous 18F-FDG-PET/MRI prospectively on an integrated 3-Tesla hybrid PET/MRI scanner. PET images were analyzed visually and semiquantitatively measuring standardized uptake values (SUV) including lesion SUVmax and SUVmean, lesion to pancreas and lesion to liver SUVmax and SUVmean ratio independent of MRI diagnosis. The reference standard for lesion diagnosis was by MRI features and interval follow-up.

RESULTS

Visual assessment of PET images demonstrated uptake in 57% of SCNs. Lesion to liver SUVmax ratio of ≥0.5 showed the highest accuracy (90%) and area under the curve (0.9) followed by lesion SUVmax of ≥1.6 and lesion to pancreas SUVmax ratio of ≥0.77 for diagnosis of SCN. The sensitivity for lesion SUVmax of ≥1.6 was less than two other ones (71 versus 100%). All non-SCNs exhibited SUVmax value less than 1.6 while 33 and 66% demonstrated lesion to liver SUVmax ratio of >0.5 and lesion to pancreas SUVmax ratio of >0.77, respectively. PET/MRI specificity was 67, 100, 67 and 33% through lesion to liver SUVmax ratio, lesion SUVmax, lesion SUVmean and lesion to pancreas SUVmax ratio, respectively, for diagnosis of SCN.

CONCLUSION

Preliminary results show that PET/MRI utilization is promising for differentiation of pancreatic SCN from non-SCN lesions. This could reduce need for surveillance imaging or avoidance of unnecessary intervention in pancreatic cystic neoplasms with uncertain diagnoses.

Pancreatic cystic neoplasms: a review of current recommendations for surveillance and management

Pancreatic cystic neoplasms (PCN) comprise of a diverse array of pancreatic cysts, including intraductal papillary mucinous neoplasms (IPMN), mucinous cystic neoplasms (MCN), serous cystic neoplasms (SCN), cystic neuroendocrine tumors (cNET), and many others. Increasing use of cross-sectional imaging has resulted in greater numbers of PCNs discovered incidentally. The overall risk of malignancy is low, but can vary considerably between different classes of PCNs. Furthermore, many pancreatic cysts are indeterminate on imaging, and the inability to reliably predict the course of disease remains a challenge for radiologists. Due to the variability in disease course and a lack of high-quality studies on PCNs, there is no universal consensus when it comes to balancing optimal surveillance while avoiding the risk for overtreatment. Currently, there are three widely accepted international guidelines outlining guidelines for surveillance and management of PCNs: the American Gastroenterological Association (AGA) in 2015, the International Association of Pancreatology (IAP) last revised in 2017, and the European Study Group on Cystic Tumours of the Pancreas (European) last revised in 2018. In 2017, the American College of Radiology released its own comprehensive set of recommendations for managing indeterminate pancreatic cysts that are detected incidentally on CT or MRI. The purpose of this paper is to describe the key differences between the ACR recommendations and the aforementioned three sets of guidelines regarding cyst management, imaging surveillance, performance, and cost-effectiveness.

An abbreviated MRI protocol for surveillance of cystic pancreatic lesions

PURPOSE

Cystic pancreatic lesions (CPLs) are common and increasingly encountered in clinical radiology practice. The appropriate imaging surveillance strategy for lower-risk CPLs (branch duct-intraductal papillary mucinous neoplasms and indeterminant small cystic lesions) has been a topic of intense study and debate in recent years. MRI is considered the investigation of choice for initial characterisation and follow-up of CPLs. Follow-up intervals for CPLs vary from 6 months to 2 years and surveillance may be lifelong or until the patient is no longer considered fit for potential surgical intervention. This creates a significant burden on MRI resources as a standard protocol pancreatic MRI may have an acquisition time of up to 35-50 min. However, the necessity of contrast-enhanced sequences and diffusion weighted imaging (DWI) for routine follow-up of CPLs has been questioned in recent years.

METHODS

We reviewed the available evidence to determine whether an abbreviated MRI (A-MRI) protocol may be safely adopted for surveillance of CPLs, as has been implemented in other clinical scenarios.

RESULTS

A number of recent retrospective studies have indicated that an A-MRI, omitting contrast-enhanced and DWI, may be used for CPL surveillance without any suspicious features or cases of malignancy being missed. Although small number of cases may need to be recalled for additional MR sequences based on the A-MRI findings, there is still a significant overall timesaving.

CONCLUSION

The best available evidence currently suggests that an A-MRI protocol should be considered for routine surveillance of CPLs. Prospective studies are required to ensure the findings reported in these retrospective case studies are backed up in ongoing clinical practice.

The faith of non-surveilled pancreatic cysts: a bicentric retrospective study

BACKGROUND

Incidental discovery of pancreatic cystic neoplasms (PCLs) is a common and steadily increasing occurrence. The aim of this study was to investigate a cohort of patients presenting with incidentally detected PCLs which were not included in a surveillance protocol, and to compare their risk of malignant evolution with that of systematically surveilled lesions.

MATERIALS AND METHODS

A population of PCLs which did not receive surveillance over a period >10 years (population A) was selected at the Medical University of Vienna. A group of "low risk" branch duct intraductal papillary mucinous neoplasm ≤15 mm in size upon diagnosis undergoing a regular follow-up of at least 5 years at the University of Verona was selected as control (population B). The incidence of pancreatic cancer (PC), cumulative risk of PC and disease-specific survival were compared.

RESULTS

Overall, 376 patients with non-surveilled PCLs were included in study group A and compared to 299 patients in group B. This comparison resulted in similar incidence rates of PC (1.6% vs 1.7%, p = 0.938), a strong similarity in terms of disease-specific mortality rates (1.3% vs 0.3%, p = 0.171) and the 5- and 10-year cumulative risk of PC (≅ 1% and 2%, p = 0.589) and DSS (≅ 100% and 98%, p = 0.050).

CONCLUSION

The "price to pay" for a negligence-based policy in the population of non-surveilled PCLs was reasonable, and the incidence of PC was comparable to that reported for a population of low-risk cysts enrolled to a standardized surveillance protocol.

ACR Appropriateness Criteria® Pancreatic Cyst

Incidental pancreatic cysts are increasingly detected on imaging studies performed for unrelated indications and may be incompletely characterized on these studies. Adequate morphological characterization is critical due to the small risk of malignant degeneration associated with neoplastic pancreatic cysts, as well as the risk of associated pancreatic adenocarcinoma. For all pancreatic cysts, both size and morphology determine management. Specifically, imaging detection of features, such as pancreatic ductal communication and presence or absence of worrisome features or high-risk stigmata, have important management implications. The recommendations in this publication determine the appropriate initial imaging study to further evaluate a pancreatic cyst that was incidentally detected on a nondedicated imaging study. The recommendations are designed to maximize the yield of diagnostic information in order to better risk-stratify pancreatic cysts and assist in guiding future management. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Abdominal Imaging of Pancreatic Cysts and Cyst-Associated Pancreatic Cancer in BRCA1/2 Mutation Carriers: A Retrospective Cross-Sectional Study

BACKGROUND

Direct-to-consumer BRCA testing will increase BRCA diagnoses and subsequent abdominal imaging. It is unclear whether BRCA carriers are at higher risk of developing pancreatic cysts (PCs) or cyst-associated pancreatic ductal adenocarcinoma (PDAC). We investigated the prevalence of PCs in BRCA-tested patients, and whether BRCA-carriers have higher rates of PDAC when PCs are found.

STUDY DESIGN

This is a retrospective cross-sectional study of patients with BRCA testing and abdominal imaging between 1996 and 2018. Pancreatic cysts were identified on original imaging reports. Prevalence and risk characteristics of PCs, as well as incidence of PDAC, were compared between BRCA+, BRCA-, and BRCA-untested patients.

RESULTS

Pancreatic cysts were identified in 4,045 patients among 128,164 unique patients with abdominal imaging, including 33 patients with PCs in 1,113 BRCA-tested patients. There was no difference in PC prevalence between BRCA+, BRCA-, and untested patients (3.6%, 2.6%, 3.2%, respectively; p = 0.64). Pancreatic cysts were diagnosed in BRCA+ patients at a younger age (57.1 vs 65.3 years, p < 0.001); however, there was no difference in risk stratification compared with BRCA- or untested patients by consensus criteria. Across the population of imaged patients, patients with PCs had significantly higher rates of PDAC compared with those without PCs (18.2% vs 2.4%, p < 0.001). Incidence of cyst-associated PDAC was similar in BRCA+ and BRCA- patients (13.3% vs 22.2%, p = 0.84).

CONCLUSIONS

BRCA+ patients have similar rates of PCs, high-risk features in their cysts, and PDAC as BRCA- and untested patients. BRCA+ patients likely do not require dedicated abdominal imaging to evaluate for PCs and should follow management guidelines similar to those as the untested general population if an incidental PC is identified.

Diagnosis and management of pancreatic cystic neoplasms: current evidence and guidelines

Pancreatic cystic neoplasms (PCN) are a heterogeneous group of pancreatic cysts that include intraductal papillary mucinous neoplasms, mucinous cystic neoplasms, serous cystic neoplasms and other rare cystic lesions, all with different biological behaviours and variable risk of progression to malignancy. As more pancreatic cysts are incidentally discovered on routine cross-sectional imaging, optimal surveillance for patients with PCN is becoming an increasingly common clinical problem, highlighting the need to balance cancer prevention with the risk of (surgical) overtreatment. This Review summarizes the latest developments in the diagnosis and management of PCN, including the quality of available evidence. Also discussed are the most important differences between the PCN guidelines from the American Gastroenterological Association, the International Association of Pancreatology and the European Study Group on Cystic Tumours of the Pancreas, including diagnostic and follow-up strategies and indications for surgery. Finally, new developments in the management of patients with PCN are addressed.

Evolution of Laparoscopic Pancreatic Resections for Pancreatic and Periampullary Diseases: Perioperative Outcomes of 605 Patients at a High-Volume Center

Background: Laparoscopic pancreatectomy (LP) is increasingly performed with several institutional series and comparative studies reported. We have applied LP to a variety of pancreatic resections since 2004. This article is to report results of 15-year practice of 605 LPs for pancreatic and periampullary diseases. Methods: Patients with benign or malignant diseases in the pancreas and periampullary region, who underwent LP from June 2004 to June 2018, were retrospectively reviewed. The demographics and indications, and intraoperative and perioperative outcomes were evaluated. Results: A total of 605 consecutive LPs were analyzed, including 237 (39.2%) distal pancreatectomy with splenectomy (DPS), 116 (19.2%) spleen-preserving distal pancreatectomy (SPDP), 30 (5.0%) enucleation (EN), 30 (5.0%) central pancreatectomy (CP), 186 (30.7%) pancreatoduodenectomy (PD), and 6 (1.0%) pancreatoduodenectomy with total pancreatectomy (PDTP). The most common pathologic finding was pancreatic ductal adenocarcinomas (146, 24.1%). Conversion to open procedure was required in 22 patients (3.6%) (12 with PD, 8 with DPS, 1 with CP, and 1 with PDTP). The mean operative time was 241.5 ± 105.5 minutes (range 50-550 minutes) for the entire population and 367.1 ± 61.8 minutes (range 230-550 minutes) for PD. Clinically significant pancreatic fistula (ISGPF grade B and C) rate was 12.4% for the entire cohort and 16.1% for PD. Rate of Clavien-Dindo III-V complications was 17.4% for the entire cohort and 23.7% for PD. Ninety-day mortality was observed only in the cohort of patients undergoing PD (n = 4). Conclusions: The LP procedure appears to be technically safe and feasible, with an acceptable rate of morbidity when performed at our experienced, high-volume center. However, PD has less favorable outcomes and needs further evaluation.

Outcome and prognosis after pancreatectomy in patients with solid pseudopapillary neoplasms

BACKGROUND

Solid pseudopapillary neoplasms (SPN) are rare and represent approximately 4% of all cystic pancreatic tumors. The prognosis is excellent, although 10-15% of SPN patients show metastasis at the time of surgery or tumor recurrence during follow-up after pancreatectomy. Aim of the study was to analyze surgical management, risk factors for malignancy as well as long-term outcome and prognosis of this distinct tumor entity.

METHOD

All patients with pancreatic resection for SPN between 10/2001 and 07/2018 in the authors' institution were identified from a prospective database. Clinicopathologic details, perioperative data and long-term follow-up results were retrospectively analyzed.

RESULTS

Fifty-two patients were identified, 44 (85%) of them were female and the median age was 29 years (IQR 9-71). Seven (13%) patients showed a malignant behaviour of SPN with N1 (n = 2) or M1 (n = 1) disease at resection; 5 patients developed tumor recurrence, after a median of 21 months. During follow-up time (median 54 months) all patients were alive, the 5- and 10-year rates for disease-free survival were 89.0% and 81.6%, respectively. Significant risk factors for recurrence were age <18 years (p = 0.0087) and parenchyma-preserving surgical approaches (p = 0.0006). The postoperative long-term outcome showed ECOG = 0-1 in all patients, with resection related exocrine insufficiency in 20 (41%) and diabetes mellitus in 2 (4%) patients.

CONCLUSIONS

Age < 18 years is a significant risk factor for malignancy in SPN, and parenchyma preserving resections harbor a significant risk for tumor recurrence. As recurrence may occur late, a systematic life-long follow-up should be performed.

Pancreatic Cytology

The diagnostic approach to pancreaticobiliary disease requires a multidisciplinary team in which the cytopathologist plays a crucial role. Fine-needle aspiration, obtained by endoscopic ultrasound, is the diagnostic test of choice for pancreatic lesions. Preoperative clinical management depends on many factors, many of which rely on accurate cytologic assessment. Pancreaticobiliary cytology is wrought with diagnostic pitfalls. Clinical history, imaging studies, cytology samples, and ancillary tests, including immunohistochemistry, biochemical analysis, and genetic sequencing, are integral to forming a complete diagnosis and guiding optimal patient management. This article reviews clinical aspects and the diagnostic work-up of commonly encountered diagnostic entities within the field of pancreatic cytology.

Pancreatic Cystic Neoplasms: Different Types, Different Management, New Guidelines

Pancreatic cystic neoplasms (PCN) include different types of cysts with various biological behavior. The most prevalent PCN are intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm (MCN), and serous cystic neoplasm (SCN). Management of PCN should focus on the prevention of malignant progression, while avoiding unnecessary morbidity of surgery. This requires specialized centers with dedicated multidisciplinary PCN teams. The malignant potential of PCN varies enormously between the various types of PCN. A combination of computed tomography, magnetic resonance imaging/magnetic resonance cholangiopancreatography, and endoscopic ultrasound with or without fine needle aspiration is typically needed before a reliable diagnosis can be made. Several guidelines discuss the management of PCN; however, most of these are non-evidence-based without clear consensus on the optimal treatment and follow-up strategy. The 2018 European guidelines on PCN are the first evidence-based guidelines to include IPMN, MCN, SCN, and all other PCN. This guideline advises a more conservative approach to side-branch IPMN and MCN smaller than 40 mm and more often a surgical approach in IPMN with a main duct dilatation beyond 5 mm. The goal of this review is to summarize the different types and management of the most common PCN based on the current literature and guidelines.

Prospective study on the incidence, prevalence and 5-year pancreatic-related mortality of pancreatic cysts in a population-based study

OBJECTIVE

To analyse the prevalence, incidence and clinical relevance of pancreatic cysts detected as incidental finding in a population-based longitudinal study.

DESIGN

A total of 1077 participants (521 men, mean age 55.8±12.8 years) of 2333 participants from the population-based Study of Health in Pomerania (SHIP) underwent magnetic resonance cholangiopancreaticography (MRCP) at baseline (2008-2012). MRCP was analysed for pancreatic cysts with a diameter ≥2 mm. 676/1077 subjects received a 5-year follow-up (2014-2016). The prevalence and incidence of pancreatic cysts (weighted for study participation) were assessed in association to age, gender and suspected epidemiological risk factors. Mortality follow-up was performed in 2015 for all SHIP participants (mean follow-up period 5.9 years, range 3.2-7.5 years).

RESULTS

At baseline pancreatic cysts had a weighted prevalence of 49.1%, with an average number of 3.9 (95% CI 3.2 to 4.5) cysts per subject in the subgroup harbouring cysts. Cyst size ranged from 2 to 29 mm. Prevalence (p<0.001), number (p=0.001) and maximum size (p<0.001) increased significantly with age. The 5-year follow-up revealed a weighted incidence of 12.9% newly detected pancreatic cysts. 57.1% of the subjects initially harbouring pancreatic cysts showed an increase in number and/or maximum cyst size. Of all subjects undergoing MRCP, no participant died of pancreatic diseases within mortality follow-up.

CONCLUSION

The prevalence of pancreatic cysts in the general population is unexpectedly high, and their number and size increase with age. Overall, no pancreatic cancer was observed in this collective during a 5-year follow-up. Nevertheless, prospective follow-up imaging showed minimal progress in more than 50%. Only about 6% of cysts and 2.5% of the study group initially presented with cysts of more than 1 cm and thus might be clinically meaningful.

A case of pancreatic neuroendocrine tumor with multiple cystic components of various sizes

The patient was a 51-year-old woman who, while undergoing a thorough health checkup, was found to have a tumor (measuring 60 mm in diameter) in the tail of the pancreas by abdominal ultrasonography. Contrast-enhanced computed tomography revealed delayed contrast enhancement; the tumor also contained numerous low-absorption areas showing poor contrast enhancement. On magnetic resonance imaging, the tumor was visualized as having high signal intensity areas inside the tumor on T2-weighted images. Positron emission tomography revealed an abnormal accumulation in the area corresponding to the tumor. Endoscopic ultrasonography (EUS) revealed a relatively hyperechoic solid area, with a number of echo-free areas of various sizes that assumed a honeycomb appearance. EUS-guided fine needle aspiration was carried out targeting the solid area within the tumor, which led to a diagnosis of pancreatic neuroendocrine tumor (PNET). Histopathological examination of the resected specimen revealed that the tumor was composed of numerous cysts of various sizes and solid components. The cysts contained no evidence of necrosis or bleeding. Immunohistochemically, the cystic as well as solid components were CD56 (+), synaptophysin (+) and chromogranin A (+) with MIB1 labeling index of 5%. On the basis of these findings, the final diagnosis was PNET (G2).

The Surgeon's Role in Treating Chronic Pancreatitis and Incidentally Discovered Pancreatic Lesions

Chronic pancreatitis and incidentally discovered pancreatic lesions present significant diagnostic and therapeutic challenges for surgeons. While both decompressive and resection procedures have been described for treatment of chronic pancreatitis, optimal management must be tailored to each patient's individual disease characteristics, parenchymal morphology, and ductal anatomy. Surgeons should strive to achieve long-lasting pain relief while preserving native pancreatic function. For patients with incidentally discovered pancreatic lesions, differentiating benign, pre-malignant, and malignant lesions is critical as earlier treatment is thought to result in improved survival. The purpose of this evidence-based manuscript is to review the presentation, workup, surgical management, and associated outcomes for patients with chronic pancreatitis or incidentally discovered solid and cystic lesions of the pancreas.

Classification of Pancreatic Cysts in Computed Tomography Images Using a Random Forest and Convolutional Neural Network Ensemble

There are many different types of pancreatic cysts. These range from completely benign to malignant, and identifying the exact cyst type can be challenging in clinical practice. This work describes an automatic classification algorithm that classifies the four most common types of pancreatic cysts using computed tomography images. The proposed approach utilizes the general demographic information about a patient as well as the imaging appearance of the cyst. It is based on a Bayesian combination of the random forest classifier, which learns subclass-specific demographic, intensity, and shape features, and a new convolutional neural network that relies on the fine texture information. Quantitative assessment of the proposed method was performed using a 10-fold cross validation on 134 patients and reported a classification accuracy of 83.6%.

Imaging Pancreatic Cysts with CT and MRI

CT and MRI are the imaging modalities of choice to guide the clinical management of incidentally discovered pancreatic cysts. Most of these lesions are mucinous cysts with varying degrees of malignant potential. This article reviews the CT and MRI findings that help differentiate a potentially aggressive lesion that requires EUS or surgery from a lesion of low malignant potential that is appropriate for imaging surveillance. The imaging-based societal guidelines for these cysts are reviewed.

Detection and management of retroperitoneal cystic lesions: A case report and review of the literature

The identification of cystic lesions within the retroperitoneal space is a rare event that poses clinicians the challenge of a difficult diagnosis and disease management. Retroperitoneal cystic lesions account for a group of lesions that range from common benign lesions (e.g., lymphoceles developing as a surgical complication) to rare aggressive malignant neoplasms. Currently, in the majority of cases, image-guided procedures allow for a pathological diagnosis to be achieved in these challenging lesions, thus offering the chance of an appropriate treatment; however, the overall clinical assessment of retroperitoneal cysts is highly demanding. The present study reports the management of a representative clinical case, presenting with a voluminous cystic mass able to dislocate cave vein, whose diagnosis was preceded by a deep vein thrombosis. Computed tomography-scan and ultrasound guided percutaneous drainage were performed to achieve the diagnosis. Following the discussion of the current case report, a review of the pathological and radiological characteristics of retroperitoneal cystic lesions is presented.

MDCT vs. MRI for incidental pancreatic cysts: measurement variability and impact on clinical management

PURPOSE

To investigate incidental pancreatic cysts (IPCs) size discrepancy in a cohort of patients receiving both computed tomography (CT) and magnetic resonance imaging (MRI) and its impact on clinical management based on the 2010 American College of Radiology (ACR) guidelines.

METHODS

This was a HIPAA-compliant, retrospective, IRB-approved study. Informed consent was waived. Patients with known IPCs and at least one case-pair, consisting of an abdominal CT and MRI examination within 180 days between 05/1999 and 12/2011, were included. Maximum diameter of cysts was measured in both the CT and MR examinations. A subset of 30 patients was measured by three radiologists independently to assess inter-observer variability. Absolute difference in diameter measurements between CT and MRI was calculated. Influence of cyst size, cyst location, and patient characteristics such as weight, height, and body mass index (BMI) on variability of size measurements were evaluated. Clinical impact in terms of current ACR guidelines was assessed.

RESULTS

Overall, 267 case-pairs of cysts in 113 patients were included in this study. 59/267 cysts were visualized on MRI but not on CT (22.1%, 95% CI 17.1%-27.1%; 32 patients, 64.6 ± 11.7 years, BMI 28.5 ± 4.8 kg/m²), with a median MRI cyst size of 7.8 mm, IQR 6.0-9.0 mm, range 2-17.8 mm. 208 case-pairs in 113 patients with a mean BMI of 26.9 ± 5.1 kg/m² (range 16.9-39.5 kg/m²) and mean cysts size of 13.4 ± 8.1 mm (range 3-49 mm) were seen in both CT and MRI. The mean absolute size difference for IPCs measured on MRI and CT was 2.1 ± 1.8 mm (median 1.5 mm, IQR 0.9-2.9 mm, range 0-9 mm). Absolute size difference between CT and MRI measurements increased with size of the cyst (r = 0.31, p < 0.001), whereas location of the cyst did not influence the absolute difference between CT and MRI measurements (p = 0.44). Patient weight and BMI had a negative correlation with the difference in cyst size between CT and MRI (weight r = -0.17, p = 0.023; BMI r = -0.17, p = 0.027), with cyst measurements being larger on MRI in thin patients and on CT in obese patients. Inter-reader variability was excellent (ICC = 0.99). In 12/208 (5.7%, 95% CI 2.7%-9.1%), variability between CT and MRI would have changed ACR-based follow-up recommendation.

CONCLUSION

There was a median difference of 1.5 mm between measurements of IPCs on CT vs. MRI. If imaging modality was switched during follow-up, variability of measurements may lead to inappropriate change of follow-up regimen in 6% of all cases. A single follow-up CT for incidental IPCs does not seem sufficient due to a high number (22%) of missed IPCs on CT.

Diffusion-Weighted Magnetic Resonance Imaging in Distinguishing Between Mucin-Producing and Serous Pancreatic Cysts

OBJECTIVE

The aim of this study was to evaluate the feasibility and reproducibility of diffusion-weighted imaging in distinguishing between mucin-producing and serous pancreatic cysts.

METHODS

Forty-four pancreatic cysts (43 patients, 27 women; mean age, 57 years; 26 mucin-producing cysts, 18 serous cysts) that underwent histological examination or cyst analysis after diffusion-weighted magnetic resonance imaging were retrospectively reviewed. Three blinded readers independently evaluated signal intensity and apparent diffusion coefficient (ADC). Intraobserver and interobserver agreements were calculated. Fisher exact test and Welch t test were used to compare signal intensity and ADC values, respectively, with pathological results. Receiver operating characteristic analysis was used to determine diagnostic accuracy of various thresholds for ADC. A P value less than 0.05 was considered statistically significant.

RESULTS

Mean ADC values of the mucin-producing cysts were 3.26 × 10, 3.27 × 10, and 3.35 × 10 mm/s for the 3 readers, respectively. Mean ADC values of the serous cysts were 2.86 × 10, 2.85 × 10, and 2.85 × 10 mm/s for the 3 readers, respectively. Differences in ADC values between the 2 cyst groups were 12.4%, 12.9%, and 14.8% for the 3 readers, respectively (P < 0.001). Intraobserver and interobserver agreement was excellent. A threshold ADC of 3 × 10 mm/s resulted in correct identification of cysts in 77% to 81% of cases, with sensitivity and specificity ranging between 84% and 88% and 66% and 72%, respectively.

CONCLUSIONS

Diffusion-weighted imaging may be a helpful tool in distinguishing between mucin-producing and serous pancreatic cysts.

[Diagnostic strategy and differential therapeutic approach for cystic lesions of the pancreas]

CLINICAL/METHODICAL ISSUE

Cystic pancreatic lesions (CPL) are diagnosed with increasing frequency. Because up to 60% of CPL are classified as malignant or premalignant, every CPL should be fully investigated and clarified. Serous CPL with low risk of malignancy must be differentiated from mucinous CPL with relevant potential malignancy (intraductal papillary mucinous neoplasm IPMN) and mucinous cystic neoplasm (MCN) as well as from harmless pseudocysts.

STANDARD RADIOLOGICAL METHODS

Cross-sectional imaging with computed tomography (CT) and magnetic resonance imaging (MRI) plays a crucial role in the diagnostics of CPL.

METHODICAL INNOVATIONS

An algorithm for the differential diagnostic classification of CPL is presented.

PERFORMANCE

The connection to the pancreatic duct is the key diagnostic criterion to differentiate IPMN from all other CPL. An exception to this rule is that pseudocysts can also show a connection to the pancreatic duct. A further classification of CPL with no connection to the pancreatic duct can be made by morphological criteria and correlation of the radiological findings with patient age, sex, history and symptoms.

PRACTICAL RECOMMENDATIONS

Depending on the diagnosis and hence the malignant potential the indications for surgery or watch and wait have to be discussed in an interdisciplinary cooperation. Due to its higher soft tissue contrast MRI is often superior to CT for depiction of CPL morphology.

Prevalence of incidental pancreatic cysts on 3 tesla magnetic resonance

Objectives

To ascertain the prevalence of pancreatic cysts detected incidentally on 3-Tesla magnetic resonance imaging (MRI) of the abdomen and correlate this prevalence with patient age and gender; assess the number, location, and size of these lesions, as well as features suspicious for malignancy; and determine the prevalence of incidentally detected dilatation of the main pancreatic duct (MPD).

Methods

Retrospective analysis of 2,678 reports of patients who underwent abdominal MRI between January 2012 and June 2013. Patients with a known history of pancreatic conditions or surgery were excluded, and the remaining 2,583 reports were examined for the presence of pancreatic cysts, which was then correlated with patient age and gender. We also assessed whether cysts were solitary or multiple, as well as their location within the pancreatic parenchyma, size, and features suspicious for malignancy. Finally, we calculated the prevalence of incidental MPD dilatation, defined as MPD diameter ≥ 2.5 mm.

Results

Pancreatic cysts were detected incidentally in 9.3% of patients (239/2,583). The prevalence of pancreatic cysts increased significantly with age (p<0.0001). There were no significant differences in prevalence between men and women (p=0.588). Most cysts were multiple (57.3%), distributed diffusely throughout the pancreas (41.8%), and 5 mm or larger (81.6%). In 12.1% of cases, cysts exhibited features suspicious for malignancy. Overall, 2.7% of subjects exhibited incidental MPD dilatation.

Conclusions

In this sample, the prevalence of pancreatic cysts detected incidentally on 3T MRI of the abdomen was 9.3%. Prevalence increased with age and was not associated with gender. The majority of cysts were multiple, diffusely distributed through the pancreatic parenchyma, and ≥ 5 mm in size; 12.1% were suspicious for malignancy. An estimated 2.7% of subjects had a dilated MPD.

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.

Lymphoepithelial cysts of the pancreas:a management dilemma

Pancreatic lymphoepithelial cysts (LECs) are rare, benign lesions that are typically unexpected post-operative pathological findings. We aimed to review clinical, radiological and pathological features of LECs that may allow their pre-operative diagnosis. Histopathology databases of two large pancreatic units were searched to identify LECs and notes reviewed to determine patient demographic details, mode of presentation, investigations, treatment and outcome. Five male and one female patients were identified. Their median age was 60 years. Lesions were identified on computed tomography performed for abdominal pain in two patients, and were incidentally observed in four patients. Five LECs were located in the tail and one in the body of the pancreas, with a median cyst size of 5 cm. Obtaining cyst fluid was difficult and a largely acellular aspirate was yielded. The pre-operative diagnosis was mucinous cystic neoplasm in all patients. This series of patients were treated distal pancreatectomy and splenectomy. A retrospective review of radiological examinations suggested that LECs have a relatively low signal on T2 imaging and a high signal intensity on T1 weighted images. LECs appear more common in elderly males, and are typically incidental, large, unilocular cysts. Close attention to signal intensity on MRI may allow pre-operative diagnosis of these lesions.

Moving beyond morphology: new insights into the characterization and management of cystic pancreatic lesions

The frequency of detection of cystic pancreatic lesions with cross-sectional imaging, particularly with multidetector computed tomography, magnetic resonance (MR) imaging, and MR cholangiopancreatography, is increasing, and many of these cystic pancreatic lesions are being detected incidentally in asymptomatic patients. Because there is considerable overlap in the cross-sectional imaging findings of cystic pancreatic lesions, and because many of these lesions being detected are smaller than 3 cm in diameter and lack any specific cross-sectional imaging features, it has become difficult to make informed decisions about patient management when the precise diagnosis remains uncertain. This article presents the limitations of cross-sectional imaging in patients with cystic pancreatic lesions, details advances in knowledge of the genomic and epigenomic changes that lead to progression of carcinogenesis, outlines the current understanding of the natural history of mucinous cystic lesions, and includes the current use and future potential of novel tumor markers and molecular analysis to characterize cystic pancreatic lesions more precisely. The need to move beyond cross-sectional imaging morphology and toward the use of new techniques to diagnose these lesions accurately is emphasized. An algorithm that uses these techniques is proposed and will hopefully lead to improved patient management.

Laparoscopic central pancreatectomy for benign or low-grade malignant lesions in the pancreatic neck and proximal body

INTRODUCTION

Laparoscopic central pancreatectomy (LCP) is a parenchyma-sparing minimally invasive surgical technique for removal of benign or low-grade malignant lesions from the neck and proximal body of the pancreas. The aim of this study was to compare the short- and long-term clinical outcomes of LCP with those of other pancreatectomies.

METHODS

During the study period, January 2007 to December 2010 (median follow-up 40.6 months), 287 pancreatectomies were performed for lesions in the neck and proximal body of the pancreas. To compare the clinical outcomes of LCP and other pancreatectomies, 26 cases of LCP, 14 cases of open central pancreatectomy (OCP), and 96 cases of extended laparoscopic distal pancreatectomy (E-LDP) were selected.

RESULTS

Tumor sizes in the LCP (2.2 cm) and OCP (2.9 cm) groups were smaller than in the E-LDP (4.0 cm) group. Mean operation time in the LCP group (350.2 min) was longer than in the OCP (270.3 min) and E-LDP groups (210.6 min). There were more surgical complications in the LCP (38.5 %) and OCP groups (50 %) than in the E-LDP group (14.6 %). Mean duration of postoperative hospital stay was 13.8 days for the LCP group, which was significantly shorter than for the OCP group (22.4 days). New-onset diabetes was less frequent after LCP than after E-LDP (11.5 vs. 30.8 %).

CONCLUSIONS

In selected patients with small and benign tumors in the pancreatic neck and proximal body LCP leads to increased postoperative morbidity but earlier postoperative recovery than OCP, and excellent postoperative pancreatic function (compared with E-LDP). LCP should, therefore, be considered a valid therapeutic option for selected patients.

Pancreatic cystic lesions: The value of contrast-enhanced endoscopic ultrasound to influence the clinical pathway

Background and Objectives:

Cystic pancreatic lesions are a growing diagnostic challenge. The aim of this study was to proof a new diagnostic concept based on contrast-enhanced endoscopic ultrasound (CE-EUS) for differential diagnosis.

Patients and Methods:

A total of 125 patients with unclear cystic pancreatic lesions were included. The initial diagnostic was made by CE-EUS dividing the lesions in a group without contrast enhancing effect in the cystic wall, septae or nodule indicating pseudocysts or dysontogenetic cysts and a group with contrast enhancing effect in the described structures indicating cystic neoplasias. The investigations were performed using a Pentax echoendoscope and Hitachi Preirus ultrasound machine. The contrast enhancer used was 4.8 mL SonoVue^® (Bracco, Italy). The group with suspected cystic neoplasia was referred for endoscopic fine-needle puncture for further diagnostic or treatment decisions.

Results:

The dividing of the groups by contrast-enhanced ultrasound was feasible because all (n = 56) suspected cystic neoplasias showed a contrast enhancing effect, whereas in only 4 from 69 pseudocystic or dysontogenetic cystic lesions a contrast enhancing effect in the wall could be observed. Endoscopic fine-needle puncture could diagnose all malignant neoplasias and relevant premalignant conditions. The long-term follow-up did not show any development of malignant cystic lesions.

Conclusion:

Using CE-EUS and endoscopic fine-needle puncture as diagnostic criteria seemed to be a feasible method to deal with different cystic lesions in daily practice.