Imaging of indeterminate pancreatic cystic lesions: a systematic review

Exploring patient experiences of surveillance for pancreatic cystic neoplasms: a qualitative study

BACKGROUND

Pancreatic cystic neoplasms (PCN) are considered premalignant conditions to pancreatic adenocarcinoma with varying degrees of cancerous potential. Management for individuals who do not require surgical treatment involves surveillance to assess for cancerous progression. Little is known about patients' experience and the impact of living with surveillance for these lesions.

AIMS

To explore the experiences of patients living with surveillance for PCNs.

METHODS

Semi-structured qualitative interviews were conducted with patients under surveillance for pancreatic cystic neoplasms in the UK. Age, gender, time from surveillance and surveillance method were used to purposively sample the patient group. Data were analysed using reflexive thematic analysis.

RESULTS

A PCN diagnosis is incidental and unexpected and for some, the beginning of a disruptive experience. How patients make sense of their PCN diagnosis is influenced by their existing understanding of pancreatic cancer, explanations from clinicians and the presence of coexisting health concerns. A lack of understanding of the diagnosis and its meaning for their future led to an overarching theme of uncertainty for the PCN population. Surveillance for PCN could be seen as a reminder of fears of PCN and cancer, or as an opportunity for reassurance.

CONCLUSIONS

Currently, individuals living with surveillance for PCNs experience uncertainty with a lack of support in making sense of a prognostically uncertain diagnosis with no immediate treatment. More research is needed to identify the needs of this population to make improvements to patient care and reduce negative experiences.

Pancreatic Cysts: Radiology

This article reviews the types of pancreatic cysts encountered in Radiologic practice. It summarizes the malignancy risk of each of the following: serous cystadenoma, mucinous cystic tumor, intraductal papillary mucinous neoplasm main duct and side branch, and some miscellaneous cysts such as neuroendocrine tumor and solid pseudopapillary epithelial neoplasm. Specific reporting recommendations are given. The choice between radiology follow-up versus endoscopic analysis is discussed.

Diagnostic value of EUS-guided SF6 pancreatography for pancreatic cystic lesions on cyst communication with the pancreatic duct

Background and Objectives

ERCP remains the reliable method to determine whether pancreatic cystic lesions (PCLs) and pancreatic duct communicate when other modalities (computed tomography, magnetic resonance imaging, and EUS) fail. However, complications after ERCP are still a risk that should not be ignored. In this study, we evaluated the value of EUS-guided SF6 pancreatography (ESP) for the diagnosis of PCLs focusing on pancreatic cyst communication with the pancreatic duct.

Patients and Methods

We reviewed the database of medical records to retrieve the clinicopathological data of the patients with PCLs who had undergone ESP, and analyzed the diagnostic value of ESP to determine communication between the cyst and the pancreatic duct. The inclusion criteria were as follows: (1) PCLs were pathologically diagnosed by postsurgery specimen or through-the-needle biopsy and (2) ESP was performed to determine communication between the pancreatic cyst and the pancreatic duct.

Results

Pathological diagnosis confirmed communication with the pancreatic duct in all eight patients with positive pancreatography, among whom seven were branch-duct-intraductal papillary mucinous neoplasm (BD-IPMN) and one was the main duct-IPMN. Pathological diagnosis confirmed noncommunication with the pancreatic duct in 20 of the 21 patients with negative pancreatography, among whom 11 were mucinous cystic neoplasm, 7 were serous cystic neoplasm, 1 was solid pseudopapillary neoplasm, 1 was pancreatic pseudocyst, and 1 was BD-IPMN. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of ESP to determine communication between the pancreatic cyst and the pancreatic duct were 96.6% (28/29), 88.9% (8/9), 100% (20/20), 100% (8/8), and 95.2% (20/21), respectively.

Conclusions

ESP achieved high accuracy to determine communication between the pancreatic cyst and the pancreatic duct.

Lower Interobserver Reliability for Nondimensional Intracystic Features Among Abdominal Radiologists for Characterizing Intraductal Papillary Mucinous Neoplasms Using Magnetic Resonance Imaging

OBJECTIVES

Current guidelines recommend magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP) for risk stratification of intraductal papillary mucinous neoplasms (IPMNs). We assessed the interobserver agreement among radiologists in evaluating and risk stratifying IPMNs.

METHODS

This single-center study evaluated 30 patients with IPMNs who had undergone MRI/MRCP, endoscopic ultrasound, and/or surgical resection. Six abdominal radiologists evaluated the MRI/MRCPs to document multiple parameters. The analysis applied Landis and Koch κ interpretation for categorical variables and intraclass correlation coefficient (r) for continuous variables.

RESULTS

Radiologists demonstrated almost perfect agreement for location (κ = 0.81, 95% confidence interval [CI], 0.74-0.87), size (r = 0.95; 95% CI, 0.89-0.98), and main pancreatic duct diameter (r = 0.98; 95% CI, 0.96-0.99). Substantial agreement was observed for communication with the main pancreatic duct (κ = 0.66; 95% CI, 0.57-0.75) and classification of IPMN subtype (κ = 0.77; 95% CI, 0.67-0.86). Presence of intracystic nodules (κ = 0.31; 95% CI, 0.21-0.42) and wall thickening (κ = 0.09; 95% CI, -0.01 to 0.18) reached only fair and slight agreement, respectively.

CONCLUSIONS

Although MRI/MRCP is excellent in the evaluation of spatial aspects, there is lower reliability for nondimensional characteristics of IPMNs. These data support guideline-recommended complementary evaluation of IPMNs with MRI/MRCP and endoscopic ultrasound.

The Natural History of Pancreatic Cystic Lesions in Liver Transplant Recipients: A Systematic Review and Meta-analysis

OBJECTIVES

The management of incidentally discovered pancreatic cystic lesions (PCLs) with surveillance or resection often requires shared decision-making. Patients with cirrhosis are more likely to have PCLs discovered due to increased imaging, and those undergoing liver transplantations (LTs) may be at increased risk of carcinogenesis due to immunosuppressive medications. Our study aimed to characterize the outcomes and risk of malignant progression of PCLs in post-LT patients.

METHODS

Multiple databases were searched for studies looking at PCLs in post-LT patients from inception until February 2022. Primary outcomes were the incidence of PCLs in LT recipients and progression to malignancy. Secondary outcomes included development of worrisome features, outcomes of surgical resection for progression, and change in size.

RESULTS

A total of 12 studies with 17,862 patients with 1411 PCLs were included. The pooled proportion of new PCL development in post-LT patients was 68% (95% confidence interval [CI], 42-86; I2 = 94%) over the follow-up of 3.7 (standard deviation, 1.5) years. The pooled progression of malignancy and worrisome features was 1% (95% CI, 0-2; I2 = 0%) and 4% (95% CI, 1-11; I2 = 89%), respectively.

CONCLUSIONS

Compared with nontransplant patients, incidental PCLs do not carry a higher risk of malignancy.

Advances in the Diagnosis of Pancreatic Cystic Lesions

Pancreatic cystic lesions (PCLs) are a heterogenous group of lesions ranging from benign to malignant. There has been an increase in PCLs prevalence in recent years, mostly due to advances in imaging techniques, increased awareness of their existence and population aging. Reliable discrimination between neoplastic and non-neoplastic cystic lesions is paramount to ensuring adequate treatment and follow-up. Although conventional diagnostic techniques such as ultrasound (US), magnetic resonance imaging (MRI) and computer tomography (CT) can easily identify these lesions, assessing the risk of malignancy is limited. Endoscopic ultrasound (EUS) is superior to cross-sectional imaging in identifying potentially malignant lesions due to its high resolution and better imaging characteristics, and the advantage of allowing for cyst fluid sampling via fine-needle aspiration (FNA). More complex testing, such as cytological and histopathological analysis and biochemical and molecular testing of the aspirated fluid, can ensure an accurate diagnosis.

Machine learning principles applied to CT radiomics to predict mucinous pancreatic cysts

PURPOSE

Current diagnostic and treatment modalities for pancreatic cysts (PCs) are invasive and are associated with patient morbidity. The purpose of this study is to develop and evaluate machine learning algorithms to delineate mucinous from non-mucinous PCs using non-invasive CT-based radiomics.

METHODS

A retrospective, single-institution analysis of patients with non-pseudocystic PCs, contrast-enhanced computed tomography scans within 1 year of resection, and available surgical pathology were included. A quantitative imaging software platform was used to extract radiomics. An extreme gradient boosting (XGBoost) machine learning algorithm was used to create mucinous classifiers using texture features only, or radiomic/radiologic and clinical combined models. Classifiers were compared using performance scoring metrics. Shapely additive explanation (SHAP) analyses were conducted to identify variables most important in model construction.

RESULTS

Overall, 99 patients and 103 PCs were included in the analyses. Eighty (78%) patients had mucinous PCs on surgical pathology. Using multiple fivefold cross validations, the texture features only and combined XGBoost mucinous classifiers demonstrated an area under the curve of 0.72 ± 0.14 and 0.73 ± 0.14, respectively. By SHAP analysis, root mean square, mean attenuation, and kurtosis were the most predictive features in the texture features only model. Root mean square, cyst location, and mean attenuation were the most predictive features in the combined model.

CONCLUSION

Machine learning principles can be applied to PC texture features to create a mucinous phenotype classifier. Model performance did not improve with the combined model. However, specific radiomic, radiologic, and clinical features most predictive in our models can be identified using SHAP analysis.

State-of-the-art surgical treatment of IPMNs

Background

A “pandemic” of incidentally discovered pancreatic cyst neoplasms (PCNs) is ongoing. Among PCNs, intraductal papillary mucinous cystic neoplasms (IPMNs) are the most common and with their complex biology could represent a precursor lesion of pancreatic cancer. Although multiple guidelines exist to guide their treatment, there are still many “gray areas” on indications for surgery for IPMNs.

Methods

The current indications for surgery of IPMNs were reappraised, considering potential discrepancies between available evidence and guidelines policies. The practice at a high-volume center for the diagnosis and treatment of PCN was presented and discussed.

Results

Most IPMNs do not and will never require surgery, as they won’t progress to malignancy. The current literature is solid in identifying high-grade dysplasia (HGD) as the right and timely target for IPMN resection, but how to precisely assess its presence remains controversial and guidelines lack of accuracy in this regard. Multiple tumorigenic pathways of progression of IPMNs exist, and their knowledge will likely lead to more accurate tests for malignancy prediction in the future.

Conclusions

The surgical management of IPMNs still is a matter of debate. Indication for resection should be considered only in highly selected cases with the ideal target of HGD. Clinicians should critically interpret the guidelines’ indications, refer to a multidisciplinary team discussion, and always consider the outcome of an adequate counselling with the patient.

High-Risk Characteristics Associated with Advanced Pancreatic Cystic Lesions: Results from a Retrospective Surgical Cohort

BACKGROUND AND AIM

The management of pancreatic cystic lesions (PCLs) remains controversial. We performed a retrospective study to determine characteristics associated with advanced PCLs (A-PCLs) and whether these characteristics vary in different pathological types of PCLs. The additional diagnostic value of endoscopic ultrasound (EUS) was also evaluated.

METHODS

Patients who underwent surgical resection for an identified PCLs by imaging modalities were included. A logistic regression model was developed to identify significant characteristics for A-PCLs. EUS data was assessed separately.

RESULTS

Three hundred and fifty-three patients were included, and 125 patients (35.4%) were A-PCLs. The presence of main pancreatic duct (MPD) diameter ≥ 10 mm (odds ratio [OR], 11.7; 95% confidence interval [CI], 1.53-89.2; P = 0.018), mural nodules ≥ 5 mm (OR, 11.67; 95% CI, 2.3-59.05; P = 0.003), solid components within cysts (OR, 30.87; 95% CI, 7.23-131.7; P < 0.0001) and high serum CA19-9 levels (OR, 1.006; 95% CI, 1.001-1.011; P = 0.02) were independently associated with the presence of A-PCLs. The presence of septa was independently associated with the presence of non-A-PCLs (OR, 0.147; 95% CI, 0.04-0.6; P = 0.008). Males who had a history of tobacco abuse (P < 0.0001) and had a greatly dilated MPD (P < 0.0001) were more common in advanced intraductal papillary mucinous neoplasms (IPMC) patients. Solid pseudopapillary neoplasm (SPT) often occurred in young women (P < 0.0001), mostly asymptomatically (P < 0.0001) and with lower serum CA19-9 levels (P < 0.0001). In the 124 patients who underwent EUS-guided fine-needle aspiration (EUS-FNA), five additional characteristics (4 mural nodules and 1 MPD involvement) were identified by EUS imaging and 17 patients were identified with abnormal cytological results (13 atypical cells and 4 suspicious for malignancy cells) by EUS-FNA.

CONCLUSION

On the basis of a retrospective study with large sample size, the presence of MPD ≥ 10 mm, mural nodules, solid components, and high serum CA19-9 levels were independently associated with the presence of A-PCLs. The high-risk characteristics may vary across different types of A-PCLs. EUS and EUS-FNA could provide additional diagnostic information for PCLs.

[Management of Cystic Lesions of the Pancreas]

Cystic pancreatic lesions are a frequent incidental finding on ultrasound or cross sectional imaging. The incidence of pancreatic lesions experience a steady climb in recent years due to an increased number of cross sectional imaging and an increasing life expectancy. The clinical challenge is to identify individuals bearing lesions with potentially malignant or pre-malignant features. Indeed, by far most cystic pancreatic lesions are not associated with an increased risk for the development of cancer. Taking into account the increasing incidence rates of cystic pancreatic lesions a rational and economic use of diagnostics is warranted. This review provides an overview on the different types of cystic lesions, the appropriate use of diagnostics and a clinical management algorithm balancing intervention and surveillance.

Magnetic resonance (MR) for mural nodule detection studying Intraductal papillary mucinous neoplasms (IPMN) of pancreas: Imaging-pathologic correlation

PURPOSE

Magnetic Resonance (MR) is recommended to diagnose Intraductal Papillary Mucinous Neoplasms (IPMN) and in the follow-up of borderline lesions. The purpose of this work is to evaluate the diagnostic accuracy of dynamic MR with Diffusion Weighted Imaging (DWI) in the identification of mural nodules of pancreatic IPMN by using pathological analysis as gold standard.

MATERIALS AND METHODS

Ninety-one preoperative MR with histopathological diagnosis of IPMN were reviewed by two radiologists. Presence, number and size of mural nodule, signal intensity of the nodule on T1-weighted imaging (T1-WI) after contrast medium administration and on DWI. Inter-observer agreement was evaluated.

RESULTS

Significant correlation (p < 0.0001) were found for presence of nodules > 5 mm on MR and pathological specimen, size and number of mural nodules evaluated on pathological review and degree of dysplasia, size and number of mural nodules evaluated on MR and tumoral dysplasia, presence of nodule > 5 mm with enhancement after contrast medium administration and hyperintensity on DWI and degree of dysplasia. Interobserver agreement was moderate for the presence of mural nodule (K = 0.56), for the presence of high signal intensity on DWI (K = 0.57) and enhancement of mural nodule (K = 0.58). Apparent Diffusion Coefficient (ADC) map histogram analysis showed a correlation between Entropy of the entire cystic lesion and the degree of dysplasia (p < 0.034).

CONCLUSIONS

MR with dynamic and DWI sequences was an accurate method for the identification of ≥ 5 mm solid nodules of the IPMNs and correlate with the lesion malignancy. Entropy, calculated from the histogram analysis of the IPMN ADC map, correlated with the lesion dysplasia.

Application of EUS-based techniques in the evaluation of pancreatic cystic neoplasms

Pancreatic cystic neoplasms (PCNs) are being detected increasingly frequently due to the widespread use of high-resolution abdominal imaging modalities. Some subtypes of PCNs have the potential for malignant transformation. Therefore, accurate diagnosis of PCNs is crucial to determine whether surgical resection or surveillance is the best management strategy. However, the current cross-section imaging modalities are not accurate enough to enable definite diagnoses. In the last decade, EUS-based techniques have emerged, aiming to overcome the limitations of standard cross-section imaging modalities. These novel EUS-based techniques were primarily designed to acquire distinct images to make radiological diagnoses, collect cyst fluid to undergo biochemical or molecular analyses, and obtain tissue to conclude the pathological diagnoses. In this article, we present a comprehensive and critical review of these emerging EUS techniques for the diagnosis of PCNs, with emphasis being placed on the advantages, feasibilities, diagnostic performances, and limitations of these novel techniques.

EUS is accurate in characterizing pancreatic cystic lesions; a prospective comparison with cross-sectional imaging in resected cases

Background

Imaging modalities for characterizing pancreatic cystic lesions (PCLs) is a known uncertainty. The aim of this prospective study was to compare the diagnostic performance of endoscopic ultrasound morphology, cytology and cyst fluid carcinoembryonic antigen (EUS-FNA-CEA) with cross-sectional imaging in resected PCLs.

Methods

The cross-sectional imaging and EUS-FNA-CEA results were collected in an academic tertiary referral centre using histology of the surgical specimen as the diagnostic standard.

Results

Of 289 patients undergoing evaluation for PCL with cross-sectional imaging and EUS-FNA between February 2007 and March 2017, 58 underwent surgical resection providing a final diagnosis of the PCLs: 45 mucinous, 5 serous, 1 pseudocyst, 2 endocrine, 2 solid pseudopapillary neoplasms and 3 other. EUS-FNA-CEA was more accurate than cross-sectional imaging in diagnosing mucinous PCLs (95% vs. 83%, p = 0.04). Ninety-two percent of the PCLs with high-grade dysplasia or adenocarcinoma were smaller than 3 cm in diameter. The sensitivity of EUS-FNA-CEA and cross-sectional imaging for detecting PCLs with high-grade dysplasia or adenocarcinoma were 33% and 5% (p = 0.03), respectively. However, there was no difference in accuracy between the modalities (62% vs. 66%, p = 0.79). The sensitivity for detecting pancreatic adenocarcinomas only was 64% for EUS-FNA-CEA and 9% for cross-sectional imaging (p = 0.03). Overall, EUS-FNA-CEA provided a correct diagnosis in more patients with PCLs than cross-sectional imaging (72% vs. 50%, p = 0.01).

Conclusions

EUS-FNA-CEA is accurate and should be considered a complementary test in the diagnosis of PCLs. However, the detection of PCLs with high-grade dysplasia or adenocarcinoma needs to be improved. Cyst size does not seem to be a reliable predictor of high-grade dysplasia or adenocarcinoma.

Electronic supplementary material

The online version of this article (10.1007/s00464-020-08166-3) contains supplementary material, which is available to authorized users.

Pancreatic mesothelial cyst

A 60-year-old woman was investigated for abdominal pain and increasing asthenia. Abdominal CT revealed a 25 mm hypodense cystic lesion in the tail of the pancreas. MRI showed a multiloculated cystic lesion, T1-hypointense and T2-hyperintense lesion, without wall enhancement. Endoscopic ultrasound detected a 25 mm multi-loculated cystic lesion, with regular margin and without pancreatic duct communication. Diagnosis of pancreatic mucinous cystadenoma was discussed and the patient was referred to surgery. She underwent distal pancreatectomy with spleen preservation. Pathological examination revealed the diagnosis of pancreatic mesothelial cyst. Histologically, the cyst was multiloculated, lined by cuboidal epithelium, ovoid nuclei and amphophilic cytoplasm, without mucin deposition or cytological atypia. Immunohistochemistry examination revealed positive staining for cytokeratin 5/6, vimentin and calretinin. At 1-year follow-up, she is in her usual health, without any symptoms.

PET-MR Imaging and MR Texture Analysis in the Diagnosis of Pancreatic Cysts: A Prospective Preliminary Study

RATIONALE AND OBJECTIVES

Our aim was to evaluate the capability of textural and metabolic parameters measured at pretreatment ¹⁸F-fluorodeoxyglucose Positron emission tomography (PET)-MR in differentiating malignant from benign pancreatic cystic lesions.

MATERIALS AND METHOD

Forty consecutive patients were prospectively enrolled in this study. They underwent simultaneous PET-MR for the diagnosis of pancreatic cysts. Thirty texture parameters were extracted from manually contoured axial T2-weighted imaging with fat suppression (T2FS) and apparent diffusion coefficient images, respectively. Maximal and mean standardized uptake values (SUV_max and SUV_mean, respectively) of pancreatic cysts were measured at PET-MR imaging. The Mann-Whitney test was used to compare both textural and metabolic parameters between benign and malignant group.

RESULTS

FDG uptake was significantly higher in patients with malignant pancreatic cysts (SUV_maxp = 0.002, SUV_meanp < 0.001). Malignant cysts showed significantly lower standard deviation for spatial scaling factor at 3-6mm on T2FS images and lower skewness for spatial scaling factor at 2-4mm on apparent diffusion coefficient images (p < 0.01). SUV_mean had the highest Area under the curve of 0.892 on receiver-operating characteristic analysis with a sensitivity, specificity, and accuracy of 88.9%, 87.1%, and 87.6%, respectively. When metabolic and textural features were combined into a single diagnostic model, the AUC increased to 0.961, with a sensitivity, specificity, and accuracy of 88.9%, 96.8%, and 95.0%, respectively.

CONCLUSION

Our study implied that PET-MR showed no obvious advantages over traditional PET-related imaging in differentiating malignant from benign pancreatic cystic lesions. Diagnostic model based on the combination of metabolic and textural parameters showed satisfactory performance.

Impact of EUS-guided microforceps biopsy sampling and needle-based confocal laser endomicroscopy on the diagnostic yield and clinical management of pancreatic cystic lesions

BACKGROUND AND AIMS

EUS-guided microforceps biopsy sampling (MFB) and needle-based confocal laser endomicroscopy (nCLE) are emerging diagnostic tools for pancreatic cystic lesions (PCLs). There is a paucity of data regarding their performance and impact. The aim of this study was to compare diagnostic outcomes and changes in clinical management resulting from MFB and nCLE use in PCLs.

METHODS

This was a single-center retrospective study of patients with PCLs who underwent combined EUS-guided FNA, MFB, and nCLE. Primary outcomes included diagnostic yield (specific PCL type) and change in clinical management for each modality compared with the current "composite standard" (CS) obtained by combining clinical, morphologic, cyst fluid cytology, and chemical analysis.

RESULTS

Forty-four cysts were studied in 44 patients. Technical success was 100% for EUS-FNA, 88.6% for MFB, and 97.7% for nCLE. Of 44 procedures, there was 1 adverse event (2.3%, an infected pseudocyst). Diagnostic yield for each individual modality was 34.1% for CS, 75.0% for MFB (P < .05 vs CS), and 84.1% for nCLE (P < .05 vs CS). Diagnostic yield for combined tests was 79.5% for CS/MFB, 88.6% for CS/nCLE, and 93.2% for CS/MFB/nCLE (P = not significant). Compared with the CS, the use of MFB, nCLE, and their combination led to overall change in clinical management in 38.6%, 43.2%, and 52.3% of cases, respectively. MFB and nCLE led to an overall increase in discontinuation of surveillance (MFB, 34.1% [P < .05]; nCLE, 31.8% [P < .05]), led by a reduction in the indication for follow-up radiologic or endoscopic studies (MFB, 34.1% [P < .05]; nCLE, 38.6% [P < .05]). Based on MFB and nCLE, 2 of 28 (7.1%) and 3 of 28 (10.7%) patients who would have undergone further surveillance were referred for surgery.

CONCLUSIONS

In the evaluation of PCLs, the use of combined EUS-guided FNA, MFB, and nCLE is safe. MFB and nCLE led to significant improvements in specific PCL diagnosis, which in turn has major impacts in clinical management.

Elevating pancreatic cystic lesion stratification: Current and future pancreatic cancer biomarker(s)

Pancreatic ductal adenocarcinoma (PDAC) is an incredibly deadly disease with a 5-year survival rate of 9%. The presence of pancreatic cystic lesions (PCLs) confers an increased likelihood of future pancreatic cancer in patients placing them in a high-risk category. Discerning concurrent malignancy and risk of future PCL progression to cancer must be carefully and accurately determined to improve survival outcomes and avoid unnecessary morbidity of pancreatic resection. Unfortunately, current image-based guidelines are inadequate to distinguish benign from malignant lesions. There continues to be a need for accurate molecular and imaging biomarker(s) capable of identifying malignant PCLs and predicting the malignant potential of PCLs to enable risk stratification and effective intervention management. This review provides an update on the current status of biomarkers from pancreatic cystic fluid, pancreatic juice, and seromic molecular analyses and discusses the potential of radiomics for differentiating PCLs harboring cancer from those that do not.

Prevalence of pancreatic cystic lesions detected by magnetic resonance imaging in the Chinese population

BACKGROUND AND AIM

Incidental pancreatic cystic lesions (PCLs) are being diagnosed more frequently. However, little is known about the prevalence of PCLs in the Chinese population. The aim of the study was to assess the crude prevalence of PCLs in individuals who underwent magnetic resonance imaging (MRI).

METHODS

Data from consecutive patients who underwent MRI without pancreatic indications were included. MRI images were reviewed for the presence of pancreatic cysts. The prevalence of PCLs and high-risk PCLs in different gender and age groups was calculated. To assess the crude prevalence, the prevalence and demographic data were standardized on the basis of Chinese national population data in 2017.

RESULTS

A total of 10 987 individuals were included (7344 men). Incidental PCLs were identified in 212 individual (128 men). The prevalence of PCLs was 1.93%, and PCLs were more often discovered in women (1.74% vs 2.31%, P = 0.043). Prevalence increased with age (r = 0.804, P < 0.001). The prevalence of high-risk PCLs was 0.12% (n = 13). Gender predominance and age distribution showed no difference between high-risk PCLs and low-risk PCLs (P = 0.234 and P = 0.855), but cysts located in the pancreatic head were more likely to develop into high-risk PCLs (P = 0.001). After data standardization, the crude prevalence of PCLs was 1.31%, and PCLs were more often discovered in women (1.11% vs 1.5%, P < 0.001). The crude prevalence of high-risk PCLs was 0.07%.

CONCLUSION

Pancreatic cystic lesions in the Chinese population are not rare. The prevalence of PCLs increased with age and is higher in the female population. The prevalence of high-risk PCLs should not be ignored.

Pancreatic Cysts: Sinister Findings or Incidentalomas?

Pancreatic cysts are common and are incidentally detected in up to 13.5% of individuals. Intraductal papillary mucinous neoplasm (IPMN) and mucinous cystic neoplasm (MCN) are precursors to pancreatic adenocarcinoma. Most will never develop into pancreatic cancer. Several types of pancreatic cysts have no malignant potential. Solid tumors can present as a pancreatic cysts. Guidelines recommend surveillance. Management includes differentiating IPMNs and MCNs from other types, identifying those at highest risk of harboring pancreatic cancer or high-grade dysplasia, and referral to a multidisciplinary group for evaluation and consideration of surgical resection.

Current Guideline Controversies in the Management of Pancreatic Cystic Neoplasms

Pancreatic cystic lesions are a common clinical entity. The majority are neoplastic and have the potential for malignant transformation. To assist with patient management, a number of clinical guidelines have been developed over the past decade. However, controversies exist in regards to the various guidelines and treatment strategies they offer. This article will review the various clinical guidelines for management of pancreatic cysts, describe the limitations of these guidelines, and present future directions for improvement in clinical decision making for patients diagnosed with a pancreatic cystic neoplasm.

Management Algorithm for Cystic Pancreatic Lesions

Cystic pancreatic lesions are common findings in an aging society due to an increasing availability of high-resolution cross-sectional imaging. Although the overall prevalence of malignancy and the rate of malignant conversion are low, especially mucinous pancreatic cystic lesions such as intraductal papillary mucinous neoplasm and mucinous cystic neoplasm harbor significant malignant potential depending on their morphology and size. Recently updated guidelines recommend sophisticated algorithms for initial workup and surveillance based on individual characteristics of the cystic lesion and the patient, thus weighing the lifetime risk for malignancy against the adverse event rate of potentially curative surgery in the light of number and location of cystic lesions, age of the patient, comorbidities, and the resulting life expectancy as well as the effect of repeated follow-up examinations on the patient's quality of life. This article summarizes recommendations from available guidelines and proposes a pragmatic approach to the clinical management of pancreatic cystic lesions.

Radiological Workup of Cystic Neoplasms of the Pancreas

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

ACG Clinical Guideline: Diagnosis and Management of Pancreatic Cysts

Pancreatic cysts are very common with the majority incidentally identified. There are several types of pancreatic cysts; some types can contain cancer or have malignant potential, whereas others are benign. However, even the types of cysts with malignant potential rarely progress to cancer. At the present time, the only viable treatment for pancreatic cysts is surgical excision, which is associated with a high morbidity and occasional mortality. The small risk of malignant transformation, the high risks of surgical treatment, and the lack of high-quality prospective studies have led to contradictory recommendations for their immediate management and for their surveillance. This guideline will provide a practical approach to pancreatic cyst management and recommendations for cyst surveillance for the general gastroenterologist.

Novel Biomarkers for Pancreatic Cysts

With increased utilization and ongoing advancements in cross-sectional abdominal imaging, the identification of a pancreatic cyst has become a frequent finding. While many pancreatic cysts are associated with a benign clinical course, others may transform into pancreatic ductal adenocarcinoma. However, distinguishing a benign from a malignant pancreatic cyst or pancreatic cyst with malignant potential on the basis of standard clinical findings, imaging parameters and ancillary studies can be challenging. Hence, a significant interest within the past decade has been the identification of novel biomarkers to accurately classify and prognosticate a pancreatic cyst. Within this review, we discuss novel DNA, miRNA, protein and metabolite biomarkers, and their relevance in clinical practice. In addition, we focus on future areas of research that have the potential to change pancreatic cyst management.

Pancreatic Cysts - Part 2: Should We Be Less Cyst Centric?

The management of pancreatic cysts is a common problem faced by physicians and surgeons. Pancreatic cysts are important because some of them are mucin-producing cysts (MPCs), which may harbor or develop pancreatic ductal adenocarcinoma. Thus, accurate classification of pancreatic cysts and diagnosis of MPCs offer a potential for the prevention or early detection of pancreatic cancer. However, the diagnosis and management of asymptomatic pancreatic cysts are complicated by 2 factors. First, incidentally detected pancreatic cysts are often misdiagnosed as branch duct intraductal papillary mucinous neoplasms. Although most are MPCs, there are other types of cysts, such as serous cystadenomas, which are managed differently. Second, only a minority of MPCs will ultimately develop into invasive pancreatic ductal adenocarcinoma. Thus, on the one hand, pancreatic cysts offer a unique opportunity to identify precursors to pancreatic cancer and improve outcomes. On the other hand, misdiagnosis and overzealous testing or unnecessary surgery may lead to high cost and harm to patients. Several guidelines have been developed by various groups for the management of pancreatic cysts. In this article, we review the strengths and weaknesses of the American Gastroenterology Association guidelines, highlight key recommendations requiring further validation, and provide our balanced approach to diagnosing and managing pancreatic cysts.

Natural history of intraductal papillary mucinous neoplasm and non-neoplastic cyst: long-term imaging follow-up study

BACKGROUND

To identify differences in incidence and mortality of pancreatic cancer (PC) between intraductal papillary mucinous neoplasm (IPMN) and non-neoplastic cyst.

METHODS

Patients with pancreatic cyst (n = 526; 263 with IPMN and 263 with non-neoplastic cyst matched for age, sex, and diagnosis year) were periodically followed-up with imaging. Hazard ratio (HR), standardized incidence ratio (SIR), and standardized mortality ratio (SMR) for PC and PC-related mortality were estimated.

RESULTS

During a mean follow-up of 57.5 months with 3,376 computed tomography scans and 1,079 magnetic resonance imaging scans, 5-year cumulative PC incidence was 4.0% for IPMN and 0% for non-neoplastic cyst, respectively (HR 5.2; P = 0.031). During a mean follow-up of 73.1 months, 5-year cumulative PC-related mortality was 2.6% for IPMN and 0% for non-neoplastic cyst, respectively (HR 4.5; P = 0.05). Compared with the general population in Japan, patients with IPMN, but not those with non-neoplastic cyst, had significantly increased risks of PC incidence (SIR 22.03) and related mortality (SMR 15.9).

CONCLUSIONS

During long-term imaging follow-up, patients with IPMN developed PC over time, whereas none of the patients with non-neoplastic cyst developed it within 5 years. Compared with the general population, patients with IPMN, but not those with non-neoplastic cyst, were at risk of PC and related mortality.

Biliary and pancreatic complications of molecular targeted therapies in cancer imaging

The purpose of this review is to familiarize radiologists with the different imaging manifestations of biliary and pancreatic toxicity of molecular targeted therapies. The advent of molecular targeted therapies for cancer treatment has prompted radiologists to be familiar with these new molecules, their patterns of response, and their class-specific toxicities. While liver and bowel toxicities have been extensively reported in literature, less is known about the pathogenesis and imaging of toxicity involving the pancreatobiliary system. Biliary and pancreatic toxicity of molecular targeted therapies present with variable manifestations and varying degrees of severity, from asymptomatic liver function tests elevation to acute pancreatitis or cholecystitis. Management of these conditions depends on the clinical scenario and the severity of the findings. In this article, we will (1) present the various classes of molecular targeted therapies most commonly associated with biliary and pancreatic toxicity; (2) illustrate imaging findings of drug-associated biliary and pancreatic injuries and their possible differential diagnosis; and (3) provide a guide for management of these conditions.

Management of Incidental Pancreatic Cysts: A White Paper of the ACR Incidental Findings Committee

The ACR Incidental Findings Committee (IFC) presents recommendations for managing pancreatic cysts that are incidentally detected on CT or MRI. These recommendations represent an update from the pancreatic component of the JACR 2010 white paper on managing incidental findings in the adrenal glands, kidneys, liver, and pancreas. The Pancreas Subcommittee-which included abdominal radiologists, a gastroenterologist, and a pancreatic surgeon-developed this algorithm. The recommendations draw from published evidence and expert opinion, and were finalized by informal iterative consensus. Algorithm branches successively categorize pancreatic cysts based on patient characteristics and imaging features. They terminate with an ascertainment of benignity and/or indolence (sufficient to discontinue follow-up), or a management recommendation. The algorithm addresses most, but not all, pathologies and clinical scenarios. Our goal is to improve quality of care by providing guidance on how to manage incidentally detected pancreatic cysts.

Comparison of endoscopic ultrasound, computed tomography and magnetic resonance imaging in assessment of detailed structures of pancreatic cystic neoplasms

AIM

To evaluate the advantages of endoscopic ultrasound (EUS) in the assessment of detailed structures of pancreatic cystic neoplasms (PCNs) compared to computed tomography (CT) and magnetic resonance imaging (MRI).

METHODS

All patients with indeterminate PCNs underwent CT, MRI, and EUS. The detailed information, including size, number, the presence of a papilla/nodule, the presence of a septum, and the morphology of the pancreatic duct of PCNs were compared among the three imaging modalities. The size of each PCN was determined using the largest diameter measured. A cyst consisting of several small cysts was referred to as a mother-daughter cyst. Disagreement among the three imaging modalities regarding the total number of mother cysts resulted in the assumption that the correct number was the one in which the majority of imaging modalities indicated.

RESULTS

A total of 52 females and 16 males were evaluated. The median size of the cysts was 42.5 mm by EUS, 42.0 mm by CT and 38.0 mm by MRI; there was no significant difference in size as assessed among the three imaging techniques. The diagnostic sensitivity and ability of EUS to classify PCNs were 98.5% (67/68) and 92.6% (63/68), respectively. These percentages were higher than those of CT (73.1%, P < 0.001; 17.1%, P < 0.001) and MRI (81.3%, P = 0.001; 20.3%, P < 0.001). EUS was also able to better assess the number of daughter cysts in mother cysts than CT (P = 0.003); however, there was no significant difference between EUS and MRI in assessing mother-daughter cysts (P = 0.254). The papilla/nodule detection rate by EUS was 35.3% (24/68), much higher than those by CT (5.8%, 3/52) and MRI (6.3%, 4/64). The detection rate of the septum by EUS was 60.3% (41/68), which was higher than those by CT (34.6%, 18/52) and by MRI (46.9%, 30/64); the difference between EUS and CT was significant (P = 0.02). The rate of visualizing the pancreatic duct using EUS was 100%, whereas using CT and MRI it was less than 10%.

CONCLUSION

EUS helps visualize the detailed structures of PCNs and has many advantages over CT and MRI. EUS is valuable in the diagnosis and assessment of PCNs.

[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.

Pancreatic Cystosis in Two Adolescents with Cystic Fibrosis

We present pancreatic cystosis in two adolescents with cystic fibrosis, a 13-year-old girl and an 18-year-old boy. In pancreatic cystosis, which is a rare manifestation of CF, the pancreatic parenchyma is replaced with multiple cysts of different sizes. Pancreatic cystosis is mainly an imaging based diagnosis and frequent follow-up should be recommended.

Role of endoscopic ultrasound-guided fine-needle aspiration cytology, viscosity, and carcinoembryonic antigen in pancreatic cyst fluid

Due to the advances and increased utility of abdominal cross-sectional imaging, the diagnosis of pancreatic cysts continues to increase. Many endosonographers, pancreatologists, and surgeons consider endoscopic ultrasound (EUS) to be an essential tool in the management of pancreatic cystic lesions (PCLs). EUS can help distinguish between mucinous and nonmucinous lesions and may identify the specific cyst type. EUS achieves these goals by delineating the cyst morphology, identifying high risk stigmata and worrisome features, and through image-guided fine-needle aspiration (FNA) and cyst fluid analysis. However, recent consensus statements have called to question the utility and diminished the role of EUS in this setting. The aim of this review is to assess the role and advances of EUS-FNA in pancreatic cyst fluid analysis, specifically in terms of fluid cytology, viscosity, and carcinoembryonic antigen (CEA) analysis.

Preoperative Diagnosis of Pancreatic Cystic Lesions: The Accuracy of Endoscopic Ultrasound and Cross-Sectional Imaging

OBJECTIVE

This study aimed to evaluate the accuracy of endoscopic ultrasound (EUS) and cross-sectional imaging including multidetector computed tomography (MDCT) or magnetic resonance imaging (MRI) as a preoperative diagnostic modality for the pancreatic cystic lesions.

METHODS

Three hundred eighteen patients with surgically proven pancreatic cystic lesions were enrolled as a study cohort from 1998 to 2011. Preoperative radiological, EUS, and final histopathologic diagnosis were correlated to measure several kinds of diagnostic performance.

RESULTS

A total of 318 patients underwent preoperative MDCT, with additional imaging modalities such MRI and/or EUS in 215 (67.6%) and 108 (34.0%) patients, respectively. κ Values among the different modalities were as follows: MDCT versus pathology = 0.52 (P < 0.0001), MDCT + MRI versus pathology = 0.674 (P < 0.0001), and EUS versus pathology = 0.558 (P < 0.0001). The sensitivity and specificity in terms of ability to predict neoplastic cysts were as follows: MDCT, 83.1%/70.0%; MDCT + MRI, 94.7%/58.7%; and EUS, 88.5%/52.9%. The diagnostic accuracies of MDCT and MDCT + MRI were 61.4% (62/101) and 80.5% (173/215), respectively, and that of EUS was 70.4% (76/108).

CONCLUSIONS

Magnetic resonance imaging as an additional diagnostic modality to MDCT increased the accuracy, sensitivity, and specificity, as well in terms of predicting neoplastic cysts.

Cyst Features and Risk of Malignancy in Intraductal Papillary Mucinous Neoplasms of the Pancreas: Imaging and Pathology

Background

Intraductal papillary mucinous neoplasms (IPMNs) display diverse macroscopic, histological, and immunohistochemical characteristics with typical morphological appearance in magnetic resonance imaging. Depending on those, IPMNs may show progression into invasive carcinomas with variable frequency. Overall, IPMN-associated invasive carcinomas are found in about 30% of all IPMNs, revealing phenotpyes comparable with conventional ductal adenocarcinomas or mucinous (colloid) carcinomas of the pancreas. In Sendai-negative side-branch IPMNs, however, the annual risk of the development of invasive cancer is 2%; thus, risk stratification with regard to imaging and preoperative biomarkers and cytology is mandatory.

Methods and Results

The present study addresses the radiological and interventional preoperative measures including histological features to determine the risk of malignancy and the prognosis of IPMNs.

Conclusion

While preoperative imaging largely relies on the detection of macroscopic features of IPMNs, which are associated with a divergent risk of malignant behavior, in resected specimens the determination of the grade of dysplasia and the detection of an invasive component are the most important features to estimate the prognosis of IPMNs.

Diagnosis and management of cystic lesions of the pancreas

Pancreatic cystic lesions (PCLs) are being increasingly identified in recent years. They show a wide spectrum of imaging and clinical features. The diagnosis and discrimination of these lesions are very important because of the risk for concurrent or later development of malignancy. PCLs are usually first diagnosed and characterized by conventional imaging modalities such as trans-abdominal ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI). However, their ability to differentiate the benign and malignant lesions remains limited. Endoscopic US may be more helpful for the diagnosis and differentiation of PCLs because of its high resolution and better imaging characteristics than cross-sectional imaging modalities. It also allows for fine-needle aspiration (FNA) of cystic lesions for biochemical, cytological and DNA analysis that might be further helpful for diagnosis and differentiation. The management options of PCLs are to observe, endoscopic treatment or surgical resection. However, the decision for management is sometimes hampered by limitations in current diagnostic and tissue sampling techniques. As further diagnostic and non-invasive management options become available, clinical decision-making will become much easier for these lesions.

Systematic Review of Pancreatic Cyst Fluid Biomarkers: The Path Forward

There is significant research interest in developing and validating novel pancreatic cyst-fluid biomarkers given the increasing recognition of the prevalence of pancreatic cysts and their associated malignant potential. Although current international consensus guidelines are helpful, they fail to diagnose with certainty the cyst type and the level of epithelial dysplasia. They also fall short in predicting the future likelihood of malignant transformation. A systematic review was performed with the objective of summarizing cyst-fluid-based biomarkers that have been published in the medical literature over the past 10 years and characterizing the current quality of evidence. Our review demonstrates that there is an increasing interest in this topic with several different and innovative approaches including DNA, RNA, proteomic, and metabolomics profiling. Further techniques to improve upon cytological yield have also been studied. Besides identifying potentially useful clinical biomarkers, these empiric approaches have provided further insight into their pathogenesis. The level of evidence for the vast majority of these studies, however, is limited to retrospective early validation studies. The path forward will be to select out the most promising biomarkers and develop multicenter consortiums capable of capturing adequate sample sizes with appropriate study designs.

Estimation of the prevalence of asymptomatic pancreatic cysts in the population of San Marino

BACKGROUND

There has been a dramatic increase in the number of pancreatic cystic lesions observed in the past two decades but data regarding the prevalence of cysts in the general population are lacking.

METHODS

All the individuals who undergo CT at the San Marino State Hospital are residents of the Republic of San Marino; their demographic distribution is available and precise. CT scans carried out over 1 year at the State Hospital were reviewed for asymptomatic pancreatic cysts.

RESULTS

1061 relevant CT scans were carried out on 814 patients; 762 individuals were eligible for the study and 650 patients underwent contrast-enhanced CT. Thirty-five patients had at least one cyst at contrast-enhanced CT (5.4%). The prevalence of cysts increased with increasing age up to 13.4% (95% CI 6.6-20) in individuals 80-89 years of age (p < .001). Cyst prevalence was significantly higher in patients who underwent CT for malignancy (p = .038) but this difference was no longer significant in multivariate analysis. The odds of a cyst being present increased by 1.05 (95% CI 1.02-1.09) for each increasing year of age (p = .002). Approximately a quarter of the patients with cysts died within 1 year after CT from non pancreas-related disease. The estimated standardized age-adjusted cyst prevalence is 2194 per 100,000 people.

CONCLUSIONS

The likelihood of having a pancreatic cyst correlates with increasing age, not with the presence of extra-pancreatic malignancies. The estimated prevalence of CT-detectable asymptomatic pancreatic cysts in the general population is 2.2%.

Automated pancreatic cyst screening using natural language processing: a new tool in the early detection of pancreatic cancer

INTRODUCTION

As many as 3% of computed tomography (CT) scans detect pancreatic cysts. Because pancreatic cysts are incidental, ubiquitous and poorly understood, follow-up is often not performed. Pancreatic cysts may have a significant malignant potential and their identification represents a 'window of opportunity' for the early detection of pancreatic cancer. The purpose of this study was to implement an automated Natural Language Processing (NLP)-based pancreatic cyst identification system.

METHOD

A multidisciplinary team was assembled. NLP-based identification algorithms were developed based on key words commonly used by physicians to describe pancreatic cysts and programmed for automated search of electronic medical records. A pilot study was conducted prospectively in a single institution.

RESULTS

From March to September 2013, 566,233 reports belonging to 50,669 patients were analysed. The mean number of patients reported with a pancreatic cyst was 88/month (range 78-98). The mean sensitivity and specificity were 99.9% and 98.8%, respectively.

CONCLUSION

NLP is an effective tool to automatically identify patients with pancreatic cysts based on electronic medical records (EMR). This highly accurate system can help capture patients 'at-risk' of pancreatic cancer in a registry.

To fine needle aspiration or not? An endosonographer's approach to pancreatic cystic lesions

Endoscopic ultrasound (EUS) guided fine needle aspiration (FNA) is an established diagnostic tool in the management of pancreatic cystic lesions (PCLs). Due to the proximity to the target lesion, the fine diagnostic needle travels through only minimal normal tissues. The risks of bleeding, pancreatitis and infection are small. Valuable diagnostic morphological information can be obtained by EUS before the use of FNA. The additional cytopathologic and cyst fluid analysis for the conventional markers such as amylase, carcinoembryonic antigen (CEA) and CA19.9 improves the diagnostic capability. Pancreatic cyst fluid CEA concentration of 192 ng/mL is generally the most agreed cutoff to differentiate mucinous from non-mucinous lesion. A fluid amylase level of <250 IU/L excludes the diagnosis of pseudocyst. Technical tips of EUS-FNA and the limitations of the procedure are discussed. Promising technique and FNA needle modifications have been described to improve the diagnostic yield at the cytopathologic analysis. The use of novel cyst fluid proteomics and deoxyribonucleic acid-based biomarkers of the PCLs are reviewed. Although it is considered a safe procedure, EUS-FNA is not a routine in every patient. Recommendations of the role of EUS-FNA at various common clinical scenarios are discussed.