Incidental pancreatic cystic lesions: is there a relationship with the development of pancreatic adenocarcinoma and all-cause mortality?

Percentage of Pancreatic Cysts on MRI With a Pancreatic Carcinoma: Systematic Review and Meta-Analysis

BACKGROUND

Pancreatic cystic lesions (PCLs) are frequent on MRI and are thought to be associated with pancreatic adenocarcinoma (PDAC) necessitating long-term surveillance based on older studies suffering from selection bias.

PURPOSE

To establish the percentage of patients with PCLs on MRI with a present or future PDAC.

STUDY TYPE

Systematic review, meta-analysis.

POPULATION

Adults with PCLs on MRI and a present or future diagnosis of PDAC were eligible. MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Scopus were searched to April 2022 (PROSPERO:CRD42022320502). Studies limited to PCLs not requiring surveillance, <100 patients, or those with a history/genetic risk of PDAC were excluded.

FIELD STRENGTH/SEQUENCE

≥1.5 T with ≥1 T2-weighted sequence.

ASSESSMENT

Two investigators extracted data, with discrepancies resolved by a third. QUADAS-2 assessed bias. PDAC was diagnosed using a composite reference standard.

STATISTICAL TESTS

A meta-analysis of proportions was performed at the patient-level with 95% confidence intervals (95% CI).

RESULTS

Eight studies with 1289 patients contributed to the percentage of patients with a present diagnosis of PDAC, and 10 studies with 3422 patients to the percentage with a future diagnosis. Of patients with PCLs on MRI, 14.8% (95% CI 2.4-34.9) had a PDAC at initial MRI, which decreased to 6.0% (2.2-11.3) for studies at low risk of bias. For patients without PDAC on initial MRI, 2.0% (1.1-3.2) developed PDAC during surveillance, similar for low risk of bias studies at 1.9% (0.7-3.6), with no clear trend of increased PDAC for longer surveillance durations. For patients without worrisome features or high-risk stigmata, 0.9% (0.1-2.2) developed PDAC during surveillance. Of 10, eight studies had a median surveillance ≥3 years (range 3-157 months). Sources of bias included retrospectively limiting PCLs to those with histopathology and inconsistent surveillance protocols.

DATA CONCLUSION

A low percentage of patients with PCLs on MRI develop PDAC while on surveillance. The first MRI revealing a PCL should be scrutinized for PDAC.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Pancreatic cancer risk in diabetic patients using the Japanese Regional Insurance Claims

Pancreatic cancer presents a critical health issue characterized by low survival rates. Identifying risk factors in specific populations, such as those with diabetes, is crucial for early detection and improved outcomes. This study aimed to identify risk factors for pancreatic cancer in diabetic patients using a longitudinal cohort from the Shizuoka Kokuho database, spanning April 2012 to September 2021. Diabetic patients were identified and monitored for the onset of pancreatic cancer. Factors analyzed included age, sex, the Elixhauser comorbidity index, and specific comorbidities. Statistical analyses involved univariate and multivariate Cox proportional hazards regression. The study identified 212,775 as diabetic patients and 1755 developed pancreatic cancer during the period. The annual incidence rate of pancreatic cancer in this group was 166.7 cases per 100,000 person-years. The study identified older age, male sex, a history of liver disease, chronic pancreatitis, and pancreatic cystic lesions as significant risk factors for pancreatic cancer in diabetic patients. The study also highlighted the absence of a significant association between diabetes type or diabetic complications and the onset of pancreatic cancer. These findings may aid in the early diagnosis of pancreatic cancer in diabetic patients and may inform revisions in screening practices in diabetic patients.

Pancreatic cyst prevalence and detection with photon counting CT compared with conventional energy integrating detector CT

PURPOSE

To calculate the prevalence of pancreatic cysts on photon counting CT (PCCT) and compare with that of 128-slice conventional energy-integrating detector CT (EIDCT).

METHOD

A retrospective single institution database search identified all contrast-enhanced abdominal CT examinations performed at an outpatient facility that has both a PCCT and EIDCT between 4/11/2022 and 7/26/2022. The presence and size of pancreatic cysts were recorded. In patients with PCCT reported pancreatic cysts, prior CT imaging (EIDCT) was reviewed for reported pancreatic cysts. Fisher's exact test was used to compare the pancreatic cyst detection rate for PCCT and EIDCT. Wilcoxon rank sum test was used to compare cyst size and patient age. A p <.05 indicated statistical significance.

RESULTS

2494 patients were included. Our pancreatic cyst detection rate was 4.9 % (49/1009) with PCCT and 3.0 % (44/1485) for EIDCT (p =.017). For CT angiograms, pancreatic cysts were detected in 6.6 % (21/319) with PCCT and 0.0 % (0/141) with EIDCT (p <.001). Pancreatic cyst detection rate was not statistically different for portal venous, enterography, renal mass, pancreas, 3-phase liver, or venogram protocols (all p >.05). Mean[SD] pancreatic cyst size was 13.7[9.7]mm for PCCT and 15.3[14.7] for EIDCT (p =.95). 55.1 % (27/49) of PCCT and 61.4 % (27/44) of EIDCT that described pancreatic cysts had prior contrast-enhanced EIDCTs. Of these, 40.7 % (11/27) of PCCT and 14.8 % (4/27) of EIDCT described pancreatic cysts were not previously reported (p =.027).

CONCLUSIONS

Photon-counting CT afforded greater pancreatic cyst detection than conventional energy-integrating detector CT, particularly with CT angiograms.

International evidence-based Kyoto guidelines for the management of intraductal papillary mucinous neoplasm of the pancreas

This study group aimed to revise the 2017 international consensus guidelines for the management of intraductal papillary mucinous neoplasm (IPMN) of the pancreas, and mainly focused on five topics; the revision of high-risk stigmata (HRS) and worrisome features (WF), surveillance of non-resected IPMN, surveillance after resection of IPMN, revision of pathological aspects, and investigation of molecular markers in cyst fluid. A new development from the prior guidelines is that systematic reviews were performed for each one of these topics, and published separately to provide evidence-based recommendations. One of the highlights of these new "evidence-based guidelines" is to propose a new management algorithm, and one major revision is to include into the assessment of HRS and WF the imaging findings from endoscopic ultrasound (EUS) and the results of cytological analysis from EUS-guided fine needle aspiration technique, when this is performed. Another key element of the current guidelines is to clarify whether lifetime surveillance for small IPMNs is required, and recommends two options, "stop surveillance" or "continue surveillance for possible development of concomitant pancreatic ductal adenocarcinoma", for small unchanged BD-IPMN after 5 years surveillance. Several other points are also discussed, including identifying high-risk features for recurrence in patients who underwent resection of non-invasive IPMN with negative surgical margin, summaries of the recent observations in the pathology of IPMN. In addition, the emerging role of cyst fluid markers that can aid in distinguishing IPMN from other pancreatic cysts and identify those IPMNs that harbor high-grade dysplasia or invasive carcinoma is discussed.

Investigating the early diagnosis of pancreatic cancer by surveillance of patients with "K-sign" of the pancreas by computed tomography: A prospective study

BACKGROUND

We previously conducted a retrospective study investigating pancreatic morphological abnormalities that lead to early diagnosis of pancreatic cancer (PC) using computed tomography (CT). We reviewed 41 of 308 PC patients between 2011 and 2017 who had previously undergone CT to look for morphological changes leading to cancer development. In 24 patients (58.5%), a K-shaped constriction of the pancreas ("K-sign") was observed before the appearance of cancer. This study aimed to investigate whether an early PC diagnosis is possible by prospective CT follow-up of patients with the K-sign.

METHODS

We investigated PC development through prospective surveillance of patients exhibiting K-signs identified on CT.

RESULTS

Of approximately 87 000 CT scans performed between April 2019 and August 2022, the K-sign was observed in 54 patients. A total of 30 patients provided informed consent and were subsequently monitored using CT. Five patients (16.7%) were diagnosed with PC and underwent surgery after 3-24 months follow-up. Pathologically, four of five patients (80%) were diagnosed with early-stage pancreatic cancer (stage 0-IA). All patients exhibited defects in acinar structure, fibrous tissue, fat replacement, and inflammatory cells, suggesting their potential involvement in PC development.

CONCLUSION

The detection and surveillance of the K-sign may be helpful for early PC diagnosis.

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.

Burden of New Pancreatic Cyst Diagnosis

Pancreatic cysts are an increasingly identified entity with significant health care implications. Although some cysts present with concurrent symptoms that often require operative intervention, the advent of improved cross-sectional imaging has heralded an era of increased incidentally detected pancreatic cysts. Although the rate of malignant progression in pancreatic cysts remains low, the poor prognosis of pancreatic malignancy has driven recommendations for ongoing surveillance. A uniform consensus has not been reached on the management and surveillance of pancreatic cysts leading clinicians to grapple with the burden of how best to approach pancreatic cysts from a health, psychosocial, and cost perspective.

Deep Learning to Detect Pancreatic Cystic Lesions on Abdominal Computed Tomography Scans: Development and Validation Study

BACKGROUND

Pancreatic cystic lesions (PCLs) are frequent and underreported incidental findings on computed tomography (CT) scans and can evolve to pancreatic cancer-the most lethal cancer, with less than 5 months of life expectancy.

OBJECTIVE

The aim of this study was to develop and validate an artificial deep neural network (attention gate U-Net, also named "AGNet") for automated detection of PCLs. This kind of technology can help radiologists to cope with an increasing demand of cross-sectional imaging tests and increase the number of PCLs incidentally detected, thus increasing the early detection of pancreatic cancer.

METHODS

We adapted and evaluated an algorithm based on an attention gate U-Net architecture for automated detection of PCL on CTs. A total of 335 abdominal CTs with PCLs and control cases were manually segmented in 3D by 2 radiologists with over 10 years of experience in consensus with a board-certified radiologist specialized in abdominal radiology. This information was used to train a neural network for segmentation followed by a postprocessing pipeline that filtered the results of the network and applied some physical constraints, such as the expected position of the pancreas, to minimize the number of false positives.

RESULTS

Of 335 studies included in this study, 297 had a PCL, including serous cystadenoma, intraductal pseudopapillary mucinous neoplasia, mucinous cystic neoplasm, and pseudocysts . The Shannon Index of the chosen data set was 0.991 with an evenness of 0.902. The mean sensitivity obtained in the detection of these lesions was 93.1% (SD 0.1%), and the specificity was 81.8% (SD 0.1%).

CONCLUSIONS

This study shows a good performance of an automated artificial deep neural network in the detection of PCL on both noncontrast- and contrast-enhanced abdominal CT scans.

Association of Standardized Radiology Reporting and Management of Abdominal CT and MRI With Diagnosis of Pancreatic Cancer

BACKGROUND & AIMS

Follow-up of abdominal computed tomography (CT) and magnetic resonance imaging (MRI) findings suspicious for pancreatic cancer may be delayed if documentation is unclear. We evaluated whether standardized reporting and follow-up of imaging results reduced time to diagnosis of pancreatic cancer.

METHODS

We used a quasi-experimental stepped-wedge cluster design to evaluate the effectiveness of newly implemented radiology reporting system. The system standardizes the reporting of CT and MRI reports using hashtags that classify pancreatic findings. The system also automates referral of patients with findings suspicious for pancreatic cancer to a multidisciplinary care team for rapid review and follow-up. The study examined 318,331 patients who underwent CT or MRI that included the abdomen from 2016 through 2019 who had not had an eligible CT or MRI in the preceding 24 months. We evaluated the association of the intervention with incidence of pancreatic cancer within 60 days and 120 days after imaging.

RESULTS

Thirty-eight percent of patients received the intervention, and 1523 patients (0.48%) were diagnosed with pancreatic cancer. In multivariable analysis accounting for age, race/ethnicity, sex, Charlson comorbidity, history of cancer, diabetes, and 4-month calendar period, the intervention was associated with nearly 50% greater odds of diagnosing pancreatic cancer within 60 days (adjusted odds ratio, 1.47; 95% confidence interval, 1.05-2.06) and 120 days (adjusted odds ratio, 1.46; 95% confidence interval, 1.04-2.06).

CONCLUSIONS

In this large quasi-experimental, community-based observational study, implementing standardized reporting of abdominal CT and MRI reports with clinical navigation was effective for increasing the detection and diagnosis of pancreatic cancer.

Accelerated Pancreatobiliary MRI for Pancreatic Cancer Surveillance in Patients With Pancreatic Cystic Neoplasms

BACKGROUND

Pancreatobiliary MRI is often recommended for patients at risk of developing pancreas cancer. But the surveillance MRI protocol has not yet been widely accepted.

PURPOSE

To establish an accelerated MRI protocol targeting the table time of 15 minutes for pancreatic cancer surveillance and test its performance in lesion characterization.

STUDY TYPE

Prospective.

POPULATION

A total of 30 participants were enrolled, who were undergoing follow-up care for intraductal papillary mucinous neoplasms or newly diagnosed pancreatic cysts (≥10 mm) and were scheduled for or had recently undergone contrast-enhanced CT (CECT).

FIELD STRENGTH/SEQUENCE

A 3 T; heavily T2WI, 3D MRCP, DWI, dynamic T1WI, two-point Dixon.

ASSESSMENT

In-room time and table time were measured. Seven radiologists independently reviewed image quality of MRI and then the presence of high-risk stigmata and worrisome features in addition to diagnostic confidence for accelerated MRI, CECT, and the noncontrast part of accelerated MRI (NC-MRI).

STATISTICAL ANALYSIS

Fisher's exact test was used for categorical variables and either the Student's t-test or Mann-Whitney test was performed for continuous variables. The generalized estimated equation was used to compare the diagnostic performance of examinations on a per-patient basis. Interobserver agreement was evaluated via Fleiss kappa. A P value of <0.05 was considered to be statistically significant.

RESULTS

The in-room time was 18.5 ± 2.6 minutes (range: 13.7-24.9) and the table time was 13.9 ± 1.9 minutes (range: 10.7-17.5). There was no significant difference between the diagnostic performances of the three examinations (pooled sensitivity: 75% for accelerated MRI and CECT, 68% for NC-MRI, P = 0.95), with the highest significant diagnostic confidence for accelerated MRI (4.2 ± 0.1). With accelerated MRI, the interobserver agreement was fair to excellent for high-risk stigmata (κ = 0.34-0.98).

DATA CONCLUSION

Accelerated MRI protocol affords a table time of 15 minutes, making it potentially suitable for cancer surveillance in patients at risk of developing pancreatic cancer.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY STAGE: 2.

Pancreatic Cystic Lesions: Review of the Current State of Diagnosis and Surveillance

Pancreatic cystic lesions (PCLs) are both common and often incidental. These encompass a range of pathologies with varying degrees of concern for malignancy. Although establishing a diagnosis is helpful for determining malignant potential, many PCLs are either too small to characterize or demonstrate nonspecific morphologic features. The most salient modalities involved in diagnosis and surveillance are magnetic resonance imaging, multidetector computerized tomography, and endoscopic ultrasound. Fine needle aspiration has a role in conjunction with molecular markers as a diagnostic tool, particularly for identifying malignant lesions. Although several major consensus guidelines exist internationally, there remains uncertainty in establishing the strength of the association between all PCLs and pancreatic adenocarcinoma, and in showing a benefit from extended periods of imaging surveillance. No consensus exists between the major guidelines, particularly regarding surveillance duration, frequency, or endpoints. This review paper discusses PCL subtypes, diagnosis, and compares the major consensus guidelines with considerations for local adaptability along with questions regarding current and future priorities for research.

Pancreatic Cystic Lesions on MRI: What Is The Likelihood of a Present or Future Diagnosis of Pancreatic Carcinoma?

BACKGROUND

Pancreatic cystic lesions (PCLs) are followed for years due to older and likely biased works demonstrating a strong association with pancreatic carcinoma; more recent data are needed clarifying this relationship.

PURPOSE

To determine the association between PCLs on MRI and a synchronous or future diagnosis of pancreatic carcinoma.

STUDY TYPE

Single-center retrospective cohort.

POPULATION

A total of 192 patients (111 female, 58%) with median age 66 years (range 26-87 years) with PCLs on abdominal MRI from 2011 to 2016.

FIELD STRENGTH/SEQUENCES

1.5 T and 3 T, including T₂ WI, T₁ WI, diffusion weighted imaging and contrast-enhanced T₁ WI.

ASSESSMENT

Each PCL was reviewed independently by 2 of 10 fellowship-trained abdominal radiologists. Fukuoka guideline worrisome features and high-risk stigmata were evaluated. Follow-up imaging and clinical notes were reviewed within a system that captures pancreatic carcinoma for the region, for a median follow-up of 67 months (interquartile range: 43-88 months).

STATISTICAL TESTS

Pancreatic carcinoma prevalence and incidence rate for future carcinoma with 95% confidence intervals (95% CI). Fisher exact test, logistic regression with odds ratios (OR) and the Wilcoxon rank-sum test were used to assess PCL morphologic features with the Kolmogorov-Smirnov test used to assess for normality. P < 0.05 defined statistical significance.

RESULTS

The prevalence of pancreatic carcinoma on initial MRI showing a PCL was 2.4% (95% CI: 0.9%, 5.2%). Thickened/enhancing cyst wall was associated with pancreatic carcinoma, OR 52 (95% CI: 4.5, 1203). Of 189 patients with a PCL but without pancreatic carcinoma at the time of initial MRI, one developed high-grade dysplasia and none developed invasive carcinoma for an incidence rate of 0.97 (95% CI: 0.02, 5.43) and 0 (95% CI: 0, 3.59) cases per 1000 person-years, respectively.

DATA CONCLUSION

A low percentage of patients with a PCL on MRI had a pancreatic carcinoma at the time of initial evaluation and none developed carcinoma over a median 67 months of follow-up.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: 5.

Pancreatic Cystic Neoplasms

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

Incidence of pancreatic cancer during long-term follow-up in patients with incidental pancreatic cysts smaller than 2 cm

PURPOSE

To assess the long-term malignancy risk of incidental small pancreatic cysts.

MATERIALS AND METHODS

In this HIPAA-compliant, IRB-approved, retrospective, multi-institutional study, the long-term incidence of pancreatic cancer was compared between patients with and without small pancreatic cysts. Patients with incidental pancreatic cysts ≥ 0.5 and < 2.0 cm in maximal diameter, detected on MRI performed between 1999 and 2011, represented the "small pancreatic cyst" group. Patients that underwent MRI between 2005 and 2011 and had no reported pancreatic cysts represented the comparison "no cyst" group.

RESULTS

The "small pancreatic cyst" group included 267 patients, ages 63.4 ± 11.8 years, 166/267 (62%) women with a mean follow-up of 8.6 ± 4.3 years, median 9.2 years; the "no cyst" group included 1,459 patients, ages 64.6 ± 12 years, 794/1,459 (54%) women with a mean follow-up of 7.0 ± 4.2 years, median 7.8 (p values 0.12, 0.02, < 0.001, respectively). Two/267 (0.7%) patients developed pancreatic cancer at a separate location from the known cyst in the "small pancreatic cyst" group, with a cancer rate of 0.9 (95% CI 0.1-3.1) cases per 1,000 patient-years. In the "no cyst" cohort, 18/1,459 (1.2%) patients developed pancreatic cancer, with a cancer rate of 1.8 (95% CI 1.2-3.1) cases per 1,000 patient-years (p = 0.6). The all-cause mortality was similar in both groups: 57/267 (21%) vs. 384/1,459 (26%) (p = 0.09).

CONCLUSION

The long-term risk of pancreatic malignancy in asymptomatic patients with incidental pancreatic cysts less than 2 cm is 0.9 cases per 1,000 patient-years of follow-up, similar to those without pancreatic cysts. These very few pancreatic cancers developed at a separate location from the known cyst.

KEY POINTS

• After a median of 9.2 years of follow-up, the risk of pancreatic malignancy in patients with an asymptomatic small pancreatic cyst was 0.9 cases per 1,000 patient-years of follow-up, similar to those without pancreatic cysts. • Very few pancreatic cancer cases developed in the location separate from the known pancreatic cyst.

Utility of gadolinium for identifying the malignant potential of pancreatic cystic lesions

PURPOSE

To determine if gadolinium is necessary for the diagnosis of a pancreatic cystic lesion (PCL) as benign or malignant by assessing inter- and intra-observer agreement and diagnostic accuracy for the presence of worrisome features/high-risk stigmata on non-contrast MRI compared to MRI with and without contrast, with cytopathology as a reference standard.

METHODS

The institutional database was searched to identify consecutive patients that underwent EUS/FNA or surgical resection of an asymptomatic PCL performed from 01/01/2015 to 01/01/2019. Two abdominal radiologists independently evaluated PCLs on MRI with all sequences except for contrast-enhanced sequences followed by a second reading with data from the entire MRI including pre- and post-contrast sequences. Cyst size, growth, and the presence of worrisome features/high-risk stigmata were assessed for each cyst on both datasets.

RESULTS

There were 87 patients with 87 pancreatic cysts; 76(87.4%) were benign and 11 (12.7%) were malignant. The presence of any worrisome features/high-risk stigmata for reader 1 was concordant on both MRIs in 95.4% (83/87; k = 0.874) of cases and for reader 2 was concordant in 96.6% (84/87; k = 0.920) of cases. The diagnostic accuracy of the two datasets when the presence of any worrisome feature/high-risk stigmata was predictive of malignancy was identical for reader 1 (AUC = 0.622 for both; p = 1.0) and similar for reader 2 (AUC 0.569 and 0.589; p = 0.08) for both MRI datasets.

CONCLUSION

The addition of gadolinium had no significant impact in the diagnosis of a benign versus malignant PCL, with similar intra-observer agreement and diagnostic accuracy for both readers when using contrast-enhanced and unenhanced MRI datasets.

Updates in diagnosis and management of pancreatic cysts

Incidental pancreatic cysts are commonly encountered with some cysts having malignant potential. The most common pancreatic cystic neoplasms include serous cystadenoma, mucinous cystic neoplasm and intraductal papillary mucinous neoplasm. Risk stratifying pancreatic cysts is important in deciding whether patients may benefit from endoscopic ultrasound (EUS) or surgical resection. Surgery should be reserved for patients with malignant cysts or cysts at high risk for developing malignancy as suggested by various risk features including solid mass, nodule and dilated main pancreatic duct. EUS may supplement magnetic resonance imaging findings for cysts that remain indeterminate or have concerning features on imaging. Various cyst fluid markers including carcinoembryonic antigen, glucose, amylase, cytology, and DNA markers help distinguish mucinous from nonmucinous cysts. This review will guide the practicing gastroenterologist in how to evaluate incidental pancreatic cysts and when to consider referral for EUS or surgery. For presumed low risk cysts, surveillance strategies will be discussed. Managing pancreatic cysts requires an individualized approach that is directed by the various guidelines.

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.

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas: recommendations for Standardized Imaging and Reporting from the Society of Abdominal Radiology IPMN disease focused panel

There have been many publications detailing imaging features of malignant transformation of intraductal papillary mucinous neoplasms (IPMN), management and recommendations for imaging follow-up of diagnosed or presumed IPMN. However, there is no consensus on several practical aspects of imaging IPMN that could serve as a clinical guide for radiologists and enable future data mining for research. These aspects include how to measure IPMN, define reporting terminology, standardize reporting and unify guidelines for surveillance. The Society of Abdominal Radiology (SAR) created multiple Disease-Focused Panels (DFP) comprised multidisciplinary panel members who focus on a particular disease, with the goal to develop ways for radiologists to improve patient care, education, and research. DFP members met to identify the current controversies and limitations of imaging pancreatic IPMN. This paper aims to provide a practical review of the key imaging characteristics of IPMN for trainees and practicing radiologists, to guide uniformity of performance and interpretation of surveillance imaging studies, and to improve communication with clinicians by providing a lexicon and reporting template based on the experience of the SAR-DFP panel members.

Sonographic characteristics and follow-up of pancreatic cysts

OBJECTIVES

To assess sonographic characteristics and outcome of patients with pancreatic cystic lesions seen by ultrasound.

METHODS

From our ultrasound electronic reporting database we identified all patients in which "pancreatic cyst" or "pancreatic cysts" were reported from 1995 to 2018. In patients with more than one sonogram, the first was used for our study. For each case, we recorded sonographic characteristics, maximal diameter, cyst location, and results of follow-up ultrasound, CT or magnetic resonance imaging, as well as patient sex, age, relative clinical history, and endoscopic ultrasound (EUS) or surgical findings when available.

RESULTS

Our study included 177 patients of whom 121 were female (68.4%). Mean age at diagnosis was 65 (±16, SD, range 22-99). Ultrasound was the initial diagnostic test in 122 (68.9%). Mean diameter of the index cyst was 13.7 mm (±11.5 mm, SD, range 2-91 mm). Among 177 index cysts, 155 were simple and 22 complex. Three complex cysts were surgically resected, yielding a primary pancreatic malignancy, a metastasis, and an epithelial-lined cyst. One simple cyst was resected, yielding a benign intraductal papillary mucinous neoplasm. Seventeen patients underwent EUS showing six mucinous cysts and 11 nonmucinous cysts. One hundred-eighteen patients had follow-up imaging for a mean time of 5.6 years (±3.8, range 0.25-21 years). One patient was presumed to have primary pancreatic cancer. The overall rate for primary pancreatic malignancy was 1.7% (2/118).

CONCLUSIONS

Cystic pancreatic lesions seen on ultrasound are most often benign, with a low risk of pancreatic malignancy. Ultrasound is an excellent method to follow-up these cysts.

Molecular analysis of pancreatic cystic neoplasm in routine clinical practice

BACKGROUND

Cystic pancreatic lesions consist of a wide variety of lesions that are becoming increasingly diagnosed with the growing use of imaging techniques. Of these, mucinous cysts are especially relevant due to their risk of malignancy. However, morphological findings are often suboptimal for their differentiation. Endoscopic ultrasound fine-needle aspiration (EUS-FNA) with molecular analysis has been suggested to improve the diagnosis of pancreatic cysts.

AIM

To determine the impact of molecular analysis on the detection of mucinous cysts and malignancy.

METHODS

An 18-month prospective observational study of consecutive patients with pancreatic cystic lesions and an indication for EUS-FNA following European clinical practice guidelines was conducted. These cysts included those > 15 mm with unclear diagnosis, and a change in follow-up or with concerning features in which results might change clinical management. EUS-FNA with cytological, biochemical and glucose and molecular analyses with next-generation sequencing were performed in 36 pancreatic cysts. The cysts were classified as mucinous and non-mucinous by the combination of morphological, cytological and biochemical analyses when surgery was not performed. Malignancy was defined as cytology positive for malignancy, high-grade dysplasia or invasive carcinoma on surgical specimen, clinical or morphological progression, metastasis or death related to neoplastic complications during the 6-mo follow-up period. Next-generation sequencing results were compared for cyst type and malignancy.

RESULTS

Of the 36 lesions included, 28 (82.4%) were classified as mucinous and 6 (17.6%) as non-mucinous. Furthermore, 5 (13.9%) lesions were classified as malignant. The amount of deoxyribonucleic acid obtained was sufficient for molecular analysis in 25 (69.4%) pancreatic cysts. The amount of intracystic deoxyribonucleic acid was not statistically related to the cyst fluid volume obtained from the lesions. Analysis of KRAS and/or GNAS showed 83.33% [95% confidence interval (CI): 63.34-100] sensitivity, 60% (95%CI: 7.06-100) specificity, 88.24% (95%CI: 69.98-100) positive predictive value and 50% (95%CI: 1.66-98.34) negative predictive value (P = 0.086) for the diagnosis of mucinous cystic lesions. Mutations in KRAS and GNAS were found in 2/5 (40%) of the lesions classified as non-mucinous, thus recategorizing those lesions as mucinous neoplasms, which would have led to a modification of the follow-up plan in 8% of the cysts in which molecular analysis was successfully performed. All 4 (100%) malignant cysts in which molecular analysis could be performed had mutations in KRAS and/or GNAS, although they were not related to malignancy (P > 0.05). None of the other mutations analyzed could detect mucinous or malignant cysts with statistical significance (P > 0.05).

CONCLUSION

Molecular analysis can improve the classification of pancreatic cysts as mucinous or non-mucinous. Mutations were not able to detect malignant lesions.

Factors affecting the ability of abdominal ultrasonography to detect focal pancreatic lesions identified using endoscopic ultrasonography

Purpose

This study was conducted to determine which factors influence the ability of abdominal ultrasonography (US) to detect focal pancreatic lesions identified using endoscopic ultrasonography (EUS).

Methods

In this study, 338 consecutive patients with focal pancreatic lesions (cyst, n=253; adenocarcinoma, n=54; pancreatic neuroendocrine tumor, n=24; solid pseudopapillary neoplasm, n=4; intrapancreatic accessory spleen, n=1; metastasis, n=1; and lymphoma, n=1) detected by EUS who underwent US were enrolled. We reviewed their radiologic reports and assessed the presence or absence of a focal lesion, the multiplicity of the lesions, and their size and location on US. We evaluated how these parameters differed depending on whether the lesion was solid or cystic. Univariate and multivariate logistic regression analysis were performed.

Results

The overall detection rate of focal pancreatic lesions by US was 61.5% (208 of 338). Using US, the detection rate of cystic lesions was 58.5% (148 of 253), while that of solid lesions was 70.6% (60 of 85). In the univariate analysis, location in the neck or body, solid characteristics, and a relatively large size (15.50±10.08 mm vs. 23.09±12.93 mm) were associated with a significantly higher detection rate (P<0.001, P=0.047, and P<0.001, respectively). In the multivariate analysis, location in the neck or body (odds ratio [OR], 3.238; 95% confidence interval [CI], 1.926 to 5.443; P<0.001) and size (OR, 1.070; 95% CI, 1.044 to 1.096; P<0.001) were proven to be significant predictors of detectability (P<0.001).

Conclusion

US is useful for detecting focal pancreatic lesions, especially when they are located in the neck or body and are relatively large.

Pancreatic cystic lesions in diabetes mellitus patients

Introduction

According to the literature exocrine pancreatic insufficiency is relatively common among patients with diabetes mellitus (DM). Pseudocysts are the most common cystic lesions and may be formed in the setting of acute or chronic pancreatitis. However, whether DM is involved or not in pancreatic cyst formation is still not well established.

Aim

To investigate the frequency and risk factors of cystic lesions in diabetic patients.

Material and methods

One hundred and sixty-one patients with DM, with no previous history of pancreatic diseases, were prospectively included in the study. Endosonography followed by fine needle aspiration biopsy was then performed.

Results

Finally, 33 of 161 patients (20.5%) were recognized with cystic lesions of the pancreas. Among them 5 patients were classified as cystic neoplasms, and 28 as pseudocysts. In the group of patients with pseudocysts, cystic lesions were significantly more prevalent in individuals with DM lasting less than 3 years. Prevalence of cystic lesions was significantly higher in metformin users in comparison to other diabetic patients (p < 0.05). Cystic lesions were more frequent in patients above 50 years of age (p < 0.05).

Conclusions

The prevalence of cystic lesions in the diabetic population is higher than in the general population. DM seems to play a major role in the process of cyst development, especially in patients without previous history of pancreatitis. Higher prevalence of cystic lesions in early diabetes seems to be the first stage of pancreatic injury. The exact role of diabetes duration and type of treatment should be established.

Follow-up Recommendation Rates Associated With Spectral Detector Dual-Energy CT of the Abdomen and Pelvis: A Retrospective Comparison to Single-Energy CT

BACKGROUND

Dual-energy CT image sets have many applications in abdominopelvic imaging but no demonstrated clinical effect.

PURPOSE

To determine the effect of dual-energy CT iodine maps on abdominopelvic imaging follow-up recommendation rates.

MATERIALS AND METHODS

Retrospective study of abdominopelvic CTs acquired from April 2017 through June 2018. CT reports were analyzed for radiologic follow-up recommendation and follow-up recommendation reason. Follow-up MRI reports were analyzed for benign or nonbenign diagnosis. CT scans with iodine maps (CTIMs) and conventional CT scans (CCTs) subgroups were compared using χ² testing.

RESULTS

In all, 3,221 abdominopelvic CT scans of 2,401 patients (1,326 men, 1,075 women, mean age 54.1 years) were analyzed; 1,423 were CTIMs and 1,798 were CCTs. Follow-up recommendation rates were not significantly different for CTIMs and CCTs (19.5% and 21.4%, respectively, P = .19). Follow-up recommendations because of incomplete diagnosis were significantly lower in CTIMs (9.1%) than in CCTs (11.9%, P = .01). Follow-up recommendations for MRI and PET/CT were significantly lower in CTIMs (9.6%) than CCTs (13.0%, P = .003). Follow-up MRI outcomes (n = 111) were not different between CTIMs (61.2% benign) and CCTs (59.6%, P = .87).

CONCLUSION

Dual-energy CT iodine maps are associated with decreased follow-up examinations because of incomplete diagnosis and decreased recommendations for follow-up MRI, suggesting that abdominopelvic iodine maps may benefit patient care and decrease institutional cost.

Single-session esophagogastroduodenoscopy and endoscopic ultrasound using a forward-viewing radial scan ultrasonic endoscope

BACKGROUND

Endoscopic ultrasound is useful for obtaining high-resolution images of pancreaticobiliary diseases, but is not readily available for physical checkups. In this study, we evaluated the safety and efficacy of single-session esophagogastroduodenoscopy and endoscopic ultrasound in the detection of upper-gastrointestinal and pancreaticobiliary diseases using a forward-viewing radial scan ultrasonic endoscope.

METHODS

A total of 148 patients who were scheduled for upper-gastrointestinal screening using an endoscope were prospectively included. All patients were examined by EUS in combination with EGD using a forward-viewing radial scan ultrasonic endoscope. The primary endpoint was the safety of the procedures. The secondary endpoints were the prevalence of diseases, the basal imaging capability of EUS, the procedure time, total dose of propofol, and the correlation between background factors and the prevalence of pancreatic disease. The imaging capability at each region was scored as 0 (invisible) to 2 (sufficient visualization to evaluate the organs).

RESULTS

Intraoperative hypotension occurred as an adverse event of intravenous anesthesia in one patient. There were 82 pancreaticobiliary findings and 165 upper-gastrointestinal findings (malignancy not included). Follicular lymphoma of the intra-abdominal lymph nodes was detected in one patient. The mean imaging scores of each section were 1.95 (pancreatic head and papilla), 2.0 (pancreatic body), 1.99 (pancreatic tail), and 1.89 (common bile duct and gallbladder). Age, history of diabetes mellitus, and smoking history were significantly associated with the prevalence of pancreatic diseases.

CONCLUSION

The simultaneous performance of EGD and EUS using a new ultrasonic endoscope is tolerable and safe for upper-gastrointestinal and pancreaticobiliary screening.

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.

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.

Role of transabdominal ultrasonography in the diagnosis of pancreatic cystic lesions

Pancreatic cystic lesions (PCLs) are incidental findings that are being increasingly identified because of recent advancements in abdominal imaging technologies. PCLs include different entities, with each of them having a peculiar biological behavior, and they range from benign to premalignant or malignant neoplasms. Therefore, accurate diagnosis is important to determine the best treatment strategy. As transabdominal ultrasonography (US) is noninvasive, inexpensive, and widely available, it is considered to be the most appropriate imaging modality for the initial evaluation of abdominal diseases, including PCLs, and for follow-up assessment. We present a review of the possibilities and limits of US in the diagnosis of PCLs, the technical development of US, and the ultrasonographic characteristics of PCLs.

Association Between Pancreatic Cystic Lesions and High-grade Intraepithelial Neoplasia and Aging: An Autopsy Study

OBJECTIVES

This study aimed to clarify clinicopathological features of pancreatic cysts.

METHODS

Pancreata from 280 autopsies (median, 83 years; male, 146; female, 134) were sectioned every 5 mm. Cysts (<10 mm) were diagnosed as a simple cyst or low-grade, intermediate-grade, or high-grade dysplasia.

RESULTS

We found 236 cysts in 93 patients (33.2%). The number and diameter of cysts increased according to the age. Of the 236 cysts, 9 (3.8%) were with high-grade dysplasia. Cysts with high-grade dysplasia arose in the pancreata of older patients with larger numbers of cysts. In contrast, 15 noncystic lesions with high-grade dysplasia were also detected. Hence, in total, 24 high-grade dysplastic lesions in 15 patients (5.4%) were noted. Of the 15 patients with high-grade dysplastic lesions, in 10 patients, the condition was accompanied by pancreatic cysts, whereas 5 patients did not have any cysts in the pancreas; therefore, patients with cyst showed higher incidence of high-grade dysplasia (10.8%; P = 0.0047) than patients without cyst (2.7%). All cysts with high-grade dysplasia were located in the branch duct of the pancreatic head/body, whereas 20% of noncystic lesions with high-grade dysplasia were located in the main pancreatic duct.

CONCLUSIONS

Cystic lesions with high-grade dysplasia may have different characteristics compared with noncystic high-grade dysplasia.

Systematic review and meta-analysis: Prevalence of incidentally detected pancreatic cystic lesions in asymptomatic individuals

BACKGROUND & AIMS

Pancreatic cystic lesions (PCLs) are frequent incidental findings. As most PCLs require costly diagnostic evaluation and active surveillance, it is important to clarify their prevalence in asymptomatic individuals. We therefore aimed at performing a systematic review and meta-analysis to determine it.

METHODS

a systematic search was conducted and studies meeting inclusion criteria were included. The prevalence of PCLs was pooled across studies. A random effect model was used with assessment of heterogeneity.

RESULTS

17 studies, with 48,860 patients, were included. Only 3 were prospective; 5 studies were conducted in the US, 7 in Europe, 4 in Asia and 1 in Brazil. The pooled prevalence of PCLs was 8% (95% CI 4-14) with considerable heterogeneity (I² = 99.5%). This prevalence was higher in studies of higher quality, examining older subjects, smaller cohorts, and employing MRCP (24.8% vs 2.7% with CT-scan). The pooled rate of PCLs was four times higher in studies conducted in the US than in Asia (12.6% vs 3.1%). 7 studies reported the prevalence of mucinous lesions, with a pooled rate of 4.3% (95% CI 2-10; I² = 99.2%), but of 0.7% only for worrisome features or high risk stigmata.

CONCLUSION

The rate of incidentally detected PCLs is of 8%. Mucinous lesions are the most common incidentally detected PCLs, although they rarely present with potential indication for surgery. The observed different rates in the US and other geographic Areas suggest that different protocols might be necessary to help balancing costs and effectiveness of follow-up investigations in asymptomatic subjects.

Downstream Costs Associated With Incidental Pancreatic Cysts Detected at MRI

OBJECTIVE

The purpose of this study is to assess downstream costs associated with pancreatic cysts incidentally detected at MRI.

MATERIALS AND METHODS

Two hundred patients with an incidental pancreatic cyst detected at MRI were identified. Downstream events (imaging, office visits, endoscopic ultrasound-guided fine-needle aspiration, or chemotherapy) were identified from the electronic medical record. Radiologists' recommendations and ordering physician management were classified relative to the American College of Radiology (ACR) incidental findings committee recommendations. Costs for the downstream events were estimated using national Medicare rates and a 3% annual discount rate. Mean costs were computed.

RESULTS

Estimated downstream costs averaged $460 per cyst ($872 per cyst with any follow-up testing). Nine patients had a clinically relevant outcome during follow-up (increase in cyst size, development of new cyst, or development of pancreatic cancer). Downstream cost per cyst with a clinically relevant outcome was $1364. Costs were greater when ordering physicians overmanaged ($842) versus when they were adherent ($631) or undermanaged ($252) relative to radiologist recommendation. Although costs were $252 when ordering physicians undermanaged relative to ACR incidental findings committee recommendations, costs were similar when ordering physicians were adherent ($811) or overmanaged ($845) relative to ACR incidental findings committee recommendations. Costs did not vary significantly according to whether radiologists recommended follow-up testing ($317-$491) or whether radiologist recommendations were adherent, undermanaged, or overmanaged relative to ACR incidental findings committee recommendations ($344-$528).

CONCLUSION

The findings suggest a role for targeted educational efforts, collaborative partnerships, and other initiatives to foster greater adherence to radiologist recommendations, including critical test results notification systems, automated reminders within electronic health systems, and stronger language within radiology reports when no follow-up testing is recommended.

Prevalence of pancreatic cystic neoplasms on imaging exams: association with signs of malignancy risk

Objective

To analyze the prevalence of cystic lesions of the pancreas on imaging exams and their association with signs of malignancy risk.

Materials and methods

This was an observational cross-sectional study, in which we evaluated 924 sequential computed tomography and magnetic resonance imaging scans of the abdomen. For all of the patients included in the study, we reviewed the demographic data available in the medical records and evaluated the images.

Results

Cysts were observed in 4.5% of patients, the prevalence of cysts being highest (7.6%) in patients over 60 years of age. Lesions were detected at higher rates on magnetic resonance imaging and in patients with pancreatic symptoms (6.1% and 42.9%, respectively). Signs of malignancy risk were observed in 26.3% of the patients, more frequently in those who were male and over 60 years of age.

Conclusion

The prevalence of pancreatic cysts was 4.5%. Signs of malignancy risk were observed in 26.3% of the cystic neoplasms identified.

Technical feasibility, diagnostic yield, and safety of microforceps biopsies during EUS evaluation of pancreatic cystic lesions (with video)

BACKGROUND AND AIMS

Through-the-needle microforceps are a recent addition to the EUS armamentarium for evaluation of pancreatic cystic lesions (PCLs). The main aim of this study was to assess the technical feasibility, diagnostic yield, and safety of EUS-guided microforceps biopsy for PCLs.

METHODS

Our electronic endoscopy database was queried to identify patients who underwent EUS-guided FNA (EUS-FNA) of PCLs and microforceps biopsies during the same procedure. A biopsy was done on the wall of the cyst with the microforceps through the 19-gauge needle, and cyst fluid was collected for cytology and carcinoembryonic antigen (CEA) levels. Adverse events were recorded per published American Society for Gastrointestinal Endoscopy criteria.

RESULTS

Twenty-seven patients underwent EUS-FNA and microforceps biopsy of PCLs from February 2016 to July 2017. Fourteen cysts were located in the pancreatic head and/or uncinate, and 13 were located in the body and/or tail region. Microforceps biopsies were technically successful in all cases and provided a pathology diagnosis in 24 of 27 cases (yield 88.9%). Microforceps biopsies diagnosed mucinous cyst in 9 patients (33.3%), serous cystadenoma in 4 (14.8%), neuroendocrine tumor in 1 (3.7%), and benign and/or inflammatory cyst in 10 (37.1%). In 7 patients (26%), microforceps biopsy results drastically changed the diagnosis, providing diagnoses otherwise not suggested by cytology or cyst fluid CEA levels. However, cytology provided a diagnosis of mucinous cyst in 4 cases (14.8%) not detected by microforceps biopsies. No adverse events were noted.

CONCLUSION

Microforceps biopsies were associated with high technical success, and an excellent safety profile and may be a useful adjunctive tool, complementing existing EUS-FNA sampling protocols for PCLs.

Fukuoka criteria accurately predict risk for adverse outcomes during follow-up of pancreatic cysts presumed to be intraductal papillary mucinous neoplasms

OBJECTIVE

Fukuoka consensus guidelines classify pancreatic cystic lesions (PCLs) presumed to be intraductal papillary mucinous neoplasms (IPMNs) into Fukuoka positive (FP) (subgroups of high-risk (HR) and worrisome features (WFs)) and Fukuoka negative (FN) (non-HR feature/WF cysts). We retrospectively estimated 5-year risk of pancreatic cancer (PC) in FN, WF and HR cysts of patients with PCL-IPMN.

DESIGN

From Mayo Clinic databases, we randomly selected 2000 patients reported to have a PCL; we excluded inflammatory or suspected non-IPMN cysts and those without imaging follow-up. We re-reviewed cross-sectional imaging and abstracted clinical and follow-up data on PCL-IPMNs. The study contained 802 patients with FN cysts and 358 with FP cysts.

RESULTS

Patients with PCL-IPMN had median (IQR) follow-up of 4.2 (1.8-7.1) years. Among FN cysts, 5-year PC risk was low (2-3%) regardless of cyst size (p=0.67). After excluding events in the first 6 months, 5-year PC risk remained low (0-2%) regardless of cyst size (p=0.61). Among FP cysts, HR cysts (n=66) had greater 5-year PC risk than WF cysts (n=292) (49.7% vs 4.1%; p<0.001). In HR cysts, 3-year PC risk was greatest for obstructive jaundice versus enhancing solid component or main pancreatic duct >10 mm (79.8% vs 37.3% vs 39.4%, respectively; p=0.01).

CONCLUSIONS

Fukuoka guidelines accurately stratify PCL-IPMNs for PC risk, with FN cysts having lowest and HR cysts having greatest risk. After 6-month follow-up, WF and FN cysts had a low 5-year PC risk. Surveillance strategies should be tailored appropriately.

Incidental, Small (< 3 cm), Unilocular, Pancreatic Cysts: Factors That Predict Lesion Progression during Imaging Surveillance

OBJECTIVE

To explore the features that predict size increase and development of potential malignant features in incidentally detected, unilocular cystic pancreatic lesions (CPLs) less than 3 cm in diameter, during subsequent follow-up.

MATERIALS AND METHODS

We retrieved data of patients diagnosed with unilocular CPLs less than 3 cm in diameter during the period from November 2003 through December 2014, using a computerized search. All serial CT and MR images were analyzed to identify the number, size, and location of CPLs; dilatation of the main pancreatic duct; and occurrence of worrisome features and high-risk stigmata of malignancy in the lesion. The characteristics of CPLs were compared between the increase (i.e., size increase during subsequent follow-up) and no-increase groups. For CPLs in the increase group, subgroup analysis was performed according to the lesion size at the last follow-up (< 3 cm vs. ≥ 3 cm).

RESULTS

Among 553 eligible patients, 132 (23.9%) had CPLs that increased in size, and 421 (76.1%) had CPLs that did not, during follow-up. Of the 132, 12 (9.1%) CPLs increased to diameters ≥ 3 cm at the final follow-up. Among the various factors, follow-up duration was a significant independent factor for an interval size increase of CPLs (p < 0.001). In the increase group, initial cyst size was a significant independent factor to predict later size increase to or beyond 3 cm in diameter (p < 0.001), and the initial cyst diameter ≥ 1.5 cm predicted such a growth with a sensitivity and specificity of 83% and 72%, respectively. No significant factors to predict the development of potential malignant features were identified.

CONCLUSION

Follow-up duration was associated with an interval size increase of CPLs. Among the growing CPLs, initial cyst size was associated with future lesion growth to and beyond 3 cm.

Appropriate Interval for Imaging Follow-up of Small Simple Pancreatic Cysts

CONTEXT

The frequency at which patients should undergo follow-up imaging of small pancreatic cysts is problematic because different medical societies have different follow-up guidelines.

OBJECTIVE

To determine whether short-term follow-up of small pancreatic cysts is necessary to detect pancreatic cancer or cystic neoplasia.

DESIGN

We retrospectively reviewed all abdominal magnetic resonance imaging (MRI) studies obtained in a geographically isolated health maintenance organization between January 1, 2012, and December 31, 2014, looking for pancreatic cysts. For each patient with one or more simple cysts, we recorded the size of the largest cyst. For patients with cysts, all their other computed tomography and MRI studies were reviewed to determine any change in size or morphology. The electronic medical record of every patient who underwent MRI was reviewed to determine development of pancreatic cancer.

MAIN OUTCOME MEASURES

Change in cyst size on images.

RESULTS

Of 1946 patients, 342 were found to have at least 1 pancreatic cyst. A total of 228 patients had additional imaging from which to determine rates of change. The mean rate (standard deviation) of change for these cysts was 0.1 ± 2.0 mm/y. None of those cysts measuring 2 cm or smaller on MRI grew more than 5 mm in 2 years.

CONCLUSION

Our data validate the clinical efficacy of obtaining follow-up imaging no sooner than 24 months after the initial detection of a simple pancreatic cyst 2 cm or smaller. Patients with cysts are more likely to have pancreatic cancer, but earlier follow-up imaging would not change their diagnosis of pancreatic cancer.

Prevalence of Pancreatic Cystic Lesions Is Associated With Diabetes Mellitus and Obesity: An Analysis of 5296 Individuals Who Underwent a Preventive Medical Examination

OBJECTIVES

Pancreatic cystic lesions (PCLs) are considered precursors of pancreatic cancer. Diabetes mellitus (DM) and obesity are known as risk factors for pancreatic cancer. We investigated the prevalence of PCLs in the general population and the relationship between PCLs and DM/obesity.

METHODS

This cross-sectional analysis included 5296 individuals who underwent a preventive medical examination between October 2006 and June 2013 at our institution. Magnetic resonance imaging, including magnetic resonance cholangiopancreatography, was performed using a 3.0-T system as part of a comprehensive health screening program. We investigated the prevalence and risk factors of PCLs.

RESULTS

The prevalence of PCLs was 13.7%, which was increased according to age. Individuals with PCLs were more prone to obesity (body mass index, 24.0 vs 23.7 kg/m [P = 0.015]; waist circumference, 87.4 vs 85.5 cm [P < 0.001]). DM was more prevalent in individuals with PCLs (18.4% vs 10.5%, P < 0.001). In a multivariate analysis, age (odds ratio [OR], 1.06; P < 0.001), excess body mass index (OR, 1.26; P = 0.039), and DM (OR, 1.39; P = 0.005) were associated with PCLs.

CONCLUSIONS

The prevalence of PCLs detected by magnetic resonance imaging in a preventive medical examination was 13.7%. Pancreatic cystic lesions were significantly associated with DM and obesity.

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.

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.

Incidental pancreatic cystic neoplasms in an asymptomatic healthy population of 21,745 individuals: Large-scale, single-center cohort study

Although incidental pancreatic cystic neoplasms are being diagnosed with increasing frequency, little is known about the accurate prevalence of pancreatic cysts in the general population. The aims of this study were to evaluate the crude prevalence rate of pancreatic cystic neoplasms in asymptomatic healthy adults, and calculate the age- and sex-adjusted nationwide prevalence rate.A total of 21,745 asymptomatic individuals who underwent abdominal computed tomography (CT) as a health screening examination were enrolled between 2003 and 2013 at the Seoul National University Hospital Healthcare System Gangnam Center. Nationwide population data of 2010 were collected from the National Statistical Office, Korea.Incidental pancreatic cystic neoplasms were found in 457 individuals whose mean age was 58.7 years. The types of neoplasms were reviewed by 2 separate designated radiologists and the final diagnosis was made as follows: intraductal papillary mucinous neoplasm: 376 (82%), serous cystic neoplasm: 19 (4%), mucinous cystic neoplasm: 7 (2%), and indeterminate cysts: 55 (12%). Eight cases underwent operation. The crude prevalence rate was 2.1% and the age- and sex-adjusted expected nationwide prevalence was 2.2%. The prevalence increased with age.Here, we reported the first large-scale study among the healthy population to find out the prevalence rate of pancreatic cystic neoplasms; the age- and sex-adjusted prevalence was 2.2%, and increased with age. Further investigations regarding the clinical implications of incidental pancreatic neoplasms are necessary.

Pancreatic cysts in general population on ultrasonography: Prevalence and development of risk score

BACKGROUND

Pancreatic cysts are related to the presence of ductal adenocarcinomas elsewhere in the pancreas, and are also associated with an increased risk of pancreatic adenocarcinoma in the future. Most of the previous studies that investigated the prevalence of pancreatic cysts focused on patients within a hospital or out-patient setting, which may not be representative of the general population. We investigated the prevalence and predictive factors for the presence of pancreatic cysts within a large number of subjects via general health examination.

METHODS

Between December 2007 and December 2013, a total of 5198 subjects were enrolled that underwent ultrasonography (US) on general health examination. We established a scoring system for predicting the presence of one or more pancreatic cysts using a split-sample method.

RESULTS

Among the enrolled subjects, the prevalence of a pancreatic cyst was 3.5 %. In multivariate analysis, the prevalence was significantly increased with older age, female sex, and the presence of gall bladder adenomyomatosis (GB-ADM). Based on multivariate analysis in the training sample (n = 2,599), we established the scoring system consisting of age, sex, and the presence of GB-ADM to predict the presence of pancreatic cysts. This scoring system was validated in the testing sample (n = 2,599) and produced an area under the curve of 0.711.

CONCLUSIONS

The prevalence of pancreatic cyst detected by US was 3.5 % in the general population, and increased with age, female sex, and the presence of GB-ADM. A new scoring system developed in the present study may help to identify better candidates for further examination when the pancreas is not visible by US.

Management of Patients With Pancreatic Cysts: Analysis of Possible False-Negative Cases of Malignancy

GOALS

To examine the utility of integrated molecular pathology (IMP) in managing surveillance of pancreatic cysts based on outcomes and analysis of false negatives (FNs) from a previously published cohort (n=492).

BACKGROUND

In endoscopic ultrasound with fine-needle aspiration (EUS-FNA) of cyst fluid lacking malignant cytology, IMP demonstrated better risk stratification for malignancy at approximately 3 years' follow-up than International Consensus Guideline (Fukuoka) 2012 management recommendations in such cases.

STUDY

Patient outcomes and clinical features of Fukuoka and IMP FN cases were reviewed. Practical guidance for appropriate surveillance intervals and surgery decisions using IMP were derived from follow-up data, considering EUS-FNA sampling limitations and high-risk clinical circumstances observed. Surveillance intervals for patients based on IMP predictive value were compared with those of Fukuoka.

RESULTS

Outcomes at follow-up for IMP low-risk diagnoses supported surveillance every 2 to 3 years, independent of cyst size, when EUS-FNA sampling limitations or high-risk clinical circumstances were absent. In 10 of 11 patients with FN IMP diagnoses (2% of cohort), EUS-FNA sampling limitations existed; Fukuoka identified high risk in 9 of 11 cases. In 4 of 6 FN cases by Fukuoka (1% of cohort), IMP identified high risk. Overall, 55% of cases had possible sampling limitations and 37% had high-risk clinical circumstances. Outcomes support more cautious management in such cases when using IMP.

CONCLUSIONS

Adjunct use of IMP can provide evidence for relaxed surveillance of patients with benign cysts that meet Fukuoka criteria for closer observation or surgery. Although infrequent, FN results with IMP can be associated with EUS-FNA sampling limitations or high-risk clinical circumstances.

Pancreatic cysts: What imaging characteristics are associated with development of pancreatic ductal adenocarcinoma?

PURPOSE

To assess relationship between pancreatic cysts (PC) and pancreatic ductal adenocarcinoma (PDAC) and to compare imaging features of PC in subjects who develop PDAC and those who do not.

MATERIAL AND METHODS

This case-control IRB-approved HIPAA-compliant study included patients with PDAC (cases) and lung cancer (controls), diagnosed between 1/1/05-1/1/14. The most recent abdominal CT/MR of each patient done >6months prior to cancer diagnosis date was reviewed by radiologist blinded to case/control status. Presence of PC, number and size of largest PC, presence of main pancreatic duct (MPD) dilatation (MPD >3mm) were recorded. Simple PC was defined as lack of calcifications, septations and enhancement. Logistic regression models with binary outcome of PDAC were constructed.

RESULTS

There were 88 cases and 273 controls with mean ages of 69.6 years (±10.3) and 69.8 years (±12.0), respectively (p=0.864). PC were present in 21.6% (19/88) cases and in 9.2% (25/273) controls (p=0.002). The OR of PC for development of PDAC was 2.83, adjusting for age, sex and race (p=0.001). Mean PC size was 14.8mm (±8.7) in cases and 7.6mm (±8.0) in controls (p=0.007). PC were solitary in 6 (31.6%) of 19 cases and 21 (84.0%) of 25 controls (p=0.001). There was no significant difference in proportions of simple cysts or MPD dilatation between cases and controls. Multiple PC had 8.2 times increased odds of PDAC compared with solitary PC, adjusting for cyst size (p=0.007).

CONCLUSION

Multiple PC are associated with 8.2 times higher odds of PDAC compared with solitary PC.

Breast findings incidentally detected on body MRI

Objectives

To evaluate breast findings incidentally detected on body MRI.

Methods

A retrospective review of the institutional database identified 1752 body MRI performed between January 2015 and September 2015. MRI of women with breast tissue visible in the field-of-view were reviewed for breast findings. Breast findings were classified with the breast imaging reporting and data system (BI-RADS) lexicon. The standard statistic, costs of additional work-up, and the clinical relevance were used to describe breast findings, and we calculated 95 % exact confidence intervals (CIs).

Results

440 body MRI of 440 women (mean age: 57 ± 20 years) included breast tissue in the field-of-view. A total of 41 breast findings were identified in 41 patients. Breast findings were classified BI-RADS 2 N = 25, BI-RADS 3 N = 13, BI-RADS 4 N = 3. A total of 3.6 % [95 % CI 1.6 %, 5.6 %] women with breast tissue visible on MRI had a recommendation for further imaging work-up for a breast finding. The 18.7 % (3 of 16) of these patients had a clinically important finding (breast cancer). Further imaging evaluation increased costs of €108.3 per patient with a breast finding.

Conclusions

Clinically important breast findings could be detected on body MRI in up to 0.7 % (3 of 440) of women.