Objective: Intraductal papillary mucinous neoplasm (IPMN) is a rare pancreatic lesion. The identification of malignancy is critical for the establishment of treatment strategies. Main pancreatic duct (MPD) diameter is one critical feature for malignant IPMNs. However, the threshold of 1.0 cm is challenged. In this study, we explored independent risk factors and further calculated the threshold of MPD in identifying malignant IPMNs. Method: A total of 151 IPMN patients were included in this retrospective study. Demographic information, clinicopathological features, laboratory testing, and preoperative radiological characteristics by magnetic resonance imaging were collected. The receiver operating characteristic (ROC) curves were performed to determine the MPD diameter's cutoff levels and evaluate the predicted factors' diagnostic ability. Results: A cutoff value of 0.77 cm MPD (an area under the curve (AUC) = 0.746) in all IPMNs and 0.82 cm (AUC = 0.742) in the main duct involved IPMNs was obtained. MPD diameter (odds ratio (OR), 12.67; 95% confidence interval (CI), 4.80-33.48) and the mural nodule (OR, 12.98; 95% CI, 3.18-52.97) were the independent associated factors with high-risk IPMNs. The combined model with MPD and mural nodule showed a better predictive performance than mural nodule or MPD diameter alone (AUC = 0.803 vs 0.619, 0.746). A nomogram was developed and showed good performance (C index = 0.803). Conclusion: Our data show that mural nodule and MPD diameter are independent risk factors in identifying malignant intraductal papillary mucinous neoplasms. A cutoff value of 0.77 cm of MPD diameter may be a threshold value in identifying malignant intraductal papillary mucinous neoplasms or undergoing surgical resection.

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.

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.

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).

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.

Patients with pancreatic cystic neoplasms (PCN), without surgical indication at the time of diagnosis according to current guidelines, require lifetime image-based surveillance follow-up. In these patients, the current European evidenced-based guidelines advise magnetic resonance imaging (MRI) scanning every 6 mo in the first year, then annually for the next five years, without reference to any role for trans-abdominal ultrasound (US). In this study, we report on our clinical experience of a follow-up strategy of image-based surveillance with US, and restricted use of MRI every two years and for urgent evaluation whenever suspicious changes are detected by US.

To report the results and cost-efficacy of a US-based surveillance follow-up for known PCNs, with restricted use of MRI.

We retrospectively evaluated the records of all the patients treated in our institution with non-surgical PCN who received follow-up abdominal US and restricted MRI from the time of diagnosis, between January 2012 and January 2017. After US diagnosis and MRI confirmation, all patients underwent US surveillance every 6 mo for the first year, and then annually. A MRI scan was routinely performed every 2 years, or at any stage for all suspicious US findings. In this communication, we reported the clinical results of this alternative follow-up, and the results of a comparative cost-analysis between our surveillance protocol (abdominal US and restricted MRI) and the same patient cohort that has been followed-up in strict accordance with the European guidelines recommended for an exclusive MRI-based surveillance protocol.

In the 5-year period, 200 patients entered the prescribed US-restricted MRI surveillance follow-up. Mean follow-up period was 25.1 ± 18.2 mo. Surgery was required in two patients (1%) because of the appearance of suspicious features at imaging (with complete concordance between the US scan and the on-demand MRI). During the follow-up, US revealed changes in PCN appearance in 28 patients (14%). These comprised main pancreatic duct dilatation (n = 1), increased size of the main cyst (n = 14) and increased number of PNC (n = 13). In all of these patients, MRI confirmed US findings, without adding more information. The bi-annual MRI identified evolution of the lesions not identified by US in only 11 patients with intraductal papillary mucinous neoplasms (5.5%), largely consisting of an increased number of very small PCN (P = 0.14). The overall mean cost of surveillance, based on a theoretical use of the European evidenced-based exclusive MRI surveillance in the same group of patients, would have been 1158.9 ± 798.6 € per patient, in contrast with a significantly lower cost of 366.4 ± 348.7 € (P < 0.0001) incurred by the US-restricted MRI surveillance used at our institution.

In patients with non-surgical PCN at the time of diagnosis, US surveillance could be a safe complementary approach to MRI, delaying and reducing the numbers of second level examinations and therefore reducing the costs.

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.

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

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

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

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

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