[Pancreatic cystic neoplasms]. / Zystische Pankreastumoren.

Pancreatic cystic lesions represent a challenging heterogeneous entity with a potential risk of malignant transformation. The diagnostics include in particular medical history taking with collection of relevant clinical information and high-resolution imaging, preferably using magnetic resonance imaging (MRI) with MR cholangiopancreatography (MRCP) and/or endoscopic ultrasonography. A differentiation between different cystic entities and identification of risk factors are crucial for making appropriate treatment decisions. Only a small proportion of pancreatic cystic neoplasms require surgery. Pancreatic cystic lesions with a relevant risk of malignancy, such as main duct intraductal papillary mucinous neoplasms (IPMN), mucinous cystic neoplasms (MCN), solid pseudopapillary neoplasms (SPN) and general cystic pancreatic lesions with risk factors regardless of the entity, should be resected, whereas an individualized approach is required for branch duct IPMN and serous cystic neoplasms (SCN) and dysontogenetic cysts require no treatment. Parenchyma-sparing and minimally invasive resection techniques should be preferred whenever possible for resecting pancreatic cystic tumors. Approximately 10% of patients develop recurrences over time.

Disease Progression of Branch-Duct Intraductal Papillary Mucinous Neoplasms Following Solid Organ Transplant.

INTRODUCTION: Branch-Duct intraductal papillary mucinous neoplasms (BD-IPMNs) are becoming more prevalent with advanced medical imaging, and account for the majority of pancreatic cystic neoplasms (PCNs). Most incidental lesions should be surveyed, with resection reserved for specific, high-risk cases. Solid organ transplantation candidates maybe high risk for resection prior to transplant, and will require systemic immunosuppression after transplant, which has been theorized to alter the natural history of the IPMN. We aim to describe the of progression in surveilled cysts after solid organ transplantation. METHODS: A prospectively maintained database of pancreatic cystic neoplasms was queried for patients with IPMN. Patients who had received a previous solid organ transplantation and with >2 imaging studies >6 months apart after transplantation were included. Clinically relevant progression (CR-Progression) was defined as symptoms, worrisome/high-risk stigmata, or invasive cancer (IC). Growth >5mm in 2 years is considered CR-Progression; size>3cm alone is not. RESULTS: Between 1997-2023, 252 patients received solid organ transplantation (liver=86, kidney=113, and lung=54) and were diagnosed with an IPMN. This cohort was compared to a set of 770 patients surveilled for IPMN who did not have previous transplantation. Median follow-up period was 3.7 years (IQR 1.6-6.8). Two transplant patients (0.8%) developed IC, and four (1.6%) high-grade dysplasia. Both were less common in transplant patients than the non-transplant population (IC=3.3%, HGD=2.9%), though this was not significant on time-to-event analysis (IC p=0.152, HGD p=0.352). The rate of CR-progression was high in the transplant cohort (n=118, 47%). Features of CR-progression included size growth (n=79, 67%), other worrisome/high-risk stigmata (n=25, 21%), new main duct involvement (n=14, 12%). Compared with the non-transplant (n=128, 17%), transplant patients had a higher rate of CR-progression (p<0.001), which was mostly explained by a more frequent size growth (31% vs 9%, p<0.001). However, no transplant patients with size growth CR-progression developed IC. Seventeen (6.7%) required pancreatic surgery for CR-progression after transplant versus 58 (7.5%) in the non-transplant population. Six (35%) resected cysts harbored high-risk pathology after transplant (IC=2, HGD=4), versus 40 (69%) in the general population (p<0.001, IC=29, HGD=11) CONCLUSIONS: Malignant transformation of BD-IPMNs is rare despite systemic immunosuppression in solid organ transplant patients. This supports transplantation in patients with IPMN without fear of worsening their risk of pancreatic cancer, although it was associated with a higher risk of disease progression. Patients with IPMNs should be surveilled with yearly scans after transplant, with pancreatic resection reserved for only high-risk features as we continue to define the optimal criteria for those with CR-progression.

Acvr1b Loss Increases Formation of Pancreatic Precancerous Lesions from Acinar and Ductal Cells of Origin.

BACKGROUND & AIMS: Pancreatic ductal adenocarcinoma can develop from precursor lesions, including pancreatic intraepithelial neoplasia and intraductal papillary mucinous neoplasm (IPMN). Previous studies indicated that loss of Acvr1b accelerates the Kras-mediated development of papillary IPMN in the mouse pancreas; however, the cell type predominantly affected by these genetic changes remains unclear. METHODS: We investigated the contribution of cellular origin by inducing IPMN associated mutations (KRASG12D expression and Acvr1b loss) specifically in acinar (Ptf1aCreER;KrasLSL-G12D;Acvr1bfl/fl mice) or ductal (Sox9CreER;KrasLSL-G12D;Acvr1bfl/fl mice) cells in mice. We then performed magnetic resonance imaging and a thorough histopathologic analysis of their pancreatic tissues. RESULTS: The loss of Acvr1b increased the development of pancreatic intraepithelial neoplasia and IPMN-like lesions when either acinar or ductal cells expressed a Kras mutation. Magnetic resonance imaging, immunohistochemistry, and histology revealed large IPMN-like lesions in these mice that exhibited features of flat, gastric epithelium. In addition, cyst formation in both mouse models was accompanied by chronic pancreatitis. Experimental acute pancreatitis accelerated the development of large mucinous cysts and pancreatic intraepithelial neoplasia when acinar, but not ductal, cells expressed mutant Kras and lost Acvr1b. CONCLUSIONS: These findings indicate that loss of Acvr1b in the presence of the Kras oncogene promotes the development of large and small precancerous lesions from both ductal and acinar cells. However, the IPMN-like phenotype was not equivalent to that observed when these mutations were made in all pancreatic cells during development. Our study underscores the significance of the cellular context in the initiation and progression of precursor lesions from exocrine cells.

Prospective multicenter surveillance study of branch-duct intraductal papillary mucinous neoplasm of the pancreas; risk of dual carcinogenesis.

BACKGROUND: The natural history of branch-duct intraductal papillary mucinous cystic neoplasms (BD-IPMNs) in the pancreas remains unclear. This study aimed to answer this clinical question by focusing on the development of concomitant pancreatic ductal adenocarcinomas (cPDAC). METHODS: The Japan Pancreas Society conducted a prospective multicenter surveillance study of BD-IPMN every six months for five years. The primary endpoints were progression of BD-IPMN, progression to high-grade dysplasia/invasive carcinoma (HGD/IC), and cPDAC. Factors predicting the progression of BD-IPMN to HGD/IC and development of cPDAC were also assessed as secondary endpoints. RESULTS: Among the 2104 non-operated patients, 348 (16.5 %) showed progression of primary BD-IPMN. Cumulative incidences of BD-IPMN with HGD/IC and cPDAC during the 5.17-year surveillance period were 1.90 % and 2.11 %, respectively, and standard incidence ratios of BD-IPMN with HGD/IC and cPDAC were 5.28 and 5.73, respectively. Of 38 cPDACs diagnosed during surveillance, 25 (65.8 %) were resectable. The significant predictive characteristics of BD-IPMN for progression to HGD/IC were larger cyst size (p = 0.03), larger main pancreatic duct size (p < 0.01), and mural nodules (p = 0.02). Significant predictive characteristics for the development of cPDAC were male sex (p = 0.03) and older age (p = 0.02), while the size of IPMN was not significant. CONCLUSION: Careful attention should be given to "dual carcinogenesis" during BD-IPMN surveillance, indicating the progression of BD-IPMN to HGD/IC and development of cPDAC distinct from BD-IPMN, although the establishment of risk factors that predict cPDAC development remains a challenge (UMIN000007349).

Outcomes in intraductal papillary mucinous neoplasm-derived pancreatic cancer differ from PanIN-derived pancreatic cancer.

BACKGROUND AND AIM: Intraductal papillary mucinous neoplasm (IPMN)-derived pancreatic ductal adenocarcinoma (PDAC) management is generally extrapolated from pancreatic intraepithelial neoplasia (PanIN)-derived PDAC guidelines. However, these are biologically divergent, and heterogeneity further exists between tubular and colloid subtypes. METHODS: Consecutive upfront surgery patients with PanIN-derived and IPMN-derived PDAC were retrospectively identified from international centers (2000-2019). One-to-one propensity score matching for clinicopathologic factors generated three cohorts: IPMN-derived versus PanIN-derived PDAC, tubular IPMN-derived versus PanIN-derived PDAC, and tubular versus colloid IPMN-derived PDAC. Overall survival (OS) was compared using Kaplan-Meier and log-rank tests. Multivariable Cox regression determined corresponding hazard ratios (HR) and 95% confidence intervals (95% CI). RESULTS: The median OS (mOS) in 2350 PanIN-derived and 700 IPMN-derived PDAC patients was 23.0 and 43.1 months (P < 0.001), respectively. PanIN-derived PDAC had worse T-stage, CA19-9, grade, and nodal status. Tubular subtype had worse T-stage, CA19-9, grade, nodal status, and R1 margins, with a mOS of 33.7 versus 94.1 months (P < 0.001) in colloid. Matched (n = 495), PanIN-derived and IPMN-derived PDAC had mOSs of 30.6 and 42.8 months (P < 0.001), respectively. In matched (n = 341) PanIN-derived and tubular IPMN-derived PDAC, mOS remained poorer (27.7 vs 37.4, P < 0.001). Matched tubular and colloid cancers (n = 112) had similar OS (P = 0.55). On multivariable Cox regression, PanIN-derived PDAC was associated with worse OS than IPMN-derived (HR: 1.66, 95% CI: 1.44-1.90) and tubular IPMN-derived (HR: 1.53, 95% CI: 1.32-1.77) PDAC. Colloid and tubular subtype was not associated with OS (P = 0.16). CONCLUSIONS: PanIN-derived PDAC has worse survival than IPMN-derived PDAC supporting distinct outcomes. Although more indolent, colloid IPMN-derived PDAC has similar survival to tubular after risk adjustment.

Endoscopic Ultrasound-Guided Through-the-Needle Biopsy: A Narrative Review of the Technique and Its Emerging Role in Pancreatic Cyst Diagnosis.

Pancreatic cystic lesions (PCLs) pose a diagnostic challenge due to their increasing incidence and the limitations of cross-sectional imaging and endoscopic-ultrasound-guided fine-needle aspiration (EUS-FNA). EUS-guided through the needle biopsy (EUS-TTNB) has emerged as a promising tool for improving the accuracy of cyst type determination and neoplastic risk stratification. EUS-TTNB demonstrates superior diagnostic performance over EUS-FNA, providing critical preoperative information that can significantly influence patient management and reduce unnecessary surgeries. However, the procedure has risks, with an overall adverse event rate of approximately 9%. Preventive measures and further prospective studies are essential to optimize its safety and efficacy. This review highlights the potential of EUS-TTNB to enhance the diagnostic and management approaches for patients with PCLs. It examines the current state of EUS-TTNB, including available devices, indications, procedural techniques, specimen handling, diagnostic yield, clinical impact, and associated adverse events.

Benign Etiology for High-Risk Intraductal Papillary Mucinous Neoplasm: A Case Report and Literature Review.

Intraductal papillary mucinous neoplasms are relatively common and entail a variable risk of malignant potential. The Fukuoka guidelines present criteria for the risk of malignant transformation and are used for risk stratification and treatment decision-making. However, these guidelines entail some fallibility with limited sensitivity and specificity. In this case, we present an individual who had many of the hallmarks of malignant transformation but was found to have no evidence of malignancy or high-grade dysplasia. We discuss the suspected etiology of this individual's condition and how it might arise in others, as well as a brief review of the literature on risk factors in intraductal papillary mucinous neoplasms.

Comprehensive Characterization of Intraductal Oncocytic Papillary Neoplasm of the Pancreas: A Systematic and Critical Review.

Intraductal oncocytic papillary neoplasm (IOPN) of the pancreas is a recently recognized pancreatic tumor. Here, we aimed to determine its most essential features with the systematic review tool. PubMed, Scopus, and Embase were searched for studies reporting data on pancreatic IOPN. The clinicopathologic, immunohistochemical, and molecular data were extracted and summarized. Then, a comparative analysis of the molecular alterations of IOPN with those of pancreatic ductal adenocarcinoma and intraductal papillary mucinous neoplasm from reference cohorts (including The Cancer Genome Atlas) was conducted. The key findings from 414 IOPNs were as follows: 1) The male-to-female ratio was 1.5:1. Pancreatic head was the most common site (131/237; 55.3%), but a diffuse tumor extension involving more than one pancreatic segment was described in about 1 out of 5 cases (49/237; 20.6%). The mean size was 45.5 mm. An associated invasive carcinoma was present in 50% of cases (168/336). In those cases, most tumors were pT1 or pT2 and pN0 (>80%), and vascular invasion was uncommon (20.6%). Regarding survival, more than 90% of patients were alive after surgical resection. 2) Immunohistochemical and molecular features were as follows. The most commonly expressed mucins were MUC5AC (110/112; 98.2%) and MUC6 (78/84; 92.8%). Compared with pancreatic ductal adenocarcinoma and intraductal papillary mucinous neoplasm, the classic pancreatic drivers KRAS, TP53, CDKN2A, SMAD4, and GNAS were less altered in IOPN (P < .01). Moreover, fusions involving PRKACA or PRKACB gene were detected in all of the 68 cases examined, with PRKACB::ATP1B1 being the most common (27/68 cases; 39.7%). These genomic events emerged as an entity-defining molecular alteration of IOPN (P < .01). Thus, such fusions represent a promising biomarker for diagnostic purposes. Recent evidence also suggests their role in influencing the acquisition of oncocytic morphology. IOPN is a distinct pancreatic neoplasm with specific clinicopathologic and molecular features. Considering the clinical or prognostic implications, its recognition is essential for pathologists and, ultimately, patients' management.

An international Multi-Institutional validation of T1 Sub-staging of intraductal papillary mucinous neoplasm-derived pancreatic cancer.

BACKGROUND: Intraductal papillary mucinous neoplasm (IPMN)-derived pancreatic ductal adenocarcinoma (PDAC) is resected at smaller sizes compared to its biologically distinct counterpart, pancreatic intraepithelial neoplasia (PanIN)-derived PDAC. Thus, experts proposed T1 sub-staging for IPMN-derived PDAC. However, this has never been validated. METHODS: Consecutive upfront surgery patients with IPMN-derived PDAC from five international high-volume centers were classified by the proposed T1 sub-staging classification (T1a ≤ 0.5, T1b > 0.5 and ≤1.0, and T1c >1.0 and ≤2.0 cm) using the invasive component size. Kaplan-Meier and log-rank tests were utilized to compare overall survival (OS). A multivariable Cox-regression was used to determine hazard ratios (HR) with confidence intervals (95%CI). RESULTS: Among 747 patients, 69 (9.2%), 50 (6.7%), 99 (13.0%), and 531 patients (71.1%), comprised the T1a, T1b, T1c, and T2-4 subgroups, respectively. Increasing T-stage was associated with elevated CA19-9, poorer grade, nodal positivity, R1-margin, and tubular subtype. Median OS for T1a, T1b, T1c, and T2-4 were 159.0 (95%CI:126.0-NR), 128.8 (98.3-NR), 77.6 (48.3-108.2), and 31.4 (27.5-37.7) months, respectively (p < .001). OS decreased with increasing T-stage for all pairwise comparisons (all p < .05). After risk-adjustment, age > 65, elevated CA19-9, T1b [HR : 2.55 (1.22-5.32)], T1c [HR : 3.04 (1.60-5.76)], and T2-4 [HR : 3.41 (1.89-6.17)] compared to T1a, nodal positivity, R1-margin, and no adjuvant chemotherapy were associated with worse OS. Disease recurrence was more common in T2-4 tumors (56.4%) compared to T1a (18.2%), T1b (23.9%), and T1c (36.1%, p < .001). CONCLUSION: T1 sub-staging of IPMN-derived PDAC is valid and has significant prognostic value. Advancing T1 sub-stage is associated with worse histopathology, survival, and recurrence. T1 sub-staging is recommended for future guidelines.

Lymphocyte-to-Monocyte Ratio Predicts Survival for Intraductal Papillary Mucinous Neoplasm with Associated Invasive Carcinoma of the Pancreas: Results from a High-Volume Center.

INTRODUCTION: Intraductal papillary mucinous neoplasm (IPMN) is an important precursor lesion of pancreatic cancer. Systemic inflammatory parameters are widely used in the prognosis prediction of cancer; however, their prognostic implications in IPMN with associated invasive carcinoma (IPMN-INV) are unclear. This study aims to explore the prognostic value of systemic inflammatory parameters in patients with IPMN-INV. METHODS: From 2015 to 2021, patients with pathologically confirmed IPMN who underwent surgical resection at Peking Union Medical College Hospital were enrolled. The clinical, radiological, and pathological data of the enrolled patients were collected and analyzed. Preoperative systemic inflammatory parameters were calculated as previously reported. RESULTS: Eighty-six patients with IPMN-INV met the inclusion criteria. The lymphocyte-to-monocyte ratio (LMR) was the only systemic inflammatory parameter independently associated with the cancer-specific survival (CSS). An LMR higher than 3.5 was significantly associated with a favorable CSS in univariate (hazard ratio [HR] 0.305, p = 0.003) and multivariate analyses (HR 0.221, p = 0.001). Other independently prognostic factors included the presence of clinical symptoms, cyst size, N stage, and tumor differentiation. Additionally, a model including LMR was established for the prognosis prediction of IPMN-INV and had a C-index of 0.809. CONCLUSIONS: Preoperative LMR could serve as a feasible prognostic biomarker for IPMN-INV. A decreased LMR (cutoff value of 3.5) was an independent predictor of poor survival for IPMN-INV.

Utility of Radiological Follow Up of Main-Duct Intraductal Papillary Mucinous Neoplasms and Mixed-Type Intraductal Papillary Mucinous Neoplasms.

BACKGROUND: Intraductal papillary mucinous neoplasms (IPMNs) have the potential to evolve into pancreatic adenocarcinoma (PDAC). While main-duct IPMNs (MD-IPMNs), involving the main pancreatic duct (MPD), are less common than side-branch IPMNs (SB-IPMNs) or mixed-type IPMNs (mixed-IPMNs), their malignant transformation potential is far greater. Controversy exists between different guidelines in terms of recommended management strategies. This study was aimed at assessing the utility of the radiological follow up of MD-IPMNs and mixed-type IPMNs, including prevalence of worrisome radiological findings as well as clinical and laboratory parameters, and their correlation with the development of progression or pancreatic adenocarcinoma. METHODS: Eighty-four patients with MD-IPMNs or mixed-type IPMNs who underwent at least one magnetic resonance cholangiopancreatography (MRCP) were included. Clinical and laboratory data were obtained retrospectively. A cross-sectional analysis was carried out to establish clinical and laboratory parameters associated with development of PDAC. A retrospective cohort analysis was performed on 44 patients who had at least six months of follow up, trying to identify factors correlating with worrisome radiological features. RESULTS: Nine cases (10.7%) of PDAC were recorded in this cohort. The laboratory and imaging factors associated with cyst size progression greater than 5 mm during follow up were elevated alanine transaminase (ALT) levels, the maximal cyst size, and the MPD diameter. Cross-sectional analysis indicated that PDAC was associated with nausea (p = 0.01), as well as increased levels of aspartate aminotransferase (AST) (p = 0.05), gamma glutamyl transpeptidase (GGT) (p = 0.01), and alkaline phosphatase (ALP) (p = 0.01). CONCLUSIONS: Elevated levels of liver enzymes were associated with IPMN progression and, subsequently, the development of PDAC. ALT levels, maximal cyst size, and MPD diameter are associated with the progression of cyst size. These data may aid in risk-stratifying patients when determining the follow up approach for IPMNs.

Pancreatoscopy-Guided Endotherapies for Pancreatic Diseases.

Per-oral pancreatoscopy (POP) is a pancreas-preserving modality that allows for targeted pancreatic duct interventions, particularly in cases where standard techniques fail. POP specifically has an emerging role in the diagnosis, risk stratification, and disease extent determination of main duct intraductal papillary mucinous neoplasms (IPMNs). It has also been successfully used for laser ablation of IPMNs in poor surgical candidates, lithotripsy for complex stone disease, and laser stricturoplasty. As experience with POP increases beyond select referral center practices, further studies validating POP efficacy with long-term follow-up will help clarify when POP-guided intervention is most beneficial in relation to surgical intervention.

The Incidental Pancreatic Cyst: When to Worry About Cancer.

Incidental pancreatic cystic lesions are a common challenge encountered by diagnostic radiologists. Specifically, given the prevalence of benign pancreatic cystic lesions, determining when to recommend aggressive actions such as surgical resection or endoscopic ultrasound with sampling is difficult. In this article, we review the common types of cystic pancreatic lesions including serous cystadenoma, intraductal papillary mucinous neoplasm, and mucinous cystic neoplasm with imaging examples of each. We also discuss high-risk or worrisome imaging features that warrant a referral to a surgeon or endoscopist and provid several examples of these features. These imaging features adhere to the latest guidelines from the International Consensus Guidelines, American Gastroenterological Association (2015), American College of Gastroenterology (2018), American College of Radiology (2010, 2017), and European Guidelines (2013, 2018). Our focused article addresses the imaging dilemma of managing incidental cystic pancreatic lesions, weighing the options between imaging follow-up and aggressive interventions.

SpyGlass guided PDT for advanced intraductal papillary mucinous neoplasm of the bile tract: A case report and literature review.

Intraductal papillary mucinous neoplasm of the bile tract is a rare biliary tumor characterized by mucin growth within the bile duct. In the early stages, it often presents without significant obstruction, this often leads to its discovery in the advanced stages. We report a case of a 63-year-old female with an intraductal papillary mucinous neoplasm of the bile duct (IPMN-B). The patient had a history of intrahepatic bile duct stones and biliary ascariasis. She gradually developed symptoms such as jaundice and intermittent fever before admission, and a bile duct biopsy confirmed the diagnosis of IPMN-B. Currently, endoscopic photodynamic therapy (PDT) is considered an effective treatment for bile duct cancer. In this case, we performed two sessions of PDT guided by SpyGlass. The patient experienced complete remission postoperatively, and there has been no evidence of tumor recurrence or metastasis in the three years following the procedure.

The role of biomarkers in the early detection of pancreatic cancer.

Pancreatic surveillance can detect early-stage pancreatic cancer and achieve long-term survival, but currently involves annual endoscopic ultrasound and MRI/MRCP, and is recommended only for individuals who meet familial/genetic risk criteria. To improve upon current approaches to pancreatic cancer early detection and to expand access, more accurate, inexpensive, and safe biomarkers are needed, but finding them has remained elusive. Newer approaches to early detection, such as using gene tests to personalize biomarker interpretation, and the increasing application of artificial intelligence approaches to integrate complex biomarker data, offer promise that clinically useful biomarkers for early pancreatic cancer detection are on the horizon.

Total pancreatectomy in a patient with a dermadrome caused by intraductal papillary mucinous neoplasm: A case report.

INTRODUCTION: Dermadrome is a term coined by combining the words "dermatology" and "syndrome," and it refers to dermatological symptoms that reflect visceral lesions. PRESENTATION OF CASE: Herein, we present the case of an 83-year-old female patient who presented with generalized blistering and erythema during treatment for acute pancreatitis. She was referred to our dermatology department with worsening erythema, although the acute pancreatitis improved. The cause of the erythema was suspected to be drug-induced, infectious, or related to collagen disease; however, the exact cause was unknown. Computed tomography and endoscopic ultrasonography findings revealed a mixed-type intraductal papillary mucinous neoplasm (IPMN). Refractory erythema was suspected to have been caused by a dermadrome due to IPMN. Consequently, she was referred to our department. The main pancreatic duct was dilated along its entire length, and tumor extension was difficult to determine; therefore, a total pancreatectomy was performed. The postoperative course was uneventful, and erythema gradually improved. The histopathological evaluation indicated high-grade dysplasia of the IPMN. DISCUSSION: The patient's skin rash, which did not improve with treatment that included high-dose steroids, began to improve after surgery, and the disease was thought to be a dermadrome caused by IPMN. CONCLUSION: We believe that this is the first reported case of IPMN with a dermadrome that resolved after a total pancreatectomy.

Premalignant Lesions in the Kidney Transplant Candidate.

End-stage kidney disease patients who are referred for transplant undergo an extensive evaluation process to ensure their health prior to transplant due in part to the shortage of available organs. Although management and surveillance guidelines exist for malignancies identified in the transplant and waitlist populations, less is written about the management of premalignant lesions in this population. This review covers the less common premalignant lesions (intraductal papillary mucinous neoplasm, gastrointestinal stromal tumor, thymoma, and pancreatic neuroendocrine tumor) that can be found in the transplant candidate population. High-level evidence for the management of these rarer premalignant lesions in the transplant population is lacking, and this review extrapolates evidence from the general population and should not be a substitute for a multidisciplinary discussion with medical and surgical oncologists.

Systematic review on surveillance for non-resected branch-duct intraductal papillary mucinous neoplasms of the pancreas.

BACKGROUND: The management of branch-duct type intraductal papillary mucinous neoplasms (BD-IPMN) varies in existing guidelines. This study investigated the optimal surveillance protocol and safe discontinuation of surveillance considering natural history in non-resected IPMN, by systematically reviewing the published literature. METHODS: This review was guided by PRISMA. Research questions were framed in PICO format "CQ1-1: Is size criteria helpful to determine surveillance period? CQ1-2: How often should surveillance be carried out? CQ1-3: When should surveillance be discontinued? CQ1-4: Is nomogram predicting malignancy useful during surveillance?". PubMed was searched from January-April 2022. RESULTS: The search generated 2373 citations. After screening, 83 articles were included. Among them, 33 studies were identified for CQ1-1, 19 for CQ1-2, 26 for CQ1-3 and 12 for CQ1-4. Cysts <1.5 or 2 cm without worrisome features (WF) were described as more indolent, and most studies advised an initial period of surveillance. The median growth rate of cysts <2 cm ranged from 0.23 to 0.6 mm/year. Patients with cysts <2 cm showing no morphological changes and no WF after 5-years of surveillance have minimal malignancy risk of 0-2%. Two nomograms created with over 1000 patients had AUCs of around 0.8 and appear to be feasible in a real-world practice. CONCLUSIONS: For patients with suspected BD-IPMN <2 cm and no other WF, less frequent surveillance is recommended. Surveillance may be discontinued for cysts that remain stable during 5-year surveillance, with consideration of patient condition and life expectancy. With this updated surveillance strategy, patients with non-worrisome BD-IPMN should expect more streamlined management and decreased healthcare utilization.

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

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