Duct Intraductal Papillary Mucinous Neoplasms Research Articles

Endoscopic ultrasound-guided fine-needle aspiration for pancreatic cystic lesions: a comprehensive review.

Advancements in diagnostic radiology have amplified the incorporation of these techniques into routine clinical practice. Concurrently, the frequency of incidentally identifying pancreatic cystic lesions (PCLs) has surged. PCLs encompass diverse categories contingent upon their origin. Among them, branch duct-intraductal papillary mucinous neoplasms (BD-IPMN) and mucinous cystic neoplasms (MCN) are categorized as mucinous cystic lesions that have malignant potential. Even solid neoplasms occasionally show cystic degeneration. Therefore, precise differential PCL diagnosis is crucial to optimize clinical management strategies and detect malignant transformations. Endoscopic ultrasound (EUS) affords comprehensive visualization of the pancreas with high-resolution ultrasound, complemented by fine-needle aspiration (FNA) under real-time EUS guidance, which is a minimally invasive procedure for obtaining pathological samples. This synergy has established EUS and EUS-FNA as vital procedures in the management of PCLs, enabling differentiation of PCLs. Cyst fluid analysis has played a pivotal role in deciding the optimal management strategy. The efficacy of cytological analysis is limited by scant cytologic material. The "string sign" test evaluates fluid viscosity, and its simplicity warrants initial consideration. Amylase and tumor markers, such as CEA, have been studied, but they yield varied sensitivity and specificity. Glucose and genetic mutations (KRAS, GNAS) exhibit promise, while comprehensive genomic profiling underscores genetic insights. Through-the-needle biopsy and needle-based confocal laser endomicroscopy also show high diagnostic yield. EUS-FNA, however, entails risks like infection and needle tract seeding, emphasizing the need for proper utilization. Pancreatic cyst fluid analysis augments diagnostic accuracy and informs clinical decisions, making it a valuable adjunct to imaging.

Concomitant cancer at another site may be a new prognosticator in patients with branch duct intraductal papillary mucinous neoplasm who are not suitable candidates for surgical treatment

Concomitant cancer at another site may be a new prognosticator in patients with branch duct intraductal papillary mucinous neoplasm who are not suitable candidates for surgical treatment

Accompanying cancer of other site may be a new prognosticator in patients with branch duct intraductal papillary mucinous neoplasm unfit for surgical treatment

Accompanying cancer of other site may be a new prognosticator in patients with branch duct intraductal papillary mucinous neoplasm unfit for surgical treatment

S1997 Long-Standing Main Pancreatic Duct Intraductal Papillary Mucinous Neoplasm Treated With Double Papillae Endoscopic Sphincterotomy and Stent Placement

S1997 Long-Standing Main Pancreatic Duct Intraductal Papillary Mucinous Neoplasm Treated With Double Papillae Endoscopic Sphincterotomy and Stent Placement

Are the screening guidelines for branch duct intraductal papillary mucinous neoplasms cost-effective in an Australian setting?

Intraductal papillary mucinous neoplasms (IPMN) are cystic neoplasms of the pancreatic ductal system. These incidental cystic lesions are increasingly found on radiological imaging and screened for malignant transformation. The Fukuoka consensus guidelines recommend screening with computed tomography, magnetic resonance imaging or endoscopic ultrasound. Branch duct IPMN (BD-IPMN) have significantly lower malignancy and mortality rates compared to main duct IPMN. Our aim was to assess the cost-effectiveness of guideline's recommendations for BD-IPMN screening of cysts between 2 and 3 cm in an Australian context. Markov model decision analysis was used to calculate the incremental cost-effectiveness ratio (ICER) of screening. The ICER was compared to a willingness to pay (WTP) threshold of $50 000. We performed scenario analysis to examine the effect of cyst size and non-linearity of malignancy rate on ICER. Probabilistic sensitivity analyses (PSA) were performed on our input parameters. Screening resulted in 586 quality adjusted life years gained and a net present value of $20 379 939, resulting in a base-case ICER of $34 758. After scenario analysis for non-linearity of malignancy rate the ICER increases to $64 555, which is above the WTP threshold. PSA indicates that ICER is most susceptible to the pre-test malignancy rate. This cost analysis demonstrates that screening of 2-3 cm BD-IPMN according to current guidelines is unlikely to be cost-effective in an Australian context. To determine the true ICER, a cost analysis on real-world data is required.

Surveillance for Presumed BD-IPMN of the Pancreas: Stability, Size, and Age Identify Targets for Discontinuation

Currently, most patients with branch duct intraductal papillary mucinous neoplasms (BD-IPMN) are offered indefinite surveillance, resulting in health care costs with questionable benefits regarding cancer prevention. This study sought to identify patients in whom the risk of cancer is equivalent to an age-matched population, thereby justifying discontinuation of surveillance. International multicenter study involving presumed BD-IPMN without worrisome features (WFs) or high-risk stigmata (HRS) at diagnosis who underwent surveillance. Clusters of individuals at risk for cancer development were defined according to cyst size and stability for at least 5 years, and age-matched controls were used for comparison using standardized incidence ratios (SIRs) for pancreatic cancer. Of 3844 patients with presumed BD-IPMN, 775 (20.2%) developed WFs and 68 (1.8%) HRS after a median surveillance of 53 (interquartile range 53) months. Some 164 patients (4.3%) underwent surgery. Of the overall cohort, 1617 patients (42%) remained stable without developing WFs or HRS for at least 5 years. In patients 75 years or older, the SIR was 1.12 (95% CI, 0.23-3.39), and in patients 65 years or older with stable lesions smaller than 15 mm in diameter after 5 years, the SIR was 0.95 (95% CI, 0.11-3.42). The all-cause mortality for patients who did not develop WFs or HRS for at least 5 years was 4.9% (n= 79), and the disease-specific mortality was 0.3% (n= 5). The risk of developing pancreatic malignancy in presumed BD-IPMN without WFs or HRS after 5 years of surveillance is comparable to that of the general population depending on cyst size and patient age. Surveillance discontinuation could be justified after 5 years of stability in patients older than 75 years with cysts <30 mm, and in patients 65 years or older who have cysts ≤15 mm.

Enhancing Mural Nodules in the Main Pancreatic Duct of Main and Mixed Types of Intraductal Papillary Mucinous Neoplasms: Does Size Matter in Malignancy Risk?

Most guidelines recommend surgical resection of all main duct (MD) and mixed-type (MT) intraductal papillary mucinous neoplasms (IPMNs) in suitable patients. However, there is little evidence regarding the malignancy risk of enhancing mural nodules (EMNs) that are present only in the main pancreatic duct (MPD) in patients with MD- and MT-IPMNs. Therefore, this study aimed to identify the clinical and morphological features associated with malignancy in MD- and MT-IPMNs with EMNs only in the MPD. We retrospectively enrolled 50 patients with MD- and MT-IPMNs with EMNs only in the MPD on contrast-enhanced magnetic resonance imaging. We evaluated the clinical characteristics and preoperative radiologic imaging results of MPD morphology and EMN size and analyzed the risk factors associated with malignancy. Histological findings of EMNs were low-grade dysplasia (38%), malignant lesions (62%), high-grade dysplasia (34%), and invasive carcinoma (28%). On the receiver operating characteristic curve, the cutoff value of EMN size on magnetic resonance imaging for best predicting malignancy was 5 mm (sensitivity, 93.5%; specificity, 52.6%; area under the curve, 0.753). Multivariate analysis showed that only EMN >5 mm (odds ratio, 27.69; confidence interval, 2.75 to 278.73; p=0.050) was an independent risk factor for malignancy. EMNs of >5 mm are associated with malignancy in patients with MD- and MT-IPMNs with EMNs that are present only in the MPD, in accordance with the international consensus guidelines.

Intraoperative pancreatoscopy can improve the detection of skip lesions during surgery for intraductal papillary mucinous neoplasia: A pilot study

ObjectivesIntraoperative pancreatoscopy is a promising procedure that might guide surgical resection for suspected main duct (MD) and mixed type (MT) intraductal papillary mucinous neoplasms (IPMNs). The aim of the present study was to assess the diagnostic yield and clinical impact of intraoperative pancreatoscopy in patients operated on for MD and MT-IPMNs. MethodsThis is a retrospective cohort study. Patients undergoing surgery for suspected MD or MT-IPMN underwent intraoperative pancreatoscopy and frozen section analysis. In all patients who required extended resection due to pancreatoscopic findings, we compared the final histology with the results of the intraoperative frozen section analysis. ResultsIn total, 46 patients, 48% females, mean age (range) 67 years (45–82 years) underwent intraoperative pancreatoscopy. No mortality or procedure related complications were observed. Pancreatoscopy changed the operative course in 30 patients (65%), leading to extended resections in 20 patients (43%) and to parenchyma sparing procedures in 10 patients (22%). Analyzing the group of patients who underwent extended resections, 7 (35%) displayed lesions that needed further surgical treatment (six high grade dysplasia and one with G1 pancreatic neuroendocrine tumor) and among those 7, just 1 (14%) would have been detected exclusively with histological frozen section analysis of the transection margin. The combination of both pancreatoscopy and frozen section analysis lead to 86% sensitivity and 92% specificity for the detection of pathological tissue in the remnant pancreas. ConclusionIntraoperative pancreatoscopy is a safe and feasible procedure and might allow the detection of skip lesions during surgery for suspect MD-involving IPMNs.

Total pancreatectomy: Experience within an integrated health care system.

e16269 Background: Total pancreatectomy (TP) is most used for pancreatic adenocarcinoma (PC) but also for main duct intra-ductal papillary mucinous neoplasm. The authors report on a retrospective study of 61 patients who underwent TP in an integrated healthcare system. Methods: A retrospective review was performed of all patients treated with TP between January 2012 and December 2022. Patient demographics, tumor characteristics, treatment modalities, and mean overall survival (OS) were evaluated. Results: An intra-operative positive pancreatic neck margin for cancer or high-grade dysplasia was the most common indication for TP in 77% (47/61) of patients. The mean OS for patients with pancreatic cancer was 18 months, however, patients with a pre-op diagnosis of IPMN had a mean OS of 50 months. Multivariate analysis of PC without IPMN showed that neoadjuvant and NPH insulin were associated with a decrease in overall survival ( p&lt; .05). Overall HbA1c were higher in patients after one year after surgery for patients taking NPH (8.6) as opposed to an insulin pump (7.6) or Lantus (7.6) but not significant ( p= .346). Mean OS for patients with PC and type of insulin used was statistically significant at 24.4 months vs 13.1 months respectively for Lantus vs NPH ( p= .033). Conclusions: Conversion to TP for positive neck margins did not improve survival in patients who receive neoadjuvant chemotherapy but may be helpful in patients with IPMN. Blood sugar control after one year was similar among the various indication groups as well the type of insulin use. Although Lantus insulin was associated with improved overall survival for patients with pancreatic cancer, the exact reason is unclear and requires further studies.

Long-term (10-year) outcomes and prognostic factors in resected intraductal papillary mucinous neoplasm tumors in Finland: A nationwide retrospective study

BackgroundThe degree of dysplasia is the most important prognostic factor for patients with resected intraductal papillary mucinous neoplasms. Intraductal papillary mucinous neoplasms are predominantly premalignant conditions; in most cases, surveillance is an adequate treatment. If worrisome features are present, surgery should be considered. However, there is limited data on the long-term prognosis of resected intraductal papillary mucinous neoplasms. We aimed to ascertain the nationwide survival of patients with resected intraductal papillary mucinous neoplasms and identify factors associated with survival. MethodsThis is a retrospective nationwide cohort study. All intraductal papillary mucinous neoplasms operated on in Finland between 2000 and 2008 were identified. Patient records were evaluated, and original radiologic data and histologic samples were re-evaluated. Survival data were collected after a 10-year follow-up period. ResultsOut of 2,024 pancreatic resections, 88 were performed for intraductal papillary mucinous neoplasm. The median age of the patients was 65 years. Histologic diagnoses were main duct intraductal papillary mucinous neoplasm 47/88 (53,4%), mixed-type intraductal papillary mucinous neoplasm 27/88 (30.7%), and branchduct intraductal papillary mucinous neoplasm 14/88 (15.9%). Of the tumors, 40/88 (45.5%) were low-grade dysplasia, 9/88 (10.2%) high-grade, and 39/88 (44.3%) were invasive cancer. The median survival was 121 (range 0–252) months. Ten-year survival was 72.5%, 66.7%, and 23.1% in the low-grade dysplasia, high-grade dysplasia, invasive cancer groups, respectively. Ten-year mortality for pancreatic cancer was 5%, 9.1%, and 71.8% in the low-grade dysplasia, high-grade dysplasia, invasive cancer groups, respectively. ConclusionOverall, 44.3% of the patients had a malignant tumor, and three-quarters (74.5%) of the main duct intraductal papillary mucinous neoplasms were malignant or high-grade dysplasia at the time of surgery. Ten-year survival was significantly better in patients operated on at the stage of a premalignant tumor (low-grade dysplasia + high-grade dysplasia) than in patients operated on at the stage of a malignant tumor.

Branch duct-intraductal papillary mucinous neoplasms (BD-IPMNs): an MRI-based radiomic model to determine the malignant degeneration potential.

Branch duct-intraductal papillary mucinous neoplasms (BD-IPMNs) are the most common pancreatic cystic tumors and have a low risk of malignant transformation. Features able to early identify high-risk BD-IPMNs are lacking, and guidelines currently rely on the occurrence of worrisome features (WF) and high-risk stigmata (HRS). In our study, we aimed to use a magnetic resonance imaging (MRI) radiomic model to identify features linked to a higher risk of malignant degeneration, and whether these appear before the occurrence of WF and HRS. We retrospectively evaluated adult patients with a known BD-IPMN who had had at least two contrast-enhanced MRI studies at our center and a 24-month minimum follow-up time. MRI acquisition protocol for the two examinations included pre- and post-contrast phases and diffusion-weighted imaging (DWI)/apparent diffusion coefficient (ADC) map. Patients were divided into two groups according to the development of WF or HRS at the end of the follow-up (Group 0 = no WF or HRS; Group 1 = WF or HRS). We segmented the MRI images and quantitative features were extracted and compared between the two groups. Features that showed significant differences (SF) were then included in a LASSO regression method to build a radiomic-based predictive model. We included 50 patients: 31 in Group 0 and 19 in Group 1. No patients in this cohort developed HRS. At baseline, 47, 67, 38, and 68 SF were identified for pre-contrast T1-weighted (T1-W) sequence, post-contrast T1-W sequence, T2-weighted (T2- W) sequence, and ADC map, respectively. At the end of follow-up, we found 69, 78, 53, and 91 SF, respectively. The radiomic-based predictive model identified 16 SF: more particularly, 5 SF for pre-contrast T1-W sequence, 6 for post-contrast T1-W sequence, 3 for T2-W sequence, and 2 for ADC. We identified radiomic features that correlate significantly with WF in patients with BD-IPMNs undergoing contrast-enhanced MRI. Our MRI-based radiomic model can predict the occurrence of WF.

Real-world costs and dynamics of surveillance in patients who underwent surgery for low-risk branch duct intraductal papillary mucinous neoplasms.

Surveillance costs and appropriateness of surgery of "low-risk" BD-IPMNs are relevant issues. In this study we evaluated the rate of correct indication for pancreatectomy defined as high grade dysplasia (HGD) at histology in 961 patients who underwent surveillance for a median of 5.1 years. Undertreatment and overtreatment were defined as invasive cancer and low grade dysplasia (LGD) at histology, respectively. Of the 66 patients (6.9%) who were operated, only 16 (23.8%) had a HGD while 40 (59.7%) had a LGD and 10 (14.9%) an invasive cancer, without differences regarding timing of surgery. The mean surveillance cost was € 194.9±107.6 per patient-year, with a median cost of € 277.1±148.2 in the correct surgery group compared with € 222.7±111.6 and € 197±102.7 in the overtreatment and undertreatment groups. The surveillance mean cost from diagnosis to surgery was € 854.8. Rate of appropriate surgery in BD-IPMNs under surveillance is low.

Molecular Analysis of Pancreatic Cyst Fluid for the Management of Intraductal Papillary Mucinous Neoplasms.

Pancreatic cancer is one of the most lethal human cancers. Early detection and diagnosis of precursor lesions for pancreatic malignancy is essential to improve the morbidity and mortality associated with this diagnosis. Of the cystic precursor lesions, branch duct intraductal papillary mucinous neoplasm (IPMN) is the most frequently identified lesion and has a wide range of malignant potential. Currently, Carcinogenic embryonic antigen (CEA) levels in the cyst fluid and cytology are the two most often utilized tools to diagnose these lesions; however, their diagnostic and risk stratification capabilities are somewhat limited. Within the last decade, the use of endoscopic ultrasound-guided fine-needle aspiration has opened the door for molecular analysis of cystic fluid as an option to enhance both the diagnosis and risk stratification of these lesions. The first step is to differentiate branch duct IPMNs from other lesions. KRAS and GNAS alterations have been shown to be accurate markers for this purpose. Following cyst type identification, mutational analysis, telomere fusion, microRNAs, long non-coding RNA, and DNA methylation have been identified as potential targets for stratifying malignant potential using the cystic fluid. In this review, we will examine the various targets of cyst fluid molecular analysis and their utility in the diagnosis and risk stratification of branch duct IPMNs.

Segmental Versus Diffuse Main Duct Intraductal Papillary Mucinous Neoplasm: Examination of Main Pancreatic Duct Morphology and Implications for Malignancy Risk and Extent of Surgical Resection.

To determine whether the morphologic features of the main pancreatic duct (MPD) of main-duct-involved-intraductal papillary mucinous neoplasm (IPMN) (ie, main duct or mixed main duct/side branch) have implications for the risk of malignancy and extent of resection. International consensus guidelines acknowledge the presence of various MPD morphologies (ie, diffuse vs segmental main-duct-involved-IPMN) without a precise definition of each entity and with limited data to guide treatment strategy. All consecutive main-duct-involved-IPMN patients (2005-2019) with a MPD diameter ≥5mm by cross-sectional imaging were reviewed from a prospective institutional database. Morphologic features of the MPD were correlated with the identification of high-grade dysplasia or pancreatic ductal adenocarcinoma (HGD/PDAC) by logistic regression modeling. In patients who underwent partial pancreatectomy, preoperative MPD morphologic features were correlated with the future development of HGD/PDAC in the pancreatic remnant by Cox hazards modeling. In a cohort of 214 main-duct-involved-IPMN patients, the overall rate of HGD/PDAC was 54.2%. MPD morphologic characteristics associated with HGD/PDAC included: maximal MPD diameter (5-10mm: 29.8%; 10-14mm: 59.0%; 15-19mm: 78.6%; ≥20mm: 95.8%; P <0.001), segmental extent of maximal dilation (<25%: 28.2%; 25%-49%: 54.9%; 50%-74%: 63.1%; ≥75%: 67.9%; P =0.002), and nonsegmental MPD diameter (<5mm: 21.5% vs ≥5mm: 78.5%, P <0.001). Diffuse MPD dilation involving ≥90% extent was rare (5.6%). After a median follow-up of 50 months, 7 (7.2%) patients who underwent partial pancreatectomy for IPMN without associated PDAC developed HGD/PDAC in the pancreatic remnant. Maximal MPD diameter, segmental extent of maximal dilation, or nonsegmental MPD diameter were not associated with the development of HGD/PDAC in the pancreatic remnant. However, a mural nodule on preoperative imaging was associated with the development of HGD/PDAC in the pancreatic remnant. "Diffuse" involvement with homogenous dilation of the MPD was rare. For the majority of patients with segmental main-duct-involved-IPMN, the MPD morphology conferred malignancy risk. Duct morphology was not predictive for the development of HGD or invasive disease in the pancreatic remnant, implying the safety of limited pancreatic resection for initial surgical management.

Higher volume growth rate is associated with development of worrisome features in patients with branch duct-intraductal papillary mucinous neoplasms.

BACKGROUNDBranch duct-intraductal papillary mucinous neoplasms (BD-IPMNs) are the most common pancreatic cystic tumours and have a low risk of malignant transformation. Current guidelines only evaluate cyst diameter as an important risk factor but it is not always easy to measure, especially when comparing different methods. On the other side, cyst volume is a new parameter with low inter-observer variability and is highly reproducible over time.AIMTo assess both diameter and volume growth rate of BD-IPMNs and evaluate their correlation with the development of malignant characteristics.METHODSComputed tomography scans and magnetic resonance imaging exams were retrospectively reviewed. The diameter was measured on three planes, while the volume was calculated by segmentation: The volume of the entire cyst was determined by manually drawing a region of interest along the edge of the neoplasm on each consecutive slice covering the whole lesion; therefore, a three-dimensional volume of interest was finally obtained with the calculated value expressed in cm3. Changes in size over time were measured. The development of worrisome features was evaluated.RESULTSWe evaluated exams of 98 patients across a 40.5-mo median follow-up time. Ten patients developed worrisome features. Cysts at baseline were significantly larger in patients who developed worrisome features (diameters P = 0.0035, P = 0.00652, P = 0.00424; volume P = 0.00222). Volume growth rate was significantly higher in patients who developed worrisome features (1.12 cm3/year vs 0 cm3/year, P = 0.0001); diameter growth rate was higher as well, but the difference did not always reach statistical significance. Volume but not diameter growth rate in the first year of follow-up was higher in patients who developed worrisome features (0.46 cm3/year vs 0 cm3/year, P = 0.00634).CONCLUSIONThe measurement of baseline volume and its variation over time is a reliable tool for the follow-up of BD-IPMNs. Volume measurement could be a better tool than diameter measurement to predict the development of worrisome features.

Application of Artificial Intelligence in the Management of Pancreatic Cystic Lesions.

The rate of incidentally detected pancreatic cystic lesions (PCLs) has increased over the past decade and was recently reported at 8%. These lesions pose a unique challenge, as each subtype of PCL carries a different risk of malignant transformation, ranging from 0% (pancreatic pseudocyst) to 34–68% (main duct intraductal papillary mucinous neoplasm). It is imperative to correctly risk-stratify the malignant potential of these lesions in order to provide the correct care course for the patient, ranging from monitoring to surgical intervention. Even with the multiplicity of guidelines (i.e., the American Gastroenterology Association guidelines and Fukuoka/International Consensus guidelines) and multitude of diagnostic information, risk stratification of PCLs falls short. Studies have reported that 25–64% of patients undergoing PCL resection have pancreatic cysts with no malignant potential, and up to 78% of mucin-producing cysts resected harbor no malignant potential on pathological evaluation. Clinicians are now incorporating artificial intelligence technology to aid in the management of these difficult lesions. This review article focuses on advancements in artificial intelligence within digital pathomics, radiomics, and genomics as they apply to the diagnosis and risk stratification of PCLs.

Enucleation for low-grade branch duct intraductal papillary mucinous neoplasms: Long-term follow-up

BackgroundPancreatic enucleation allows resection of branch-duct intraductal papillary mucinous neoplasms with full parenchyma preservation. The aim of this study was to assess intraductal papillary mucinous neoplasms recurrence and functional outcomes during long-term follow-up after enucleation. MethodsPatient characteristics, as well as radiologic and clinicopathologic follow-up data of patients who underwent enucleation for branch-duct intraductal papillary mucinous neoplasms between 2004 and 2014, were analyzed. Quality of life was assessed using the EORTC QLQ-C30 and QLQ-PAN26 questionnaires. ResultsSeventy-four patients underwent enucleation for low-grade branch-duct intraductal papillary mucinous neoplasms in 71 and high-grade branch-duct intraductal papillary mucinous neoplasms in 3 patients. Long-term follow-up data were available for 66 patients (89%; median follow-up: 87 months). Radiologic imaging (n = 56) showed intraductal papillary mucinous neoplasm recurrence in 10 patients (18%) including local recurrence at the site of enucleation in 3 patients (5%) and new onset intraductal papillary mucinous neoplasms manifestation in 7 patients (13%) at a distant site in the pancreatic remnant. Four patients (6%) underwent reoperation. Two of these patients had intraductal papillary mucinous neoplasm-associated carcinoma, one of them at the enucleation site. During the follow-up period, no intraductal papillary mucinous neoplasm-related deaths occurred and no new onsets of insulin-dependent diabetes mellitus were observed. QLQ-C30 revealed a global health status of 66.0% and overall functioning and symptom scores of 81.0% and 22.8%, respectively. Additionally, QLQ-PAN26 showed an overall symptom score of 26.5%. ConclusionEnucleation is an organ-preserving surgical treatment option for low-grade branch-duct intraductal papillary mucinous neoplasms with low local recurrence risk and excellent functional long-term outcome. However, postoperative life-long follow-up must be performed as for any type of partial pancreatectomy for intraductal papillary mucinous neoplasms due to the risk of recurrence and potential malignancy.

Prediction of malignancy in main duct or mixed-type intraductal papillary mucinous neoplasms of the pancreas.

Surgical indications of main duct-involved intraductal papillary mucinous neoplasm (IPMN), especially for main pancreatic duct (MPD) of 5-9 mm, remain controversial. We aimed to predict malignancy risk of main duct-involved IPMN. Total 258 patients with main duct-involved IPMN between 2000 and 2017 in our institute were retrospectively analyzed. Main duct IPMN was classified into segmental and diffuse-type by dilated MPD pattern. Clinicopathologic features and predictive factors for malignancy were analyzed. Among 258 patients, 47 and 211 had pure main duct (segmental: 27, diffuse type: 20) and mixed type, respectively. Malignant IPMN presented higher in main duct type (66.0%) compared to mixed type (46.9%). The diffuse type (72.2%) had more invasive carcinoma than the segmental type (40.7%). Invasive IPMN risk increased proportionally to the MPD diameter (5 ≤ MPD <10 mm vs 10 ≤ MPD < 15 mm vs MPD ≥ 15 mm; 23.4% vs 40.0% vs 48.6%). Symptoms, elevated serum carbohydrate antigen, MPD ≥10 mm, mural nodule, thickened wall, and distal atrophy were independent predictive factors for malignancy. Patients with MPD of 5-9 mm with at least one predictive factor had 35.0% of malignancy risk. The invasive IPMN risk was different according to the dilated main duct pattern. Patients with main duct type, diffuse type, MPD ≥10 mm, and MPD 5-9 mm with at least one predictive factor should be candidates for immediate surgery.

[Resection Strategies in BD-IPMN - Enucleation or Standard Resection?]

The malignant potential and the surgical management of branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) remain controversial. Enucleation (EN), as parenchyma-sparing resections of the pancreas, may be a valuable alternative to standard resections (SR), e.g., Whipple or distal pancreatectomy, for the treatment of BD-IPMN. However, its role is still poorly defined. The objective of this review is to compare indications and postoperative outcomes after pancreatic EN versus SR. A review of the literature was carried out. Short- and long-term postoperative outcomes of both surgical approaches were evaluated. EN is associated with shorter operation time and less blood loss than SR. The overall surgical morbidity does not differ between the two approaches. Although EN is less invasive, the development of pancreatic fistula is the most important complication after EN, as several studies have reported a higher rate of pancreatic fistula than after SR. However, the differences between the two procedures are mitigated in high-volume centres. EN more frequently allows the preservation of pancreatic exocrine and endocrine function in comparison to SR and this is the most important advantage of this procedure. EN appears to be a safe and effective alternative to treat low-risk BD-IPMN, and allows preservation of endocrine and exocrine function. Moreover, postoperative complications and recurrence rates after EN are comparable to the much more extensive surgical procedures. However, pancreatic EN should be performed by experienced surgeons and, as non-oncological procedure, patients should be very accurately selected. This underlines the importance of treatment in high-volume institutions.

Pancreatic duct biopsies using a novel device delivery system for preoperative evaluation of main duct intraductal papillary mucinous neoplasm.

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