Pancreatic resections for cystic neoplasms: from the surgeon's presumption to the pathologist's reality

Pancreas Cyst Diagnosis and Advances in Cyst Fluid Analysis

Pancreatic Cystic Neoplasms (PCN) represent a diverse group of tumors, some of which may progress to pancreatic cancer. Considering their high prevalence in the general population, the development of reliable biomarkers is crucial. The ideal biomarker will accurately diagnose the subtype of PCN and assess the risk of high-grade dysplasia or invasive cancer. Cyst fluid analysis has emerged as a promising approach to accomplish this goal, yet no single marker has yet gained unanimous support for routine inclusion in PCN evaluation.

The multidisciplinary pancreatic cyst clinic: A collaborative approach to streamlined management

BACKGROUND

Pancreatic cysts are often incidentally detected on routine imaging studies. Of these, mucinous cysts have a malignant potential. Several guidelines propose different management strategies, and implementation in patient care is inconsistent in the absence of dedicated infrastructure.

METHODS

To address the challenges of pancreatic cyst diagnosis and management, we established a multidisciplinary pancreas cyst clinic (PCC) within our health system. This clinic encompasses both tertiary care academic centers and community hospitals, with leadership from surgical oncology, gastroenterology, and radiology. Our PCC's primary goal is to provide accurate diagnosis and tailored management recommendations for all patients with pancreatic cysts. Additionally, we maintain a prospective database to study the disease's natural history and the outcomes of various treatment strategies.

CLINIC INFRASTRUCTURE

The clinic meets once per week for 45 min virtually via Zoom in the mornings. Patients are referred via electronic medical record (EMR) order, telephone call, or email from patient or referring provider. A dedicated advanced practice provider reviews referrals several times per day, calls patients to gather clinical data, ensures imaging is uploaded, and coordinates logistical aspects of the meeting during the dedicated time. Conferences are attended by representatives from surgery, radiology, medical pancreatology, and interventional gastroenterology. Each patient case is reviewed in detail and recommendations are submitted to referring providers and patients via an EMR message and letter. For patients requiring imaging surveillance, patients are followed longitudinally by the referring provider, gastroenterology team, or surgical team. For patients requiring endoscopic ultrasound (EUS) or surgical consultation, expedited referral to these services is made with prompt subsequent evaluation.

RESULTS

A total of 1052 patients from our health system were evaluated between 2020 and 2021. Of these, 196 (18.6 %) underwent EUS, 41 (3.9 %) underwent upfront surgical resection, and the remainder were referred to gastroenterology (141-13.4 %), surgery (314-29.8 %), or back to their referring provider (597-56.7 %) for ongoing surveillance in collaboration with their primary care provider (PCP). Of cysts under surveillance, 61.3 % remained stable, 13.2 % increased in size, and 2 % decreased in size. A total of 2.3 % of patients were recommended to discontinue surveillance.

CONCLUSIONS

The PCC provides infrastructure that has served to provide multidisciplinary review and consensus recommendations to patients with pancreatic cysts. This has served to improve the application of guidelines while providing individualized recommendations to each patient, while aiding non-expert referring providers throughout the region.

Surveillance of Individuals at High Risk of Developing Pancreatic Cancer: A Prevalence Meta-analysis to Estimate the Rate of Low-yield Surgery

OBJECTIVE

To quantify the rate of low-yield surgery, defined as no high-grade dysplastic precursor lesions or T1N0M0 pancreatic cancer at pathology, during pancreatic cancer surveillance.

BACKGROUND

Global efforts have been made in pancreatic cancer surveillance to anticipate the diagnosis of pancreatic cancer at an early stage and improve survival in high-risk individuals (HRIs) with a hereditary predisposition. The negative impact of pancreatic cancer surveillance when surgery is performed for low-grade dysplasia or a non-neoplastic condition is not well quantified.

MATERIALS AND METHODS

A systematic search and prevalence meta-analysis was performed for studies reporting surgery with final diagnoses other than those defined by the Cancer of the Pancreas Screening (CAPS) goals from January 2000 to July 2023. The secondary outcome was the pooled proportion of final diagnoses matching the CAPS goals (PROSPERO: #CRD42022300408).

RESULTS

Twenty-three articles with 5027 patients (median 109 patients/study, interquartile range 251) were included. The pooled prevalence of low-yield surgery was 2.1% (95% CI: 0.9-3.7, I2 : 83%). In the subgroup analysis, this prevalence was nonsignificantly higher in studies that only included familial pancreatic cancer subjects without known pathogenic variants, compared with those enrolling pathogenic variant carriers. No effect modifiers were found. Overall, the pooled prevalence of subjects under surveillance who had a pancreatic resection that contained target lesions was 0.8% (95% CI, 0.3-1.5, I2 : 24%]. The temporal analysis showed that the rate of low-yield surgeries decreased in the last decades and stabilized at around 1% (test for subgroup differences P <0.01).

CONCLUSIONS

The risk of "low-yield" surgery during pancreatic cancer surveillance is relatively low but should be thoroughly discussed with individuals under surveillance.

Rare Pancreatic/Peripancreatic Cystic Lesions Can Be Accurately Characterized by EUS with Through-the-Needle Biopsy-A Unique Pictorial Essay with Clinical and Histopathological Correlations

Due to their aspecific macroscopic appearance, uncommon pancreatic cystic lesions (PCLs) are often misdiagnosed as mucinous lesions and improperly resected. We aimed to evaluate the endoscopic ultrasound (EUS)-guided through-the-needle biopsy (TTNB) capacity of the preoperative diagnosis of uncommon PCLs. Overall, 136 patients with PCLs who underwent EUS-TTNB between 2016 and 2022 were retrospectively identified. Common histotypes (e.g., IPMN, serous cystadenoma, and mucinous cystadenoma) were excluded and 26 (19.1%) patients (15 female, mean age 52.9 ± 10.4) were analyzed. The EUS findings, adverse events (AEs), and TTNB outcomes in uncommon PCLs were evaluated. The cysts histotype was accurately diagnosed by TTNB in 24/26 (92.3%) cases (seven cystic neuroendocrine tumors, four squamoid cysts, three acinar cells cystadenomas, two lymphoepithelial cysts, two mucinous non-neoplastic cysts, two bronchogenic cysts, two cystic lymphangiomas, one solid-pseudopapillary neoplasm, and one schwannoma). In the remaining two cases, lymphangioma was eventually diagnosed after resection. Surgery was performed in 15/26 (57.7%) patients. The mean follow-up of non-surgical patients was 32.5 months. One severe acute case of pancreatitis (3.8%) that required surgery occurred after EUS-TTNB. Uncommon pancreatic/peripancreatic lesions represent the 19.1% of PCLs in our series, with mainly benign histotypes. TTNB demonstrated a high diagnostic performance with a low rate of AEs in this setting, representing a reliable tool with which to avoid useless surgery.

Pancreatic cystic neoplasms: Still high rates of preoperative misdiagnosis in the guidelines and endoscopic ultrasound era

BACKGROUND

A wrong diagnosis of nature is common in pancreatic cystic neoplasms. The aim of the current study is to reappraise the diagnostic errors for presumed pancreatic cystic neoplasms in patients undergoing surgery.

METHODS

All pancreatic resections for presumed pancreatic cystic neoplasms following international guidelines between 2011 and 2020 were analyzed. Misdiagnosis was defined as the discrepancy between preoperative diagnosis of nature and final pathology. Mismatch was defined as the discrepancy between the preoperative suspect of malignancy (or its absence) and final pathology.

RESULTS

A total of 601 patients were included. Endoscopic ultrasound was performed in 301 (50%) patients. Overall misdiagnosis and mismatch were 19% and 34%, respectively, with no significant benefit for those patients who underwent endoscopic ultrasound. The highest rate of misdiagnosis was reached for cystic neuroendocrine tumors (61%) and the lowest for solid pseudopapillary tumors (6%). Several diagnostic errors had clinical relevance, including 7 (13%) presumed serous cystic neoplasms eventually found to be other malignant entities, 50 (24%) intraductal papillary mucinous neoplasms with high-risk stigmata revealed to be non-malignant, and 38 (33%) intraductal papillary mucinous neoplasms without high-risk stigmata revealed to be malignant at final pathology. A preoperative presumption of malignant mucinous cystic neoplasm was correct in only 20 (16%) patients.

CONCLUSIONS

Despite not always being clinically relevant, diagnostic errors are still common among resected pancreatic cystic neoplasms when applying international guidelines. New diagnostic tools beyond endoscopic ultrasound are needed to refine the diagnosis of those lesions at higher risk for unnecessary surgery or accidentally observed, nevertheless being malignant.

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

BACKGROUND & AIMS

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Risk Models for Pancreatic Cyst Diagnosis

The overall prevalence of pancreatic cysts (PCs) is high in the general population. In clinical practice PCs are often incidentally discovered and are classified into benign, premalignant, and malignant lesions according to the World Health Organization. For this reason, in the absence of reliable biomarkers, to date clinical decision-making relies mostly on risk models based on morphological features. The aim of this narrative review is to present the current knowledge regarding PC's morphologic features with related estimated risk of malignancy and discuss available diagnostic tools to minimize clinically relevant diagnostic errors.

It is not necessary to resect all mucinous cystic neoplasms of the pancreas: current guidelines do not reflect the actual risk of malignancy

BACKGROUND

Mucinous Cystic Neoplasms (MCN) of the pancreas are premalignant cysts for which current guidelines support pancreatic resection. The primary aim of this systematic review and meta-analysis is to define the pooled rate of malignancy for MCN.

METHODS

A systematic review of eligible studies published between 2000 and 2021 was performed on PubMed and Embase. Primary outcome was rate of malignancy. Data regarding high-risk features, including cyst size and mural nodules, were collected and analyzed.

RESULTS

A total of 40 studies and 3292 patients with resected MCN were included in the final analysis. The pooled rate of malignancy was 16.1% (95%CI 13.1-19.0). The rate of malignant MCN in studies published before 2012 was significantly higher than that of studies published after recent guidelines were published (21.0% vs 14.9%, p < 0.001). Malignant MCN were larger than benign (mean difference 25.9 mm 95%CI 14.50-37.43, p < 0.001) with a direct correlation between size and presence of malignant MCN (R2 = 0.28, p = 0.020). A SROC identified a threshold of 65 mm to be associated with the diagnosis of malignant MCN. Presence of mural nodules was associated with the diagnosis of a malignant MCN (OR = 4.34, 95%CI 3.00-6.29, p < 0.001).

CONCLUSION

Whereas guidelines recommend resection of all MCN, the rate of malignancy in resected MCN is 16%, implying that surveillance has a role in most cases, and that surgical selection criteria are warranted. Size and presence of mural nodules are significantly associated with an increased risk of malignant degeneration, small MCN and without mural nodules can be considered for surveillance.

"Evolving Trends in Pancreatic Cystic Tumors: A 3-Decade Single-Center Experience With 1290 Resections"

OBJECTIVE

The aim of this study was to describe our institutional experience with resected cystic tumors of the pancreas with emphasis on changes in clinical presentation and accuracy of preoperative diagnosis.

SUMMARY BACKGROUND DATA

Incidental discovery of pancreatic cystic lesions has increased and has led to a rise in pancreatic resections. It is important to analyze surgical outcomes from these procedures, and the prevalence of malignancy, pre-malignancy and resections for purely benign lesions, some of which may be unintended.

METHODS

Retrospective review of a prospective database spanning 3 decades. Presence of symptoms, incidental discovery, diagnostic studies, type of surgery, postoperative outcomes, and concordance between presumptive diagnosis and final histopathology were recorded.

RESULTS

A total of 1290 patients were identified, 62% female with mean age of 60 years. Fifty-seven percent of tumors were incidentally discovered. Ninety-day operative mortality was 0.9% and major morbidity 14.4%. There were 23 different diagnosis, but IPMN, MCN, and serous cystadenoma comprised 80% of cases. Concordance between preoperative and final histopathological diagnosis increased by decade from 45%, to 68%, and is presently 80%, rising in parallel with the use of endoscopic ultrasound, cytology, and molecular analysis. The addition of molecular analysis improved accuracy to 91%. Of misdiagnosed cases, half were purely benign and taken to surgery with the presumption of malignancy or premalignancy. The majority of these were serous cystadenomas.

CONCLUSIONS

Indications and diagnostic work-up of cystic tumors of the pancreas have changed over time. Surgical resection can be performed with very low mortality and acceptable morbidity and diagnostic accuracy is presently 80%. About 10% of patients are still undergoing surgery for purely benign lesions that were presumed to be malignant or premalignant. Further refinements in diagnostic tests are required to improve accuracy.

Pancreatic Cystic Tumors: A Single-Center Observational Study

Background and Objectives: The aim of the study was to analyze the prevalence and characteristics of pancreatic cystic tumors (PCTs). Material and Methods: A retrospective analysis of the medical records of 124 patients, 102 (69%) women and 46 (31%) men, who had undergone surgery for pancreatic cystic tumors in 2014-2018. Among 148 pancreatic cysts, 24 (16%) were non-neoplasmatic and 124 (84%) were neoplasmatic. The neoplasmatic cysts (n = 124) were included in our analysis. There were five main types of PCTs: IPMN (intraductal papillary mucinous neoplasm) (n = 45), MCN (mucinous cystic neoplasm) (n = 30), SCN (serous cystic neoplasm) (n = 28), SPN (solid pseudopapillary neoplasm) (n = 8), and CPEN (cystic pancreatic endocrine neoplasm) (n = 8), as well as mixed-type tumors (n = 5). Results: A statistically significant dependency between PCT type and age was proven (p= 0.0001): IPMNs were observed in the older group of patients with an average age of 66.12 (40-79) years while SPNs were noted in the youngest group of patients with an average age of 36.22 (22-55) years. A statistically significant association between PCT type and gender (p = 0.0001) was found: IPMNs occurred among 24 (53.33%) men and 21 (46.6%) women. In the MCN and SPN groups, all patients were female (100%). Among the SCN group, the majority were women (27 (96.43%)), and there was only 1 (3.57%) man. A statistically significant dependency between PCT type and size was proven (p = 0.0007). The mean size of IPMNs was the smallest 2.95 (0.6-10 cm) and the mean size of MCNs was the largest 6.78 (1.5-19 cm). A statistically significant dependency between PCT type and tumor location was proven (p = 0.000238). The most frequent location of IPMN was the pancreatic head: 27 (60%). MCN was most frequently located in the pancreatic tail (18 (60%)). Most (10/28) SCNs were found in the pancreatic tail (10 (35.71%)). CPENs were most frequently located in the pancreatic tail (three (37.5%)) and pancreatic body and tail (three (37.5%)). SPNs were located commonly in the pancreatic head (five (62.5%)). The type of surgery depended on the tumor location. The most frequent surgery for IPMNs was pancreatoduodenectomy (44.4%), while for MCNs and SCNs, it was distal pancreatectomy (81%). The postoperative morbidity and mortality were 34.68% and 1.61%, respectively. Postoperative pancreatic fistula (POPF) was the most frequent (29%) complication. Conclusions: IPMN was the most frequent resected PCT in our material. A statistically significant association between the type of cyst and location within the pancreas, size, local lymph node involvement, and patient's age and sex was proved. POPF was the most frequent postoperative complication. In patients with PCTs, due to substantial postoperative morbidity, adequate patient selection, considering both the surgical risk as well as the long-term risk of malignant transformation, is very important during qualification for surgery.

Online calculator for predicting the risk of malignancy in patients with pancreatic cystic neoplasms: A multicenter, retrospective study

BACKGROUND

Efficient and practical methods for predicting the risk of malignancy in patients with pancreatic cystic neoplasms (PCNs) are lacking.

AIM

To establish a nomogram-based online calculator for predicting the risk of malignancy in patients with PCNs.

METHODS

In this study, the clinicopathological data of target patients in three medical centers were analyzed. The independent sample t-test, Mann–Whitney U test or chi-squared test were used as appropriate for statistical analysis. After univariable and multivariable logistic regression analysis, five independent factors were screened and incorporated to develop a calculator for predicting the risk of malignancy. Finally, the concordance index (C-index), calibration, area under the curve, decision curve analysis and clinical impact curves were used to evaluate the performance of the calculator.

RESULTS

Enhanced mural nodules [odds ratio (OR): 4.314; 95% confidence interval (CI): 1.618–11.503, P = 0.003], tumor diameter ≥ 40 mm (OR: 3.514; 95%CI: 1.138–10.849, P = 0.029), main pancreatic duct dilatation (OR: 3.267; 95%CI: 1.230–8.678, P = 0.018), preoperative neutrophil-to-lymphocyte ratio ≥ 2.288 (OR: 2.702; 95%CI: 1.008–7.244, P = 0.048], and preoperative serum CA19-9 concentration ≥ 34 U/mL (OR: 3.267; 95%CI: 1.274–13.007, P = 0.018) were independent risk factors for a high risk of malignancy in patients with PCNs. In the training cohort, the nomogram achieved a C-index of 0.824 for predicting the risk of malignancy. The predictive ability of the model was then validated in an external cohort (C-index: 0.893). Compared with the risk factors identified in the relevant guidelines, the current model showed better predictive performance and clinical utility.

CONCLUSION

The calculator demonstrates optimal predictive performance for identifying the risk of malignancy, potentially yielding a personalized method for patient selection and decision-making in clinical practice.

Improving diagnostic accuracy and appropriate indications for surgery in pancreatic cystic neoplasms: the role of EUS

BACKGROUND AND AIMS

Pancreatic cystic neoplasms (PCNs) represent a difficult preoperative diagnosis despite improvements in imaging. In this study, we compared preoperative and final pathologic diagnosis in a large cohort of resected PCNs, evaluating diagnostic accuracy with a specific focus on the value of EUS.

METHODS

A retrospective analysis of patients undergoing resection between 2009 and 2019 for presumed PCNs was performed. Preoperative workup was reviewed by analyzing the role of imaging and EUS. Patients with a benign histology who did not show absolute indication were categorized as "delayable surgery."

RESULTS

Of 585 patients who were retrospectively analyzed, in 108 (18.5%) final histology did not confirm preoperative diagnosis. EUS was associated with a lower rate of incorrect diagnosis (16%; P = .03), but the risk of overtreatment was similar regardless of instrumental diagnostic path (33/131 vs 68/328, P = .298). Dilatation of the main pancreatic duct and cytologic sampling were the only variables independently associated with a correct diagnosis (P < .001 and P = .041, respectively). Based on clinical presentation and final histology, pancreatic resection could have been spared or delayed in 101 of 459 patients (22%), and this was influenced by age (odds ratio [OR], .97; P = .002), cyst larger than 30 mm (OR, 1.89; P = .005), and type of operation (OR, 3.46 [P < .001] and 3.18 [P = .023] for distal pancreatectomies and other resections, respectively).

CONCLUSIONS

The overall risk of unnecessary immediate surgery for PCNs is about 22% in a high-volume referral center. EUS with cytologic sampling is a useful procedure in the diagnostic management of PCNs, improving their diagnostic accuracy.

Artificial intelligence for the detection of pancreatic lesions

PURPOSE

Pancreatic cancer is one of the most lethal neoplasms among common cancers worldwide, and PCLs are well-known precursors of this type of cancer. Artificial intelligence (AI) could help to improve and speed up the detection and classification of pancreatic lesions. The aim of this review is to summarize the articles addressing the diagnostic yield of artificial intelligence applied to medical imaging (computed tomography [CT] and/or magnetic resonance [MR]) for the detection of pancreatic cancer and pancreatic cystic lesions.

METHODS

We performed a comprehensive literature search using PubMed, EMBASE, and Scopus (from January 2010 to April 2021) to identify full articles evaluating the diagnostic accuracy of AI-based methods processing CT or MR images to detect pancreatic ductal adenocarcinoma (PDAC) or pancreatic cystic lesions (PCLs).

RESULTS

We found 20 studies meeting our inclusion criteria. Most of the AI-based systems used were convolutional neural networks. Ten studies addressed the use of AI to detect PDAC, eight studies aimed to detect and classify PCLs, and 4 aimed to predict the presence of high-grade dysplasia or cancer.

CONCLUSION

AI techniques have shown to be a promising tool which is expected to be helpful for most radiologists' tasks. However, methodologic concerns must be addressed, and prospective clinical studies should be carried out before implementation in clinical practice.

Diagnostic Concordance and Preoperative Risk Factors for Malignancy in Pancreatic Mucinous Cystic Neoplasms

Background/Aims

Methods

Results

Conclusions

State-of-the-art surgical treatment of IPMNs

Background

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

Methods

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

Results

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

Conclusions

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

Pancreatic incidentalomas: Investigation and management

The incidence of pancreatic incidentalomas (PIs) detected in otherwise asymptomatic patients is growing with the increasing quality and use of advanced imaging techniques. PI can present as isolated main pancreatic duct dilation or as a solid or cystic lesion. Although historically thought to be relatively rare, PIs are rather common, particularly cystic lesions of the pancreas, which can be detected in up to 49% of the general population. With the poor prognosis of pancreatic cancer, PIs are an opportunity for prevention and early diagnosis, but when managed poorly, they can also lead to overtreatment and unnecessary morbidity. The management of PI should begin with a dedicated pancreas protocol computed tomography (CT) scan or magnetic resonance imaging (MRI) to accurately characterize duct size, lesion characteristics and establish an accurate baseline for subsequent follow up. Diagnosis and subsequent management depends on the extent of main duct dilation and solid versus cystic appearance. Solid lesions are highly concerning for malignancy. Cystic lesions can be further categorized as intraductal papillary mucinous neoplasms of the pancreas (IPMNs) or mucinous cystic neoplasms (MCNs), both of which harbour malignant potential, or as serous cystic neoplasms (SCNs) that are benign. In this paper, we summarize the major challenges related to PI and present pragmatic suggestions for management.

Progression vs Cyst Stability of Branch-Duct Intraductal Papillary Mucinous Neoplasms After Observation and Surgery

Importance

The progression of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas to malignant disease is still poorly understood. Observational and surgical series have failed to provide comprehensive information.

Objective

To identify dynamic variables associated with the development of malignant neoplasms by combining pathological features with data from preoperative repeated observations.

Design, Setting, and Participants

The Crossover Observational Multicentric Study included a retrospective cohort of patients with branch-duct IPMNs (BD IPMNs) enrolled in a surveillance program from January 1, 2000, to December 31, 2019. Patients were enrolled from 5 referral centers: the Pancreas Institute, Verona, Italy; Seoul National University Hospital, Seoul, South Korea; Singapore General Hospital, Singapore; Johns Hopkins School of Medicine, Baltimore, Maryland; and University of Texas MD Anderson Cancer Center, Houston. Patients underwent a minimum of 12 months of preoperative surveillance (median, 37 [interquartile range (IQR), 20-68] months).

Main Outcomes and Measures

Dynamic variables associated with malignant disease were explored to estimate the presence of high-grade dysplasia (HGD) and invasive cancer at final pathological examination.

Results

A total of 292 patients were included in the analysis (137 women [46.9%] and 155 men [53.1%]; median age, 64 [IQR, 56-71] years). During surveillance, 27 patients (9.2%) developed a worrisome feature after 5 years, and 46 of 276 (16.7%) developed high-risk stigmata (HRS). At final pathological evaluation, 107 patients (36.6%) had HGD or invasive cancer, and 16 (5.5%) had IPMNs with concomitant pancreatic ductal adenocarcinoma. Rates of HGD and invasive cancer at pathological evaluation significantly differed between those without worrisome features and those developing HRS from a previous worrisome feature (9 [27.3%] vs 13 [61.9%]; P < .001). Developing an additional worrisome feature during surveillance (odds ratio [OR], 3.24 [95% CI, 1.38-7.60]; P = .007) or an HRS from a baseline worrisome feature (OR, 2.87 [95% CI, 1.01-8.17]; P = .048) was associated with HGD at final pathological evaluation. Among HRS, development of jaundice on a low-risk cyst was independently associated with invasive cancer (OR, 16.04 [95% CI, 2.94-87.40]; P = .001).

Conclusions and Relevance

These findings suggest that in BD IPMNs under surveillance, harboring a stable worrisome feature carries the lowest risk of malignant disease. Development of additional worrisome features or HRS is associated with the presence of HGD, whereas the occurrence of jaundice is associated with invasive cancer.

Actual malignancy risk of either operated or non-operated presumed mucinous cystic neoplasms of the pancreas under surveillance

BACKGROUND

Despite the low malignant potential of pancreatic mucinous cystic neoplasms (MCNs), surgery is still performed. The aim of this pragmatic study was to assess the outcome of surgery and surveillance for patients presenting with a presumed MCN at the first evaluation.

METHODS

Data for patients with a presumed MCN observed from 2000 to 2016 at the Verona Pancreas Institute and San Raffaele Hospital were extracted from prospective databases. The endpoints were risk of malignancy at pathology and rate of misdiagnosis for the surgical series, expressed as an odds ratio (OR) with 95 per cent confidence interval, and disease-specific survival (DSS) for the surveillance cohort investigated by the Kaplan-Meier method.

RESULTS

A total of 424 patients were identified. In the surgical series (229 patients), the rate of misdiagnosis was 19.2 per cent. The rate of malignant MCNs was 10.9 per cent (25 patients). The overall rate of malignancy, including misdiagnoses, was 11.3 per cent (26 patients). Predictors of malignancy were mural nodules (OR 27.75, 95 per cent c.i. 4.44-173.61; P < 0.001), size at least 50 mm (OR 13.39, 2.01 to 89.47; P = 0.007), and carbohydrate antigen 19.9 level (OR 3.98, 1.19 to 13.30; P = 0.025). In the absence of mural nodules and enhancing walls, none of the resected presumed MCNs smaller than 50 mm were malignant. Only patients with high-risk stigmata undergoing surgery experienced a significantly reduced 5-year DSS compared with all other patients (88 versus 100 per cent; P = 0.031).

CONCLUSION

Presumed MCNs with mural nodules, enhancing walls or cysts of 50 mm or larger should be considered for upfront surgical resection owing to the high risk of malignancy. In the absence of these features, the incidence of malignancy is negligible, favouring surveillance in selected patients given the low risk of malignancy and the high rate of misdiagnosis.

GRAPHICAL ABSTRACT

Pancreatic mucinous cystic neoplasms (MCNs) are well known preneoplastic lesions. Despite the low rate of cancer, lesions without radiological features of malignancy are resected systematically. In the absence of mural nodules, enhancing walls or cyst size 50 mm or more, the incidence of malignancy is negligible. Given the high risk of misdiagnosis, in the absence of such radiological features, surveillance of presumed MCNs seems safer.

Reappraisal of a 2-Cm Cut-off Size for the Management of Cystic Pancreatic Neuroendocrine Neoplasms: A Multicenter International Study

OBJECTIVE

The aim of this study was to characterize an international cohort of resected cystic pancreatic neuroendocrine neoplasms (cPanNENs) and identify preoperative predictors of aggressive behavior.

BACKGROUND

The characteristics of cPanNENs are unknown and their clinical management remains unclear. An observational strategy for asymptomatic cPanNENs ≤2 cm has been proposed by recent guidelines, but evidence is scarce and limited to single-institutional series.

METHODS

Resected cPanNENs (1995-2017) from 16 institutions worldwide were included. Solid lesions (>50% solid component), functional tumors, and MEN-1 patients were excluded. Aggressiveness was defined as lymph node (LN) involvement, G3 grading, distant metastases, and/or recurrence.

RESULTS

Overall, 263 resected cPanNENs were included, among which 177 (63.5%) were >2 cm preoperatively. A preoperative diagnosis of cPanNEN was established in 162 cases (61.6%) and was more frequent when patients underwent endoscopic ultrasound [EUS, odds ratio (OR) 2.69, 95% confidence interval (CI) 1.52-4.77] and somatostatin-receptor imaging (OR 3.681, 95% CI 1.809-7.490), and for those managed in specialized institutions (OR 3.12, 95% CI 1.57-6.21). Forty-one cPanNENs (15.6%) were considered aggressive. In the whole cohort, LN involvement on imaging, age >65 years, preoperative size >2 cm, and pancreatic duct dilation were independently associated with aggressive behavior. In asymptomatic patients, older age and a preoperative size >2 cm remained independently associated with aggressiveness. Only 1 of 61 asymptomatic cPanNENs ≤2 cm displayed an aggressive behavior.

CONCLUSIONS

The diagnostic accuracy of cPanNENs is increased by the use of EUS and somatostatin-receptor imaging and is higher in specialized institutions. Preoperative size >2 cm is independently associated with aggressive behavior. Consequently, a watch-and-wait policy for sporadic asymptomatic cPanNENs ≤2 cm seems justified and safe for most patients.

Ductal Dilatation of ≥5 mm in Intraductal Papillary Mucinous Neoplasm Should Trigger the Consideration for Pancreatectomy: A Meta-Analysis and Systematic Review of Resected Cases

Simple Summary

Intraductal papillary mucinous neoplasms (IPMN) are common but difficult to manage since accurate tools for diagnosing malignancy are unavailable. This study evaluates the diagnostic value of main pancreatic duct (MPD) diameter for detecting IPMN malignancy, using a meta-analysis of published data. The result suggests that malignancy is highly prevalent in IPMN with ductal dilatation of >5 mm.

Abstract

Intraductal papillary mucinous neoplasms (IPMN) are common but difficult to manage since accurate tools for diagnosing malignancy are unavailable. This study tests the diagnostic value of the main pancreatic duct (MPD) diameter for detecting IPMN malignancy using a meta-analysis of published data of resected IPMNs. Collected from a comprehensive literature search, the articles included in this analysis must report malignancy cases (high-grade dysplasia (HGD) and invasive carcinoma (IC)) and MPD diameter so that two MPD cut-offs could be created. The sensitivity, specificity, and odds ratios of the two cutoffs for predicting malignancy were calculated. A review of 1493 articles yielded 20 retrospective studies with 3982 resected cases. A cutoff of ≥5 mm is more sensitive than the ≥10 mm cutoff and has pooled sensitivity of 72.20% and 75.60% for classification of HGD and IC, respectively. Both MPD cutoffs of ≥5 mm and ≥10 mm were associated with malignancy (OR = 4.36 (95% CI: 2.82, 6.75) vs. OR = 3.18 (95% CI: 2.25, 4.49), respectively). The odds of HGD and IC for patients with MPD ≥5 mm were 5.66 (95% CI: 3.02, 10.62) and 7.40 (95% CI: 4.95, 11.06), respectively. OR of HGD and IC for MPD ≥10 mm cutoff were 4.36 (95% CI: 3.20, 5.93) and 4.75 (95% CI: 2.39, 9.45), respectively. IPMN with MPD of >5 mm could very likely be malignant. In selected IPMN patients, pancreatectomy should be considered when MPD is >5 mm.

KRAS/GNAS-testing by highly sensitive deep targeted next generation sequencing improves the endoscopic ultrasound-guided workup of suspected mucinous neoplasms of the pancreas

Pancreatic cysts or dilated pancreatic ducts are often found by cross-sectional imaging, but only mucinous lesions can become malignant. Therefore, distinction between mucinous and non-mucinous lesions is crucial for adequate patient management. We performed a prospective study including targeted next generation sequencing (NGS) of cell-free DNA in the diagnostic endoscopic ultrasound (EUS)-guided workup. Pancreatic cyst(s) or main duct fluid obtained by EUS-guided FNA was analysed by carcinoembryonic antigen (CEA), cytology and deep targeted NGS of 14 known gastrointestinal cancer genes (AKT1, BRAF, CTNNB1, EGFR, ERBB2, FBXW7, GNAS, KRAS, MAP2K1, NRAS, PIK3CA, SMAD4, TP53, APC) with a limit of detection down to variant allele frequency of 0.01%. Results were correlated to histopathology and clinical follow-up. One hundred and thirteen patients with pancreatic cyst(s) and/or a dilated pancreatic main duct (≥5 mm) were screened. Sixty-six patients had to be excluded, mainly due to inoperability or small cyst size (≤10 mm). Forty-seven patients were enrolled for further analysis. A final diagnosis was available in 27 cases including 8 negative controls. In 43/47 (91.5%) of patients a KRAS- and/or GNAS-mutation was diagnosed by NGS. 27.0% of the KRAS-mutated and 10.0% of the GNAS-mutated lesions harbored multiple mutations. KRAS/GNAS-testing by NGS, cytology, and CEA had a sensitivity and specificity of 94.7/100%, 38.1/100%, and 42.1/75.0%, respectively. KRAS/GNAS-testing was significantly superior to CEA (P = .0209) and cytology (P = .0016). In conclusion, KRAS/GNAS-testing by deep targeted NGS is a suitable method to distinguish mucinous from non-mucinous pancreatic lesions, suggesting its usage as a single diagnostic test. Results must be confirmed in a larger cohort.

The pathological features and prognoses of intraductal papillary mucinous neoplasm and mucinous cystic neoplasm after surgical resection: a single institution series

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs) represent the tumors with malignant transformation potential. The objective of the study was to verify their pathological characteristics, prognoses, and recurrence factors.

METHODS

Two hundred eighteen IPMNs and 27 MCNs resected at a single institution were included. The demographic, preoperative, histopathological, and follow-up data of the patients were recorded and analyzed. Overall survival (OS) and disease-free survival (DFS) were defined as the interval from the date of initial surgery to death or the last follow-up (OS) and to diagnosis of recurrence or death at follow-up (DFS).

RESULTS

Of the 218 IPMN and 27 MCN patients, 93 (42.7%) and 8 (29.6%) cases were malignant, respectively. IPMNs occurred in older patients compared with MCN patients (median 63 years vs 54 years, P < 0.0001), and MCNs occurred exclusively in females (100%). Of the overall study cohort, the pathological specimens presented peripheral invasion in 37 (15.1%) patients and incisal margin invasion was observed in 46 (18.8%) patients. After a median follow-up of 34 months, 37 (14.9%) patients relapsed. The 5-year OS and DFS rates of IPMNs were 97.5% and 80.6%; and the OS and DFS rates of MCNs were 95.7% and 87.0%, respectively. There were four independent risk factors associated with recurrence: pathological diagnoses with malignancy (odds ratio, OR = 3.65), presence of oncocytic type for IPMN (OR = 1.69), peripheral invasion (OR = 12.87), and incisal margin invasion (OR = 1.99).

CONCLUSIONS

IPMNs and MCNs are indolent tumors with favorable prognoses after surgical resection in terms of their relatively high OS and DFS rate. Patients with malignant pathological-related diagnoses should accept strict tumor surveillance in view of their higher risk of recurrence.

Prophylactic total pancreatectomy in individuals at high risk of pancreatic ductal adenocarcinoma (PROPAN): systematic review and shared decision-making programme using decision tables

Background

Individuals with a very high lifetime risk of developing pancreatic ductal adenocarcinoma; for example, hereditary pancreatitis and main-duct or mixed-type intraductal papillary mucinous neoplasm, may wish to discuss prophylactic total pancreatectomy but strategies to do so are lacking.

Objective

To develop a shared decision-making programme for prophylactic total pancreatectomy using decision tables.

Methods

Focus group meetings with patients were used to identify relevant questions. Systematic reviews were performed to answer these questions.

Results

The first tables included hereditary pancreatitis and main-duct or mixed-type intraductal papillary mucinous neoplasm. No studies focused on prophylactic total pancreatectomy in these groups. In 52 studies (3570 patients), major morbidity after total pancreatectomy was 25% and 30-day mortality was 6%. After minimally invasive total pancreatectomy (seven studies, 35 patients) this was, respectively, 13% and 0%. Exocrine insufficiency-related symptoms occurred in 33%. Quality of life after total pancreatectomy was slightly lower compared with the general population.

Conclusion

The decision tables can be helpful for discussing prophylactic total pancreatectomy with individuals at high risk of pancreatic ductal adenocarcinoma.

The management of intraductal papillary mucinous neoplasms of the pancreas

Intraductal papillary mucinous neoplasms (IPMN) of the pancreas are one of the most common preneoplastic entities among pancreatic cystic neoplasms (PCN). Their incidence is increasing due to an extensive use of cross-sectional imaging, but management still remains controversial. Among IPMNs, the main duct (MD-IPMN) and mixed (MT-IPMN) types harbor a high risk of malignant degeneration requiring resection in most of cases. The branch duct type (BD-IPMN), on the other side, can be safely surveilled as surgical resection is limited to selected cases deemed at high risk of malignant progression according to specific clinical and radiological features. An accurate diagnosis and a correct assessment of malignant potential are often hard to achieve, and clinical management still relies on the experience of the gastroenterologist/surgeon that is called to choose between a major pancreatic resection burdened by high morbidity and mortality rates and a life-long surveillance. The purpose of this report is to summarize the available evidence supporting the current practice for the management of IPMN and to offer a useful practical guide from first observation to postoperative follow-up.

Molecular Diagnostics and Testing for Pancreatic Cysts

PURPOSE OF REVIEW

In current clinical practice, the diagnosis and management of pancreatic cystic lesions (PCLs) are based on guidelines that combine clinical and imaging findings. These guidelines usefully identify a large category of low-risk PCLs that do not require treatment. However, they have limited accuracy for diagnosis of advanced neoplasia in worrisome and high-risk PCLs. Novel molecular markers that can accurately detect advanced neoplasia in PCLs can transform the care of patients with PCLs. We reviewed the recent medical literature on molecular diagnostics of PCLs and summarized molecular biomarkers assayed in cyst fluid, pancreatic juice, and blood.

RECENT FINDINGS

Several studies have been recently published describing promising early results in genetic, epigenetic, and protein biomarkers from cyst fluid to help in both histologic diagnosis and detection of advanced neoplasia. The majority of studies have been completed using opportunistically collected archival cyst fluid and few report validation in independent sample sets. Results of ongoing multicenter prospective validation studies are awaited and will help define the best combination of cyst fluid molecular markers. In multifocal PCLs communicating with the pancreatic ductal system, a pancreatic juice biomarker is likely to be less invasive and more informative. Novel biomarkers in pancreatic juice and blood are in early phases of study.

SUMMARY

The field of molecular diagnostic biomarkers for PCLs is rapidly evolving with several promising candidate markers being prospectively evaluated. In the near future, these novel molecular markers, combined with advances in imaging technology, will transform clinical decision-making in the management of PCLs and improve patient outcomes.

Branch Duct Intraductal Papillary Mucinous Neoplasms: Recommendations for Follow-Up and Surgery

BACKGROUND AND AIMS

Pancreatic cysts are increasingly diagnosed, mainly during abdominal imaging performed for other reasons. Between pancreatic cystic neoplasm, intraductal papillary mucinous neoplasms are the most common pre-malignant entities. Intraductal papillary mucinous neoplasms involving side branches overall harbor a low risk of malignancy, and in the recent past, a progressively more conservative approach has been consolidated. Purpose of this report is to summarize the evidence supporting the current practice for the management of branch duct intraductal papillary mucinous neoplasm and to offer a useful practical guide from first observation to post-operative follow-up.

MATERIALS AND METHODS

Review of the most important scientific literature on intraductal papillary mucinous neoplasms was made. In this review article, we also report the experience of a high volume center in managing Pancreatic cystic neoplasms.

RESULTS

The correct management during surveillance still is a matter of debate, since many guidelines have been published suggesting different clinical approaches. Recently, follow-up discontinuation has also been proposed in selected cases.

CONCLUSION

Despite significant improvements made by the increase of evidence, selecting surgical candidates because of an increased risk of malignant progression remains an unsolved issue and a hot topic for pancreatologists.

Differential diagnosis of pancreatic serous cystadenoma and mucinous cystadenoma: utility of textural features in combination with morphological characteristics

Background

Texture analysis of medical images has been reported to be a reliable method for differential diagnosis of neoplasms. This study was to investigate the performance of textural features and the combined performance of textural features and morphological characteristics in the differential diagnosis of pancreatic serous and mucinous cystadenomas.

Methods

We retrospectively reviewed 59 patients with pancreatic serous cystadenoma and 32 patients with pancreatic mucinous cystadenoma at our hospital. A three-dimensional region of interest (ROI) around the margin of the lesion was drawn manually in the CT images of each patient, and textural parameters were retrieved from the ROI. Textural features were extracted using the LifeX software. The least absolute shrinkage and selection operator (LASSO) method was applied to select the textural features. The differential diagnostic capabilities of morphological features, textural features, and their combination were evaluated using receiver operating characteristic (ROC) analysis, and the area under the receiver operating characteristic curve (AUC) was used as the main indicator. The diagnostic accuracy based on the AUC value is defined as follows: 0.9–1.0, excellent; 0.8–0.9, good; 0.7–0.8, moderate; 0.6–0.7, fair; 0.5–0.6, poor.

Results

In the differential diagnosis of pancreatic serous and mucinous cystadenomas, the combination of morphological characteristics and textural features (AUC 0.893, 95% CI 0.816–0.970) is better than morphological characteristics (AUC 0.783, 95% CI 0.665–0.900) or textural features (AUC 0.777, 95% CI 0.673–0.880) alone.

Conclusions

In conclusion, our preliminary results highlighted the potential of CT texture analysis in discriminating pancreatic serous cystadenoma from mucinous cystadenoma. Furthermore, the combination of morphological characteristics and textural features can significantly improve the diagnostic performance, which may provide a reliable method for selecting patients with surgical intervention indications in consideration of the different treatment principles of the two diseases.

Review of the diagnosis and management of intraductal papillary mucinous neoplasms

Intraductal papillary mucinous neoplasms are common lesions with the potential of harbouring/developing a pancreatic cancer. An accurate evaluation of intraductal papillary mucinous neoplasms with high-resolution imaging techniques and endoscopic ultrasound is mandatory in order to identify patients worthy either of surgical treatment or surveillance. In this review, the diagnosis and management of patients with intraductal papillary mucinous neoplasms are discussed with a specific focus on current guidelines. Areas of uncertainty are also discussed, as there are controversies related to the optimal indications for surgery, surveillance protocols and surveillance discontinuation.

Association between macroscopically visible tissue samples and diagnostic accuracy of EUS-guided through-the-needle microforceps biopsy sampling of pancreatic cystic lesions

BACKGROUND AND AIMS

EUS-guided through-the-needle biopsy (TTNB) sampling has been reported to improve diagnostic yield compared with cytology for the evaluation of pancreatic cystic lesions (PCLs). The number of macroscopically visible tissue samples needed to reach an adequate diagnosis is still unknown.

METHODS

This is a retrospective, single-center study on consecutive patients with PCLs with risk features (cyst >3 cm, thickened wall, cyst growth during follow-up, and mural nodules) who underwent TTNB sampling. The capability of differentiating mucinous versus nonmucinous cysts, ability to obtain a cyst-lining epithelium, definition of the grade of dysplasia, and specific diagnosis of cyst histotype were evaluated for 1, 2, or 3 TTNB macroscopically visible specimens.

RESULTS

Sixty-one patients were evaluated. A 100% histologic adequacy was reached by 2 samples (P = .05 versus 1). Compared with cytology, 1 TTNB specimen improved the possibility of defining cyst histotype (P < .0001), whereas 2 specimens increased all 4 diagnostic categories (P < .003). Two specimens also increased diagnostic yield compared with 1 sample (P < .085). The collection of a third sample did not improve the value of any diagnostic categories. A specific diagnosis was reached in 74% of patients with 2 histologic samples. The diagnostic reliability of TTNB sampling compared with surgical histology was 90%, with a 22.9% rate of adverse events.

CONCLUSIONS

Two TTNB macroscopically visible specimens reached 100% histologic adequacy and a specific diagnosis in 74% of patients. The collection of a third specimen did not add any additional information and should be avoided to possibly decrease the risk of adverse events.

Interobserver agreement among expert pathologists on through-the-needle microforceps biopsy samples for evaluation of pancreatic cystic lesions

BACKGROUND AND AIMS

The recent development of microforceps for EUS through-the-needle biopsy (TTNB) sampling of the wall of pancreatic cystic lesions (PCLs) allows the collection of histologic specimens never handled and evaluated before by pathologists. We aimed to estimate the interobserver agreement among pathologists in evaluating such samples.

METHODS

TTNB specimen slides from 40 PCLs with worrisome features were retrieved and independently evaluated for specimen adequacy, presence of lining epithelium, grade of epithelial dysplasia, presence of ovarian type stroma, and specific diagnosis by 6 expert pathologists from 6 different tertiary care centers. The Gwet's AC1 was used to assess interobserver agreement.

RESULTS

An almost perfect agreement was observed for specimen adequacy (AC1, .82; 95% confidence interval [CI], .79-.98), presence of lesional epithelium (AC1, .90; 95% CI, .86-.92), epithelial dysplasia (AC1, .97; 95% CI, .95-.99), and ovarian-like stroma (AC1, .90; 95% CI, .86-.93). When considering all diagnoses separately, a moderate to substantial agreement was observed (AC1, .62; 95% CI, .57-.67), similarly to mucinous cysts versus serous adenoma versus other diagnoses (AC1, .65; 95% CI, .59-.70) and for mucinous cysts versus all other diagnoses (AC1,.74; 95% CI, .68-.84). The agreement for diagnosis of mucinous cystic neoplasm versus intraductal mucinous papillary neoplasm was almost perfect (AC1, .88; 95% CI, .81-.95).

CONCLUSIONS

Interobserver agreement between expert pathologists in the evaluation of TTNB samples from PCLs with worrisome features was close to perfection for all evaluated parameters, except definitive diagnosis. When mucinous cystic lesions were compared versus all other diagnoses, the agreement became substantial, thus indicating that TTNB specimens can provide important information for PCL management decisions.

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.

Endoscopic diagnosis of pancreatic cysts

PURPOSE OF REVIEW

Pancreatic cystic lesions (PCLs) are increasingly identified on abdominal imaging. Given the malignant potential of certain cyst subtypes and the poor survival rates of pancreatic cancer, accurate diagnosis and appropriate management of these cysts are critical.

RECENT FINDINGS

Advances in endoscopic ultrasound (EUS)-guided diagnostics have increased the accuracy of differentiating PCLs. These include cyst fluid molecular analysis, EUS-guided needle-based confocal laser endomicroscopy, and EUS-guided through the needle microforceps biopsy. This review encapsulates recent advances in the endoscopic management of PCLs with a specific focus on EUS-guided diagnosis.

SUMMARY

It is important to accurately diagnose pancreatic cystic lesions with malignant potential where the definitive management is surgical resection. Misdiagnosis can result in inadvertent surgery of an otherwise benign lesion or malignant progression of a precancerous cyst. Moreover, pancreatic surgery is associated with significant morbidity and mortality. Recent advances in EUS-guided tissue acquisition, imaging, and molecular biomarkers have resulted in improved diagnostic accuracy of pancreatic cystic lesions. Future studies need to define efficient and accurate diagnostic algorithms for improved management of pancreatic cysts.

Overview and comparison of guidelines for management of pancreatic cystic neoplasms

Pancreatic cysts are identified at an increasing frequency. Although mucinous cystic neoplasms represent a pre-malignant condition, the majority of these lesions do not progress to cancer. Over the last 10 years several societies have established guidelines for the diagnosis, initial evaluation and surveillance of these lesions. Here we provide an overview of five commonly used guidelines: 2015 American Gastroenterological Association, 2017 International Association of Pancreatology, American College of Gastroenterology 2018, European Study Group and American College of Radiology. We describe the similarities and differences between the methods used to formulate these guidelines, the population they target and their approaches towards initial evaluation and surveillance of cystic lesions.

Trends in management and outcome of cystic pancreatic lesions - analysis of 322 cases undergoing surgical resection

Background: Several guidelines for the management of cystic pancreatic lesions (CPL) exists. From 2013, Oslo University Hospital adapted the European consensus guidelines (ECG) in the decision-making as to whether patients should be advised to have resection or observation for CPL. The aims of the study were to assess changes over time in the workup and diagnostic accuracy of resected CPL, and the short-term surgical outcome. Methods: Preoperative radiological workup, clinicopathological characteristics, and perioperative outcomes were retrospectively reviewed in three consecutive time periods (early: 2004-2008, intermediate: 2009-2012, late: 2013-2016). The rate of concordance between the ECG recommendations for resection (ECG+) or observation (ECG-) and the final histological diagnosis were assessed. Results: A total of 322 consecutive patients underwent resection for CPL (early: n = 89, intermediate: n = 108, late: n = 125). The most common diagnoses were intraductal papillary mucinous neoplasia (IPMN, 36.0%), serous cystic neoplasm (SCN, 23.9%), mucinous cystic neoplasm (10.6%), pseudocyst (9.6%), solid pseudopapillary neoplasm (7.8%), and cystic pancreatic neuroendocrine tumour (5.3%). The proportion of ECG+ CPL undergoing surgery increased significantly (42.7% vs. 60.7% vs. 70.4%, p < .001). The relative proportion of patients undergoing resection for SCN decreased (38.2% vs. 21.3% vs. 16.0%), whereas it increased for IPMN (31.5% vs. 30.6% vs. 44.0%). The use of magnetic resonance imaging and endoscopic ultrasound increased. There were no differences in postoperative severe complications (23.0% vs. 23.6%) or 90-day mortality (2.3% vs. 0.8%) between ECG+ and ECG- patients. Conclusion: Several changes in the management of CPL were revealed during time. Adherence to guidelines is important in order to avoid unnecessary surgery for CPL.

A case report of three synchronous tumors in the same pancreatic specimen

It is known that Duodenal adenocarcinoma (DA) is a rare malignant solid tumor that cause occlusion symptoms with orthodox dysphagia when locally advanced. Pancreatic neuroendocrine tumors (PanNETs) account for about 2% of all pancreatic neoplasms. The combination of these two lesions, with the synchronous presence of ectopic pancreatic tissue (EPT) of the duodenum, has never been described in literature, to our knowledge. Here we report a case of combined DA, EPT and PanNET affecting a 71-year-old woman.

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Simultaneous presence of Duodenal adenocarcinoma pancreatic neuroendocrine tumor ectopic pancreatic tissue of duodenum.

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Biochemical tests did not reveal abnormalities: CA 19-9 was normal, CEA was 153 U/L.

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Ultrasonography confirmed a nodule dislocating pancreas investigated with contrast-enhanced CT and esophagogastroduodenoscopy.

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The association between duodenal adenocarcinomas, PanNET and ectopic pancreatic tissue (EPT) of the duodenum is really rare.

Main pancreatic duct dilation greater than 6 mm is associated with an increased risk of high-grade dysplasia and cancer in IPMN patients

INTRODUCTION

IPMNs, considered precursor lesions of pancreatic adenocarcinoma (PDAC), might display histological alteration varying from low-grade dysplasia (LGD) to cancer. Nevertheless, the prevalence of PDAC is far below the prevalence of IPMN; therefore, not all of these precursor lesions finally progress to cancer. Preoperative features consistent with and finding at final histology of high-grade dysplasia (HGD) or cancer are currently lacking. The aim of this study is to correlate the presence of preoperative clinical features with the finding of advance lesions at final histology.

METHODS

This is retrospective cohort analysis of patients who underwent surgery for histologically confirmed IPMNs at Karolinska University Hospital, from 2008 to 2015.

RESULTS

MPD 6-9.9 mm and ≥ 10 mm were associated with an increased risk of HGD/cancer (respectively, OR 2.92, CI 1.38-6.20, p = 0.005 and OR 2.65, CI 1.12-6.25, p = 0.02). Preoperative high CA19.9 and jaundice were both associated with a higher risk of HGD/cancer at final histology (respectively, OR 4.15, CI 1.90-9.05, p = 0.0003 and OR 15.36, CI 1.94-121.22, p = 0.009). At sex- and age-adjusted multivariable logistic regression analysis, MPD between 6 and 9.9 mm (OR 2.64, CI 1.15-6.06, p = 0.02), jaundice (OR 12.43, CI 1.44-106.93, p = 0.02), and elevated CA19.9 (OR 3.71, CI 1.63-8.46, p = 0.001) remained associated with the occurrence of HGD/cancer.

DISCUSSION

The presence of MPD dilation ≥ 6 mm, jaundice, and elevated CA19.9 in IPMN patients are consistent with the finding for HGD/cancer at final histology, thus representing possible markers of advanced lesions suitable for earlier or preventive curative surgical treatment.

Computer-Aided Diagnosis of Pancreas Serous Cystic Neoplasms: A Radiomics Method on Preoperative MDCT Images

OBJECTIVE

Our aim was to propose a preoperative computer-aided diagnosis scheme to differentiate pancreatic serous cystic neoplasms from other pancreatic cystic neoplasms, providing supportive opinions for clinicians and avoiding overtreatment.

MATERIALS AND METHODS

In this retrospective study, 260 patients with pancreatic cystic neoplasm were included. Each patient underwent a multidetector row computed tomography scan and pancreatic resection. In all, 200 patients constituted a cross-validation cohort, and 60 patients formed an independent validation cohort. Demographic information, clinical information, and multidetector row computed tomography images were obtained from Picture Archiving and Communication Systems. The peripheral margin of each neoplasm was manually outlined by experienced radiologists. A radiomics system containing 24 guideline-based features and 385 radiomics high-throughput features was designed. After the feature extraction, least absolute shrinkage selection operator regression was used to select the most important features. A support vector machine classifier with 5-fold cross-validation was applied to build the diagnostic model. The independent validation cohort was used to validate the performance.

RESULTS

Only 31 of 102 serous cystic neoplasm cases in this study were recognized correctly by clinicians before the surgery. Twenty-two features were selected from the radiomics system after 100 bootstrapping repetitions of the least absolute shrinkage selection operator regression. The diagnostic scheme performed accurately and robustly, showing the area under the receiver operating characteristic curve = 0.767, sensitivity = 0.686, and specificity = 0.709. In the independent validation cohort, we acquired similar results with receiver operating characteristic curve = 0.837, sensitivity = 0.667, and specificity = 0.818.

CONCLUSION

The proposed radiomics-based computer-aided diagnosis scheme could increase preoperative diagnostic accuracy and assist clinicians in making accurate management decisions.

Intraductal papillary mucinous neoplasms of the pancreas - a cost-effectiveness analysis of management strategies for the branch-duct subtype

BACKGROUND

Branch-duct intraductal papillary mucinous neoplasm (BD-IPMN) presents a clinical conundrum. Rigorous long-term surveillance or surgical resection is recommended. The economic consequences of the management have not been fully investigated.

METHODS

A Markov decision model compared 4 strategies for low-risk BD-IPMN: I = upfront total pancreatectomy, II = upfront partial pancreatectomy, III = initial surveillance, IV = watchful waiting. Surveillance was based on the Swedish Guidelines for Pancreatic Cancer. Probabilities and costs were obtained from the participating unit and from the scientific literature. The incremental cost-effectiveness ratios (ICERs) were calculated and sensitivity analyses were performed by varying relevant parameters. Survival was reported in quality-adjusted life-years (QALYs).

RESULTS

Strategy III was the most cost-effective strategy with an ICER of €31 682 compared to strategy IV. Strategy I was the most expensive but yielded the best QALY (9.32). Total number of years, annual risk of pancreatic cancer and annual risk of a low-risk BD-IPMN turning into a high-risk lesion had the greatest impact in the model.

CONCLUSIONS

Initial surveillance seems to be the most cost-effective strategy in the management of low-risk asymptomatic BD-IPMN. However, the possibility of personalized approaches remains to be investigated.

Role of Radiological Imaging in the Diagnosis and Characterization of Pancreatic Cystic Lesions: A Systematic Review

The evidence on the ability of radiological tests to predict a specific diagnosis and also their aptitude in identifying pathological markers indicative of malignancy in cystic lesions of the pancreas remains inconclusive. We conducted a systematic review on MEDLINE for the use of computed tomography (CT), magnetic resonance imaging, and positron emission tomography/CT (PET/CT) in the diagnosis and characterization of these cysts. The accuracy of CT scan for reaching a specific diagnosis was 39% to 61.4%, whereas its accuracy for differentiating benign from malignant lesions was 61.9% to 80%. Magnetic resonance imaging showed a better accuracy in identifying a specific diagnosis of 50% to 86%, whereas its accuracy in differentiating benign from malignant lesions was 55.6% to 87%. The use of magnetic resonance imaging was superior to CT scan in identifying septations, mural nodules, and ductal communication. The sensitivity of PET/CT in diagnosing malignancy was 85.7% to 100% with a reported accuracy of 88% to 95%. The evidence gathered from this review suggests that the adequacy of CT imaging in full characterization of pancreatic cysts is suboptimal, and therefore a low threshold for supplementary imaging is advised. The use of PET/CT should be considered in high-risk patients with equivocal findings.

Importance of main pancreatic duct dilatation in IPMN undergoing surveillance

BACKGROUND

The association between risk of pancreatic cancer and a dilated main pancreatic duct (MPD) in intraductal papillary mucinous neoplasm (IPMN) is debated. The aim of this study was to assess the role of MPD size in predicting pancreatic cancer in resected IPMNs and those kept under surveillance.

METHODS

All patients with IPMN referred to the Pancreas Institute, University of Verona Hospital Trust, from 2006 to 2016 were included. The primary endpoint was the occurrence of malignancy detected at surgery or during follow-up.

RESULTS

The final cohort consisted of 1688 patients with a median follow-up of 60 months. Main pancreatic duct dilatation was associated with other features of malignancy in both the resected and surveillance groups. In patients who underwent resection, only a MPD of at least 10 mm was an independent predictor of malignancy. In patients kept under surveillance, MPD dilatation was not associated with malignancy. Fifteen of 71 patients (21 per cent) with malignancy in the resection cohort had a dilated MPD alone, whereas only one of 30 (3 per cent) under surveillance with MPD dilatation alone developed malignancy. Patients with a dilated MPD and other worrisome features had an increased 5-year cumulative incidence of malignancy compared with those with a non-dilated duct (11 versus 1·2 per cent; P < 0·001); however, the risk of malignancy was not significantly increased in patients with a dilated MPD alone (4 versus 1·2 per cent; P = 0·448).

CONCLUSION

In patients under surveillance, a dilated MPD alone was not associated with an increased incidence of malignancy in IPMN.

The "extracapsular cystic" sign in pancreatic serous cystic neoplasms: A clinicopathologic study of 177 patients with cystic pancreatic lesions

OBJECTIVE

To assess a new imaging feature that we have named the extracapsular cystic sign which can make a constructive contribution towards differentiating serous cystic neoplasms (SCNs) from other pancreatic cystic lesions.

MATERIAL AND METHODS

We retrospectively reviewed 177 CTs/MRIs of patients who underwent pancreatic resection of cystic lesions at two institutions from January 2011/2013, to September 2017. For each patient, demographic information, clinical presentation, especially imaging features were carefully investigated by two experienced abdominal radiologists, retrospectively. All statistical analyses were performed using SPSS V.23.0.

RESULTS

Twenty-one lesions had extracapsular cystic signs which were newly discovered, 17 (28.3%) of 60 SCNs and 4 (3.4%) (mucinous cystic neoplasm = 1, walled-off necrosis = 2, retention cyst = 1) of 117 Non-SCNs were included, from which indicating that the extracapsular cystic sign was more often detected on SCNs. As for 21 lesions, 86% (n = 18) were females, and mean age at diagnosis was 51.2 years. 71% (n = 15) located in the pancreatic body and tail. Average size was 27.2 mm (23.7-53.4), mean (SD) ratio of biggest daughter cyst to mother cyst was 0.51[0.14] (p = 0.99), average (SD) angle between two of them was 105.5° [14.9] (p = 0.84). The average time interval between last imaging examination and surgery was 8.4 days.

CONCLUSIONS

The new sign named the extracapsular cystic sign in SCNs may help differentiate SCNs from other pancreatic cystic lesions. Furthermore, this study supports an original diagnosis for SCNs when the sign of extracapsular cyst appears.