Neutrophil Gelatinase-Associated Lipocalin for the Differentiation of Mucinous Pancreatic Cystic Lesions.

Undetermined pancreatic cystic lesion (PCL) differentiation benefits from endoscopic ultrasound (EUS) based on morphology and cyst fluid analysis, but room for new biomarkers exists. Our aim was to assess the intracystic and serum diagnostic value of neutrophil gelatinase-associated lipocalin (Ngal) and interleukin 1 beta (IL-1ß) for differentiation of PCLs. This prospective study included patients from one tertiary hospital, evaluated between April 2018 and May 2020. EUS fine-needle aspiration or pancreatic pseudocysts drainage was the source of PCL intracystic liquid. The final diagnosis was based on surgery or EUS results (morphology, cytology, glucose, and CEA-carcinoembryogenic antigen). The intracystic samples were tested for Ngal, IL-1ß, glucose, and CEA, and serum for Ngal and IL-1ß. We evaluated 63 cysts, 33 pseudocysts, and 30 non-inflammatory cysts. The diagnostic sensitivity and specificity for mucinous PCL was 70.8% and 92.3% for intracystic Ngal (cut-off: 500-800 ng/dL), without correlation with serum Ngal, no matter the inclusion of infected pseudocysts. After exclusion of infected pseudocysts, the sensitivity and specificity for glucose were 87% and 75%, respectively, and for CEA, they were 87.1%, and 96.8%, respectively. Intracystic Ngal shows promise in differentiating mucinous PCLs, but researchers need to conduct further studies to confirm its effectiveness. Intracystic IL-1ß and serum Ngal made no diagnostic contribution.

[A Case of Lymphoepithelial Cyst of the Pancreas for Which Malignancy Could Not Be Ruled Out Difficult Preoperative Diagnosis].

Lymphoepithelial cyst(LEC)of the pancreas is a relatively rare benign cystic disease of the pancreas. In this report, we describe a case of LEC in which a malignant tumor could not be ruled out by preoperative diagnosis and surgery was performed. The patient was a 72-year-old man. A simple CT scan of the chest and abdomen performed as a follow-up for another disease incidentally revealed a mass in the pancreatic tail. Enhanced CT of the abdomen showed a tumor approximately 3 cm in size at the pancreatic tail with no contrast effect. MRCP showed moderate signal on T2WI, high signal on T1WI, and high signal on T2WI on some cysts inside the pancreas. PET-CT showed slight uptake of FDG. Both tumor markers CEA and CA19-9 were normal. Therefore, malignant disease such as pancreatic IPMC could not be ruled out, and laparoscopic distal pancreatectomy plus splenectomy was performed. The pathology results showed a diagnosis of pancreatic lymphoepithelial cyst with slight differentiation into sebaceous gland.

Pancreatic Cysts Greater Than 1 cm Are Associated With an Increased Risk for Developing Pancreatic Cancer in Individuals From Pancreatic-Cancer Prone Kindreds Undergoing Surveillance.

BACKGROUND: The International Cancer of the Pancreas Screening Consortium recommended annual imaging for individuals at increased risk for developing a pancreatic ductal adenocarcinoma (PDAC) who did not have concerning pancreatic findings or a cyst <3 cm without worrisome features. We aimed to determine if 3-cm cyst size accurately predicted advanced precursor lesions in high-risk individuals undergoing surveillance. METHODS: Imaging for high-risk individuals (HRIs) undergoing PDAC surveillance from 2007 to 2021 was reviewed and pancreatic abnormalities were recorded including dominant cyst size and number of cysts. Subjects were excluded if they had the following: (1) no follow-up imaging after baseline, (2) solid lesion at baseline, or (3) development of solid lesion without having cyst on prior imaging. RESULTS: Five of the 77 HRIs found to have a cystic lesion on surveillance developed a PDAC: 3 with cystic lesion >1 cm as compared with only 2 of 67 HRIs with cystic lesions <1 cm (P < 0.05). None of these cysts developed worrisome findings and 4/5 PDACs did not arise from visualized cystic precursor lesion. CONCLUSIONS: Patients with a cyst ≥1 cm were at increased risk for developing PDAC compared with patients with cyst <1 cm. Pancreatic ductal adenocarcinoma usually did not arise from a recognized cystic lesion.

Diagnosis and management of pancreatic cystic lesions for the non-gastroenterologist.

Although most pancreatic cystic lesions do not progress to cancer, they create concern for patients and their primary care physicians. The lack of consensus guidelines on diagnosis and surveillance of these lesions can lead to a management conundrum. We review current guidelines on diagnosis and management.

[Histopathologic diagnosis of solid and cystic pancreatic lesions with a focus on ductal adenocarcinoma : A vademecum for daily practice]. / Histopathologische Diagnostik von soliden und zystischen Pankreasläsionen mit Hauptaugenmerk auf dem duktalen Adenokarzinom : Ein Vademecum für den Alltag.

Pancreas pathology is constantly evolving and can present various challenges for pathologists. This paper is focused on providing helpful hints for daily routine diagnostics. During histopathological analysis of pancreas biopsies, pancreatic ductal adenocarcinoma must be distinguished not only from other solid neoplasms, but especially from its mimicker, autoimmune pancreatitis. This can be achieved by a systematic workup following clear diagnostic criteria. When analyzing samples from cystic pancreatic lesions, mucin-producing neoplasms must be detected due to their role as pancreatic cancer precursors; molecular analyses can help considerably with their detection and distinction. During frozen section examination, evaluation of the pancreatic neck margin and analysis of unclear lesions of the liver are two important tasks, which are explained further in this article. A special challenge is the evaluation of neoadjuvant treated pancreatic cancer, which requires a detailed macroscopic and microscopic workup. Finally, current advances in precision oncology and emerging approaches for pancreatic cancer within this field are discussed. With the advancement of technical possibilities and their increasingly broad implementation, the classification systems in pancreatic pathology will continue to gain in complexity, but also in accuracy.

Revisiting the performance of cyst fluid carcinoembryonic antigen as a diagnostic marker for pancreatic mucinous cysts: a comprehensive 20-year institutional review.

OBJECTIVE: Elevated pancreatic cyst fluid carcinoembryonic antigen (CEA) has been routinely used to classify mucinous cysts. This study incorporates original data that established the CEA ≥192 ng/mL threshold with over 20 years of additional data and reassesses the diagnostic performance of CEA for differentiating mucinous from non-mucinous cysts. DESIGN: 1169 pancreatic cysts (1999-2021) with CEA results were identified. 394 cases had histological confirmation as the diagnostic standard. Additionally, 237 cysts without histological confirmation demonstrated KRAS, GNAS, or RNF43 mutations by molecular testing and were combined with the histologically confirmed cysts for separate analysis on a total cohort of 631 cysts. RESULTS: Median CEA was significantly higher in mucinous cysts (323.9 ng/mL, n=314) versus non-mucinous cysts (204.6 ng/mL, n=80) (p<0.001). Receiver operating characteristic curve analysis demonstrated an optimal CEA cut-off of 20 ng/mL (area under the curve: 80%), though the specificity was lower than desired (sensitivity 89%, specificity 64%). At the previously established threshold of 192 ng/mL, sensitivity and specificity were 56% and 78%, respectively. To achieve a specificity of 85% as originally reported, a CEA threshold of 250 ng/mL was needed; the 13 false positive cases at this threshold included 4 benign simple cysts, 2 squamoid cysts, 1 serous cystadenoma, 1 lymphoepithelial cyst and 5 more uncommon entities. All results remained similar within the total cohort after including additional cases with KRAS/GNAS/RNF43 mutations only. CONCLUSION: Cyst fluid CEA continues to be a useful test in the diagnosis of mucinous pancreatic cysts but does not appear as specific as previously reported. Raising the CEA threshold to 250 ng/mL to maintain specificity for differentiating mucinous from non-mucinous cysts may be considered.

[Challenges of cytopathological pancreas diagnostics]. / Herausforderungen der zytopathologischen Pankreasdiagnostik.

The cytologic diagnostics of solid and cystic pancreatic lesions with endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is an integral part of the clinical workup and the decision of a surgical versus a conservative approach. Cystic lesions are increasingly being diagnosed due to improved imaging and represent numerous neoplastic as well as non-neoplastic epithelial and non-epithelial entities, which differ in biological behavior and prognosis. In particular, the differentiation of mucinous and non-mucinous cysts is significant for further clinical management. Regressive cellular changes, gastrointestinal contaminants, and overlapping morphologic changes of reactively altered ductal epithelial cells and cells of well-differentiated neoplasms and preneoplasms are special challenges of cytological diagnostics. For a uniform cytological classification of findings, an internationally developed seven-level classification system has been published and co-published by the World Health Organization (WHO). This classification system takes into account both morphological findings and further procedures on cytological material such as next-generation sequencing and immunocytochemistry and is based on the WHO classification for pancreatic tumors. Against this background, important cytologic diagnostic criteria of various solid and cystic lesions relevant in clinical practice are presented in this article, considering diagnostic possibilities and pitfalls as well as differential diagnoses.

MiR-200b categorizes patients into pancreas cystic lesion subgroups with different malignant potential.

Extracellular vesicles (EV) carry their cargo in a membrane protected form, however, their value in early diagnostics is not well known. Although pancreatic cysts are heterogeneous, they can be clustered into the larger groups of pseudocysts (PC), and serous and mucinous pancreatic cystic neoplasms (S-PCN and M-PCN, respectively). In contrast to PCs and S-PCNs, M-PCNs may progress to malignant pancreatic cancers. Since current diagnostic tools do not meet the criteria of high sensitivity and specificity, novel methods are urgently needed to differentiate M-PCNs from other cysts. We show that cyst fluid is a rich source of EVs that are positive and negative for the EV markers CD63 and CD81, respectively. Whereas we found no difference in the EV number when comparing M-PCN with other pancreatic cysts, our EV-based biomarker identification showed that EVs from M-PCNs had a higher level of miR-200b. We also prove that not only EV-derived, but also total cyst fluid miR-200b discriminates patients with M-PCN from other pancreatic cysts with a higher sensitivity and specificity compared to other diagnostic methods, providing the possibility for clinical applications. Our results show that measuring miR-200b in cyst fluid-derived EVs or from cyst fluid may be clinically important in categorizing patients.

Cyst fluid glycoproteins accurately distinguishing malignancies of pancreatic cystic neoplasm.

Pancreatic cystic neoplasms (PCNs) are recognized as precursor lesions of pancreatic cancer, with a marked increase in prevalence. Early detection of malignant PCNs is crucial for improving prognosis; however, current diagnostic methods are insufficient for accurately identifying malignant PCNs. Here, we utilized mass spectrometry (MS)-based glycosite- and glycoform-specific glycoproteomics, combined with proteomics, to explore potential cyst fluid diagnostic biomarkers for PCN. The glycoproteomic and proteomic landscape of pancreatic cyst fluid samples from PCN patients was comprehensively investigated, and its characteristics during the malignant transformation of PCN were analyzed. Under the criteria of screening specific cyst fluid biomarkers for the diagnosis of PCN, a group of cyst fluid glycoprotein biomarkers was identified. Through parallel reaction monitoring (PRM)-based targeted glycoproteomic analysis, we validated these chosen glycoprotein biomarkers in a second cohort, ultimately confirming N-glycosylated PHKB (Asn-935, H5N2F0S0; Asn-935, H4N4F0S0; Asn-935, H5N4F0S0), CEACAM5 (Asn-197, H5N4F0S0) and ATP6V0A4 (Asn-367, H6N4F0S0) as promising diagnostic biomarkers for distinguishing malignant PCNs. These glycoprotein biomarkers exhibited robust performance, with an area under the curve ranging from 0.771 to 0.948. In conclusion, we successfully established and conducted MS-based glycoproteomic analysis to identify novel cyst fluid glycoprotein biomarkers for PCN. These findings hold significant clinical implications, providing valuable insights for PCN decision-making, and potentially offering therapeutic targets for PCN treatment.

Pancreatic Acinar Cystic Transformation: Familial Forms Do Exist.

ABSTRACT: Pancreatic acinar cystic transformation (ACT) is a recently described entity of the pancreatic cysts' spectrum. It is a nonneoplastic pancreatic lesion, mostly asymptomatic, and is considered a rare disease, with less than 100 reported cases. Its benign nature and the absence of reported cases of malignant transformation or invasive lesions were a plea for a conservative approach. As a consequence, little is known about the pathogenesis of this lesion. No familial history of ACT has been previously described. Here, we report a familial case of 2 siblings with typical ACT imaging lesions giving evidence for familial aggregation. No obvious environmental exposure was identified as a potential risk factor for ACT development. No physiological data exist to suggest a congenital nature of these lesions, but for the first patient, the calcifications seem to have appeared with time. Further research, with high throughput sequencing technologies, may elucidate genetic polymorphisms explaining potential ACT familial phenotype. In practice, careful family history collection must be performed to identify a possible familial form of ACT when this diagnosis is proposed.

Lymphoepithelial cyst mimicking malignant pancreatic signs: a case report.

BACKGROUND: A lymphoepithelial cyst of the pancreas is a rare benign lesion that is difficult to diagnose preoperatively and challenging in distinguishing from potentially malignant cystic pancreatic neoplasms. A diagnostic step-up approach is recommended to clarify the lesion's dignity and specify a treatment plan. CASE PRESENTATION: Here, we describe a case of a 51-year-old male European with a lymphoepithelial cyst of the pancreas mimicking malignant features in a mid-age male patient with abdominal pain and unintended weight loss. CONCLUSION: Patients with indeterminate cystic pancreatic lesions should be examined by a multidisciplinary diagnostic team in a step-up approach to clarify the lesion's entity. In the case of incidentally found lymphoepithelial cysts of the pancreas, a watchful waiting strategy might be clinically reasonable if the diagnosis is proven.

Exploring a novel composite method using non-contrast EUS enhanced microvascular imaging and cyst fluid analysis to differentiate pancreatic cystic lesions.

BACKGROUND AND AIMS: Differentiating pancreatic cystic lesions (PCLs) remains a diagnostic challenge. The use of high-definition imaging modalities which detect tumor microvasculature have been described in solid lesions. We aim to evaluate the usefulness of cystic microvasculature when used in combination with cyst fluid biochemistry to differentiate PCLs. METHODS: We retrospectively analyzed 110 consecutive patients with PCLs from 2 Italian Hospitals who underwent EUS with H-Flow and EUS fine needle aspiration to obtain cystic fluid. The accuracy of fluid biomarkers was evaluated against morphological features on radiology and EUS. Gold standard for diagnosis was surgical resection. A clinical and radiological follow up was applied in those patients who were not resected because not surgical indication and no signs of malignancy were shown. RESULTS: Of 110 patients, 65 were diagnosed with a mucinous cyst, 41 with a non-mucinous cyst, and 4 with an undetermined cyst. Fluid analysis alone yielded 76.7% sensitivity, 56.7% specificity, 77.8 positive predictive value (PPV), 55.3 negative predictive value (NPV) and 56% accuracy in diagnosing pancreatic cysts alone. Our composite method yielded 97.3% sensitivity, 77.1% specificity, 90.1% PPV, 93.1% NPV, 73.2% accuracy. CONCLUSIONS: This new composite could be applied to the holistic approach of combining cyst morphology, vascularity, and fluid analysis alongside endoscopist expertise.

EUS-guided through the needle microbiopsy: a useful adjunct in the investigation of pancreatic cystic lesions.

OBJECTIVE: Endoscopic ultrasound-guided through-the-needle microbiopsy (EUS-TTNB) forceps is a recent development that facilitates sampling of the walls of pancreatic cystic lesions (PCL) for histological analysis. We aimed to assess the impact of EUS-TTNB and its influence on patient management in a tertiary pancreas centre. DESIGN: A prospective database of consecutive patients who underwent EUS-TTNB from March 2020 to August 2022 at a tertiary referral centre was retrospectively analysed. RESULTS: Thirty-four patients (22 women) were identified. Technical success was achieved in all cases. Adequate specimens for histological diagnosis were obtained in 25 (74%) cases. Overall, EUS-TTNB led to a change in management in 24 (71%) cases. Sixteen (47%) patients were downstaged, with 5 (15%) discharged from surveillance. Eight (24%) were upstaged, with 5 (15%) referred for surgical resection. In the 10 (29%) cases without change in management, 7 (21%) had confirmation of diagnosis with no change in surveillance, and 3 (9%) had insufficient biopsies on EUS-TTNB. Two (6%) patients developed post-procedural pancreatitis, and 1 (3%) developed peri-procedural intracystic bleeding with no subsequent clinical sequelae. CONCLUSION: EUS-TTNB permits histological confirmation of the nature of PCL, which can alter management outcomes. Care should be taken in patient selection and appropriately consented due to the adverse event rate.

The additive value of CA19.9 monitoring in a pancreatic cyst surveillance program.

BACKGROUND: Surveillance of pancreatic cysts focuses on the detection of (mostly morphologic) features warranting surgery. European guidelines consider elevated CA19.9 as a relative indication for surgery. We aimed to evaluate the role of CA19.9 monitoring for early detection and management in a cyst surveillance population. METHODS: The PACYFIC-registry is a prospective collaboration that investigates the yield of pancreatic cyst surveillance performed at the discretion of the treating physician. We included participants for whom at least one serum CA19.9 value was determined by a minimum follow-up of 12 months. RESULTS: Of 1865 PACYFIC participants, 685 met the inclusion criteria for this study (mean age 67 years, SD 10; 61% female). During a median follow-up of 25 months (IQR 24, 1966 visits), 29 participants developed high-grade dysplasia (HGD) or pancreatic cancer. At baseline, CA19.9 ranged from 1 to 591 kU/L (median 10 kU/L [IQR 14]), and was elevated (≥37 kU/L) in 64 participants (9%). During 191 of 1966 visits (10%), an elevated CA19.9 was detected, and these visits more often led to an intensified follow-up (42%) than those without an elevated CA19.9 (27%; p < 0.001). An elevated CA19.9 was the sole reason for surgery in five participants with benign disease (10%). The baseline CA19.9 value was (as continuous or dichotomous variable at the 37 kU/L threshold) not independently associated with HGD or pancreatic cancer development, whilst a CA19.9 of ≥ 133 kU/L was (HR 3.8, 95% CI 1.1-13, p = 0.03). CONCLUSIONS: In this pancreatic cyst surveillance cohort, CA19.9 monitoring caused substantial harm by shortening surveillance intervals (and performance of unnecessary surgery). The current CA19.9 cutoff was not predictive of HGD and pancreatic cancer, whereas a higher cutoff may decrease false-positive values. The role of CA19.9 monitoring should be critically appraised prior to implementation in surveillance programs and guidelines.

Extracellular vesicle analysis of plasma allows differential diagnosis of atypical pancreatic serous cystadenoma.

Increased use of cross-sectional imaging has resulted in frequent detection of incidental cystic pancreatic lesions. Serous cystadenomas (SCAs) are benign cysts that do not require surgical intervention unless symptomatic. Unfortunately, up to half of SCAs do not have typical imaging findings ("atypical SCAs"), overlap with potentially malignant precursor lesions, and thus pose a diagnostic challenge. We tested whether the analysis of circulating extracellular vesicle (EV) biomarkers using a digital EV screening technology (DEST) could enhance the discrimination of cystic pancreatic lesions and avoid unnecessary surgical intervention in these atypical SCAs. Analysis of 25 different protein biomarkers in plasma EV from 68 patients identified a putative biomarker signature of Das-1, Vimentin, Chromogranin A, and CAIX with high discriminatory power (AUC of 0.99). Analysis of plasma EV for multiplexed markers may thus be helpful in clinical decision-making.

The Use of Integrated Molecular Testing in the Assessment and Management of Pancreatic Cysts.

PURPOSE OF REVIEW: As abdominal imaging becomes more sensitive and regularly used, pancreatic cystic lesions (PCLs) are being diagnosed more frequently. A small but clinically significant minority of these lesions have a predisposition to either harbor malignancy or undergo malignant transformation. This review highlights the current state and performance of cystic fluid biomarkers and how they may be incorporated into management. RECENT FINDINGS: Among the major domains of molecular testing for PCLs, DNA based analyses have demonstrated the highest accuracy in identifying cyst type and have the most data to support their clinical use. However, epigenetic and protein biomarker based molecular assessments have emerged with the potential to complement DNA based approaches. In addition, recent studies have increasingly demonstrated the value associated with combinations of mutations and other biomarkers in identifying higher grade mucinous cystic lesions. We present the performance of individual biomarkers in cyst fluid analysis with an emphasis on an algorithmic approach to improve the accurate identification of both cyst type and risk of malignant transformation.

A Combined DNA/RNA-based Next-Generation Sequencing Platform to Improve the Classification of Pancreatic Cysts and Early Detection of Pancreatic Cancer Arising From Pancreatic Cysts.

OBJECTIVE: We report the development and validation of a combined DNA/RNA next-generation sequencing (NGS) platform to improve the evaluation of pancreatic cysts. BACKGROUND AND AIMS: Despite a multidisciplinary approach, pancreatic cyst classification, such as a cystic precursor neoplasm, and the detection of high-grade dysplasia and early adenocarcinoma (advanced neoplasia) can be challenging. NGS of preoperative pancreatic cyst fluid improves the clinical evaluation of pancreatic cysts, but the recent identification of novel genomic alterations necessitates the creation of a comprehensive panel and the development of a genomic classifier to integrate the complex molecular results. METHODS: An updated and unique 74-gene DNA/RNA-targeted NGS panel (PancreaSeq Genomic Classifier) was created to evaluate 5 classes of genomic alterations to include gene mutations (e.g., KRAS, GNAS, etc.), gene fusions and gene expression. Further, CEA mRNA ( CEACAM5 ) was integrated into the assay using RT-qPCR. Separate multi-institutional cohorts for training (n=108) and validation (n=77) were tested, and diagnostic performance was compared to clinical, imaging, cytopathologic, and guideline data. RESULTS: Upon creation of a genomic classifier system, PancreaSeq GC yielded a 95% sensitivity and 100% specificity for a cystic precursor neoplasm, and the sensitivity and specificity for advanced neoplasia were 82% and 100%, respectively. Associated symptoms, cyst size, duct dilatation, a mural nodule, increasing cyst size, and malignant cytopathology had lower sensitivities (41-59%) and lower specificities (56-96%) for advanced neoplasia. This test also increased the sensitivity of current pancreatic cyst guidelines (IAP/Fukuoka and AGA) by >10% and maintained their inherent specificity. CONCLUSIONS: PancreaSeq GC was not only accurate in predicting pancreatic cyst type and advanced neoplasia but also improved the sensitivity of current pancreatic cyst guidelines.