Imaging, pathology, and diagnosis of solitary fibrous tumor of the pancreas: A case report and review of literature

BACKGROUND A solitary fibrous tumor(SFT)is often located in the pleura,while SFT of the pancreas is extremely rare.Here,we report a case of SFT of the pancreas and discuss imaging,histopathology,and immunohistochemistry for accurate diagnosis and treatment.CASE SUMMARY A 54-year-old man presented to our hospital with pancreatic occupancy for over a month.There were no previous complaints of discomfort.His blood pressure was normal.Blood glucose,tumor markers,and enhanced computed tomography(CT)suggested a malignant tumor.Because the CT appearance of pancreatic cancer varies,we could not confirm the diagnosis;therefore,we performed endoscopic ultrasound-guided fine-needle biopsy(EUS-FNB).Pathology and immunohistochemistry were consistent with SFT of the pancreas.The posto-perative pathology and immunohistochemistry were consistent with the puncture results.The patient presented for a follow-up examination one month after discharge with no adverse effects.CONCLUSION Other diseases must be excluded in patients with a pancreatic mass that cannot be diagnosed.CT and pathological histology have diagnostic value for pancreatic tumors.Endoscopic puncture biopsy under ultrasound can help diagnose pancreatic masses that cannot be diagnosed preoperatively.Surgery is an effective treatment for SFT of the pancreas;however,long-term follow-up is strongly recommended because of the possibility of malignant transformation of the tumor.

Early diagnosis of pancreatic cancer: Shedding light on an unresolved challenge

Diagnosing early-stage pancreatic cancer(PC)remains a clinical challenge.Hence,studying novel imaging aspects that could enhance the diagnostic accuracy of malignant pancreatic precursor lesions is imperative.This article aims to un-derscore the promising role of emerging imaging aspects that may facilitate the earlier diagnosis of PC,thereby improving its management and prognosis.

Mixed neuroendocrine non-neuroendocrine neoplasms in gastroenteropancreatic tract

Mixed neuroendocrine non-neuroendocrine neoplasms(MiNENs)are a hetero-geneous group of malignant neoplasms that can settle in the gastroenteropan-creatic tract.They are composed of a neuroendocrine(NE)and a non-NE compo-nent in at least 30%of each tumour.The non-NE component can include different histological combinations of glandular,squamous,mucinous and sarcomatoid phenotypes,and one or both of the components can be low-or high grade malignant.Recent changes in the nomenclature of these neoplasms might lead to great deal of confusion,and the lack of specific clinical trials is the main reason why their management is difficult.The review aims to clarify the definition of MiNEN and analyze available evidence about their diagnosis and treatment options according to their location and extension through careful analysis of the available data.It would be important to reach a general consensus on their diagnosis in order to construct a classification that remains stable over time and facilitates the design of clinical trials that,due to their low incidence,will require long recruitment periods.

Current perspectives on pancreatic serous cystic neoplasms:Diagnosis, management and beyond

Pancreatic cystic neoplasms have been increasingly recognized recently. Comprising about 16% of all resected pancreatic cystic neoplasms, serous cystic neoplasms are uncommon benign lesions that are usually asymptomatic and found incidentally. Despite overall low risk of malignancy, these pancreatic cysts still generate anxiety, leading to intensive medical investigations with considerable financial cost to health care systems. This review discusses the general background of serous cystic neoplasms, including epidemiology and clinical characteristics, and provides an updated overview of diagnostic approaches based on clinical features, relevant imaging studies and new findings that are being discovered pertaining to diagnostic evaluation. We also concisely discuss and propose management strategies for better quality of life.

Pathological features and diagnosis of intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasm(IPMN) of the pancreas is a noninvasive epithelial neoplasm of mucinproducing cells arising in the main duct(MD) and/or branch ducts(BD) of the pancreas.Involved ducts are dilated and filled with neoplastic papillae and mucus in variable intensity.IPMN lacks ovarian-type stroma,unlike mucinous cystic neoplasm,and is defined as a grossly visible entity(≥ 5 mm),unlike pancreatic intraepithelial neoplasm.With the use of high-resolution imaging techniques,very small IPMNs are increasingly being identified.Most IPMNs are solitary and located in the pancreatic head,although 20%-40% are multifocal.Macroscopic classification in MD type,BD type and mixed or combined type reflects biological differences with important prognostic and preoperative clinical management implications.Based on cytoarchitectural atypia,IPMN is classified into low-grade,intermediategrade and high-grade dysplasia.Based on histological features and mucin(MUC) immunophenotype,IPMNs are classified into gastric,intestinal,pancreatobiliary and oncocytic types.These different phenotypes can be observed together,with the IPMN classified according to the predominant type.Two pathways have been suggested:gastric phenotype corresponds to less aggressive uncommitted cells(MUC1-,MUC2-,MUC5 AC +,MUC6 +) with the capacity to evolve to intestinal phenotype(intestinal pathway)(MUC1-,MUC2 +,MUC5 AC +,MUC6- or weak +) or pancreatobiliary /oncocytic phenotypes(pyloropancreatic pathway)(MUC1 +,MUC 2-,MUC5 AC +,MUC 6 +) becoming more aggressive.Prognosis of IPMN is excellent but critically worsens when invasive carcinoma arises(about 40% of IPMNs),except in some cases of minimal invasion.The clinical challenge is to establish which IPMNs should be removed because of their higher risk of developing invasive cancer.Once resected,they must be extensively sampled or,much better,submitted in its entirety for microscopic study to completely rule out associated invasive carcinoma.

Pathological differential diagnosis of solid-pseudopapillary neoplasm and endocrine tumors of the pancreas

AIM:To investigate differential points of solid-pseudo-papillary neoplasm (SPN) of the pancreas and pancre-atic endocrine tumor (PET).METHODS:Ten cases of SPN and fourteen cases of PET were studied in this retrospective study. Clinical and pathologic features,immunostaining reactions and β-catenin gene mutations were analyzed.RESULTS:The mean age of SPN patients was 25.6 years and these patients had no specific symptoms. The mean diameter of the tumors was 11.0 cm,9/10 cases were cystic or a mixture of solid and cystic structures,and there was hemorrhage and necrosis on the cut surface in 8/10 (80%) cases. Characteristic pseudo-papillary structure and discohesive appearance of the neoplastic cells were observed in all 10 (100%) cases. The results of immunostaining showed that nuclear expression of β-catenin and loss of E-cadherin in all the cases,was only seen in SPN. Molecular studies discov-ered that 9/10 (90%) cases harbored a point mutation of exon 3 in β-catenin gene. On the other hand,the mean age of PET patients was 43.1 years. Eight of 14 cases presented with symptoms caused by hypoglyce-mia,and the other 6 cases presented with symptoms similar to those of SPN. The mean size of the tumors was 2.9 cm,most of the tumors were solid,only 3/14 (21%) were a mixture of solid and cystic structures,and macroscopic hemorrhage and necrosis were much less common (3/14,21%). Histologically,tumor cells were arranged in trabecular,acinar or solid patterns and demonstrated no pseudopapillary structure and discohesive appearance in all 14 (100%) cases. The results of immunostaining and mutation detection were completely different with SPN that membrane and cytoplastic expression of β-catenin without loss of E-cadherin,as well as no mutation in β-catenin gene in all the cases. CONCLUSION:Both macroscopic and microscopic features of SPN are quite characteristic. It is not difficult to distinguish it from PET. If necessary,immunos-taining of β-catenin and E-cadherin is quite helpful to make the differential diagnosis.

An update on the diagnosis of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms(GEP-NENs)arise from neuroendocrine cells found throughout the gastrointestinal tract and islet cells of the pancreas.The incidence and prevalence of GEP-NENs have been increasing each year due to higher awareness,improved diagnostic modalities,and increased incidental detection on cross-sectional imaging and endoscopy for cancer screening and other conditions and symptoms.GEP-NENs are a heterogeneous group of tumors and have a wide range in clinical presentation,histopathologic features,and molecular biology.Clinical presentation most commonly depends on whether the GEP-NEN secretes an active hormone.The World Health Organization recently updated the classification of GEP-NENs to introduce a distinction between high-grade neuroendocrine tumors and neuroendocrine carcinomas,which can be identified using histology and molecular studies and are more aggressive with a worse prognosis compared to high-grade neuroendocrine tumors.As our understanding of the biology of GEP-NENs has grown,new and improved diagnostic modalities can be developed and optimized.Here,we discuss clinical features and updates in diagnosis,including histopathological analysis,biomarkers,molecular techniques,and radiology of GEP-NENs.We review established diagnostic tests and discuss promising novel diagnostic tests that are currently in development or require further investigation and validation prior to broad utilization in patient care.

New insights in diagnosis and treatment of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms(GEP-NENs)are rare epithelial neoplasms derived from pluripotent endocrine cells along the gastrointestinal tract and pancreas.GEP-NENs are classified into well-differentiated neuroendocrine tumors and poorly differentiated neuroendocrine carcinomas.Despite overlapping morphological features,GEP-NENs vary in molecular biology,epigenetic,clinical behavior,treatment response,and prognosis features and remain an unmet clinical challenge.In this review,we introduce recent updates on the histopathologic classification,including the tumor grading and staging system,molecular genetics,and systemic evaluation of the diagnosis and treatment of GEP-NENs at different anatomic sites,together with some insights into the diagnosis of challenging and unusual cases.We also discuss the application of novel therapeutic approaches for GEP-NENs,including peptide receptor radionuclide therapy,targeted therapy,and immunotherapy with immune checkpoint inhibitors.These findings will help improve patient care with precise diagnosis and individualized treatment of patients with GEP-NENs.

Current updates and future directions in diagnosis and management of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms are a heterogenous group of rare neoplasms that are increasingly being discovered,often incidentally,throughout the gastrointestinal tract with varying degrees of activity and malignant potential.Confusing nomenclature has added to the complexity of managing these lesions.The term carcinoid tumor and embryonic classification have been replaced with gastroenteropancreatic neuroendocrine neoplasm,which includes gastrointestinal neuroendocrine and pancreatic neuroendocrine neoplasms.A comprehensive multidisciplinary approach is important for clinicians to diagnose,stage and manage these lesions.While histological diagnosis is the gold standard,recent advancements in endoscopy,conventional imaging,functional imaging,and serum biomarkers complement histology for tailoring specific treatment options.In light of developing technology,our review sets out to characterize diagnostic and therapeutic advancements for managing gastroenteropancreatic neuroendocrine tumors,including innovations in radiolabeled peptide imaging,circulating biomarkers,and endoscopic treatment approaches adapted to different locations throughout the gastrointestinal system.

Endoscopic techniques for diagnosis and treatment of gastroentero-pancreatic neuroendocrine neoplasms:Where we are

BACKGROUND The correct localization of the primary tumor site and a complete histological diagnosis represent the milestones for the proper management of gastro-enteropancreatic neuroendocrine neoplasms(GEP-NENs).AIM To analyze current evidence on the role of endoscopy in the diagnosis/treatment of GEP-NENs.METHODS An extensive bibliographical search was performed in PubMed to identify guidelines and primary literature(retrospective and prospective studies,systematic reviews,case series)published in the last 15 years,using both medical subject heading(MeSH)terms and free-language keywords:gastro-enteropancreatic neuroendocrine neoplasms;endoscopy;ultrasound endoscopy;capsule endoscopy;double-balloon enteroscopy;diagnosis;therapy;staging.RESULTS In the diagnostic setting,endoscopic ultrasonography(EUS)represents the diagnostic gold standard for pancreatic NENs and the technique of choice for the locoregional staging of gastric,duodenal and rectal NENs.The diagnosis of small bowel NENs(sbNENs)has been improved with the advent of video capsule endoscopy and double-balloon enteroscopy,which allow for direct visualization of the entire small bowel;however,data regarding the efficacy/safety of these techniques in the detection of sbNENs are scanty and often inconclusive.From a therapeutic point of view,endoscopic removal is the treatment of choice for the majority of gastric NENs(type 1/2),for well-differentiated localized nonmetastatic duodenal NENs<1 cm,confined to the submucosa layer and for<10 mm,stage T1–T2,rectal NENs.EUS-guided pancreatic locoregional ablative treatments have been proposed in recent studies with promising results in order to control symptoms or reduce tumor burden in selected patients.CONCLUSION Standard axial endoscopy and EUS still play a pivotal role in several GEP-NENs.Advanced techniques for increasing the rate of R0 resection should be reserved for high-volume referral centers.

Methylation changes at the GNAS imprinted locus in pancreatic cystic neoplasms are important for the diagnosis of malignant cysts

BACKGROUND Guanine nucleotide-binding protein,alpha stimulating(GNAS)mutations are characteristic of intraductal papillary mucinous neoplasms(IPMNs).Pancreatic ductal adenocarcinomas(PDACs)harboring GNAS mutations originate in IPMNs.GNAS is a complex imprinted locus that produces five transcripts regulated by differential methylated regions,NESP55,GNASAS,GNASXL,GNAS1A,and GNAS.AIM To evaluate if methylation changes in the differential methylated regions of GNAS locus contributed to malignant progression of pancreatic cysts.METHODS GNAS locus methylation was analyzed in archival pancreatic cyst fluid(PCF)obtained by endoscopic ultrasound with fine-needle aspiration by methylation specific–multiplex ligation dependent probe amplification.Results were normalized and analyzed using Coffalyser.Net software.RESULTS Fifty-two PCF samples obtained by endoscopic ultrasound with fine-needle aspiration and previously characterized for KRAS and GNAS mutations were studied.The final diagnoses were surgical(11)and clinicopathological(41),including 30 benign cysts,14 pre-malignant cyst,and eight malignant cysts.Methylation changes at NESP55,GNASAS,GNAS1A,and especially GNASXL were more frequent in malignant cysts,and NESP55 and GNASAS were useful for diagnosis.A combined variable defined as“GNAS locus methylation changes”was significantly associated with malignancy(6/8 malignant cysts and only 2/20 benign cysts)and improved classification.Hypermethylation in both maternally(NESP55)and paternally(GNASXL)derived promoters was found in 3/3 PDACs.CONCLUSION This is the first study to identify methylation changes in the GNAS locus,improving the diagnosis of malignant pancreatic cysts and suggesting a role in progression to PDAC.

Stage at diagnosis of colorectal cancer through diagnostic route:Who should be screened?

BACKGROUND Colorectal cancer(CRC)is a global health concern,with advanced-stage diagnoses contributing to poor prognoses.The efficacy of CRC screening has been well-established;nevertheless,a significant proportion of patients remain unscreened,with>70%of cases diagnosed outside screening.Although identifying specific subgroups for whom CRC screening should be particularly recommended is crucial owing to limited resources,the association between the diagnostic routes and identification of these subgroups has been less appreciated.In the Japanese cancer registry,the diagnostic routes for groups discovered outside of screening are primarily categorized into those with comorbidities found during hospital visits and those with CRC-related symptoms.AIM To clarify the stage at CRC diagnosis based on diagnostic routes.METHODS We conducted a retrospective observational study using a cancer registry of patients with CRC between January 2016 and December 2019 at two hospitals.The diagnostic routes were primarily classified into three groups:Cancer screening,follow-up,and symptomatic.The early-stage was defined as Stages 0 or I.Multivariate and univariate logistic regressions were exploited to determine the odds of early-stage diagnosis in the symptomatic and cancer screening groups,referencing the follow-up group.The adjusted covariates were age,sex,and tumor location.RESULTS Of the 2083 patients,715(34.4%),1064(51.1%),and 304(14.6%)belonged to the follow-up,symptomatic,and cancer screening groups,respectively.Among the 2083 patients,CRCs diagnosed at an early stage were 57.3%(410 of 715),23.9%(254 of 1064),and 59.5%(181 of 304)in the follow-up,symptomatic,and cancer screening groups,respectively.The symptomatic group exhibited a lower likelihood of early-stage diagnosis than the follow-up group[P<0.001,adjusted odds ratio(aOR),0.23;95%confidence interval(95%CI):0.19-0.29].The likelihood of diagnosis at an early stage was similar between the follow-up and cancer screening groups(P=0.493,aOR for early-stage diagnosis in the cancer screening group vs follow-up group=1.11;95%CI=0.82-1.49).CONCLUSION CRCs detected during hospital visits for comorbidities were diagnosed earlier,similar to cancer screening.CRC screening should be recommended,particularly for patients without periodical hospital visits for comorbidities.

Endoscopic ultrasonography-related diagnostic accuracy and clinical significance on small rectal neuroendocrine neoplasms

This research aimed to examine the diagnostic accuracy and clinical significance of endoscopic ultrasonography(EUS)in the context of small rectal neuroendocrine neoplasms(NENs).A total of 108 patients with rectal subepithelial lesions(SELs)with a diameter of<20 mm were included in the analysis.The diagnosis and depth assessment of EUS was compared to the histology findings.The prevalence of NENs in rectal SELs was 78.7%(85/108).The sensitivity of EUS in detecting rectal NENs was 98.9%(84/85),while the specificity was 52.2%(12/23).Overall,the diagnostic accuracy of EUS in identifying rectal NENs was 88.9%(96/108).The overall accuracy rate for EUS in assessing the depth of invasion in rectal NENs was 92.9%(78/84).Therefore,EUS demonstrates reasonable diagnostic accuracy in detecting small rectal NENs,with good sensitivity but inferior specificity.EUS may also assist physicians in assessing the depth of invasion in small rectal NENs before endoscopic excision.

Solid pseudopapillary tumor of the pancreas:A systematic review of clinical,surgical and oncological characteristics of 1384 patients underwent pancreatic surgery

Background:Pancreatic solid pseudopapillary tumors(SPTs)are rare clinical entity,with low malignancy and still unclear pathogenesis.They account for less than 2%of exocrine pancreatic neoplasms.This study aimed to perform a systematic review of the main clinical,surgical and oncological characteristics of pancreatic SPTs.Data sources:MEDLINE/PubMed,Web of Science and Scopus databases were systematically searched for the main clinical,surgical and oncological characteristics of pancreatic SPTs up to April 2021,in accordance with the preferred reporting items for systematic reviews and meta-analyses(PRISMA)standards.Primary endpoints were to analyze treatments and oncological outcomes.Results:A total of 823 studies were recorded,86 studies underwent full-text reviews and 28 met inclusion criteria.Overall,1384 patients underwent pancreatic surgery.Mean age was 30 years and 1181 patients(85.3%)were female.The most common clinical presentation was non-specific abdominal pain(52.6%of cases).Mean overall survival was 98.1%.Mean recurrence rate was 2.8%.Mean follow-up was 4.2 years.Conclusions:Pancreatic SPTs are rare,and predominantly affect young women with unclear pathogenesis.Radical resection is the gold standard of treatment achieving good oncological impact and a favorable prognosis in a yearly life-long follow-up.

Overview of ectopic pancreas

This editorial discusses the article written by Zheng et al that was published in the latest edition of the World Journal of Gastrointestinal Surgery.Our primary focus is on the causes,location,diagnosis,histological classification,and therapy of ectopic pancreas.Ectopic pancreas refers to the presence of pancreatic tissue that is situated in a location outside its usual anatomical placement,and is not connected to the normal pancreas in terms of blood supply or anatomical struc-ture.Currently,the embryological origin of ectopic pancreas remains uncertain.The most prevalent form of ectopic pancreatic is gastric ectopic pancreas.Endoscopic ultrasonography examination can visualize the morphological charac-teristics of the ectopic pancreatic lesion and pinpoint its anatomical location.The histological categorization of ectopic pancreas evolves.Endoscopic treatment has been widely advocated in ectopic pancreas.

Identification of breath volatile organic compounds to distinguish pancreatic adenocarcinoma,pancreatic cystic neoplasm,and patients without pancreatic lesions

BACKGROUND Volatile organic compounds(VOCs)are a promising potential biomarker that may be able to identify the presence of cancers.AIM To identify exhaled breath VOCs that distinguish pancreatic ductal adenocar-cinoma(PDAC)from intraductal papillary mucinous neoplasm(IPMN)and healthy volunteers.METHODS We collected exhaled breath from histologically proven PDAC patients,radiological diagnosis IPMN,and healthy volunteers using the ReCIVA®device between 10/2021-11/2022.VOCs were identified by thermal desorption-gas chromatography/field-asymmetric ion mobility spectrometry and compared between groups.RESULTS A total of 156 participants(44%male,mean age 62.6±10.6)were enrolled(54 PDAC,42 IPMN,and 60 controls).Among the nine VOCs identified,two VOCs that showed differences between groups were dimethyl sulfide[0.73 vs 0.74 vs 0.94 arbitrary units(AU),respectively;P=0.008]and acetone dimers(3.95 vs 4.49 vs 5.19 AU,respectively;P<0.001).After adjusting for the imbalance parameters,PDAC showed higher dimethyl sulfide levels than the control and IPMN groups,with adjusted odds ratio(aOR)of 6.98(95%CI:1.15-42.17)and 4.56(1.03-20.20),respectively(P<0.05 both).Acetone dimer levels were also higher in PDAC compared to controls and IPMN(aOR:5.12(1.80-14.57)and aOR:3.35(1.47-7.63),respectively(P<0.05 both).Acetone dimer,but not dimethyl sulfide,performed better than CA19-9 in PDAC diagnosis(AUROC 0.910 vs 0.796).The AUROC of acetone dimer increased to 0.936 when combined with CA19-9,which was better than CA19-9 alone(P<0.05).CONCLUSION Dimethyl sulfide and acetone dimer are VOCs that potentially distinguish PDAC from IPMN and healthy participants.Additional prospective studies are required to validate these findings.

Metastatic clear cell sarcoma of the pancreas:A sporadic cancer

Primary or secondary clear cell sarcoma of the pancreas is an exceedingly rare and aggressive disease.In addition to pathology,molecular analysis is pivotal in differential diagnosis,especially with malignant melanoma.A key aspect in identifying clear cell sarcoma is specific genetic alterations,notably the translocation of t(12;22)(q13;q13),a diagnostic hallmark of this sarcoma subtype,which is absent in malignant melanoma.Treatment of primary clear cell sarcoma of the pancreas is the same as that for adenocarcinoma.

Reoperation for heterochronic intraductal papillary mucinous neoplasm of the pancreas after bile duct neoplasm resection:A case report

BACKGROUND Intraductal papillary neoplasm of the bile duct(IPNB)and intraductal papillary mucinous neoplasm(IPMN)of the pancreas have similar pathological manifestations.However,they often develop separately and it is rare for both to occur together.Patients presenting with heterochronic IPMN after IPNB are prone to be misdiagnosed with tumor recurrence.CASE SUMMARY A 67-year-old male patient was admitted 8.5 years after IPNB carcinoma and 4 years after the discovery of a pancreatic tumor.A left hepatic bile duct tumor with distal bile duct dilatation was found 8.5 years ago by the computed tomography;therefore,a left hepatectomy was performed.The postoperative pathological diagnosis was malignant IPNB with negative cutting edge and pathological stage T1N0M0.Magnetic resonance imaging 4 years ago showed cystic lesions in the pancreatic head with pancreatic duct dilatation,and carcinoembryonic antigen continued to increase.Positron emission tomography showed a maximum standard uptake value of 11.8 in the soft tissue mass in the pancreatic head,and a malignant tumor was considered.Radical pancreatoduodenectomy was performed.Postoperative pathological diagnosis was pancreatic head IPMN with negative cutting edge,pancreaticobiliary type,stage T3N0M0.He was discharged 15 d after the operation.Follow-up for 6 mo showed no tumor recurrence,and quality of life was good.CONCLUSION IPNB and IPMN are precancerous lesions with similar pathological characteristics and require active surgery and long-term follow-up.

Intraductal papillary mucinous neoplasm originating from a jejunal heterotopic pancreas:A case report

BACKGROUND Intraductal papillary mucinous neoplasm(IPMN)is a rare pancreatic tumor and has the potential to become malignant.Surgery is the most effective treatment at present,but there is no consensus on the site of resection.Heterotopic pancreas occurs in the gastrointestinal tract,especially the stomach and duodenum but is asymptomatic and rare.We report a case of ectopic pancreas with IPMN located in the jejunum.CASE SUMMARY A 56-year-old male patient suffered from severe pain,nausea and vomiting due to a traffic accident and sought emergency treatment at our hospital.Contrast-enhanced computed tomography of the whole abdomen suggested splenic congestion,which was considered to be splenic rupture.Emergency laparotomy was performed,and the ruptured spleen was removed during the operation.Unexpectedly,a cauliflower-like mass of about 2.5 cm×2.5 cm in size was incidentally found about 80 cm from the ligament of Treitz during the operation.A partial small bowel resection was performed,and postoperative pathology confirmed the small bowel mass as heterotopic pancreas with low-grade IPMN.CONCLUSION Ectopic pancreas occurs in the jejunum and is pathologically confirmed as IPMN after surgical resection.

Pancreatic cancer,autoimmune or chronic pancreatitis,beyond tissue diagnosis:Collateral imaging and clinical characteristics may differentiate them

Pancreatic ductal adenocarcinoma(PDAC)is one of the most lethal malignancies and is developing into the 2nd leading cause of cancer-related death.Often,the clinical and radiological presentation of PDAC may be mirrored by other inflammatory pancreatic masses,such as autoimmune pancreatitis(AIP)and massforming chronic pancreatitis(MFCP),making its diagnosis challenging.Differentiating AIP and MFCP from PDAC is vital due to significant therapeutic and prognostic implications.Current diagnostic criteria and tools allow the precise differentiation of benign from malignant masses;however,the diagnostic accuracy is imperfect.Major pancreatic resections have been performed in AIP cases under initial suspicion of PDAC after a diagnostic approach failed to provide an accurate diagnosis.It is not unusual that after a thorough diagnostic evaluation,the clinician is confronted with a pancreatic mass with uncertain diagnosis.In those cases,a re-evaluation must be entertained,preferably by an experienced multispecialty team including radiologists,pathologists,gastroenterologists,and surgeons,looking for disease-specific clinical,imaging,and histological hallmarks or collateral evidence that could favor a specific diagnosis.Our aim is to describe current diagnostic limitations that hinder our ability to reach an accurate diagnosis among AIP,PDAC,and MFCP and to highlight those disease-specific clinical,radiological,serological,and histological characteristics that could support the presence of any of these three disorders when facing a pancreatic mass with uncertain diagnosis after an initial diagnostic approach has been unsuccessful.