Critical considerations for the management of gastrointestinal mixed neuroendocrine non-neuroendocrine neoplasms and pure neuroendocrine carcinomas

Mixed neuroendocrine non-neuroendocrine neoplasms constitute rare tumors that are located mainly in the gastrointestinal(GI)tract and have high degrees of malignancy,and the frequency of these tumors has been increasing.They consist of a neuroendocrine neoplastic component with another component of adenocarcinoma usually and have a dismal prognosis.The rare GI pure neuroendocrine carcinoma is highly aggressive and requires complex and extensive management since a genetic distinction exists between it and GI non-neuroendocrine neoplasms,which are generally slow-growing lesions.The most common GI-mixed neuroendocrine non-neuroendocrine neoplasms are colorectal,followed by gastric,mainly in the gastroesophageal junction.Current imaging modalities of nuclear medicine and radiology play important roles in the accuracy of diagnosis.Liquid biopsy may contribute to early detection and timely diagnosis.Ultrasonography,either endoscopic or abdominal,is a technique that contributes to a diagnosis;additionally,contrast-enhanced ultrasonography is very helpful in followup appointments.Histopathology establishes a definite diagnosis and stage by evaluating the cell differentiation grade and the cell proliferation index Ki67.The genetic profile can be valuable in diagnosis and gene therapy.Surgical resection with wide lymphadenectomy,whenever possible,and adjuvant chemotherapy constitute the main therapeutic management strategies.Targeted therapy and immunotherapy achieve encouraging results.

Mixed neuroendocrine and adenocarcinoma of gastrointestinal tract:A complex diagnosis and therapeutic challenge

In this editorial we comment on the manuscript describing a case of adenocarcinoma mixed with a neuroendocrine carcinoma of the gastroesophageal junction.Mixed neuroendocrine and non-neuroendocrine neoplasms of the gastrointestinal system are rare heterogeneous group of tumors characterized by a high malignant potential,rapid growth,and poor prognosis.Due to the rarity of these cancers,the standard therapy is poorly defined.The diagnosis of these tumors is based on combination of morphological features,immunohistochemical and neuroendocrine and epithelial cell markers.Both endocrine and epithelial cell components can act independently of each other and thus,careful grading of each component separately is required.These cancers are aggressive in nature and the potential of each component has paramount importance in the choice of treatment and response.Regardless of the organ of origin,these tumors portend poor prognosis with increased proportion of neuroendocrine component.Multidisciplinary services and strategies are required for the management of these mixed malignancies to provide the best oncological outcomes.The etiopathogenesis of these mixed tumors remains obscure but poses interesting question.We briefly discuss a few salient points in this editorial.

Neuroendocrine carcinoma of the common hepatic duct coexisting with distal cholangiocarcinoma:A case report and review of literature

BACKGROUND Neuroendocrine carcinoma(NEC)of the extrahepatic bile duct is very rare,and the treatment and prognosis are unclear.Herein,we report the case of a middleaged female with primary large cell NEC(LCNEC)of the common hepatic duct combined with distal cholangiocarcinoma(dCCA).Additionally,after a review of the relevant literature,we summarize and compare mixed neuroendocrine-nonneuroendocrine neoplasm(MiNEN)and pure NEC to provide a reference for selecting the appropriate treatment and predicting the prognosis of this rare disease.CASE SUMMARY A 62-year-old female presented to the hospital due to recurrent abdominal pain for 2 months.Physical examination showed mild tenderness in the upper abdomen and a positive Courvoisier sign.Blood tests showed elevated liver transaminase and carbohydrate antigen 199 levels.Imaging examination revealed node dissection was performed,and hepatic duct tumours were unexpectedly found during surgery.Pathology suggested poorly differentiated LCNEC(approximately 0.5 cm×0.5 cm×0.4 cm),Ki-67(50%),synaptophysin+,and chromogranin A+.dCCA pathology suggested moderately differentiated adenocarcinoma.The patient eventually developed lymph node metastasis in the liver,bone,peritoneum,and abdominal cavity and died 24 months after surgery.Gene sequencing methods were used to compare gene mutations in the two primary bile duct tumours.CONCLUSION The prognosis of MiNEN and pure NEC alone is different,and the selection of treatment options needs to be differentiated.

Early adenocarcinoma mixed with a neuroendocrine carcinoma component arising in the gastroesophageal junction: A case report

BACKGROUND Early adenocarcinoma mixed with a neuroendocrine carcinoma(NEC)component arising in the gastroesophageal junctional(GEJ)region is rare and even rarer in young patients.Here,we report such a case in a 29-year-old Chinese man.CASE SUMMARY This patient presented to our hospital with a 3-mo history of dysphagia and regurgitation.Upper endoscopy revealed an elevated nodule in the distal esophagus 1.6 cm above the GEJ line,without Barrett’s esophagus or involvement of the gastric cardia.The nodule was completely resected by endoscopic submu-cosal dissection(ESD).Pathological examination confirmed diagnosis of intra-mucosal adenocarcinoma mixed with an NEC component,measuring 1.5 cm.Immunohistochemically,both adenocarcinoma and NEC components were positive for P53 with a Ki67 index of 90%;NEC was positive for synaptophysin and chromogranin.Next-generation sequencing of 196 genes demonstrated a novel germline mutation of the ERCC3 gene in the DNA repair pathway and a germline mutation of the RNF43 gene,a common gastric cancer driver gene,in addition to pathogenic somatic mutations in P53 and CHEK2 genes.The patient was alive without evidence of the disease 36 mo after ESD.CONCLUSION Early adenocarcinoma with an NEC component arising in the distal esophageal side of the GEJ region showed evidence of gastric origin.

Mixed pancreatic ductal adenocarcinoma and well-differentiated neuroendocrine tumor:A case report

BACKGROUND Pancreatic mixed neuroendocrine-non-neuroendocrine neoplasms(MiNENs)are rare malignancies affecting the pancreas.The World Health Organization defines MiNENs as neoplasms composed of morphologically recognizable neuroendocrine and non-neuroendocrine components,each constituting 30%or more of the tumor volume.Adenocarcinoma-neuroendocrine carcinoma is the most frequent MiNEN combination.A well-differentiated neuroendocrine tumor(NET)component is rarely reported in MiNENs.CASE SUMMARY Here we report a rare case with intermingled components of ductal adenocarcinoma and grade 1 well-differentiated NET in the pancreas.The two tumors show distinct histology and significant differentiation discrepancy(poorly differentiated high grade adenocarcinoma and well-differentiated low grade NET),and also present as metastases in separate lymph nodes.Next generation sequencing of the two components demonstrates KRAS and TP53 mutations in the ductal adenocarcinoma,but no genetic alterations in the NET,suggesting divergent origins for these two components.Although tumors like this meet the diagnostic criteria for MiNEN,clinicians often find the diagnosis and staging confusing and impractical for clinical management.CONCLUSION Mixed NET/non-NET tumors with distinct histology and molecular profiles might be better classified as collision tumors rather than MiNENs.

Molecular features of gastroenteropancreatic neuroendocrine carcinoma: A comparative analysis with lung neuroendocrine carcinoma and digestive adenocarcinomas

Objective: There is an ongoing debate about whether the management of gastroenteropancreatic(GEP)neuroendocrine carcinoma(NEC) should follow the guidelines of small-cell lung cancer(SCLC). We aim to identify the genetic differences of GEPNEC and its counterpart.Methods: We recruited GEPNEC patients as the main cohort, with lung NEC and digestive adenocarcinomas as comparative cohorts. All patients undergone next-generation sequencing(NGS). Different gene alterations were compared and analyzed between GEPNEC and lung NEC(LNEC), GEPNEC and adenocarcinoma to yield the remarkable genes.Results: We recruited 257 patients, including 99 GEPNEC, 57 LNEC, and 101 digestive adenocarcinomas.Among the mutations, KRAS, RB1, TERT, IL7R, and CTNNB1 were found to have different gene alterations between GEPNEC and LNEC samples. Specific genes for each site were revealed: gastric NEC(TERT amplification),colorectal NEC(KRAS mutation), and bile tract NEC(ARID1A mutation). The gene disparities between small-cell NEC(SCNEC) and large-cell NEC(LCNEC) were KEAP1 and CDH1. Digestive adenocarcinoma was also compared with GEPNEC and suggested RB1, APC, and KRAS as significant genes. The TP53/RB1 mutation pattern was associated with first-line effectiveness. Putative targetable genes and biomarkers in GEPNEC were identified in22.2% of the patients, and they had longer progression-free survival(PFS) upon targetable treatment [12.5 months vs. 3.0 months, HR=0.40(0.21-0.75), P=0.006].Conclusions: This work demonstrated striking gene distinctions in GEPNEC compared with LNEC and adenocarcinoma and their clinical utility.

Clinical analysis of 12 cases of ovarian neuroendocrine carcinoma

BACKGROUND Neuroendocrine neoplasms of the female genital tract are rare.AIM To enhance our clinical understanding of neuroendocrine carcinoma(NEC)of the ovary.METHODS A retrospective review was conducted on 12 patients diagnosed with NEC of the ovary,analyzing clinicopathological characteristics,treatment modalities,and survival status.RESULTS The median age at diagnosis was 34.5 years(range:20 to 62 years).Among the 12 cases,9 were small cell carcinoma of the ovary and 3 were large cell NEC.Five cases were stage I tumors,one case was stage IV,and six cases were stage III.Eleven patients underwent surgery as part of their treatment.All patients received adjuvant chemotherapy.Among the 12 patients,one patient received radiotherapy,and one patient with a BRCA2 mutation was administered PARP inhibitor maintenance after chemotherapy.The median progression-free survival was 13 months,and the median overall survival was 19.5 months.Four cases remained disease-free,while eight cases experienced tumor recurrence,including three cases that resulted in death due to disease recurrence.CONCLUSION NEC of the ovary is a rare condition that is more common in women of childbearing age and is associated with aggressive behavior and poor clinical outcomes.Surgical resection remains the mainstay of treatment,with some patients benefiting from adjuvant chemoradiation therapy.

Primary large cell neuroendocrine carcinoma of the bladder:A case report

BACKGROUND Large cell neuroendocrine carcinoma(LCNEC)of the bladder is a rare nonurothelial tumor of the bladder.The treatment of LCNEC of the bladder is different from that of urothelial carcinoma(UC);therefore,early and accurate diagnosis is particularly important.As LCNEC of the bladder is rare and its clinical symptoms and radiographic features are similar to those of urothelial tumors,the clinical diagnosis of the disease remains challenging.CASE SUMMARY We report a 72-year-old female patient who presented with gross hematuria for 3 mo.A solitary tumor located in the anterior wall of the bladder was found by cystoscopy.Pathological examination after biopsy suggested UC of the bladder in the absence of immunohistochemical assessment.The patient underwent partial cystectomy and was finally diagnosed with LCNEC(pT2bN0M0)based on the results of postoperative immunohistochemical examination.During the 10-mo follow-up,no signs of tumor recurrence or metastasis were found.CONCLUSION Immunohistochemical examination is essential for diagnosing LCNEC of the bladder.Accurate diagnosis and multidisciplinary treatment in the early stage of the disease are crucial for improving the prognosis.

Small Cell Neuroendocrine Carcinoma of the Vulva: Case Report and Literature Review

Background: Neuroendocrine neoplasms are those that develop from a neuroendocrine cell. They most commonly affect the lungs, gastrointestinal tract, and pancreas, being rare conditions in the female genital tract. When present, these neoplasms often manifest with nonspecific signs and symptoms such as pain, itching, swelling, single-focus lesions, bleeding, and enlargement of inguinal lymph nodes, in addition to the presence of progressively enlarging vulvar nodules. Consequently, the diagnostic investigation involves histopathological examination and confirmation through immunohistochemistry. Objective: To present a comprehensive understanding of this rarely studied pathology. The primary objective is to provide valuable insights that could aid in the future development of universally applicable treatment guidelines. Case Presentation: A 57-year-old female, with no prior comorbidities, menopause at 36, who presented with a left vulvar nodule accompanied by intense pain and swelling, later diagnosed with small cell neuroendocrine carcinoma in the vulva. Conclusion: This case report highlights the importance of enhancing our knowledge regarding small cell neuroendocrine carcinoma in the vulva, given its scarcity in medical literature. The information presented here underscores the need for standardized diagnostic and treatment approaches, paving the way for future consensus on managing this uncommon but challenging neoplasm.

Large-cell neuroendocrine carcinoma of the bladder:A case report

BACKGROUND Bladder neuroendocrine tumors are few and exhibit a high degree of aggressiveness.The bladder is characterized by four distinct forms of neuroendocrine tumors.Among them,large-cell neuroendocrine carcinoma is the least prevalent,but has the highest level of aggressiveness.The 5-year survival rate for large-cell neuroendocrine carcinoma of the bladder is exceedingly poor.To date,only a few dozen cases have been reported.CASE SUMMARY Here,we report the case of a 65-year-old man with large-cell neuroendocrine carcinoma of the bladder.The patient presented to the Department of Urology at our hospital due to the presence of painless hematuria without any identifiable etiology.During hospitalization,abdominal computed tomography revealed the presence of an irregular mass on the right anterior wall of the bladder.A cystoscopic non-radical resection of the bladder lesion was performed.The postoperative pathological examination revealed large-cell neuroendocrine bladder cancer.Previous reports on cases of large-cell neuroendocrine carcinoma cases were retrieved from PubMed,and the present paper discusses the currently recognized best diagnostic and treatment options for large-cell neuroendocrine carcinoma based on the latest research progress.CONCLUSION Large-cell neuroendocrine carcinoma of the bladder is an uncommon malignancy with a highly unfavorable prognosis.Despite ongoing efforts to prolong patient survival through multidisciplinary therapy,the prognosis remains unfavorable.Large-cell neuroendocrine carcinoma continues to be a subject of uncertainty.

Cystic ductal adenocarcinoma of pancreas complicated with neuroendocrine tumor:A case report and review of literature

BACKGROUND Difficulties in making an accurate preoperative diagnosis of cystic pancreatic lesions pose a challenge for radiologists.It would be helpful to report rare cases and review the literature.CASE SUMMARY In the present report,a case of a patient with a pancreatic cystic lesion initially misdiagnosed as a pseudocyst by radiologist was documented,which was later pathologically confirmed as pancreatic ductal adenocarcinoma with neuroendocrine tumor.However,subsequent literature review yielded no previous reports of pancreatic ductal adenocarcinoma with neuroendocrine tumors and cystic lesions.Therefore,literature on the imaging diagnosis of pancreatic cystic lesions was instead reviewed and discussed.CONCLUSION Careful evaluation of the characteristics revealed by multimodal imaging techniques,medical history,laboratory examination data and follow-up observations,is critical to the diagnosis and treatment of pancreatic cystic disease.We provide valuable insights into the diagnosis of pancreatic cystic disease through a rare case report and literature review.

Primary coexisting adenocarcinoma of the colon and neuroendocrine tumor of the duodenum: A case report and review of the literature

BACKGROUND Neuroendocrine tumors(NETs)arise from the body’s diffuse endocrine system.Coexisting primary adenocarcinoma of the colon and NETs of the duodenum(D-NETs)is a rare occurrence in clinical practice.The classification and treatment criteria for D-NETs combined with a second primary cancer have not yet been determined.CASE SUMMARY We report the details of a case involving female patient with coexisting primary adenocarcinoma of the colon and a D-NET diagnosed by imaging and surgical specimens.The tumors were treated by surgery and four courses of chemothe-rapy.The patient achieved a favorable clinical prognosis.CONCLUSION Coexisting primary adenocarcinoma of the colon and D-NET were diagnosed by imaging,laboratory indicators,and surgical specimens.Surgical resection com-bined with chemotherapy was a safe,clinically effective,and cost-effective treat-ment.

Neuroendocrine carcinoma of the endometrium concomitant with Lynch syndrome:A case report

BACKGROUND Large-cell neuroendocrine carcinoma(NEC)is an uncommon type of tumor that can occur in the endometrium.This aggressive cancer requires definitive management.Here,we describe the clinical characteristics and treatment of a postmenopausal woman with large cell NEC of the endometrium.CASE SUMMARY A 55-year-old Asian female presented with a 1-year history of postmenopausal vaginal bleeding.Transvaginal ultrasound revealed a thickened endometrium(30.2 mm)and a hypervascular tumor.Computed tomography revealed that the tumor had invaded more than half of the myometrium and spread to the pelvic lymph nodes.The tumor marker,carcinoembryonic antigen,was elevated(3.65 ng/mL).Endocervical biopsy revealed high-grade endometrial carcinoma.She underwent radical hysterectomy,bilateral salpingo-oophorectomy,omentectomy,and bilateral pelvic and para-aortic lymph node dissection.Pathological examination revealed mixed neuroendocrine and endometrioid adenocarcinoma,pT2N0M0,grade 3,and International Federation of Gynecology and Obstetrics stage 2.Immunohistochemistry showed moderate estrogen and progesterone receptor expressions(20%and 1%,respectively),focal CD56 expression(NEC marker),positive staining for vimentin,p53(wild type),and ki67(90%),and loss of expression of PMS2(Lynch syndrome marker).The patient received five cycles of cisplatin and etoposide after surgery.No recurrence was noted after 5 mo.CONCLUSION We report the characteristics and successful management of a rare case of large cell endometrial NEC concomitant with Lynch syndrome.

Three-in-one incidence of hepatocellular carcinoma,cholangiocellular carcinoma,and neuroendocrine carcinoma:A case report

BACKGROUND Primary hepatic neuroendocrine carcinoma(NEC)is rare,and a combination with hepatocellular carcinoma(HCC)and cholangiocarcinoma(CCA)is extremely rare.To date,only four combination cases have been reported.The present paper describes the fifth patient.CASE SUMMARY A 32-year-old Chinese man with chronic hepatitis B was hospitalized for persistent upper abdominal pain.Abdominal computed tomography(CT)examination revealed a liver mass.The tumor was located in the 7th and 8th segments of the liver,and CT and magnetic resonance imaging findings were consistent with the diagnosis of HCC.Laboratory examinations revealed the following:Alanine aminotransferase,243 U/L;aspartate aminotransferase,167 U/L;alpha-fetoprotein,4519μg/L.Laparoscopic right lobe hepatectomy was performed on the liver mass.Postoperative pathology showed low differentiation HCC plus medium and low differentiation CCA combined with NEC.One month after the surgery,the patient suffered from epigastric pain again.Liver metastasis was detected by CT,and tumor transcatheter arterial chemoembolization was performed.Unfortunately,the liver tumor was progressively increased and enlarged,and after 1 mo,the patient died of liver failure.CONCLUSION This is a rare case,wherein the tumor is highly aggressive,grows rapidly,and metastasizes in a short period.Imaging and laboratory tests can easily misdiagnose or miss such cases;thus,the final diagnosis relies on pathology.

Hepatoid adenocarcinoma of the stomach with neuroendocrine differentiation:A case report and review of literature

BACKGROUND Both hepatoid adenocarcinoma of the stomach(HAS)and neuroendocrine differentiation(NED)are rare histological subtypes of gastric cancer with unique clinicopathological features and unfavorable outcomes.HAS with NED is even rarer.CASE SUMMARY Here,we report a 61-year-old man with HAS with NED,as detected by gastric wall thickening by positron emission tomography/computed tomography for a pulmonary nodule.Distal gastrectomy was performed,and pathological examination led to the diagnosis of HAS with NED.However,liver metastases occurred 6 mo later despite adjuvant chemotherapy,and the patient died 27 mo postoperatively.CONCLUSION We treated a patient with HAS with NED who underwent adjuvant chemotherapy after radical surgery and still developed liver metastases.We first report the detailed processes of the treatment and development of HAS with NED,providing an important reference for the clinical diagnosis and treatment of this condition.

Neuroendocrine carcinomas arising in ulcerative colitis:Coincidences or possible correlations?

Patients with inflammatory bowel disease （IBD） are at increased risk of colorectal malignancies. Adenocarcinoma is the commonest type of colorectal neoplasm associated with ulcerative colitis （UC） and Crohn＇s disease, but other types of epithelial and non-epithelial tumors have also been described in inflamed bowel. With regards to non-epithelial malignancies, lymphomas and sarcomas represent the largest group of tumors reported in association with IBD, especially in immunosuppressed patients. Carcinoids and in particular neuroendocrine neoplasms other than carcinoids （NENs） are rare tumors and are infrequently described in the setting of IBD. Thus, this association requires further investigation. We report two cases of neoplasms arising in mild left-sided UC with immuno- histochemical staining for neuroendocrine markers： a large cell and a small cell neuroendocrine carcinoma of the rectum. The two patients were different in age （35 years vs 77 years） and disease duration （11 years vs 27 years）, and both had never received immunosuppressant drugs. Although the patients underwent regular endoscopic and histological follow-up, the two neoplasms were locally advanced at diagnosis. One of the two patients developed multiple liver metastases and died 15 mo after diagnosis. These findings confirm the aggressiveness and the poor prognosis of NENs compared to colorectal adenocarcinoma. While carcinoids seem to be coincidentally associated with IBD, NENs may also arise in this setting. In fact, long-standing inflammation could be directly responsible for the development of pancellular dysplasia involving epithelial, goblet, Paneth and neuroendocrine cells. It has yet to be established which IBD patients have a higher risk of developing NENs.

Pure large cell neuroendocrine carcinoma originating from the endometrium: A case report

BACKGROUND Large cell neuroendocrine carcinoma(LCNEC)of the endometrium is an uncommon and highly aggressive tumor that has not been comprehensively characterized.We report a case of pure endometrial LCNEC and review the current literature of similar cases to raise awareness of the histological features,treatment,and prognosis of this tumor.CASE SUMMARY We report the case of a 73-year-old woman who presented with irregular postmenopausal vaginal bleeding.Ultrasonography showed an enlarged uterus and a 5.1 cm×3.3 cm area of medium and low echogenicity in the uterine cavity.Biopsy by dilatation and curettage suggested poorly differentiated carcinoma.Magnetic resonance imaging revealed a heterogeneously enhanced uterine tumor with diffuse infiltration of the posterior wall of the uterine myometrium and enlarged pelvic lymph nodes.The patient underwent a hysterectomy and bilateral adnexal resection.Gross observation revealed an ill-defined white solid mass of the posterior wall of the uterus infiltrating into the serosa with multiple solid nodules on the serous surface.Microscopically,the tumor cells showed neuroendocrine morphology(organoid nesting).Immunohistochemistry revealed the tumor cells were diffusely positive for the neuroendocrine markers CD56,chromogranin A,and synaptophysin.Thus,the tumor was diagnosed as stage IIIC endometrial LCNEC.CONCLUSION Pathologic findings and immunohistochemistry are essential in making a diagnosis of endometrial LCNEC.

Combined choriocarcinoma, neuroendocrine cell carcinoma and tubular adenocarcinoma in the stomach

We described a patient with adenocarcinoma of the stomach combined with choriocarcinoma and neuroendocrine cell carcinoma. An 85-year-old man visited our hospital because of appetite loss. Gastric fiberscopy revealed a large tumor occupying the cardial region and anterior wall of the gastric body. The patient underwent total gastrectomy with lymphnode dissection and partial resection of the liver. Choriocarcinoma, small cell carcinoma and tubular adenocarcinoma existed in the gastric tumor. The choriocarcinomatous foci contained cells positive for beta-subunit of human chorionic gonadotropin （B-hCG） and human placental lactogen mainly in syncytiotrophoblastic cells. The small cell carcinomatous loci contained cells positive for synaptophysin, neuron-specific enolase （NSE）, and chromogranin A. The prognosis for gastric adenocarcinoma with choriocarcinoma and neuroendocrine cell carcinoma is exceedingly poor. This patient died about 2 mo after the first complaint from hepatic failure. This is the first reported case of gastric cancer with these three pathological features.

Value of Texture Analysis of Intravoxel Incoherent Motion Parameters in Differential Diagnosis of Pancreatic Neuroendocrine Tumor and Pancreatic Adenocarcinoma

Objective To evaluate the value of texture features derived from intravoxel incoherent motion(IVIM) parameters for differentiating pancreatic neuroendocrine tumor(pNET) from pancreatic adenocarcinoma(PAC).Methods Eighteen patients with pNET and 32 patients with PAC were retrospectively enrolled in this study. All patients underwent diffusion-weighted imaging with 10 b values used(from 0 to 800 s/mm2). Based on IVIM model, perfusion-related parameters including perfusion fraction(f), fast component of diffusion(Dfast) and true diffusion parameter slow component of diffusion(Dslow) were calculated on a voxel-by-voxel basis and reorganized into gray-encoded parametric maps. The mean value of each IVIM parameter and texture features [Angular Second Moment(ASM), Inverse Difference Moment(IDM), Correlation, Contrast and Entropy] values of IVIM parameters were measured. Independent sample t-test or Mann-Whitney U test were performed for the betweengroup comparison of quantitative data. Regression model was established by using binary logistic regression analysis, and receiver operating characteristic(ROC) curve was plotted to evaluate the diagnostic efficiency.Results The mean f value of the pNET group were significantly higher than that of the PAC group(27.0% vs. 19.0%, P = 0.001), while the mean values of Dfast and Dslow showed no significant differences between the two groups. All texture features(ASM, IDM, Correlation, Contrast and Entropy) of each IVIM parameter showed significant differences between the pNET and PAC groups(P = 0.000-0.043). Binary logistic regression analysis showed that texture ASM of Dfast and texture Correlation of Dslow were considered as the specific imaging variables for the differential diagnosis of pNET and PAC. ROC analysis revealed that multiple texture features presented better diagnostic performance than IVIM parameters(AUC 0.849-0.899 vs. 0.526-0.776), and texture ASM of Dfast combined with Correlation of Dslow in the model of logistic regression had largest area under ROC curve for distinguishing pNET from PAC(AUC 0.934, cutoff 0.378, sensitivity 0.889, specificity 0.854). Conclusion Texture analysis of IVIM parameters could be an effective and noninvasive tool to differentiate pNET from PAC.

Pancreatic neuroendocrine tumors G3 and pancreatic neuroendocrine carcinomas: Differences in basic biology and treatment

In 2017 the World Health Organization revised the criteria for classification of pancreatic neuroendocrine neoplasms(p NENs) after a consensus conference at the International Agency for Research on Cancer. The major change in the new classification was to subclassify the original G3 group into well-differentiated pancreatic neuroendocrine tumors G3(p NETs G3) and poorly differentiated pancreatic neuroendocrine carcinomas(p NECs), which have been gradually proven to be completely different in biological behavior and clinical manifestations in recent years. In 2019 this major change subsequently extended to NENs involving the entire digestive tract. The updated version of the p NENs grading system marks a growing awareness of these heterogeneous tumors. This review discusses the clinicopathological, genetic and therapeutic features of poorly differentiated p NECs and compare them to those of well-differentiated p NETs G3. For p NETs G3 and p NECs(due to their lower incidence), there are still many problems to be investigated. Previous studies under the new grading classification also need to be reinterpreted. This review summarizes the relevant literature from the perspective of the differences between p NETs G3 and p NECs in order to deepen understanding of these diseases and discuss future research directions.