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 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.

Metastatic stomach lymphoepithelioma-like carcinoma and immune checkpoint inhibitor therapy:A case report

BACKGROUND Pulmonary lymphoepithelioma-like carcinoma(PLELC)is a rare type of nonsmall-cell lung cancer.Stomach lymphoepithelioma-like carcinoma(LELC)metastasis secondary to PLELC has not been reported recently.CASE SUMMARY A 64-year-old female was admitted to our hospital for a regular gastroscopy examination with a 6-year history of surgical resection for left PLELC.Positron emission tomography/computed tomography suggested high accumulation of 18F-fludeoxyglucose in the gastric cardia region.Upper gastrointestinal endoscopy confirmed a large mass at the stomach fundus.Immunohistochemistry(IHC)of the biopsy suggested metastatic stomach LELC.Proximal gastrectomy showed that this 6.5 cm×5.0 cm mass was located in the stomach fundus near the cardia.Histopathological examination showed a poorly differentiated carcinoma with prominent lymphoplasmacytic infiltration.IHC demonstrated that the tumor was positive for CK(AE1/AE3),p63,p40,p53,Ki-67(70%),and EGFR(3+)and negative for CK7,CK20,Her2,and CD10.In situ hybridization analysis showed positive staining Epstein-Barr virus-encoded RNA.Tumor programmed cell death ligand 1(PD-L1)expression score was 98%,and the combined positive score was 100,with no evidence of microsatellite instability.Thus,the patient was unequivocally diagnosed with metastatic stomach LELC secondary to pulmonary LELC.After discharge,this patient underwent PD-1 inhibitor treatment(toripalimab,240 mg)every 3 wk for ten cycles,and she has had no tumor recurrence.CONCLUSION For gastric LELC metastasis,PD-1 inhibitor therapy could become a new therapeutic approach,though there is still no evidence from large data sets to support this.

Underwater endoscopic mucosal resection for neoplasms in the pyloric ring of the stomach: Four case reports

BACKGROUND Tumors located in the pylorus are technically more complex to resect by endoscopic resection,as the anatomical characteristics of this region can affect the adequate assessment of margins and performance of the procedure.We reported the results of underwater endoscopic mucosal resection(UEMR)of benign mucosal neoplasms located in the pyloric ring.CASE SUMMARY This case series describes 4 patients with 4 mucosal neoplasms located in the pyloric ring.The diameter of each neoplasm was less than 15 mm.We performed UEMR for the lesions.Water immersion enabled slight floating of the lesions,resulting in easy identification.We achieved en bloc resection with a snare and electrosurgical unit.All procedure were performed within 3 min without adverse events.Pathologic examination showed low-grade dysplasia with clear resection margins in one case and hyperplastic polyps in three cases.CONCLUSION UEMR can be an effective and safe treatment method for neoplasms in the gastric pyloric ring.

Experimental study on effect of recombinant human growth hormone combined with chemotherapy on stomach neoplasms implanted in nude mice

Objective: To investigate the effect of different doses of recombined growth hormone (rhGH) on stomach neo- plasms implanted in nude mice, and its efficacy in combining with chemotherapy (flurouracil, 5-FU). Methods: Human stom- ach neoplasms model was established in nude mice. The nude mice were divided into control group, moderate-dose of rhGH group, low-dose rhGH group, 5-FU group, moderate-dose rhGH/5-FU group, and low-dose rhGH/5-FU group. The results of each group were observed after ten days. Results: After therapy, the body mass of rhGH groups was significantly increased compared with control group (P<0.05), the body mass of rhGH/5-FU groups was significantly increased compared with 5-FU group (P<0.05), but it was no significant difference between rhGH/5-FU groups and control group (P>0.05). The average tumor mass and volume of rhGH groups were not significantly increased compared with control group (P>0.05), but they were significantly reduced in 5-FU group and rhGH/5-FU groups (P<0.05). They were no significant difference between rhGH/5- FU groups and 5-FU group (P>0.05). After treatment, the percentages of S, G0/G1 and G2/M phases and proliferation index (PI) were not significantly changed in rhGH groups compared with control group (P>0.05), and the same with rhGH/5-FU groups compared with 5-FU group (P>0.05). The difference caused by dose of rhGH was not significant. Conclusion: rhGH enhances body mass, does not stimulate tumor growth, and has no adverse effects on tumor bearing nude mice. Combined with flurouracil, rhGH does not influence the efficacy of chemotherapy, and has no effect on tumor cell cycle kinetics.

Current gene therapy for stomach carcinoma

Gastric cancer is common in China [1-42],and its early diagnosis and treatment in advanced stage are difficult [31-50].In recent years ,gene study in cancer is a hotspot ,and great progress has been achieved [41-80] .Cancer gene therapy has shifted from the imagination into the laboratory and clinical trials.

Liver metastasis from hepatoid adenocarcinoma of the stomach mimicking hepatocellular carcinoma: Dynamic computed tomography findings

AIM: To evaluate the dynamic computed tomography(CT) findings of liver metastasis from hepatoid adenocarcinoma of the stomach(HAS) and compared them with hepatocellular carcinoma(HCC).METHODS: Between January 2000 and January 2015, 8 patients with pathologically proven HAS and liver metastases were enrolled. Basic tumor status was evaluated for the primary tumor location and metastatic sites. The CT findings of the liver metastases were analyzed for tumor number and size, presence of tumor necrosis, hemorrhage, venous tumor thrombosis, and dynamic enhancing pattern.RESULTS: The body and antrum were the most common site for primary HAS(n = 7), and observed metastatic sites included the liver(n = 8), lymph nodes(n = 7), peritoneum(n = 4), and lung(n = 2). Most of the liver metastases exhibited tumor necrosis regardless of tumor size. By contrast, tumor hemorrhage was observed only in liver lesions larger than 5 cm(n = 4). Three patterns of venous tumor thrombosis were identified: direct venous invasion by the primary HAS(n = 1), direct venous invasion by the liver metastases(n = 7), and isolated portal vein tumor thrombosis(n = 2). Dynamic CT revealed arterial hyperattenuation and late phase washout in all the liver metastases.CONCLUSION: On dynamic CT, liver metastasis from HAS shared many imaging similarities with HCC. For liver nodules, the presence of isolated portal vein tumor thrombosis and a tendency for tumor necrosis are imaging clues that suggest the diagnosis of HAS.

Endoscopic submucosal dissection for superficial esophageal neoplasms

Endoscopic submucosal dissection(ESD) is currently accepted as the major treatment modality for superficial neoplasms in the gastrointestinal tract including the esophagus.An important advantage of ESD is its effectiveness in resecting lesions regardless of their size and severity of fibrosis.Based on excellent outcomes for esophageal neoplasms with a small likelihood of lymph node metastasis,the number of ESD candidates has increased.On the other hand,ESD still requires highly skilled endoscopists due to technical difficulties.To avoid unnecessary complications including perforation and postoperative stricture,the indications for ESD require careful consideration and a full understanding of this modality.This article,in the highlight topic series,provides detailed information on the indication,procedure,outcome,complications and their prevention in ESD of superficial esophageal neoplasms.

Retrospective study on mixed neuroendocrine non-neuroendocrine neoplasms from five European centres

BACKGROUND Mixed neuroendocrine non-neuroendocrine neoplasm(MiNEN)is a rare diagnosis,mainly encountered in the gastro-entero-pancreatic tract.There is limited knowledge of its epidemiology,prognosis and biology,and the best management for affected patients is still to be defined.AIM To investigate clinical-pathological characteristics,treatment modalities and survival outcomes of a retrospective cohort of patients with a diagnosis of MiNEN.METHODS Consecutive patients with a histologically proven diagnosis of MiNEN were identified at 5 European centres.Patient data were retrospectively collected from medical records.Pathological samples were reviewed to ascertain compliance with the 2017 World Health Organisation definition of MiNEN.Tumour responses to systemic treatment were assessed according to the Response Evaluation Criteria in Solid Tumours 1.1.Kaplan-Meier analysis was applied to estimate survival outcomes.Associations between clinical-pathological characteristics and survival outcomes were explored using Log-rank test for equality of survivors functions(univariate)and Cox-regression analysis(multivariable).RESULTS Sixty-nine consecutive patients identified;Median age at diagnosis:64 years.Males:63.8%.Localised disease(curable):53.6%.Commonest sites of origin:colon-rectum(43.5%)and oesophagus/oesophagogastric junction(15.9%).The neuroendocrine component was;predominant in 58.6%,poorly differentiated in 86.3%,and large cell in 81.25%,of cases analysed.Most distant metastases analysed(73.4%)were occupied only by a poorly differentiated neuroendocrine component.Ninety-four percent of patients with localised disease underwent curative surgery;53%also received perioperative treatment,most often in line with protocols for adenocarcinomas from the same sites of origin.Chemotherapy was offered to most patients(68.1%)with advanced disease,and followed protocols for pure neuroendocrine carcinomas or adenocarcinomas in equal proportion.In localised cases,median recurrence free survival(RFS);14.0 months(95%CI:9.2-24.4),and median overall survival(OS):28.6 months(95%CI:18.3-41.1).On univariate analysis,receipt of perioperative treatment(vs surgery alone)did not improve RFS(P=0.375),or OS(P=0.240).In advanced cases,median progression free survival(PFS);5.6 months(95%CI:4.4-7.4),and median OS;9.0 months(95%CI:5.2-13.4).On univariate analysis,receipt of palliative active treatment(vs best supportive care)prolonged PFS and OS(both,P<0.001).CONCLUSION MiNEN is most commonly driven by a poorly differentiated neuroendocrine component,and has poor prognosis.Advances in its biological understanding are needed to identify effective treatments and improve patient outcomes.

Myoepithelial carcinoma of the stomach: A diagnostic pitfall

Myoepithelioma/myoepithelial carcinomas are not commonly found in soft tissues and are especially rare at visceral sites.This report describes a case of a rare low-grade myoepithelial carcinoma of the stomach.A61-year-old female patient presented with postprandial abdominal discomfort.Endoscopy revealed a 1.1 cm submucosal lesion.Local excision was performed after malignancy was confirmed by biopsy.The resection margin is free of tumor and she received no adjuvant therapy.The tumor was characterized by multinodular growth with biphasic epithelioid and spindle components.Infiltrative margin and nuclear pleomorphism are seen.Tumor cells were positive for both epithelial and myoepithelial markers.Evidence of epithelial differentiation was confirmed by electron microscopy.No EWSR1 rearrangement was detected.The final diagnosis was low-grade myoepithelial gastric carcinoma.The patient is currently well, and no evidence of recurrence or metastasis was found after ten-month of follow-up.Myoepithelial carcinoma should be considered in the differential diagnosis of a biphasic gastric tumor.

Extremely well-differentiated adenocarcinoma of the stomach: Clinicopathological and immunohistochemical features

AIM： Minimal deviation carcinoma of the uterine cervix, otherwise known as extremely well-differentiated adenocarcinoma （EWDA）, is characterized by its benign microscopic appearance in contrast to its aggressive behavior. In order to elucidate the clinicopathological features and biological behavior of the gastric counterpart of EWDA, we, using immunohistochemistry, analyzed nine lesions for the phenotypic expression, proliferative activity, and the expression of oncogene-associated products. METHODS： Clinicopathological features, including preoperative biopsy diagnosis, were reviewed. Using immunohitstochemistry, Ki-67 labeling index and expression of p53 and c-erbB-2 protein in the gastric lesions were detected.RESULT： Locations in the middle or upper third of the stomach and polypoid macroscopic features are characteristic of EWDA of the stomach. Although 4 of the 9 lesions showed only focal lymphatic or venous invasion, lymph node metastasis was not present and none of the patients died of the lesions （mean follow-up period, 56 too）. All 9 cases of EWDA could be classified into gastric phenotype （5 lesions） and intestinal phenotype （4 lesions）. The former resembled gastric foveolar epithelium, mucous neck cells or pyloric glands, but their papillary structures were frequently elongated and the tumor cellsand their nuclei were slightly larger and more hyperchromatic compared to normal epithelium. The latter resembled intestinal metaplasia with minimal nulcear atypia and irregular glands; two of these lesions demonstrated complete intestinal phenotype, while two demonstrated incomplete intestinal phenotype. Ki-67 labeling index was low and none of the cases revealed over-expression of p53 and c-erbB-2 protein. CONCLUSION： Unlike minimal deviation carcinoma of the cervix, these findings suggest that EWDA of the stomach is a lesion of low-grade malignancy. This favorable biological behavior is supported by the data of a low Ki-67 labeling index and a lack of p53 or c-erbB-2 protein over-expression. Because of its resemblance to normal gastric mucosa or mucosa with intestinal metaplasia, EWDA is often misdiagnosed. To prevent the misdiagnosis of such lesions, the clinical and pathologic characteristics should be taken into consideration.

Difficulty with diagnosis of malignant pancreatic neoplasms coexisting with chronic pancreatitis

Chronic pancreatitis is a relatively common disease. We encountered two different cases of belatedly demonstrated pancreatic carcinoma featuring underlying chronic pancreatitis. The first case was one that was highly suspected as that of a malignancy based upon imaging study, but unfortunately, it could not be confirmed by intra-operative cytology at that time. Following this, the surgeon elected to perform only conservative bypass surgery for obstructive biliary complication. Peritoneal carcinomatosis was later noted and the patient finally died. The second case, a malignant mucinous neoplasm,was falsely diagnosed as a pseudocyst, based upon the lesion's sonographic appearance and associated elevated serum amylase levels. After suffering repeated hemoptysis,the patient was found to exhibit lung metastasis and peritoneal seeding. We reviewed some of the literature,including those studies discussing chronic pancreatitis predisposing to a malignant change. These two case analyses illustrate clearly that the diagnosis for such conditions, which is simply based upon imagery or pathological considerations may end up being one of a mistaken malignancy. Some of our suggestions for the treatment of such malignancies as revealed herein include,total pancreatomy for univocal mass lesion, and needle aspiration of lesion-contained tissue for amylase, CA199and CEA levels for a suspicious cystic pancreatic mass.

Mixed neuroendocrine-non-neuroendocrine neoplasms of the digestive system:A mini-review

Mixed neuroendocrine-non-neuroendocrine neoplasms(MiNENs)are rare mixed tumors containing both neuroendocrine(NE)and non-NE components.Each component must occupy at least 30%of the tumor volume by definition.Recent molecular evidence suggests MiNENs are clonal neoplasms and potentially harbor targetable mutations similar to conventional carcinomas.There have been multiple changes in the nomenclature and classification of MiNENs which has created some confusion among pathologists on how to integrate the contributions of each component in a MiNEN,an issue which in turn has resulted in confusion in communication with front-line treating oncologists.This mini review summarizes our current understanding of MiNENs and outline diagnosis,prognosis,and management of these neoplasms.The authors emphasize the importance of treating the most aggressive component of the tumor regardless of its percentage volume.

Clinicopathological features and prognostic factors associated with gastroenteropancreatic mixed neuroendocrine non-neuroendocrine neoplasms in Chinese patients

BACKGROUND The incidence of mixed neuroendocrine-non-neuroendocrine neoplasms(MiNEN)is low.To improve our understanding of this rare tumor type and optimally guide clinical treatment,associated risk factors,clinical manifestations,and prognosis must be explored.AIM To identify risk factors that influence the prognosis of patients with gastroenteropancreatic MiNEN(GEP-MiNEN).METHODS We retrospectively analyzed the clinical data of 46 patients who were diagnosed with GEP-MiNEN at the First Affiliated Hospital of Bengbu Medical College(Anhui,China)between January 2013 and December 2017.Risk factors influencing the prognosis of the patients were assessed using Kaplan-Meier curves and cox regression models.We compared the results with 55 randomly selected patients with gastroenteropancreatic GEP neuroendocrine tumors,47 with neuroendocrine carcinomas(NEC),and 58 with poorly differentiated adenocarcinoma.RESULTS Among the 46 patients with GEP-MiNEN,thirty-five had gastric tumors,nine had intestinal tumors(four in the small intestine and five in the colon and rectum),and two had pancreatic tumors.The median age of the patients was 66(41-84)years,and the male-to-female ratio was 2.83.Thirty-three(71.7%)patients had clinical stage III and IV cancers.Distant metastasis occurred in 14 patients,of which 13 had metastasis to the liver.The follow-up period was 11-72 mo,and the median overall survival was 30 mo.Ki-67 index≥50%,high proportion of NEC,lymph node involvement,distant metastasis,and higher clinical stage were independent risk factors affecting the prognosis of patients with GEP-MiNEN.The median overall survival was shorter for patients with NEC than for those with MiNEN(14 mo vs 30 mo,P=0.001),but did not significantly differ from those with poorly differentiated adenocarcinoma and MiNEN(30 mo vs 18 mo,P=0.453).CONCLUSION A poor prognosis is associated with rare,aggressive GEP-MiNEN.Ki-67 index,tumor composition,lymph node involvement,distant metastasis,and clinical stage are important factors for patient prognosis.

Mixed epithelial endocrine neoplasms of the colon and rectum–An evolution over time:A systematic review

BACKGROUND Mixed tumors of the colon and rectum,composed of a combination of epithelial and endocrine elements of benign and malignant potential are rare neoplasms.These can occur anywhere in the gastrointestinal tract and are often diagnosed incidentally.Though they have been a well-documented entity in the pancreas,where the exocrine-endocrine mixed tumors have been known for a while,recognition and accurate diagnosis of these tumors in the colon and rectum,to date,remains a challenge.This is further compounded by the different terminologies that have been attributed to these lesions over the years adding to increased confusion and misclassification.Therefore,dedicated literature reviews of these lesions in the colon and rectum are inconsistent and are predominantly limited to case reports and case series of limited case numbers.Though,most of these tumors are high grade and of advanced stage,intermediate and low grade lesions of these mixed tumors are also increasingly been reported.There are no established independent consensus based guidelines for the therapeutic patient management of these unique lesions.AIM To provide a comprehensive targeted literature review of these complex mixed tumors in the colon and rectum that chronicles the evolution over time with summarization of historical perspectives of terminology and to further our understanding regarding their pathogenesis including genomic landscape,clinicoradiological features,pathology,treatment,prognosis,the current status of the management of the primary lesions,their recurrences and metastases.METHODS A comprehensive review of the published English literature was conducted using the search engines PubMed,MEDLINE and GOOGLE scholar.The following search terms[“mixed tumors colon”OR mixed endocrine/neuroendocrine tumor/neoplasm/lesion colon OR adenocarcinoma and endocrine/neuroendocrine tumor colon OR mixed adenocarcinoma and endocrine/neuroendocrine carcinoma colon OR Amphicrine tumors OR Collision tumors]were used.Eligibility criteria were defined and all potential relevant items,including full articles and/or abstracts were independently reviewed,assessed and agreed upon items were selected for in-depth analysis.RESULTS In total 237 full articles/abstracts documents were considered for eligibility of which 45 articles were illegible resulting in a total of 192 articles that were assessed for eligibility of which 139 have been selected for reference in this current review.This seminal manuscript is a one stop article that provides a detailed outlook on the evolution over time with summarization of historical perspectives,nomenclature,clinicoradiological features,pathology,treatment,prognosis and the current status of the management of both the primary lesions,their recurrences and metastases.Gaps in knowledge have also been identified and discussed.An important outcome of this manuscript is the justified proposal for a new,simple,clinically relevant,non-ambiguous terminology for these lesions to be referred to as mixed epithelial endocrine neoplasms(MEENs).CONCLUSION MEEN of the colon and rectum are poorly understood rare entities that encompass an extensive range of heterogeneous tumors with a wide variety of combinations leading to tumors of high,intermediate or low grade malignant potential.This proposed new revised terminology of MEEN will solve the biggest hurdle of confusion and misclassification that plagues these rare unique colorectal neoplasms thus facilitating the future design of multi institutional prospective randomized controlled clinical trials to develop and evaluate newer therapeutic strategies that are recommended for continued improved understanding and personal optimization of clinical management of these unique colorectal neoplasms.

Intraductal papillary neoplasm of the bile duct in liver cirrhosis with hepatocellular carcinoma

A case of intraductal papillary neoplasm of the bile duct (IPNB) arising in a patient with hepatitis B-related liver cirrhosis with hepatocellular carcinoma (HCC) is reported. A 76-year-old man was admitted to our hospital with recurrent HCC. Laboratory data showed that levels of carcinoembryonic antigen and carbohydrate antigen 19-9 were elevated. He died of progressive hepatic failure. At autopsy,in addition to HCCs,an intraductal papillary proliferation of malignant cholangiocytes with fibrovascular cores was found in the dilated large bile ducts in the left lobe,and this papillary carcinoma was associated with an invasive mucinous carcinoma (invasive IPNB). Interestingly,extensive intraductal spread of the cholangiocarcinoma was found from the reactive bile ductular level to the interlobular bile ducts and septal bile ducts and to the large bile ducts in the left lobe. Neural cell adhesion molecule,a hepatic progenitor cell marker,was detected in IPNB cells. It seems possible in this case that hepatic progenitor cells located in reactive bile ductules in liver cirrhosis may have been responsible for the development of the cholangiocarcinoma and HCC,and that the former could have spread in the intrahepatic bile ducts and eventually formed grossly visible IPNB.

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.

Mixed neuroendocrine–nonneuroendocrine neoplasms of the gastrointestinal system:An update

Mixed neuroendocrine-nonneuroendocrine neoplasms(Mi NENs)of the digestive tract are a rare heterogeneous group of tumors that present many challenges in terms of diagnosis and treatment.Over the years,the diagnostic criteria,classification,and clinical behavior of these tumors have been the subjects of ongoing debate,and the various changes in their nomenclature have strengthened the challenges associated with Mi NENs.This review is performed to provide an understanding of the key factors involved in the evolution of the designation of these tumors as Mi NEN,highlight the current diagnostic criteria,summarize the latest data on pathogenesis and provide information on available treatments.Moreover,this work seeks to increase the awareness about these rare neoplasms by presenting the clinicopathological features and prognostic factors that play important roles in their behavior and discussing their different regions of origin in the gastrointestinal system(GIS).Currently,the Mi NEN category also includes tumors in the GIS with a nonneuroendocrine component and epithelial tumors other than adenocarcinoma,depending on the organ of origin.Diagnosis is based on the presence of both morphological components in more than 30%of the tumor.However,this value needs to be reconfirmed with further studies and may be a limiting factor in the diagnosis of Mi NEN by biopsy.Furthermore,available clinicopathological data suggest that the inclusion of amphicrine tumors in the definition of Mi NEN is not supportive and warrants further investigation.The diagnosis of these tumors is not solely based on immunohistochemical findings.They are not hybrid tumors and both components can act independently;thus,careful grading of each component separately is required.In addition to parameters such as the metastatic state of the tumor at the time of diagnosis and the feasibility of surgical resection,the aggressive potential of both components has paramount importance in the choice of treatment.Regardless of the organ of origin within the GIS,almost Mi NENs are tumors with poor prognosis and are frequently encountered in the elderly and men.They are most frequently reported in the colorectum,where data from molecular studies indicate a monoclonal origin;however,further studies are required to provide additional support for this origin.

Gastroenteropancreatic neuroendocrine neoplasms:A clinical snapshot

Our understanding about the epidemiological aspects,pathogenesis,molecular diagnosis,and targeted therapies of neuroendocrine neoplasms(NENs)have drastically advanced in the past decade.Gastroenteropancreatic(GEP)NENs originate from the enteroendocrine cells of the embryonic gut which share common endocrine and neural differentiation factors.Most NENs are welldifferentiated,and slow growing.Specific neuroendocrine biomarkers that are used in the diagnosis of functional NENs include insulin,glucagon,vasoactive intestinal polypeptide,gastrin,somatostatin,adrenocorticotropin,growth hormone releasing hormone,parathyroid hormone-related peptide,serotonin,histamine,and 5-hydroxy indole acetic acid(5-HIAA).Biomarkers such as pancreatic polypeptide,human chorionic gonadotrophin subunits,neurotensin,ghrelin,and calcitonin are used in the diagnosis of non-functional NENs.5-HIAA levels correlate with tumour burden,prognosis and development of carcinoid heart disease and mesenteric fibrosis,however several diseases,medications and edible products can falsely elevate the 5-HIAA levels.Organ-specific transcription factors are useful in the differential diagnosis of metastasis from an unknown primary of well-differentiated NENs.Emerging novel biomarkers include circulating tumour cells,circulating tumour DNA,circulating micro-RNAs,and neuroendocrine neoplasms test(NETest)(simultaneous measurement of 51 neuroendocrine-specific marker genes in the peripheral blood).NETest has high sensitivity(85%-98%)and specificity(93%-97%)for the detection of gastrointestinal NENs,and is useful for monitoring treatment response,recurrence,and prognosis.In terms of management,surgery,radiofrequency ablation,symptom control with medications,chemotherapy and molecular targeted therapies are all considered as options.Surgery is the mainstay of treatment,but depends on factors including age of the individual,location,stage,grade,functional status,and the heredity of the tumour(sporadic vs inherited).Medical management is helpful to alleviate the symptoms,manage inoperable lesions,suppress postoperative tumour growth,and manage recurrences.Several molecular-targeted therapies are considered second line to somatostatin analogues.This review is a clinical update on the pathophysiological aspects,diagnostic algorithm,and management of GEP NENs.

Simultaneous large cell neuroendocrine carcinoma and adenocarcinoma of the stomach

A large cell neuroendocrine carcinoma(LCNEC) of the stomach is very rare.A 76-year-old Japanese man was admitted to our hospital because of epigastralgia and nausea.Endoscopy revealed 2 large tumors in the stomach.He did not have multiple endocrine neoplasia typeⅠor Zollinger-Ellison syndrome.Imaging modalities,including computed tomography and magnetic resonance imaging,revealed no other tumors.Gastrectomy,cholecystectomy,and lymph node dissection were performed.The resected stomach had 2 tumors:one was an antral ulcerated type 3 tumor measuring 5 cm x 5 cm,and the other was a polypoid type 1 tumor measuring 6 cm x 6 cm x 3 cm in the fundus.Microscopically,the antral ulcerated tumor was a well differentiated adenocarcinoma with deep invasion.The fundus polypoid tumor was a LCNEC,being composed of malignant large cells arranged in trabecular and nested patterns.The tumor cells were large and the nuclei were vesicular.Nucleoli were frequently present,and there were many mitotic figures,apoptotic bodies,and necrotic areas.Much lymphovascular permeation was seen.Seven out of 29 dissected lymph nodes showed metastatic foci;6 were from the LCNEC and 1 from theadenocarcinoma.Many intravascular tumor emboli of LCNEC were seen in the peritoneum around the lymph nodes.Mucins were present in the adenocarcinoma but not in the LCNEC.Immunohistochemically,the LCNEC tumor cells were positive for pancytokeratins,synaptophysin(50%positive) ,chromogranin A(10% positive) ,Ki-67(90%labeled) ,and platelet-derived growth factor-α(80%positive) .They were negative for KIT,p53,CD56,and neuron-specific enolase.The non-cancerous stomach showed a normal number of endocrine cells.The patient is now treated with adjuvant chemotherapy.