Endoscopic treatment and management of rectal neuroendocrine tumors less than 10 mm in diameter

Rectal neuroendocrine tumors(rNETs)measuring less than 10 mm in diameter are defined as small rNETs.Due to the low risk of distant invasion and metastasis,endoscopic treatments,including modified endoscopic mucosal resection,endoscopic submucosal dissection,and other transanal surgical procedures,are effective.This review article proposes a follow-up plan according to the size and histopathology of the tumor after operation.

Is lymphatic invasion of microrectal neuroendocrine tumors an incidental event?:A case report

BACKGROUND A rectal neuroendocrine tumor(rNET)is a malignant tumor originating from neuroendocrine cells.Currently,tumor size is the primary basis for assessing tumor risk.CASE SUMMARY This article reports the case of a 46-year-old male patient who underwent a colonoscopy that found a 3 mm rectal polypoid bulge.The pathological examination of a sample collected with biopsy forceps revealed a neuroendocrine tumor.Further endoscopic submucosal dissection rescue therapy was used.The presence of lymphatic vessels indicated that the tumor had infiltrated the negative resection margin.The lesion was located in the distal rectum near the anal canal.Therefore,to ensure the patient’s quality of life,follow-up observation was conducted after full communication with the patient.No tumor recurrence or distant metastasis has been found during the 13-mo follow-up after surgery.CONCLUSION Despite the presence of lymphatic invasion and extremely small diameter rNETs in our case,this phenomenon may not imply a higher risk of distant lymph node and organ metastasis.

Endoscopic mucosal resection with double band ligation versus endoscopic submucosal dissection for small rectal neuroendocrine tumors

BACKGROUND Endoscopic resection remains an effective method for the treatment of small rectal neuroendocrine tumors(NETs)(≤10 mm).Moreover,endoscopic mucosal resection(EMR)with double band ligation(EMR-dB),a simplified modification of EMR with band ligation,is an alternative strategy to remove small rectal NETs.AIM To evaluate the feasibility and safety of EMR-dB for the treatment of small rectal NETs(≤10 mm).METHODS A total of 50 patients with small rectal NETs,without regional lymph node enlargement or distant metastasis confirmed by endoscopic ultrasound,computerized tomography scan,or magnetic resonance imaging,were enrolled in the study from March 2021 to June 2022.These patients were randomly assigned into the EMR-dB(n=25)group or endoscopic submucosal dissection(ESD)group(n=25).The characteristics of the patients and tumors,procedure time,devices cost,complete resection rate,complications,and recurrence outcomes were analyzed.RESULTS There were 25 patients(13 males,12 females;age range 28-68 years old)in the EMR-dB group,and the ESD group contained 25 patients(15 males,10 females;age range 25-70 years old).Both groups had similar lesion sizes(EMR-dB 4.53±1.02 mm,ESD 5.140±1.74 mm;P=0.141)and resected lesion sizes(1.32±0.52 cm vs 1.58±0.84 cm;P=0.269).Furthermore,the histological complete resection and en bloc resection rates were achieved in all patients(100%for each).In addition,there was no significant difference in the complication rate between the two groups.However,the procedure time was significantly shorter and the devices cost was significantly lower in the EMRdB group.Besides,there was no recurrence in both groups during the follow-up period.CONCLUSION The procedure time of EMR-dB was shorter compared with ESD,and both approaches showed a similar curative effect.Taken together,EMR-dB was a feasible and safe option for the treatment of small rectal NETs.

Is endoscopic ultrasonography essential for endoscopic resection of small rectal neuroendocrine tumors?

AIM To evaluate the importance of endoscopic ultrasonography(EUS) for small(≤ 10 mm) rectal neuroendocrine tumor(NET) treatment.METHODS Patients in whom rectal NETs were diagnosed by endoscopic resection(ER) at the Pusan National University Yangsan Hospital between 2008 and 2014 were included in this study. A total of 120 small rectal NETs in 118 patients were included in this study. Histologic features and clinical outcomes were analyzed, and the findings of endoscopy, EUS and histology were compared. RESULTS The size measured by endoscopy was not significantly different from that measured by EUS and histology(r = 0.914 and r = 0.727 respectively). Accuracy for the depth of invasion was 92.5% with EUS. No patients showed invasion of the muscularis propria or metastasis to the regional lymph nodes. All rectal NETswere classified as grade 1 and demonstrated an L-cell phenotype. Mean follow-up duration was 407.54 ± 374.16 d. No patients had local or distant metastasis during the follow-up periods. CONCLUSION EUS is not essential for ER in the patient with small rectal NETs because of the prominent morphology and benign behavior.

Rectal neuroendocrine tumors:Current advances in management,treatment,and surveillance

Rectal neuroendocrine neoplasms(r-NENs)are considered among the most frequent digestive NENs,together with small bowel NENs.Their incidence has increased over the past few years,and this is probably due to the widespread use of endoscopic screening for colorectal cancer and the advanced endoscopic procedures available nowadays.According to the current European Neuroendocrine Tumor Society(ENETS)guidelines,well-differentiated r-NENs smaller than 10 mm should be endoscopically removed in view of their low risk of local and distant invasion.R-NENs larger than 20 mm are candidates for surgical resection because of their high risk of distant spreading and the involvement of the muscularis propria.There is an area of uncertainty regarding tumors between 10 and 20 mm,in which the metastatic risk is intermediate and the endoscopic treatment can be challenging.Once removed,the indications for surveillance are scarce and poorly codified by international guidelines,therefore in this paper,a possible algorithm is proposed.

Characteristics and long-term prognosis of patients with rectal neuroendocrine tumors

AIM: To analyze the clinicopathologic characteristics and prognostic factors of rectal neuroendocrine tumors.

Clinical impact of atypical endoscopic features in rectal neuroendocrine tumors

AIM: To validate the association between atypical endoscopic features and lymph node metastasis(LNM).METHODS: A total of 247 patients with rectal neuroendocrine tumors(NETs) were analyzed. Endoscopic images were reviewed independently by two endoscopists, each of whom classified tumors by sized and endoscopic features, such as shape, color, and surface change(kappa coefficient 0.76 for inter-observer agreement). All of patients underwent computed tomography scans of abdomen and pelvis for evaluation of LNM. Univariate and multivariate analyses were performed to identify the factors associated with LNM. Additionally, the association between endoscopic atypical features and immunohistochemical staining of tumors was analyzed.RESULTS: Of 247 patients, 156(63.2%) were male and 15(6.1%) were showed positive for LNM. On univariate analysis, tumor size(P < 0.001), shape(P < 0.001), color(P < 0.001) and surface changes(P < 0.001) were significantly associated with LNM. On multivariate analysis, tumor size(OR = 11.53, 95%CI: 2.51-52.93, P = 0.002) and atypical surface(OR = 27.44, 95%CI: 5.96-126.34, P < 0.001) changes were independent risk factors for LNM. The likelihood of atypical endoscopic features increased as tumor size increased. Atypical endoscopic features were associated with LNM in rectal NETs < 10 mm(P = 0.005) and 10-19 mm(P = 0.041) in diameter. Immunohistochemical staining showed that the rate of atypical endoscopic features was higher in non L-cell tumors.CONCLUSION: Atypical endoscopic features as well as tumor size are predictive factors of LNM in patients with rectal NETs.

Neurofibromatosis type 1-associated multiple rectal neuroendocrine tumors: A case report and review of the literature

Neurofibromatosis type 1(NF-1) is commonly associated with benign or malignant tumors in both the central and peripheral nervous systems. However, rare cases of NF-1-associated multiplerectal neuroendocrine tumors have been reported. This report describes a case of a 39 year old female with NF-1 and intermittent hematochezia as a primary symptom. Physical examination showed multiple subcutaneous nodules and café au lait spots with obvious scoliosis of the back. Imaging examinations and colonoscopy found malformation of the left external iliac vein and multiple gray-yellow nodules with varying sizes and shapes in the rectal submucosal layer. Histological and immunohistochemical results suggested multiple rectal neuroendocrine tumors, a rare disease with few appreciable symptoms and a particularly poor prognosis. The patient with NF-1 presented here had not only multiple rectal neuroendocrine neoplasms but also vascular malformations, scoliosis and other multiple system lesions. This case therefore contributes to improving clinical understanding, diagnosis and treatment of related complications for patients with NF-1 who present with associated medical conditions.

Rectal neuroendocrine tumor with uncommon metastatic spread:A case report and review of literature

Neuroendocrine tumors of the gastrointestinal tract are rare neoplasms. Rectal neuroendocrine tumors consist approximately the 5%-14% of all neuroendocrine neoplasms in Europe. These tumors are diagnosed in relatively young patients,with a mean age at diagnosis of 56 years. Distant metastases from rectal neuroendocrine tumors are not very common. Herein we describe a case of a rectal neuroendocrine tumor which metastasized to the lung,mediastinum and orbit. This case underscores the importance of early identification and optimal management to improve patient's prognosis. Therefore,the clinical significance of this case is the necessity of physicians' awareness and education regarding neuroendocrine tumors' diagnosis and management.

Full-thickness excision using transanal endoscopic microsurgery for treatment of rectal neuroendocrine tumors

AIM:To assess the efficacy of full-thickness excision using transanal endoscopic microsurgery(TEM) in the treatment of rectal neuroendocrine tumors.METHODS:We analyzed the data of all rectal neuroendocrine tumor patients who underwent local full-thickness excision using TEM between December 2006 and December 2014 at our department. Data collected included patient demographics,tumor characteristics,operative details,postoperative outcomes,pathologic findings,and follow-ups. RESULTS:Full-thickness excision using TEM was performed as a primary excision(n = 38) or as complete surgery after incomplete resection by endoscopic polypectomy(n = 21). The mean size of a primary tumor was 0.96 ± 0.21 cm,and the mean distance of the tumor from the anal verge was 8.4 ± 1.4 cm. The mean duration of the operation was 57.6 ± 13.7 min,and the mean blood loss was 13.5 ± 6.6 m L. No minor morbidities,transient fecal incontinence,or wound dehiscence was found. Histopathologically,all tumors showed typical histology without lymphatic or vessel infiltration,and both deep and lateral surgical margins were completely free of tumors. Among 21 cases of complete surgery after endoscopic polypectomy,9 were histologically shown to have a residual tumor in the specimens obtained by TEM. No additional radical surgery was performed. Norecurrence was noted during the median of 3 years' follow-up.CONCLUSION:Full-thickness excision using TEM could be a first surgical option for complete removal of upper small rectal neuroendocrine tumors.

Radical Operation and Everolimus Therapy for Rectal Neuroendocrine Tumor with Liver Metastases: A Case Report with Review of the Literature

Neuroendocrine tumors (NETs) are often misdiagnosed because they can involve any part of the body and have non-specific symptoms. Here, we report a case of a 39-year-old man with rectal neuroendocrine tumor (RNET) and hepatic metastases treated with a combination of radical surgery and Everolimus therapy. The patient complained of abdominal distension, pain, and constipation of one month duration. Enhanced CT scan of the abdomen, colonoscopy and Biopsy findings confirmed the diagnosis of rectal neuroendocrine tumor. As the anatomical structures were clear and the masses seemed to be resectable, we decided to initiate treatment with radical operation and Everolimus therapy. The patient has responded well to the treatment with no evidence of recurrence after 4 years of follow-up. This case is interesting because of the rarity of this neoplasm and its initial misdiagnosis as a giant hepatic carcinoma (hepatoma). It also demonstrates that a combination of curative surgical resection and Everolimus is a good option in a patient with large colorectal neuroendocrine tumors and massive hepatic metastases.

Risk factors of lymph node metastasis in rectal neuroendocrine tumors

Objective The aim of this study was to investigate the risk factors of lymph node metastasis in rectal neuroendocrine neoplasms(RNENs).Methods We enrolled 168 patients with RNENs as the research object,and their clinicopathological and survival data were collected.The risk factors affecting lymph node metastasis were analyzed retrospectively,and independent risk factors affecting prognosis were evaluated.Results Analysis showed that age,tumor diameter,tumor function,grade,and T stage were correlated with lymph node metastasis(P<0.05).Multiple logistic regression analysis showed that tumor size,grade,and T stage were independent risk factors for lymph node metastasis in patients with RNENs.Kaplan-Meier analysis showed that the 5-year overall survival(OS)of patients with lymph node metastasis was 40.0%(10/25),and that of patients without lymph node metastasis was 93.0%(133/143).The prognosis of RNENs patients with lymph node metastasis along with patients with large tumor diameter and high grade was poor.Cox multivariate analysis showed that tumor diameter(HR=1.985,P=0.008),grade(HR=3.416,P=0.004),T stage(HR=2.413,P=0.014),and lymph node metastasis(HR=3.119,P=0.000)were independent risk factors affecting the prognosis of patients with RNENs.Conclusion Tumor size,grade,and T stage are the main risk factors for lymph node metastasis and prognosis in patients with RNENs.These risk factors should be fully evaluated before surgery.

Gastrointestinal neuroendocrine tumors in 2020

Gastrointestinal neuroendocrine tumors are rare slow-growing tumors with distinct histological,biological,and clinical characteristics that have increased in incidence and prevalence within the last few decades.They contain chromogranin A,synaptophysin and neuron-specific enolase which are necessary for making a diagnosis of neuroendocrine tumor.Ki-67 index and mitotic index correlate with cellular proliferation.Serum chromogranin A is the most commonly used biomarker to assess the bulk of disease and monitor treatment and is raised in both functioning and non-functioning neuroendocrine tumors.Most of the gastrointestinal neuroendocrine tumors are non-functional.World Health Organization updated the classification of neuroendocrine tumors in 2017 and renamed mixed adenoneuroendocrine carcinoma into mixed neuroendocrine neoplasm.Gastric neuroendocrine tumors arise from enterochromaffin like cells.They are classified into 4 types.Only type I and type II are gastrin dependent.Small intestinal neuroendocrine tumor is the most common small bowel malignancy.More than two-third of them occur in the terminal ileum within 60 cm of ileocecal valve.Patients with small intestinal neuroendrocrine tumors frequently show clinical symptoms and develop distant metastases more often than those with neuroendocrine tumors of other organs.Duodenal and jejunoileal neuroendocrine tumors are distinct biologically and clinically.Carcinoid syndrome generally occurs when jejuno-ileal neuroendocrine tumors metastasize to the liver.Appendiceal neuroendocrine tumors are generally detected after appendectomy.Colonic neuroendocrine tumors generally present as a large tumor with local or distant metastasis at the time of diagnosis.Rectal neuroendocrine tumors are increasingly being diagnosed since the implementation of screening colonoscopy in 2000.Gastrointestinal neuroendocrine tumors are diagnosed and staged by endoscopy with biopsy,endoscopic ultrasound,serology of biomarkers,imaging studies and functional somatostatin scans.Various treatment options are available for curative and palliative treatment of gastrointestinal neuroendocrine tumors.

Long-term complete response in metastatic poorly-differentiated neuroendocrine rectal carcinoma with a multimodal approach: A case report

BACKGROUND Neuroendocrine gastrointestinal tumors(NETs)are rare and have different natural behaviors.Surgery is the gold standard treatment for local disease while radiotherapy has been demonstrated to be ineffective.Poorly differentiated neuroendocrine carcinomas(NECs)represent only 5%-10%of digestive NETS.Due to aggressive growth and rapid metastatic diffusion,early diagnosis and a multidisciplinary approach are mandatory.The role of surgery and radiotherapy in this setting is still debated,and chemotherapy remains the treatment of choice.CASE SUMMARY A 42-year-old male with an ulcerated bleeding rectal lesion was diagnosed with a NEC G3(Ki67 index>90%)on May 2015 and initially treated with 3 cycles of first-line chemotherapy,but showed early local progressive disease at 3 mo and underwent sphincter-sparing open anterior low rectal resection.In September 2015,the first post-surgery total-body computed tomography(CT)scan showed an early pelvic disease relapse.Therefore,systemic chemotherapy with FOLFIRI was started and the patient obtained only a partial response.This was followed by pelvic radiotherapy(50 Gy).On April 2016,a CT scan and 18F-fluorodeoxy-glucose positron emission tomography imaging showed a complete response(CR)of the pelvic lesion,but pathological abdominal inter-aortocaval lymph nodes were observed.Due to disease progression of abdominal malignant nodes,the patient received radiotherapy at 45 Gy,and finally obtained a CR.As of January 2021,the patient has no symptoms of relapse and no late toxicity after chemotherapy or radiotherapy.CONCLUSION This case demonstrates how a multimodal approach can be successful in obtaining long-term CR in metastatic sites in patients with high grade digestive NECs.

直肠肛管区特殊类型肿瘤的诊治进展

直肠肛管区存在诸如直肠神经内分泌肿瘤、胃肠间质瘤、肛管鳞癌、直肠肛管黑色素瘤、原发性直肠淋巴瘤等特殊类型肿瘤,其临床特征与直肠癌存在差异,且发病率较低,导致临床医师对其认识不足。本文对直肠肛管区特殊类型肿瘤的临床诊疗进展进行综述。

Risk factors and clinical outcomes of incomplete endoscopic resection of small rectal neuroendocrine tumors in southern China:a 9-year data analysis

Background:The histologically complete resection(CR)rate of small rectal neuroendocrine tumors(RNETs)is unsatisfactory at the first endoscopy.Risk factors and clinical outcomes associated with incomplete resection(IR)have not been explicitly elucidated.This study aims to explore the relevant factors of IR.Methods:This retrospective study reviewed patients with small RNETs(10mm)in eight centers from January 2013 to December 2021.Clinicopathological characteristics and clinical outcomes were compared between the CR and IR groups,and the polypectomy and advanced treatment groups.Results:Of the 326 patients included,83(25.5%)were diagnosed with IR.Polypectomy(odds ratio[OR]=16.86),a central depression(OR=7.50),and treatment in the early period(OR=2.60)were closely associated with IR.Further analysis revealed that an atypical hyperemic appearance(OR=7.49)and treatment in the early period(OR=2.54)were significantly associated with the inappropriate use of polypectomy(both P<0.05).In addition,a total of 265(81.3%)were followed up with a median follow-up period of 30.9 months.No death,metastasis,or recurrence was found during the follow-up period.Conclusions:Polypectomy,a central depression,and treatment in the early period were risk factors for IR.Further,an atypical hyperemic appearance and treatment in the early period were significant predisposing factors for inappropriate choice of polypectomy.For histologically incompletely resected small RNETs,follow-up may be a safe and feasible alternative to rigorous salvage therapy.

直肠神经内分泌肿瘤的内镜精查特征及内镜下切除治疗效果

目的探讨直肠神经内分泌肿瘤的内镜精查特征,并观察患者接受内镜下切除治疗的效果及安全性。方法选取2020年1月至2024年1月在新乡医学院第一附属医院接受治疗的60例直肠神经内分泌肿瘤患者,记录患者的内镜精查特征。采用信封法对患者进行分组:30例患者接受内镜下黏膜剥离术(ESD)治疗,纳入ESD组,30例患者接受内镜下黏膜切除术(EMR)治疗,纳入EMR组,比较其病变切除情况、临床手术资料、生存质量及并发症发生情况。结果60例直肠神经内分泌肿瘤患者中男性占比较高,年龄多为60岁以下,肿瘤多大于5 mm,距离肛门位置较远,WHO分类为G1级。ESD组治愈性切除率及整块切除率均高于EMR组(P<0.05),但组间基底病灶残余率差异无统计学意义(P>0.05)。ESD组手术时间、术后住院时间长于EMR组,创面直径大于EMR组(P<0.05),但组间切除标本直径及厚度差异无统计学意义(P>0.05)。治疗前两组生活质量评分差异无统计学意义(P>0.05),治疗后7 d两组生活质量评分均较治疗前降低,且ESD组低于EMR组(P<0.05)。两组术后迟发性出血、穿孔、皮下气肿、局部复发及感染的发生率差异无统计学意义(P>0.05)。结论直肠神经内分泌肿瘤患者多数年龄<60岁,男性占比较高,肿瘤多数≥5 mm,距离肛门位置多数≥5 cm以及免疫组化结果显示Syn阳性患者占比较高;ESD治疗可提高治愈性切除率、整块切除率及生存质量,但患者的手术时间、术后住院时间较EMR延长,创面直径较大,因此应根据临床实际灵活选择治疗方案。

内镜超声检查指导下内镜黏膜下剥离术治疗直肠神经内分泌肿瘤患者的临床研究

目的探讨内镜超声检查(EUS)指导下内镜黏膜下剥离术(ESD)治疗直肠神经内分泌肿瘤(RNET)患者的临床疗效。方法选取60例RNET患者,均在EUS指导下行ESD治疗并随访1年,记录全部患者EUS检查结果、ESD治疗情况及随访情况。比较治疗前后RNET患者的生活质量[胃肠神经内分泌肿瘤患者生活质量量表(QLQ-GI.NET21)]、血清肿瘤标志物[癌胚抗原(CEA)、神经元特异性烯醇化酶(NSE)、糖类抗原19-9(CA19-9)、嗜铬粒蛋白A(CGA)]水平。结果60例患者共67个病灶,EUS检查显示,4个病灶来源于黏膜层,5个病灶来源于黏膜肌层,58个病灶来源于黏膜下层;5个病灶距肛门﹥10 cm,28个病灶距肛门≤10 cm且﹥5 cm,34个病灶距肛门≤5 cm。60例患者均采取ESD治疗,平均手术时间为(30.86±9.86)min,平均病灶直径为(0.82±0.26)cm。62个病灶实现了完全切除,另外5个病灶基底切缘呈阳性(均在术中追加外科手术治疗),完全切除率为92.54%(62/67)。术后病理检查结果显示,63个病灶为G1级,4个病灶为G2级。术后5例患者发生出血,3例患者在内镜下经钛夹止血,2例患者予以药物保守治疗。治疗后,RNET患者QLQ-GI.NET21各维度评分及血清NSE、CEA、CGA、CA19-9水平均明显低于治疗前,差异均有统计学意义(P﹤0.01)。60例患者随访过程中均未发生复发和/或转移。结论EUS能够清楚地显示RNET病灶,并能有效指导ESD治疗,EUS指导下ESD治疗RNET具有一定的有效性和安全性。

内镜下治疗直肠神经内分泌肿瘤的临床效果

目的比较不同内镜下治疗方式对直肠神经内分泌肿瘤(rectal neuroendocrine tumors,R-NET)的临床疗效。方法回顾性分析2015年1月至2022年5月于武汉大学人民医院消化内科经内镜下治疗后确诊为R-NET的81例患者的临床资料。结果81例R-NET患者均在内镜下成功切除病灶,病灶多呈表面光滑隆起型或息肉样病变(95.1%),色泽多为正常或淡黄色(92.6%),大部分位于距肛门5~10 cm处(72.8%)。内镜黏膜下剥离术(endoscopic submucosal dissection,ESD)组61例,其中50例行超声肠镜检查,结果提示,肿瘤起源于黏膜层、黏膜下层43例,固有肌层7例;内镜下黏膜切除术(endoscopic mucosal resection,EMR)组20例,仅2例行EUS检查,其中黏膜层1例,黏膜下层1例;两组在术前EUS检出率差异有统计学意义(P<0.001)。内镜治疗中,EMR较ESD手术时间短、住院时间短、治疗费用低(P均<0.001),而手术并发症发生率差异无统计学意义(P>0.05)。免疫组化结果提示CD56(91.4%)、Syn(69.1%)的阳性率高,CgA(28.4%)阳性率较低,两组R-NET的组织学分级、病灶大小及完全切除率方面差异无统计学意义(P>0.05)。术后随访中5例患者失访,其余患者中ESD组术后3例患者因切缘阳性追加外科手术,术后均无复发,EMR组1例患者术后2年复发,再次行EMR切除后随访至今无复发,其余患者无复发。结论病灶<10 mm的R-NET大部分处于G 1、G 2期,不同内镜下治疗方式对其均安全有效,辅助EUS有利于术前辅助诊断,且术后需进行长期严格随访。

高分化直肠神经内分泌肿瘤的临床病理特征及预后分析

目的 探讨高分化直肠神经内分泌肿瘤(RNET)的临床病理特征及预后。方法 回顾性分析2017年8月-2021年12月在该院住院治疗的83例高分化RNET患者的临床资料,包括:临床表现、内镜检查、内镜下治疗、术后并发症、术后病理、随访情况和预后。以2019年世界卫生组织(WHO)确定的消化系统肿瘤分类为标准,根据病理分期,将83例患者分为G1期组(72例)和G2期组(11例);根据患者瘤体数,将83例患者分为单发RNET组(77例)和多发RNET组(6例);比较两种分组之间嗜铬粒蛋白A(CgA)、突触素(Syn)和CD56的表达情况。结果 根据病理结果分组时,G1期组CgA阳性率明显高于G2期组,差异有统计学意义(χ^(2)=4.23,P=0.040);根据瘤体数分组时,多发RNET组CgA阳性率明显高于单发RNET组,差异有统计学意义(χ^(2)=5.74,P=0.017);Syn和CD56在以上两种分组中比较,差异均无统计学意义(P> 0.05)。结论 高分化RNET常无特异性临床表现,多为单发直肠G1期,ESD切除安全性高,预后良好,G1期患者中CgA阳性率较高,多发RNET患者中CgA阳性率较高。