Rectal Endometriosis Revealed by a Colonic Tumor Obstruction: A Case Report

Endometriosis is defined as the presence of endometrial tissue that is located outside the uterine cavity, associated with fibrosis and inflammatory reaction. The most common atypical locations are the gastrointestinal tract, urinary tract, lung, as well as abdominal surgical scars. Its diagnosis is still very difficult, especially when it manifests itself as an acute large bowel obstruction. We report the rare case of a 41-year-old patient diagnosed with acute colonic obstruction following a rectal tumor. She had undergone colonostomy even though colonoscopy biopsies were nonspecific, and a computed tomography (CT) scan was requested. It showed an adnexal heterogenous mass, therefore the patient had a laparotomy and a subtotal hysterectomy with bilateral salpingo-oophorectomy and a biopsy of the recto-colonic hinge. Histologic examination revealed a diagnosis of rectal endometriosis. The purpose of this work is to report a rare case of colonic endometriosis responsible for an acute large bowel obstruction.

Colon and rectal cancer:An emergent public health problem

Colorectal cancer ranks third globally,with a high mortality rate.In the United States,and different countries in Europe,organized population screenings exist and include people between 50 and 74 years of age.These screenings have allowed an early diagnosis and consequently an improvement in health indicators.Colon and rectal cancer(CRC)is a disease of particular interest due to the high global burden associated with it and the role attributed to prevention and early diagnosis in reducing morbidity and mortality.This study is a review of CRC pathology and includes the most recent scientific evidence regarding this pathology,as well as a diagnosis of the epidemiological situation of CRC.Finally,the recommendation from a public health perspective will be discussed in detail taking into account the context and the most current recommendations.

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.

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.

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.

Transrectal ultrasound and magnetic resonance imaging measurement of extramural tumor spread in rectal cancer

AIM:To evaluate the agreement between transrectal ultrasound(TRUS) and magnetic resonance imaging(MRI) in classification of ≥ T3 rectal tumors.METHODS:From January 2010 to January 2012,86 consecutive patients with ≥ T3 tumors were included in this study.The mean age of the patients was 66.4 years(range:26-91 years).The tumors were all ≥ T3 on TRUS.The sub-classification was defined by the penetration of the rectal wall:a:0 to 1 mm;b:1-5 mm;c:6-15;d:> 15 mm.Early tumors as ab(≤ 5 mm) and advanced tumors as cd(> 5 mm).All patients underwent TRUS using a 6.5 MHz transrectal transducer.The MRI was performed with a 1.5 T Philips unit.The TRUS findings were blinded to the radiologist performing the interpretation of the MRI images and measuring the depth of extramural tumor spread.RESULTS:TRUS found 51 patients to have an early ≥ T3 tumors and 35 to have an advanced tumor,whereas MRI categorized 48 as early ≥ T3 tumors and 38 as advanced tumors.No patients with tumors classified as advanced by TRUS were found to be early on MRI.The kappa value in classifying early versus advanced T3 rectal tumors was 0.93(95% CI:0.85-1.00).We found a kappa value of 0.74(95% CI:0.63-0.86) for the total sub-classification between the two methods.The mean maximal tumor outgrowth measured by TRUS,5.5 mm ± 5.63 mm and on MRI,6.3 mm ± 6.18 mm,P = 0.004.In 19 of the 86 patients the following CT scan or surgery revealed distant metastases;of the 51 patients in the ultrasound ab group three(5.9%) had metastases,whereas 16(45.7%) of 35 in the cd group harbored distant metastases,P = 0.00002.The odds ratio of having distant metastases in the ultrasound cd group compared to the ab group was 13.5(95% CI:3.5-51.6),P = 0.00002.The mean maximal ultrasound measured outgrowth was 4.3 mm(95% CI:3.2-5.5 mm) in patients without distant metastases,while the mean maximal outgrowth was 9.5 mm(95% CI:6.2-12.8 mm) in the patients with metastases,P = 0.00004.Using the MRI classification three(6.3%) of 48 in the MRI ab group had distant metastases,while 16(42.1%) of the 38 in the MRI cd group,P = 0.00004.The MRI odds ratio was 10.9(95% CI:2.9-41.4),P = 0.00008.The mean maximal MRI measured outgrowth was 4.9 mm(95% CI:3.7-6.1 mm) in patients without distant metastases,while the mean maximal outgrowth was 11.5 mm(95% CI:7.8-15.2 mm) in the patients with metastases,P = 0.000006.CONCLUSION:There is good agreement between TRUS and MRI in the pretreatment sub-classification of ≥ T3 tumors.Distant metastases are more frequent in the advanced group.

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.

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

AIM:To analyze the clinicopathologic characteristics and prognostic factors of rectal neuroendocrine tumors.METHODS:The records of 48 patients with rectal neuroendocrine tumors who were treated at the Cancer Institute and Hospital,Chinese Academy of Medical Sciences,Beijing,from March 2004 to September 2009were retrospectively reviewed.The clinicopathological data were extracted and analyzed,and patients were followed-up by telephone or follow-up letter to determine their survival status.Follow-up data were available for all 48 patients.Uni-and multivariate Cox regression analyses were performed to determine the prognostic factors significantly associated with overall survival.RESULTS:The tumors occurred mostly in the middle and lower rectum,and the most prominent symptoms experienced by patients were hematochezia and diarrhea.The median distance between the tumors andthe anal edges was 5.0±2.257 cm,and the median diameter of the tumors was 0.8±1.413 cm.The major pathological type was a typical carcinoid tumor,which accounted for 93.8%(45/48)of patients.Tumor-nodemetastasis(TNM)stagesⅠ,Ⅱ,ⅢandⅣtumors accounted for 78.8%,3.9%,9.6%and 7.7%of patients,respectively.The main treatment method,in 72.9%(35/48)of patients,was transanal extended excision.The 1-,3-and 5-year survival rates of the whole group of patients were 100%,93.7%,and 91.3%,respectively.Univariate analysis showed that age(P=0.032),tumor diameter(P<0.001),histological type(P<0.001),TNM stage(P<0.001),and surgical approach(P=0.002)were all prognostic factors.On multivariate analysis,only the pathological type was shown to be an independent prognostic factor(HR=2.797,95%CI:1.676-4.668,P=0.004).CONCLUSION:In patients with rectal neuroendocrine tumors,TNM stage Ⅰ is the most common stage found,and lymph node or distant metastases are rarely seen.The pathological type of the tumor is an independent prognostic factor.

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.

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.

Morphological observation of tumor infiltrating immunocytes in human rectal cancer

瞄准：调查渗入树枝状的房间(TIDC ) 的肿瘤和在人的直肠的癌症渗入淋巴细胞(TIL ) 的肿瘤的词法描述。方法：象免疫组织化学一样的光和电子显微镜学被用来观察 TIDC 和 TIL 的分发、词法的变化。结果：TIDC 主要位于包围肿瘤的织物。在更早的阶段的 TIDC 的数字在以后的舞台(P【0.01 ) 比那高。TIL 主要在癌症的邻近的织物和包围肿瘤的织物被看见。在以后的舞台(P【0.01 ) 比那在更早的阶段有更多的 TIL。在电子显微镜下面， TIDC 在形状是不规则的并且展出了许多树枝状的伸出。癌症房间穿孔了，不是明显的地下室膜和 TIL 在更早的阶段沿着地下室膜被安排。在以后的舞台，癌症房间穿孔了，是明确的地下室膜并且由 TIL 包围了。在 TIDC， TIL 和肿瘤房间之中有接触。一 TIDC 联系了在 TIDC 附近聚类的或几 TIL。肝糖小粒在 TIDC 和 TIL 之间被看见。结论：TIDC 和 TIL 的数字与在那里的肿瘤前进被联系近存在在 TIDC， TIL 和肿瘤房间之中的关系。

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.

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.

Prognostic value of preoperative carcinoembryonic antigen/tumor size in rectal cancer

BACKGROUND Carcinoembryonic antigen(CEA)is a commonly used biomarker in colorectal cancer.However,controversy exists regarding the insufficient prognostic value of preoperative serum CEA alone in rectal cancer.Here,we combined preoperative serum CEA and the maximum tumor diameter to correct the CEA level,which may better reflect the malignancy of rectal cancer.AIM To assess the prognostic impact of preoperative CEA/tumor size in rectal cancer.METHODS We retrospectively reviewed 696 stage I to III rectal cancer patients who underwent curative tumor resection from 2007 to 2012.These patients were randomly divided into two cohorts for cross-validation:training cohort and validation cohort.The training cohort was used to generate an optimal cutoff point and the validation cohort was used to further validate the model.Maximally selected rank statistics were used to identify the optimum cutoff for CEA/tumor size.The Kaplan-Meier method and log-rank test were used to plot the survival curve and to compare the survival data.Univariate and multivariate Cox regression analyses were used to determine the prognostic value of CEA/tumor size.The primary and secondary outcomes were overall survival(OS)and disease-free survival(DFS),respectively.RESULTS In all,556 patients who satisfied both the inclusion and exclusion criteria were included and randomly divided into the training cohort(2/3 of 556,n=371)and the validation cohort(1/3 of 556,n=185).The cutoff was 2.429 ng/mL per cm.Comparison of the baseline data showed that high CEA/tumor size was correlated with older age,high TNM stage,the presence of perineural invasion,high CEA,and high carbohydrate antigen 19-9(CA 19-9).Kaplan-Meier curves showed a manifest reduction in 5-year OS(training cohort:56.7%vs 81.1%,P<0.001;validation cohort:58.8%vs 85.6%,P<0.001)and DFS(training cohort:52.5%vs 71.9%,P=0.02;validation cohort:50.3%vs 79.3%,P=0.002)in the high CEA/tumor size group compared with the low CEA/tumor size group.Univariate and multivariate analyses identified CEA/tumor size as an independent prognostic factor for OS(training cohort:hazard ratio(HR)=2.18,95%confidence interval(CI):1.28-3.73,P=0.004;validation cohort:HR=4.83,95%CI:2.21-10.52,P<0.001)as well as DFS(training cohort:HR=1.47,95%CI:0.93-2.33,P=0.096;validation cohort:HR=2.61,95%CI:1.38-4.95,P=0.003).CONCLUSION Preoperative CEA/tumor size is an independent prognostic factor for patients with stage I-III rectal cancer.Higher CEA/tumor size is associated with worse OS and DFS.

Identifi cation of the differential expressive tumor associated genes in rectal cancers by cDNA microarray

AIM: To identify tumor associated genes of rectal cancer and to probe the application possibility of gene expression profi les for the classifi cation of tumors. METHODS: Rectal cancer tissues and their paired normal mucosa were obtained from patients undergoing surgical resection of rectal cancer. Total RNA was extracted using Trizol reagents. First strand cDNA synthesis was indirectly labeled with aminoallyl-dUTP and coupled with Cy3 or Cy5 dye NHS mono-functional ester. After normalization to total spots, the genes which background subtracted intensity did not exceed 2 SD above the mean blank were excluded. The data were then sorted to obtain genes differentially expressed by ≥ 2 fold up or down in at least 5 of the 21 patients.RESULTS: In the 21 rectal cancer patients, 23 genes were up-regulated in at least 5 samples and 15 genes were down-regulated in at least 5 patients. Hierachical cluster analysis classified the patients into two groups according to the clinicopathological stage, with one group being all above stage II and one group all below stage II. CONCLUSION: The up-regulated genes and down-regulated genes may be molecular markers of rectalcancer. The expression profiles can be used for classifi cation of rectal cancer.

Predicting tumor response after preoperative chemoradiation using clinical parameters in rectal cancer

AIM: To evaluate the clinical parameters and identify a better method of predicting pathological complete response (pCR). METHODS: We enrolled 249 patients from a database of 544 consecutive rectal cancer patients who underwent surgical resection after preoperative chemoradiation therapy (PCRT). A retrospective review of morphological characteristics was then performed to collect data regarding rectal examination findings. A scoring model to predict pCR was then created. To validate the ability of the scoring model to predict complete regression.RESULTS: Seventy patients (12.9%) achieved a pCR. A multivariate analysis found that pre-CRT movability (P = 0.024), post-CRT size (P = 0.018), post-CRT morphology (P = 0.023), and gross change (P = 0.009) were independent predictors of pCR. The accuracy of the scoring model was 76.8% for predicting pCR with the threshold set at 4.5. In the validation set, the accuracy was 86.7%. CONCLUSION: Gross changes and morphological findings are important predictors of pathological response. Accordingly, PCRT response is best predicted by a combination of clinical, laboratory and metabolic information.

Tumor-stroma ratio as prognostic factor for survival in rectal adenocarcinoma: A retrospective cohort study

AIM To evaluate the prognostic value of the tumor-stroma ratio(TSR) in rectal cancer.METHODS TSR was determined on hematoxylin and eosin stained histological sections of 154 patients treated for rectal adenocarcinoma without prior neoadjuvant treatment in the period 1996-2006 by two observers to assessreproducibility. Patients were categorized into three categories: TSR-high [carcinoma percentage(CP) ≥ 70%], TSR-intermediate(CP 40%, 50% and 60%) and TSR-low(CP ≤ 30%). The relation between categorized TSR and survival was analyzed using Cox proportional hazards model.RESULTS Thirty-six(23.4%) patients were scored as TSR-low, 70(45.4%) as TSR-intermediate and 48(31.2%) as TSRhigh. TSR had a good interobserver agreement(κ = 0.724, concordance 82.5%). Overall survival(OS) and disease free survival(DFS) were significantly better for patients with a high TSR(P = 0.01 and P = 0.02, respectively). A similar association existed for disease specific survival(P = 0.06). In multivariate analysis, patients without lymph node metastasis and an intermediate TSR had a higher risk of dying from rectal cancer(HR = 5.27, 95%CI: 1.54-18.10), compared to lymph node metastasis negative patients with a high TSR. This group also had a worse DFS(HR = 6.41, 95%CI: 1.84-22.28). An identical association was seen for OS. These relations were not seen in lymph node metastasis positive patients. CONCLUSION The TSR has potential as a prognostic factor for survival in surgically treated rectal cancer patients, especially in lymph node negative cases.

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.

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.