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.

Prediction of the lymphatic,microvascular,and perineural invasion of pancreatic neuroendocrine tumors using preoperative magnetic resonance imaging

BACKGROUND Significant correlation between lymphatic,microvascular,and perineural invasion(LMPI)and the prognosis of pancreatic neuroendocrine tumors(PENTs)was confirmed by previous studies.There was no previous study reported the relationship between magnetic resonance imaging(MRI)parameters and LMPI.AIM To determine the feasibility of using preoperative MRI of the pancreas to predict LMPI in patients with non-functioning PENTs(NFPNETs).METHODS A total of 61 patients with NFPNETs who underwent MRI scans and lymphadenectomy from May 2011 to June 2018 were included in this retrospective study.The patients were divided into group 1(n=34,LMPI negative)and group 2(n=27,LMPI positive).The clinical characteristics and qualitative MRI features were collected.In order to predict LMPI status in NF-PNETs,a multivariate logistic regression model was constructed.Diagnostic performance was evaluated by calculating the receiver operator characteristic(ROC)curve with area under ROC,sensitivity,specificity,positive predictive value(PPV),negative predictive value(NPV)and accuracy.RESULTS There were significant differences in the lymph node metastasis stage,tumor grade,neuron-specific enolase levels,tumor margin,main pancreatic ductal dilatation,common bile duct dilatation,enhancement pattern,vascular and adjacent tissue involvement,synchronous liver metastases,the long axis of the largest lymph node,the short axis of the largest lymph node,number of the lymph nodes with short axis>5 or 10 mm,and tumor volume between two groups(P<0.05).Multivariate analysis showed that tumor margin(odds ratio=11.523,P<0.001)was a predictive factor for LMPI of NF-PNETs.The area under the receiver value for the predictive performance of combined predictive factors was 0.855.The sensitivity,specificity,PPV,NPV and accuracy of the model were 48.1%(14/27),97.1%(33/34),97.1%(13/14),70.2%(33/47)and 0.754,respectively.CONCLUSION Using preoperative MRI,ill-defined tumor margins can effectively predict LMPI in patients with NF-PNETs.

Relations of proliferative activities of gastric carcinoma cells to lymphatic involvement, venous invasion and prognosis

Background This study was to evaluate bivariate bromodeoxyuridine(BrdUrd)/DNA flow cytometric analysis in detection of gastric carcinoma and to study the relations of cellular BrdUrd labeling indices (LI), G_2/M-phase fraction(G_2/MPF) and DNA ploidy pattern to lymphatic involvement, venous invasion and prognosis.Methods Fresh tumor samples from 60 patients with gastric carcinoma were analyzed by bivariate BrdUrd/DNA flow cytometry. The results were correlated with lymphatic vessel invasion, lymphatic node metastasis, the number of matastatic lymphatic nodes, and venous invasion. Propidium iodide (PI) was used as a fluorescent probe for total cellular DNA, and a monoclonal antibody against BrdUrd was used as a probe for BrdUrd incorporated into DNA. Fluorescent-labeled goat anti-mouse antibody was used as a second antibody. S-phase fractions were measured by in vitro BrdUrd labeling, and DNA ploidy and G_2/MPF were also measured. Comparison of survival was performed with the log-rank test, the Chi-square test for qualitative data, and Student’s t test for quantu data. Results BrdUrd LI and G_2/MPF values were significantly higher in tumors with lymphatic vessel invasion than in those without invasion respectively (P<0.01); the patients who had tumors with lymphatic vessel invasion showed a significantly poor prognosis (P<0.01). Both BrdUrd LI and G_2/MPF values were significantly higher in tumors with lymphatic node metastasis than in those without metastasis (P<0.01). A statistical significant difference was noted in the 5-year survival rates between the patients with lymph node metastasis and those without metastasis. Compared with diploid carcinoma, the incidence of lymph node metastasis was significantly higher in aneuploid carcinoma (P<0.05), and the patients with aneuploid carcinoma showed a significantly poor prognosis (P<0.05). BrdUrd LI was significantly higher in patients with more than 5 metastatic lymph nodes than those with 1-4 metastatic lymph nodes (P<0.05) and those without metastasis (P<0.01). G_2/MPF values in those patients either with more than 5 metastatic lymph nodes or 1-4 metastatic lymph nodes were higher than those without metastasis (P<0.01 and P<0.05). A statistical significance was seen in the 5-year survival rates among the patients with no metastatic lymph node, 1-4 metastatic nodes and more than 5 metastatic nodes (P<0.01). G_2/MPF values were significantly higher in patients with venous invasion than in those without invasion (P<0.01).Conclusions Positive correlations exist between cellular BrdUrd LI, G_2/MPF with lymphatic involvement and prognosis, and DNA aneuploid with lymphatic involvement and prognosis. The same was true between G_2/MPF value and venous invasion in gastric carcinoma.