Long-term follow up of endoscopic resection for type 3 gastric NET

AIM:To clarify the short and long-term results and to prove the usefulness of endoscopic resection in type 3gastric neuroendocrine tumors(NETs).METHODS:Of the 119 type 3 gastric NETs diagnosed from January 1996 to September 2011,50 patients treated with endoscopic resection were enrolled in this study.For endoscopic resection,endoscopic mucosal resection(EMR)or endoscopic submucosal dissection(ESD)was used.Therapeutic efficacy,complications,and follow-up results were evaluated retrospectively.RESULTS:EMR was performed in 41 cases and ESD in 9 cases.Pathologically complete resection was performed in 40 cases(80.0%)and incomplete resection specimens were observed in 10 cases(7 vs 3 patients in the EMR vs ESD group,P=0.249).Upon analysis of the incomplete resection group,lateral or vertical margin invasion was found in six cases(14.6%)in the EMR group and in one case in the ESD group(11.1%).Lymphovascular invasions were observed in two cases(22.2%)in the ESD group and in one case(2.4%)in the EMR group(P=0.080).During the follow-up period(43.73;13-60 mo),there was no evidence of tumor recurrence in either the pathologically complete resection group or the incomplete resection group.No recurrence was reported during follow-up.In addition,no mortality was reported in either the complete resection group or the incomplete resection group for the duration of the follow-up period.CONCLUSION:Less than 2 cm sized confined submucosal layer type 3 gastric NET with no evidence of lymphovascular invasion,endoscopic treatment could be considered at initial treatment.

Reevaluation of the expanded indications in undifferentiated early gastric cancer for endoscopic submucosal dissection

BACKGROUND Although the criteria for the indication of endoscopic submucosal dissection(ESD)for undifferentiated early gastric cancer(UD-EGC)have been recently proposed,accumulating reports on the non-negligible rate of lymph node metastasis(LNM)after indicated ESD raise questions on the reliability of the current criteria.AIM To investigate the prevalence and risk factors of LNM in UD-EGC cases meeting the expanded indication for ESD.METHODS We retrospectively reviewed 4780 UD-EGC cases that underwent surgical resection between January 2008 and February 2019 at Asan Medical Center,a tertiary university hospital in Korea.To identify the risk factors of LNM of UDEGC meeting the expanded criteria for ESD,we performed a case-control study by matching the cases with LNM to those without at a ratio of 1:4.We reviewed the clinical,endoscopic,and histologic features of the cases to identify features with a significant difference according to the presence of LNM.Univariate and multivariate logistic regression analyses were performed to estimate the odds ratios(ORs).RESULTS Of the 4780 UD-EGC cases,1240(25.9%)were identified to meet the expanded indication for ESD.Of the 1240 cases,14(1.1%)cases had LNM.Among the various clinical,endoscopic,and histopathological features that were evaluated,mixed histology(tumors consisting of 10%-90%of signet ring cells)had a marginally significant association(P=0.059)with the risk of LNM.Moreover,diffuse blurring of the muscularis mucosae(MM)underneath the tumorous epithelium,a previously unrecognized histologic feature,had a significant association with the absence of LNM(P=0.028).Multivariate logistic regression analysis showed that the blurring of MM was the only explanatory variable significantly associated with a reduced risk of LNM(OR:0.12,95%CI:0.02-0.95;P=0.045).CONCLUSION The risk of LNM is higher than expected when using the current expanded indication for UDEGC.Histological evaluation could provide useful clues for reducing the risk of LNM.

Endoscopic submucosal dissection as alternative to surgery for complicated gastric heterotopic pancreas

BACKGROUND Gastric heterotopic pancreas(GHP)is generally asymptomatic and rarely features complications such as pancreatitis,pseudocysts,gastric outlet obstruction,bleeding,obstructive jaundice,or intussusception.However,the treatment of complicated GHP is challenging and often requires surgical resection.AIM To investigate the clinical outcomes of endoscopic submucosal dissection(ESD)as alternative to surgical resection for complicated GHP.METHODS This is a single-center,retrospective study.Between January 2013 and December 2017,a total of 5 patients underwent ESD for complicated GHP at Asan Medical Center.Patients who were diagnosed with complicated GHP were treated conservatively as with general practice for acute pancreatitis.After conservative management for resolving the acute phase of pancreatitis,ESD was performed as definitive treatment for complicated GHP.ESD was performed using the conventional method under conscious sedation.The clinical features of patients and tumors,procedure-related characteristics,and long-term outcomes were investigated.RESULTS The age of the 5 patients ranged from 28-43 years.Two of the patients were males.All lesions were located in the greater curvature of the antrum.On endoscopic ultrasonography during the pain episode,all lesions were located across the muscularis mucosa,submucosa,and proper muscle layers.The median lesion size was 20[interquartile range(IQR),18-35]during the pain episode at the time of the diagnosis of complicated GHP,and 15 mm(IQR,9-33)at the time of ESD after conservative treatment.The procedure time ranged from 15-120 min.There were no procedure-related adverse events such as perforation or bleeding.The length of hospital stay after the procedure ranged from 2-4 d.All patients were symptom free during the median follow-up period of 46.0 mo(IQR,39-60).CONCLUSION ESD appears to be a feasible and effective treatment option for complicated GHP based on the favorable clinical outcomes.