Application value of dexmedetomidine in anesthesia for elderly patients undergoing radical colon cancer surgery

BACKGROUND Colon cancer presents a substantial risk to the well-being of elderly people worldwide.With advancements in medical technology,surgical treatment has become the primary approach for managing colon cancer patients.However,due to age-related physiological changes,especially a decline in cognitive function,older patients are more susceptible to the effects of surgery and anesthesia,increasing the relative risk of postoperative cognitive dysfunction(POCD).There-fore,in the surgical treatment of elderly patients with colon cancer,it is of pa-ramount importance to select an appropriate anesthetic approach to reduce the occurrence of POCD,protect brain function,and improve surgical success rates.METHODS One hundred and seventeen patients with colon cancer who underwent elective surgery under general anesthesia were selected and divided into two groups:A and B.Group A received Dex before anesthesia induction,and B group received an equivalent amount of normal saline.Changes in the mini-mental state exami-nation,regional cerebral oxygen saturation(rSO2),bispectral index,glucose uptake rate(GluER),lactate production rate(LacPR),serum S100βand neuron-specific enolase(NSE),POCD,and adverse anesthesia reactions were compared between the two groups.RESULTS Surgical duration,duration of anesthesia,and intraoperative blood loss were comparable between the two groups(P>0.05).The overall dosage of anesthetic drugs used in group A,including propofol and remifentanil,was significantly lower than that used in group B(P<0.05).Group A exhibited higher rSO2 values at the time of endotracheal intubation,30 min after the start of surgery,and immediately after extubation,higher GluER values and lower LacPR values at the time of endotra-cheal intubation,30 min after the start of surgery,immediately after extubation,and 5 min after extubation(P<0.05).Group A exhibited lower levels of serum S100βand NSE 24 h postoperatively and a lower incidence of cognitive dysfunction on the 1st and 5th postoperative days(P<0.05).CONCLUSION The use of Dex in elderly patients undergoing radical colon cancer surgery helps maintain rSO2 Levels and reduce cerebral metabolic levels and the incidence of anesthesia-and surgery-induced cognitive dysfunction.

Advances in the Diagnosis and Treatment of Appendiceal Mucinous Neoplasms

Primary appendiceal neoplasms represent a relatively low percentage of all gastrointestinal cancers. A subset of these neoplasms, those of epithelial origin, are characterised by the production of a considerable amount of mucus, which is referred to as appendiceal mucinous neoplasms (AMN). Appendiceal mucinous neoplasms (AMN) have a low incidence, are easily misdiagnosed, depend on postoperative examination for confirmation of the diagnosis, are prone to form a “diagnosis”, and have a high incidence of the disease. Furthermore, they are prone to form peritoneal pseudomyxoma peritonei (PMP), are controversial in surgical decision-making, are prone to recurring after surgery alone, and are tricky to manage clinically. In this paper, we review the pathological characteristics, diagnosis and treatment of appendiceal mucinous tumours in the light of recent literature reports, with a view to providing certain references for the clinical diagnosis and treatment of this disease. .

Oncologic safety of colonic stenting as a bridge to surgery in leftsided malignant colonic obstruction:Current evidence and prospects

Approximately 7%-29%of patients with colorectal cancer present with colonic obstruction.The concept of self-expandable metal stent(SEMS)insertion as a bridge to surgery(BTS)is appealing.However,concerns on colonic stenting possibly impairing oncologic outcomes have been raised.This study aimed to review current evidence on the short-and long-term oncologic outcomes of SEMS insertion as BTS for left-sided malignant colonic obstruction.For short-term outcomes,colonic stenting facilitates a laparoscopic approach,increases the likelihood of primary anastomosis without a stoma,and may decrease postoperative morbidity.However,SEMS-related perforation also increases local recurrence and impairs overall survival.Moreover,colonic stenting may cause negative oncologic outcomes even without perforation.SEMS can induce shear forces on the tumor,leading to increased circulating cancer cells and aggressive pathological characteristics,including perineural and lymphovascular invasion.The conflicting evidence has led to discordant guidelines.Well-designed collaborative studies that integrate both oncologic outcomes and data on basic research(e.g.,alteration of circulating tumors)are needed to clarify the actual benefit of colonic stenting as BTS.

Preoperative colonic stents vs emergency surgery for acute left-sided malignant colonic obstruction: meta-analysis with systematic review of the literature

AIM To investigate by meta-analytic study and systematic review, advantages of colonic stent placement in comparison with emergency surgery.METHODS We conducted an extensive literature search by PubMed, Google Scholar, Embase and the Cochrane Libraries. We searched for all the papers in English published till February 2016, by applying combinations of the following terms: Obstructive colon cancer, colon cancer in emergency, colorectal stenting, emergency surgery for colorectal cancer, guidelines for obstructive colorectal cancer, stenting vs emergency surgery in the treatment of obstructive colorectal cancer, selfexpanding metallic stents, stenting as bridge to surgery. The study was designed following the PrismaStatement. By our search, we identified 452 studies, and 57 potentially relevant studies in full-text were reviewed by 2 investigators; ultimately, 9 randomized controlled trials were considered for meta-analysis and all the others were considered for systematic review.RESULTS In the meta-analysis, by comparing colonic stenting(CS) as bridge to surgery and emergency surgery, the pooled analysis showed no significant difference between the two techniques in terms of mortality [odds ratio(oR) = 0.91], morbidity(oR = 2.38) or permanent stoma rate(oR = 1.67); primary anastomosis was more frequent in the stent group(oR = 0.45; P = 0.004) and stoma creation was more frequent in the emergency surgery group(oR = 2.36; P = 0.002). No statistical difference was found in disease-free survival and overall survival. The pooled analysis showed a significant difference between the colonic stent and emergency surgery groups(oR = 0.37), with a significantly higher 1-year recurrence rate in the stent group(P = 0.007).CONCLUSION CS improves primary anastomosis rate with significantly high 1-year follow-up recurrence and no statistical difference in terms of disease-free survival and overall survival.

Prevention of metastasis to liver by using 5-FU intraperitoneal chemotherapy in nude mice inoculated with human colonic cancer cells

AIMS Using a new approach of regional adjuvant chemotherapy to prevent cancer cells hepatic metasta- sis after radical surgery of large bowel cancer. METHODS A model of liver with metastasis of hu- man colonic cancer (HCC) cells in nude mice was used to observe the effect in prevention of metastasis of HCC cells inoculated via spleen applied with early postoper- ative intraperitoneal (IP) chemotherapy using large dose of 5-FU. RESULTS The incidence of metastasis to liver was decreased by 40%,the mean number of metastatic liv- er nodules in each animal was reduced by 50.89% and the mean survival times of each animal was prolonged by 48.21% by using 5-FU 40 mg/NS 40 ml/kg IP for two consecutive days as compared with the controls. CONCLUSIONS IP is a new and more effective re- gional adjuvant chemotheraputic approach in the pre- vention of liver metastasis HCC cells after radical surgery of large bowel cancer.

Synchronous colonic mucosa-associated lymphoid tissue lymphoma found after surgery for adenocarcinoma:A case report and review of literature

BACKGROUND Mucosa-associated lymphoid tissue (MALT) lymphoma is a subtype of non-Hodgkin lymphoma that is mainly involved in the gastrointestinal tract. Thesynchronous occurrence of colonic MALT lymphoma and adenocarcinoma in thesame patient is extremely rare. We here report a case of synchronous colonicMALT lymphoma found on surveillance colonoscopy five months after surgeryand chemotherapy for sigmoid adenocarcinoma.CASE SUMMARY A 67-year-old man was admitted because of hematochezia for two months.Colonoscopy suggested a colonic tumor before hospitalization. Abdominalcomputed tomography (CT) revealed local thickening of the sigmoid colon. Thepatient underwent a left hemicolectomy with local lymph node dissection. Thehistopathology revealed moderately differentiated adenocarcinoma and partiallymucinous adenocarcinoma. The pTNM stage was T3N1Mx. The patient receivedchemotherapy with six cycles of mFOLFOX6 after surgery. Colonoscopy wasperformed five months later and revealed single, flat, polypoid lesions of thecolon 33 cm away from the anus. Subsequently, the patient underwent endoscopic mucosal resection for further diagnosis. The pathological diagnosis was MALTlymphoma. Positron emission tomography /CT suggested metastasis. The patientrefused further treatment and died ten months later.CONCLUSION Colonic MALT lymphoma may occur after surgery and chemotherapy foradenocarcinoma as a synchronous malignancy. Regular surveillance colonoscopyand careful monitoring after surgery are critical.

Inhibitory effect of sulindac against chemically induced primary colonic tumours by N methyl N nitrosourea in mice

AIM To investigate the chemopreventive effect of sulindac, one of the nonstroidal anti inflammatory drugs (NSAIDs), on the growth of N methyl N nitrosourea (MNU) induced mouse colonic tumors.

Clinicopathologic characteristics and prognosis of gastroenteropancreatic neuroendocrine neoplasms: a multicenter study in South China

Background: Gastroenteropancreatic neuroendocrine neoplasms(GEP-NENs) are a heterogeneous group of rare tumors. Many issues in terms of epidemiologic features, pathogenesis, and treatment of GEP-NENs are still under discussion. Our study aimed to analyze the clinicopathologic characteristics and prognosis of Chinese patients with GEP-NENs.Methods: Complete clinicopathologic data and survival information of 1183 patients with GEP-NENs treated between 2005 and 2015 were collected from five medical centers in Guangdong Province, China. Patient survival was estimated using the Kaplan–Meier method and analyzed using the log-rank test; prognostic factors were analyzed using the Cox proportional hazards model.Results: The most common tumor location was the rectum(37.4%), followed by the pancreas(28.1%), stomach(20.7%), small intestine(7.2%), appendix(3.4%), and colon(3.3%). After initial definitive diagnosis, 1016(85.9%) patients underwent surgery. The 1-, 3-, and 5-year overall survival(OS) rates for the entire cohort were 87.9%, 78.5%, and 72.8%, respectively. The 3-year OS rates of patients with G1, G2, and G3 tumors were 93.1%, 82.7%, and 43.1%, respectively(P < 0.001). The 3-year OS rates of patients with stage I, II, III, and IV tumors were 96.0%, 87.3%, 64.0%, and 46.8%, respectively(P < 0.001). Patients with distant metastasis who underwent palliative surgery had a longer survival than those who did not(P = 0.003). Similar survival benefits of palliative surgery were observed in patients with neuroendocrine tumor(P y, M category, and sur= 0.031) or neuroendocrine carcinoma(P gery were found to be independent prog= 0.046). In multivariate analysis, age, grade, N categornostic factors.Conclusions: Patients with GEP-NENs who are women, younger than 50 years old, have smaller tumor size, have lower tumor grade, have lower T/N/M category, and who undergo surgery can have potentially longer survival time. Our data showed that surgery can improve the prognosis of GEP-NEN patients with distant metastasis. However, randomized controlled trials need to be conducted to establish the optimal criteria for selecting patients to undergo surgery.

Five-year long-term outcomes of laparoscopic surgery for colon cancer

AIM:To perform a meta-analysis to answer whether long-term recurrence rates after laparoscopic-assisted surgery are comparable to those reported after open surgery.METHODS:A comprehensive literature search of the MEDLINE database,EMBASE database,and the Cochrane Central Register of Controlled Trials for the years 1991-2010 was performed.Prospective randomized clinical trials(RCTs)were eligible if they included patients with colon cancer treated by laparoscopic surgery vs open surgery and followed for more than five years.RESULTS:Three studies involving 2147 patients reported long-term outcomes based on five-year data and were included in the analysis.The overall mortality was similar in the two groups(24.9%,268/1075 in the laparoscopic group and 26.4%,283/1072 in open group).No significant differences between laparoscopic and open surgery were found in overall mortality during the follow-up period of these studies[OR(fixed) 0.92,95%confidence intervals(95%CI):0.76-1.12,P=0.41].No significant difference in the development of overall recurrence was found in colon cancer patients,when comparing laparoscopic and open surgery [2147 pts,19.3%vs 20.0%;OR(fixed)0.96,95% CI:0.78-1.19,P=0.71].CONCLUSION:This meta-analysis suggests that laparoscopic surgery was as efficacious and safe as open surgery for colon cancer,based on the five-year data of these included RCTs.

Current perspectives on pancreatic serous cystic neoplasms:Diagnosis, management and beyond

Pancreatic cystic neoplasms have been increasingly recognized recently. Comprising about 16% of all resected pancreatic cystic neoplasms, serous cystic neoplasms are uncommon benign lesions that are usually asymptomatic and found incidentally. Despite overall low risk of malignancy, these pancreatic cysts still generate anxiety, leading to intensive medical investigations with considerable financial cost to health care systems. This review discusses the general background of serous cystic neoplasms, including epidemiology and clinical characteristics, and provides an updated overview of diagnostic approaches based on clinical features, relevant imaging studies and new findings that are being discovered pertaining to diagnostic evaluation. We also concisely discuss and propose management strategies for better quality of life.

Extent of surgery in cancer of the colon:Is more better?

Since the introduction of total mesorectal excision as the standard approach in mid and low rectal cancer,the incidence of local recurrence has sharply declined.Similar attention to surgical technique in colon cancer(CC) has resulted in the concept of complete mesocolic excision(CME),which consists of complete removal of the intact mesentery and high ligation of the vascular supply at its origin.Although renewed attention to meticulous surgical technique certainly has its merits,routine implementation of CME is currently unfounded.Firstly,in contrast to rectal cancer,local recurrence originating from an incompletely removed mesenteryis rare in CC and usually a manifestation of systemic disease.Secondly,although CME may increase nodal counts and therefore staging accuracy,this is unlikely to affect survival since the observed relationship between nodal counts and outcome in CC is most probably not causal but confounded by a range of clinical variables.Thirdly,several lines of evidence suggest that metastasis to locoregional nodes occurs early and is a stochastic rather than a stepwise phenomenon in CC,in essence reflecting the tumor-host-metastasis relationship.Unsurprisingly,therefore,comparative studies in CC as well as in other digestive cancers have failed to demonstrate any survival benefit associated with extensive,additional or extra-mesenteric lymphadenectomy.Finally,routine implementation of CME may cause patient harm by longer operating times,major vascular damage and autonomic nerve injury.Therefore,data from randomized trials reporting relevant endpoints are required before CME can be recommended as a standard approach in CC surgery.

Diagnosis and treatment of spontaneous colonic perforation:Analysis of 10 cases

AIM: To investigate the etiology, diagnosis and treatment of spontaneous perforation of the colon. METHODS: The clinical data of 10 cases of spontaneous perforation of the colon, observed at Fuding hospital from January 2004 to December 2007, were analyzed retrospectively. RESULTS: The mean age at onset was 65 years (range from 45 to 73). Seven patients had a history of chronic constipation. All patients complained of sudden lower abdominal pain. The perforation occurred after coloclysis and administration of senna leaves in two patients. Nine patients had signs of peritoneal irritation. Seven cases underwent abdominal paracentesis, which was diagnostic in six. Only one case was definitely diagnosed prior to surgery. One patient underwent neoplasty of the colon, another a partial resection of colon, six a neoplasty of the colon plus sigmoid colostomy, and two underwent Hartmann surgery. All perforation sites were opposite to the mesenteric edge. The perforation sites were located on descending colon in one case, sigmoid colon in three cases, and rectosigmoid colon in six cases. In five patients, surgical pathological examination was consistent with the microscopical changes of colonic perforation caused by feces. Three patients died after surgery. CONCLUSION: Spontaneous perforation of the colon most commonly occurs among the elderly with chronic constipation. Abdominal paracentesis is helpful for the diagnosis. The perforation site is located opposite to the mesenteric edge. Sigmoid colon and rectosigmoid colon are the most frequent locations. Neoplasty of the colon and sigmoid colostomy are the most frequenttreatment. The prognosis is bad and the mortality rate after surgery is high.

Primary early-stage intestinal and colonic non-Hodgkin's lymphoma: Clinical features, management, and outcome of 37 patients

AIM： To analyze the clinical features, management, and outcome of treatment of patients with primary intestinal and colonic non-Hodgkin＇s lymphoma （PICL）. METHODS： A retrospective study was performed in 37 patients with early-stage PICL who were treated in our hospital from 1958 to 1998. Their clinical features, management, and outcome were assessed. Prognostic factors for survival were analyzed by univariate analysis using the Kaplan-Meier product-limit method and log-rank test. RESULTS： Twenty-five patients presented with Ann Arbor stage Ⅰ PICL and 12 with Ann Arbor stage Ⅱ PICL. Thirty-five patients underwent surgery （including 31 with complete resection）, 22 received postoperative chemotherapy or radiotherapy or both. Two patients with rectal tumors underwent biopsy and chemotherapy with or without radiotherapy. The 5- and 10-year overall survival （OS） rates were 51.9% and 44.5%. The corresponding diseasefree survival （DIS） rates were 42.4% and 37.7%. In univariate analysis, multiple-modality treatment was associated with a better DFS rate compared to single treatment （P= 0.001）. While age, tumor size, tumor site, stage, histology, or extent of surgery were not associated with OS and DFS, use of adjuvant chemotherapy significantly improved DFS （P = 0.031） for the 31 patients who underwent complete resection. Additional radiotherapy combined with chemotherapy led to a longer survival than chemotherapy alone in six patients with gross residual disease after surgery or biopsy.CONCLUSION： Combined surgery and chemotherapy is recommended for treatment of patients with PICL, Additional radiotherapy is needed to improve the outcome of patients who have gross residual disease after surgery.

Differences between main-duct and branch-duct intraductal papillary mucinous neoplasms of the pancreas

In the last decade,intraductal papillary mucinous neoplasms(IPMNs) have become commonly diagnosed.From a morphological standpoint,they are classified in main-duct IPMNs(MD-IPMNs) and branch-duct IPMNs(BD-IPMNs),depending on the type of involvement of the pancreatic ductal system by the neoplasm.Despite the fact that our understanding of their natural history is still incomplete,recent data indicate that MD-IPMNs and BD-IPMNs show significant differences in terms of biological behaviour with MD-IPMNs at higher risk of malignant degeneration.In the present paper,clinical and epidemiological characteristics,rates of malignancy and the natural history of MD-IPMNs and BD-IPMNs are analyzed.The profile of IPMNs involving both the main pancreatic duct and its side branches(combined-IPMNs) are also discussed.Finally,general recommendations for management based on these differences are given.

Complications and survival in patients undergoing colonic stenting for malignant obstruction

AIM:To investigate whether predicting patients that might be at a higher risk for complications might serve to improve the selection of patients undergoing colonic stenting.METHODS:A retrospective review of consecutive patients who underwent an attempted self-expandable metal stent(SEMS)insertion for malignant colonic obstruction between November 2006 and March 2013.All patients were either referred for preoperative colonic decompression with the intent of a single surgical procedure,or for palliation of the malignant colorectal obstruction for unresectable cancer.Fisher’s test orχ2test was performed on categorical variables,and the t test for continuous variables.Univariable and multivariable logistic regression were used to examine the association between independent variables and the presence of complications from SEMS insertion.RESULTS:SEMS insertion was attempted in 73 patients.Males comprised 55.71%and the mean age was 67.41±12.41 years.Of these,65.15%underwent subsequent surgery,while 34.85%received SEMS as palliation for advanced disease.Extracolonic tumors were only4.76%.The majority of patients had stageⅣdisease(63.83%),while the remainder had stageⅢ(36.17%).SEMS were successfully inserted in 93.85%(95%CI:87.85%-99.85%).Perforations occurred in 4.10%,SEMS migration in 8.21%,and stent re-occlusion from ingrowth occurred in 2.74%of patients.The mean duration of follow up for the patients was 13.52±17.48 mo(range 0-73 mo).None of the variables:age,sex,time between the onset of symptoms to SEMS insertion,time between SEMS insertion and surgery,length of the stenosis,location of the stenosis,albumin level,or receiving neoadjuvant chemotherapy,could predict the development of complications from either SEMS insertion nor prolonged survival.CONCLUSION:None of the variables could predict the development of complications or survival.Further studies are required to identify patients who would benefit the most from SEMS.

Analysis of 72 patients with colorectal high-grade neuroendocrine neoplasms from three Chinese hospitals

BACKGROUND Colorectal high-grade neuroendocrine neoplasms(HGNENs)are rare and constitute less than 1%of all colorectal malignancies.Based on their morphological differentiation and proliferation identity,these neoplasms present heterogeneous clinicopathologic features.Opinions regarding treatment strategies for and improvement of the clinical outcomes of these patients remain controversial.AIM To delineate the clinicopathologic features of and explore the prognostic factors for this rare malignancy.METHODS This observational study reviewed the data of 72 consecutive patients with colorectal HGNENs from three Chinese hospitals between 2000 and 2019.The clinicopathologic characteristics and follow-up data were carefully collected from their medical records,outpatient reexaminations,and telephone interviews.A survival analysis was conducted to evaluate their outcomes and to identify the prognostic factors for this disease.RESULTS According to the latest recommendations for the classification and nomenclature of colorectal HGNENs,61(84.7%)patients in our cohort had poorly differentiated neoplasms,which were categorized as high-grade neuroendocrine carcinomas(HGNECs),and the remaining 11(15.3%)patients had well differentiated neoplasms,which were categorized as high-grade neuroendocrine tumors(HGNETs).Most of the neoplasms(63.9%)were located at the rectum.More than half of the patients(51.4%)presented with distant metastasis at the date of diagnosis.All patients were followed for a median duration of 15.5 mo.In the entire cohort,the median survival time was 31 mo,and the 3-year and 5-year survival rates were 44.3%and 36.3%,respectively.Both the univariate and multivariate analyses demonstrated that increasing age,HGNEC type,and distant metastasis were risk factors for poor clinical outcomes.CONCLUSION Colorectal HGNENs are rare and aggressive malignancies with poor clinical outcomes.However,patients with younger age,good morphological differentiation,and without metastatic disease can have a relatively favorable prognosis.

Colonic metastasis after resection of primary squamous cell carcinoma of the lung:A case report and literature review

Lung cancer is a common malignancy in the world; however symptomatic colonic metastasis from primary lung cancer is rare. A 64-year-old man was originally found poorly differentiated squamous cell carcinoma of right lung and received right lower lobectomy and lymph node dissection. Three years later, the patient presented to our emergency room with the symptom of upper abdominal pain and weight loss. Abdominal palpation and computed tomography scan of the abdomen revealed a large mass measuring 7.6 cm &#x000d7; 8.5 cm in the ascending colon. Colonoscopy and biopsy revealed poorly differentiated squamous cell carcinoma with similar morphological pattern to that of the previous lung cancer. Chemotherapy was given and the patient died 5 mo later. Lung cancer metastatic to the colon confers a poor prognosis: overall survival ranged from 5 wk to 1 year, with a median survival of 3 mo after the diagnosis of the colonic metastasis.

Gastric neuroendocrine neoplasms type 1: A systematic review and meta-analysis

BACKGROUND To date, the histopathological parameters predicting the risk of lymph node (LN) metastases and local recurrence, associated mortality and appropriateness of endoscopic or surgical resection in patients with gastric neuroendocrine neoplasms type 1 (GNENs1) have not been fully elucidated. AIM To determine the rate of LN metastases and its impact in survival in patients with GNEN1 in relation to certain clinico-pathological parameters. METHODS The PubMed, EMBASE, Cochrane Library, Web of Science and Scopus databases were searched through January 2019. The quality of the included studies and risk of bias were assessed using the Newcastle-Ottawa Scale (NOS) in accordance with the Cochrane guidelines. A random effects model and pooled odds ratios (OR) with 95%CI were applied for the quantitative meta-analysis. RESULTS We screened 2933 articles. Thirteen studies with 769 unique patients with GNEN1 were included. Overall, the rate of metastasis to locoregional LNs was 3.3%(25/769). The rate of LN metastases with a cut-off size of 10 mm was 15.3% for lesions > 10 mm (vs 0.8% for lesions < 10 mm) with a random-effects OR of 10.5 (95%CI: 1.4 -80.8;heterogeneity: P = 0.126;I2 = 47.5%). Invasion of the muscularis propria was identified as a predictor for LN metastases (OR: 17.2;95%CI: 1.8-161.1;heterogeneity: P = 0.165;I2 = 44.5%), whereas grade was not clearly associated with LN metastases (OR: 2;95%CI: 0.3-11.6;heterogeneity: P = 0.304;I2 = 17.4%). With regard to GNEN1 local recurrence, scarce data were available. The 5-year disease-specific survival for patients with and without LN metastases was 100% in most available studies irrespective of the type of intervention. Surgical resection was linked to a lower risk of recurrence (OR: 0.3;95%CI: 0.1-1.1;heterogeneity: P = 0.173;I2 = 31.9%). The reported complication rates of endoscopic and surgical intervention were 0.6 and 3.8%, respectively. CONCLUSION This meta-analysis confirms that tumor size ≥ 10 mm and invasion of the muscularis propria are linked to a higher risk of LN metastases in patients with GNEN1. Overall, the metastatic propensity of GNEN1 is low with favorable 5- year disease-specific survival rates reported;hence, no clear evidence of the prognostic value of LN positivity is available. Additionally, there is a lack of evidence supporting the prediction of local recurrence in GNEN1, even if surgery was more often a definitive treatment.

Giant colonic diverticulum,clinical presentation,diagnosis and treatment: Systematic review of 166 cases

AIM: To investigate the clinical presentation,diagnosis,and treatment of giant colonic diverticulum(GCD,by means of a complete and updated literature review).GCD is a rare manifestation of diverticular disease of the colon.Less than 200 studies on GCD were published in the literature,predominantly case reports or small patient series.METHODS: A systematic review of the literature was performed using the Embase and PubM ed databases toidentify all the GCD studies.The following MESH search headings were used: "giant colonic diverticulum"; "giant sigmoid diverticulum".The "related articles" function was used to broaden the search,and all of the abstracts,studies,and citations were reviewed by two authors.The following outcomes were of interest: the disease and patient characteristics,study design,indications for surgery,type of operation,and postoperative outcomes.Additionally,a subgroup analysis of cases treated in the last 5 years was performed to show the current trends in the treatment of GCD.A GCD case in an elderly patient treated in our department by a sigmoidectomy with primary anastomosis and a diverting ileostomy is presented as a typical example of the disease.RESULTS: In total,166 GCD cases in 138 studies were identified in the literature.The most common clinical presentation was abdominal pain,which occurred in 69% of the cases.Among the physical signs,an abdominal mass was detected in 48% of the cases,whereas 20% of the patients presented with fever and 14% with abdominal tenderness.Diagnosis is based predominantly on abdominal computed tomography.The most frequent treatment was colic resection with en-bloc resection of the diverticulum,performed in 57.2% of cases,whereas Hartmann's procedure was followed in 11.4% of the cases and a diverticulectomy in 10.2%.An analysis of sixteen cases reported in the last 5 years showed that the majority of patients were treated with sigmoidectomy and en-bloc resection of the diverticulum; the postoperative mortality was null,morbidity was very low(1 patient was hospitalized in the intensive care unit for postoperative hypotension),and the patients were discharged 4-14 d after surgery.CONCLUSION: Giant colonic diverticulum is a rare manifestation of diverticular diseases.Surgical treatment,consisting predominantly of colonic resection with en bloc resection of the diverticulum,is thepreferred option for GCD and guarantees excellent results.