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. .

Risk factors for anastomotic fistula development after radical colon cancer surgery and their impact on prognosis

BACKGROUND Colon cancer is a common malignant tumor in the gastrointestinal tract that is typically treated surgically.However,postradical surgery is prone to complic-ations such as anastomotic fistulas.AIM To investigate the risk factors for postoperative anastomotic fistulas and their impact on the prognosis of patients with colon cancer.METHODS We conducted a retrospective analysis of 488 patients with colon cancer who underwent radical surgery.This study was performed between April 2016 and April 2019 at a tertiary hospital in Wuxi,Jiangsu Province,China.A t-test was used to compare laboratory indicators between patients with and those without postoperative anastomotic fistulas.Multiple logistic regression analysis was performed to identify independent risk factors for postoperative anastomotic fistulas.The Functional Assessment of Cancer Therapy-Colorectal Cancer was also used to assess postoperative recovery.RESULTS Binary logistic regression analysis revealed that age[odds ratio(OR)=1.043,P=0.015],tumor,node,metastasis stage(OR=2.337,P=0.041),and surgical procedure were independent risk factors for postoperative anastomotic fistulas.Multiple linear regression analysis showed that the development of postoperative anastomotic fistula(P=0.000),advanced age(P=0.003),and the presence of diabetes mellitus(P=0.015),among other factors,independently affected CONCLUSION Postoperative anastomotic fistulas significantly affect prognosis and survival rates.Therefore,focusing on the clinical characteristics and risk factors and immediately implementing individualized preventive measures are important to minimize their occurrence.

Surgical management of pancreatic neuroendocrine neoplasms

Pancreatic neuroendocrine neoplasms are a rare and complex group of neoplastic lesions that develop from pancreatic islet cells.Their incidence has dramatically increased during the last two decades.Due to its complex nature and pathophysiological behaviour,surgical management continues to evolve.Surgery remains the cornerstone of treatment for most non-functional and functional pancreatic neuroendocrine tumours,while lymphadenectomy remains a controversial subject.Different techniques,such as pancreas-preserving and minimally invasive approaches,continue to evolve and offer the same overall outcomes as open surgery.This comprehensive review describes in detail the current and most up-todate classification and staging of pancreatic neuroendocrine tumours,explores the rationale for nonsurgical and surgical management,and focuses on surgical treatment and more specifically,on minimally invasive approaches.

Robotic complete mesocolic excision for right colon cancer:Learning curve,training,techniques,approach,platforms,and future perspectives

Colon cancer has the fifth highest incidence worldwide and has the sixth highest mortality.Compared with rectal cancer,colon cancer currently has the worst 5-year overall survival for patients with stage Ⅱ and Ⅲ disease.Complete mesocolic excision has been developed as a standardized and optimized surgical technique for the excision of colon cancers.This technique has traditionally been performed through an open approach since laparoscopy is generally considered technically challenging.The robotic approach has been slowly implemented for colon cancer,but the newest robotic platforms allow for a safer and optimized approach for right colon cancer.Several robotic approaches have been developed and explored.The expansion of the current robotic platform ecosystem is gradually providing new outputs in the application of the robotic approach to complete mesocolic excision.This review gains an oversight of existing literature on robotic complete mesocolic excision for right colon cancer(learning curve,training,techniques,approach,platforms,and future perspectives).

Solid pseudopapillary tumor of the pancreas:A systematic review of clinical,surgical and oncological characteristics of 1384 patients underwent pancreatic surgery

Background:Pancreatic solid pseudopapillary tumors(SPTs)are rare clinical entity,with low malignancy and still unclear pathogenesis.They account for less than 2%of exocrine pancreatic neoplasms.This study aimed to perform a systematic review of the main clinical,surgical and oncological characteristics of pancreatic SPTs.Data sources:MEDLINE/PubMed,Web of Science and Scopus databases were systematically searched for the main clinical,surgical and oncological characteristics of pancreatic SPTs up to April 2021,in accordance with the preferred reporting items for systematic reviews and meta-analyses(PRISMA)standards.Primary endpoints were to analyze treatments and oncological outcomes.Results:A total of 823 studies were recorded,86 studies underwent full-text reviews and 28 met inclusion criteria.Overall,1384 patients underwent pancreatic surgery.Mean age was 30 years and 1181 patients(85.3%)were female.The most common clinical presentation was non-specific abdominal pain(52.6%of cases).Mean overall survival was 98.1%.Mean recurrence rate was 2.8%.Mean follow-up was 4.2 years.Conclusions:Pancreatic SPTs are rare,and predominantly affect young women with unclear pathogenesis.Radical resection is the gold standard of treatment achieving good oncological impact and a favorable prognosis in a yearly life-long follow-up.

Risk of appendiceal neoplasm in patients with appendix disorders

The most common appendicular disease is acute appendicitis,with a lifetime risk of 7%–8%.Complicated cases,which can occur in 2%–7%of patients,can signi-ficantly impact the severity of the condition and may require different manage-ment approaches.Nonoperative management with possible delayed appende-ctomy has been suggested for selected patients,however,there is a non-negligible risk of missing an underlying malignancy,which is reported to be as high as 11%.Diagnostic work-up is paramount to achieve optimal treatment with good results.

Malignant myopericytoma originating from the colon: A case report

BACKGROUND Myopericytoma is a benign tumor that typically occurs within subcutaneous tissue and most often involves the distal extremities,followed by the proximal extremities,neck,thoracic vertebrae and oral cavity.Complete resection is often curative.Malignant myopericytoma is extremely rare and has a poor prognosis.Here,we report for the first time a case of malignant myopericytoma originating from the colon.CASE SUMMARY A 69-year-old male was admitted to our hospital with right upper quadrant pain for five days.Imaging suggested a liver mass with hemorrhage.A malignant hepatic tumor was the initial diagnosis.Surgical resection was performed after a complete preoperative work up.Initial postoperative pathology suggested that the mass was a malignant myoblastoma unrelated to the liver.Four months after the first surgery,an enhanced computed tomography(CT)scan revealed a recurrence of the tumor.The diagnosis of malignant myopericytoma derived from the colon was confirmed on histopathological examination of the specimen from the second surgery.The patient did not return to the hospital regularly for surveillance.The first postoperative abdominal CT examination six months after the second surgery demonstrated multiple liver metastases.Survival time between the diagnosis of the tumor to death was approximately one year.CONCLUSION Malignant myopericytoma is a rare cancer.Preoperative diagnosis may be difficult.Due to a lack of treatment options,prognosis is poor.

Quality assessment of surgery for colorectal cancer:Where do we stand?

Quality assurance in surgery has been one of the most important topics of debate among colorectal surgeons in the past decade.It has produced new surgical standards that led in part to the impressive oncological outcomes we see in many units today.Total mesorectal excision,complete mesocolic excision(CME),and the Japanese D3 lymphadenectomy are now benchmark techniques embraced by many surgeons and widely recommended by surgical societies.However,there are still ongoing discrepancies in outcomes largely based on surgeon performance.This is one of the main reasons why many countries have shifted colorectal cancer surgery only to high volume centers.Defining markers of surgical quality is thus a perquisite to ensure that standards and oncological outcomes are met at an institutional level.With the evolution of CME surgery,various quality markers have been described,mostly based on measurements on the surgical specimen and lymph node yield,while others have proposed radiological markers(i.e.arterial stumps)measured on postoperative scans as part of the routine cancer follow-up.There is no ideal marker;however,taken together and assembled into a new score or set of criteria may become a future point of reference for reporting outcomes of colorectal cancer surgery in research studies and defining subspecialization requirements both at an individual and hospital level.

Impact of dexmedetomidine-assisted anesthesia in elderly patients undergoing radical resection of colon cancer

BACKGROUND Radical resection of colon cancer under general anesthesia is one of the main treatment methods for this malignancy.However,due to the physiological charac-teristics of elderly patients,the safety of perioperative anesthesia needs special attention.As anα2-adrenergic receptor agonist,dexmedetomidine(Dex)has attracted much attention from anesthesiologists due to its stabilizing effect on heart rate and blood pressure,inhibitory effect on inflammation,and sedative and analgesic effects.Its application in general anesthesia may have a positive impact on the quality of anesthesia and postoperative recovery in elderly patients undergoing radical resection of colon cancer.METHODS A total of 165 colon cancer patients who underwent radical surgery for colon cancer under general anesthesia at Qingdao University Affiliated Haici Hospital,Qingdao,China were recruited and divided into two groups:A and B.In group A,Dex was administered 30 min before surgery,while group B received an equivalent amount of normal saline.The hemodynamic changes,pulmonary compliance,airway pressure,inflammatory factors,confusion assessment method scores,Ramsay Sedation-Agitation Scale scores,and cellular immune function indicators were compared between the two groups.RESULTS Group A showed less intraoperative hemodynamic fluctuations,better pulmonary compliance,and lower airway resistance compared with group B.Twelve hours after the surgery,the serum levels of TLR-2,TLR-4,IL-6,and TNF-αin group A were significantly lower than those of group B(P<0.05).After extubation,the Ramsay Sedation-Agitation Scale score of group A patients was significantly higher than that of group B patients,indicating a higher level of sedation.The incidence of delirium was significantly lower in group A than in group B(P<0.05).CONCLUSION The use of Dex as an adjunct to general anesthesia for radical surgery in elderly patients with colon cancer results in better effectiveness of anesthesia.

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.

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.

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.

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.

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.

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.

Prognostic factors of young patients with colon cancer after surgery

AIM： To investigate the prognostic factors of 96 young patients with colon cancer within a cancer center by univariate and multivariate analysis. METHODS： A total of 723 patients with colon cancer were treated surgically during a period of 10 years. Ninty six of them were 40 years old or younger. R0, R1 and R2 operations were performed in 69 （71.9%）, 4 （4.1%） and 23 patients （24%）, respectively. Left hemicolectomy was performed in 43 patients, right hemicolectomy in 37 patients, transverse colon resection in 9 patients and low anterior resection in 7 patients. Cox multivariate regression analysis was performed to identify predictors of survival. RESULTS： The operation mortality was 0%, 54 patients died within 111 mo after operation due to occurrence or metastases of the tumor. Liver, lung and bone metastases occurred in 3, 1 and 5 patients, respectively. The mean survival time for all patients was 77.9 ± 5.01 mo and the overall 3-, 5- and 10- year survival rates were 66.68%, 58.14% and 46.54%, respectively. In the univariate survival analysis, patient age, type of operation, radical resection, blood transfusion, histological type, diameter of tumor, depth of tumor invasion, lymphatic invasion, distant metastases, liver metastases and TNM stage were found to be predictors of survival in young patients with colon cancer. In the Cox-regression analysis, blood transfusion and lymphatic invasion were determined as independent prognostic factors of survival. CONCLUSIONS： Age, type of operation, radical resection, blood transfusion, histological type, diameter of tumor, depth of tumor invasion, lymphatic invasion, distant metastasis and TNM stage are the predictors of survival in young patients with colon cancer after surgery.

Update on surgical treatment of pancreatic neuroendocrine neoplasms

Pancreatic neuroendocrine neoplasms(PNENs) are rare and account for only 2%-4% of all pancreatic neoplasms. All PNENs are potential(neurendocrine tumors PNETs) or overt(neuroendocrine carcinomas PNECs) malignant,but a subset of PNETs is low-risk. Even in case of low-risk PNETs surgical resection is frequently required to treat hormone-related symptoms and to obtain an appropriate pathological diagnosis. Low-risk PNETs in the body and the tail are ideal for minimallyinvasive approaches which should be tailored to the individual patient. Generally,surgeons must aim for parenchyma sparing in these cases. In high-risk and malignant PNENs,indications for tumor resection are much wider than for pancreatic adenocarcinoma,in many cases due to the relatively benign tumor biology. Thus,patients with locally advanced and metastatic PNETs may benefit from extensive resection. In experienced hands,even multi-organ resections are accomplished with acceptable perioperative morbidity and mortality rates and are associated with excellent long term survival. However,poorly differentiated neoplasms with high proliferation rates are associated with a dismal prognosis and may frequently only be treated with chemotherapy. The evidence on surgical treatment of PNENs stems from reviews of mostly singlecenter series and some analyses of nation-wide tumor registries. No randomized trial has been performed to compare surgical and non-surgical therapies in potentially resectable PNEN. Though such a trial would principally be desirable,ethical considerations and the heterogeneity of PNENs preclude realization of such a study. In the current review,we summarize recent advances in the surgical treatment of PNENs.

Perivascular epithelioid cell neoplasm of the colon

A 17-year-old female presented with rectal bleeding from an ulcerated sigmoid mass in 1994.Initial pathological evaluation revealed a rare clear cell neoplasm of the colon,possibly originating from kidneys,adrenals,lung or a gynecologic source as a metastatic lesion.Extensive imaging studies were negative,and over the next 15 years,she remained well with no recurrence.The original resected neoplasm was reviewed and reclassified as a perivascular epithelioid cell neoplasm (PEComa).Although the long-term natural history of PEComas requires definition,increased clinical and pathological awareness should lead to increased recognition of an apparently rare type of colonic neoplasm that likely occurs more often than is currently appreciated.