Subclinical paraganglioma of the retroperitoneum:A case report

BACKGROUND Paraganglioma(PGL)located in the retroperitoneum presents challenges in diagnosis and treatment due to its hidden location,lack of specific symptoms in the early stages,and absence of distinctive manifestations on imaging.CASE SUMMARY A 56-year-old woman presented with a left upper abdominal mass discovered 1 wk ago during a physical examination.She did not have a history of smoking,alcohol consumption,or other harmful habits,no surgical procedures or infectious diseases,and had a 4-year history of hypertension.Upon admission,she did not exhibit fever,vomiting,or abdominal distension.Physical examination indicated mild percussion pain in the left upper abdomen,with no palpable enlargement of the liver or spleen.Laboratory tests and tumor markers showed no significant abnormalities.Enhanced computed tomography and magnetic resonance imaging of the upper abdomen revealed a cystic solid mass in the left epigastrium measuring approximately 6.5 cm×4.5 cm,with inhomogeneous enhancement in the arterial phase,closely associated with the lesser curvature of the stomach and the pancreas.The patient underwent laparoscopic resection of the retroperitoneal mass,which was successfully removed without tumor rupture.A 12-month postoperative follow-up period showed good recovery.CONCLUSION This case report details the successful laparoscopic resection of a retroperitoneal subclinical PGL,resulting in a good recovery observed at the 12-month follow-up.Interestingly,the patient also experienced unexpected cure of hypertensive disease.

C634Y mutation in RET-induced multiple endocrine neoplasia type 2A:A case report

BACKGROUND Multiple endocrine neoplasia type 2(MEN2)is a rare,autosomal dominant endocrine disease.Currently,the RET proto-oncogene is the only gene implicated in MEN2A pathogenesis.Once an RET carrier is detected,family members should be screened to enable early detection of medullary thyroid carcinoma,pheochromocytoma,and hyperparatitity.Among these,medullary thyroid carcinoma is the main factor responsible for patient mortality.Accordingly,delineating strategies to inform clinical follow-up and treatment plans based on genes is paramount for clinical practitioners.CASE SUMMARY Herein,we present RET proto-oncogene mutations,clinical characteristics,and treatment strategies in a family with MEN2A.A family study was conducted on patients diagnosed with MEN2A.DNA was extracted from the peripheral blood of family members,and first-generation exon sequencing of the RET protooncogene was conducted.The C634Y mutation was identified in three family members spanning three generations.Two patients were sequentially diagnosed with pheochromocytomas and bilateral medullary thyroid carcinomas.A 9-yearold child harboring the gene mutation was diagnosed with medullary thyroid carcinoma.Surgical resection of the tumors was performed.All family members were advised to undergo complete genetic testing related to the C634Y mutation,and the corresponding treatments administered based on test results and associated clinical guidelines.CONCLUSION Advancements in MEN2A research are important for familial management,assessment of medullary thyroid cancer invasive risk,and deciding surgical timing.

Utilizing bioinformatics for integrated analysis of multiple genes in the diagnosis and pathogenesis of metastatic pheochromocytoma and paraganglioma

Objective:The aim of the study was to investigate effective diagnostic molecular markers and the specific mechanisms of metastatic pheochromocytomas and paragangliomas(PPGLs).Methods:Data were collected from GEO datasets GSE67066 and GSE60458.The R software and various packages were utilized for the analysis of differentially expressed genes,Gene Ontology analysis,Kyoto Encyclopedia of Genes and Genomes analysis,receiver operating characteristic curve assessment,logistic model construction,and correlation analysis.The NetworkAnalyst tool was used to analyze gene-miRNA interactions and signaling networks.In addition,the TIMER database was used to estimate the immune scores.Results:A total of 203 and 499 differentially expressed genes were identified in GSE67066 and GSE60458,respectively.These genes are implicated in cytokine and cytokine receptor interactions,extracellular matrix–receptor interactions,and platelet activation signaling pathways.Notably,MAMLD1,UST,MATN2,LPL,TWIST1,SFRP4,FRMD6,RBM24,PRIMA1,LYPD1,KCND2,CAMK2N1,SPOCK3,and ALPK3 were identified as the key genes.Among them,MATN2 and TWIST1 were found to be coexpressed with epithelial-mesenchymal transition–linked markers,whereas KCND2 and LPL exhibited associations with immune checkpoint expression and immune cell infiltration.Eight miRNAs were identified as potential regulators of key gene expression,and it was noted that TWIST1 might be regulated by SUZ12.Notably,the area under the curve of the 4-gene model for distinguishing between malignant and benign groups was calculated to be 0.918.Conclusions:The combined gene and mRNA expression model enhances the diagnostic accuracy of assessing PPGL metastatic potential.These findings suggest that multiple genes may play a role in the metastasis of PPGLs through the epithelial-mesenchymal transition and may influence the immune microenvironment.

Twenty-six patients with nonfunctional pheochromocytomas

Nonfunctional pheochromocytoma is a particular type of pheochromocytoma without typical clinical features of catecholaminism. It is difficult to diagnose or differentially diagnose. This type of pheochromocytoma is rarely reported in the literature. From January 1, 1990 to June 1, 2004, we performed operations for 197 patients with pheochromocytomas, including 26 patients with nonfunctional pheochromocytoma. We analyzed the clinical data of the 26 patients.

Robot-assisted adrenalectomy:Step-by-step technique and surgical outcomes at a high-volume robotic center

Objective In the last years,robotic surgery was introduced in several different settings with good perioperative results.However,its role in the management of adrenal masses is still debated.In order to provide a contribution to this field,we described our step-by-step technique for robotic adrenalectomy(RA)and related modifications according to the type of adrenal mass treated.Methods We retrospectively analyzed 27 consecutive patients who underwent RA at Onze-Lieve-Vrouw hospital(Aalst,Belgium)between January 2009 and October 2022.Demographic,intra-and post-operative,and pathological data were retrieved from our prospectively maintained institutional database.Continuous variables are summarized as median and interquartile range(IQR).Categorical variables are reported as frequencies(percentages).Results Twenty-seven patients underwent RA were included in the study.Median age,body mass index,and Charlson's comorbidity index were 61(IQR:49-71)years,26(IQR:24-29)kg/m^(2),and 2(IQR:0-3),respectively,and 16(59.3%)patients were male.Median tumor size at computed tomography scan was 6.0(IQR:3.5-8.0)cm.Median operative time and blood loss were 105(IQR:82-120)min and 175(IQR:94-250)mL,respectively.No intraoperative complications were recorded.Overall postoperative complications rate was 11.1%,with a postoperative transfusion rate of 3.7%.A total of 10(37.0%)patients harbored malignant adrenal masses.Among them,3(11.1%)had adrenocortical carcinoma,6(22.2%)secondary metastasis,and 1(3.7%)malignant pheochromocytoma on final pathological exam.Only 1(10.0%)patient had positive surgical margins.Conclusion We described our step-by-step technique for RA,which can be safely performed even in case of high challenging settings as malignant tumors,pheochromocytoma,and large masses.The standardization of perioperative protocol should be encouraged to maximize the outcomes of this complex surgical procedure.

Extrasurrenal Pheochromocytoma: A Case Report and Review of the Literature

Introduction: Pheochromocytoma is a rare cause of endocrine hypertension. We report the case of an extra-adrenal pheochromocytoma discovered in the setting of an abdominal mass. Observation: The patient was 25-year-old and presented with headaches, excessive sweating and palpitations, followed by a sensation of abdominal weightlessness and diastolic arterial hypertension. Abdominal computed tomography revealed a retroperitoneal, right para-renal extra-adrenal mass. In biology, an increase in urinary methoxylated derivatives at the expense of normetanephrine. Conclusion: Pheochromocytoma is a rare disease, diagnosed by measuring urinary or plasma methoxylated derivatives. Conventional or nuclear imaging allows topographic diagnosis. Genetic studies helps to identify other tumors.

Recurrent Myocardial Infarction and Catecholamine-Induced Cardiomyopathy:A Case Report

Pheochromocytomas or paragangliomas are rare and the diagnosis remains a challenge for clinicians.We present a woman suffering from recurrent myocardial infarction and cardiomyopathy,who was finally diagnosed with paraganglioma.Pheochromocytomas or paraganglioma should be considered in the differential diagnosis of a patient with symptoms possibly referring to acute coronary syndrome and cardiomyopathy.

Determination of urine catecholamines and metanephrines by reversed-phase liquid chromatography-tandem mass spectrometry

The measurement of urine catecholamine and metanephrine concentrations is important for biochemical screening and diagnosis of pheochromocytoma.The goal of this work was to develop a simple liquid chromatography-tandem mass spectrometry(LC-MS/MS)method for determining catecholamines and metanephrines in urine to replace an existing liquid chromatographic method using electrochemical detection.Urine samples were prepared using Oasis weak-cation-exchange cartridges.The eluate was analyzed on an Agilent ZORBAX Eclipse Plus Phenyl-Hexyl column in 3 min.Adrenaline,noradrenaline,dopamine,metanephrine,normetanephrine,and their deuterated internal standards were monitored in positive electrospray ionization mode by multiple reaction monitoring(MRM).No evidence of ion suppression was observed.The assay was linear up to 5μmol/L for adrenaline,5μmol/L for noradrenaline,6.1μmol/L for dopamine,5.6μmol/L for metanephrine,and 34.6μmol/L for normetanephrine,with lower limits of quantification of 5,5,12,6 and 7nmol/L,respectively.The intra-day and inter-day precisions for all analytes ranged from 0.59%to 4.64%and1.98%to 4.80%,respectively.External quality assurance samples were assayed and showed excellent agreement with the target values.This simple method provides an improved assay for determining urine catecholamines and metanephrines.

Retroperitoneal paragangliomas : 4 个案例的报告

We reviewed the data of all patients managed for retroperitoneal paragangliomas(PGLs)between June 2010and June 2011 to present our experience concerning this uncommon entity to highlight diagnostic and therapeutic challenges of retroperitoneal PGLs.All patients were admitted to the department of general and hepatobiliary surgery in the regional hospital of Jendouba,Tunisia.The size of the tumor was taken at its largest dimension,as determined in a computed tomography(CT)scan and pathological reports.There were 4 patients(all women)with a median age of 48 years(range46-56 years).Abdominal pain was the commonest presentation.CT showed and localized the tumors which were all retroperitoneal.All patients had successfu surgical resection of the tumors under invasive arterial blood pressure monitoring.One patient underwent surgery for a presumed tumor of the pancreatic head.The fresh-mount microscopic study of the peroperative biopsy yielded inflammatory tissue without malignancy and no resection was performed.Final histologica examination of the biopsy concluded PGL.A secondlaparotomy was performed and the tumor was entirely resected.The diagnosis was made after surgery by histology in all patients.The control of the blood pressure was improved after surgery in 3 patients.Paragangliomas are rare tumors.The retroperitoneal localization is uncommon.Complete surgical resection remains the only curative treatment but it is often challenging as these tumors are located near multiple vital blood vessels.

Protective effects of MCI-186 on oxidative damage in a cell model of Alzheimer's disease

Oxidative stress has an important role in the development of Alzheimer＇s disease （AD）. Beta amyloid protein 25-35 （Aβ25-35） can generate oxygen free radicals, and MCI-186 （3-methyl-l-phenyl-2-pyrazolin-5-one, edaravone） can specifically eliminate hydroxyl radicals. The present study introduced Aβ25-35 into PC12 cells to establish a cell model of AD, and investigated the neuroprotective effects of MCI-186 on AD. Results showed that MCI-186 had a positive effect on the prevention and treatment of AD by inhibiting protein oxidative products, advanced glycation end products, lipid oxidative end products and DNA oxidative damage in PC12 cells induced by Aβ25-35.

Endocrine radionuclide scintigraphy with fusion single photon emission computed tomography/computed tomography

AIM: To review the benefits of single photon emission computed tomography(SPECT)/computed tomography(CT) hybrid imaging for diagnosis of various endocrine disorders.METHODS: We performed MEDLINE and Pub Med searches using the terms: "SPECT/CT"; "functional anatomic mapping"; "transmission emission tomography"; "parathyroid adenoma"; "thyroid cancer"; "neuroendocrine tumor"; "adrenal"; "pheochromocytoma"; "paraganglioma"; in order to identify relevant articles published in English during the years 2003 to 2015. Reference lists from the articles were reviewed to identify additional pertinent articles. Retrieved manuscripts(case reports, reviews, meta-analyses and abstracts) concerning the application of SPECT/CT to endocrine imaging were analyzed to provide a descriptive synthesis of the utility of this technology.RESULTS: The emergence of hybrid SPECT/CT camera technology now allows simultaneous acquisition of combined multi-modality imaging, with seamless fusion of three-dimensional volume datasets. The usefulness of combining functional information to depict the biodistribution of radiotracers that map cellular processes of the endocrine system and tumors of endocrine origin, with anatomy derived from CT, has improved the diagnostic capability of scintigraphy for a range of disorders of endocrine gland function. The literature describes benefits of SPECT/CT for ^(99m)Tc-sestamibi parathyroid scintigraphy and ^(99m)Tc-pertechnetate thyroid scintigraphy, ^(123)I- or ^(131)I-radioiodine for staging of differentiated thyroid carcinoma, ^(111)In- and ^(99m)Tclabeled somatostatin receptor analogues for detection of neuroendocrine tumors, ^(131)I-norcholesterol(NP-59) scans for assessment of adrenal cortical hyperfunction, and ^(123)I- or ^(131)I-metaiodobenzylguanidine imaging for evaluation of pheochromocytoma and paraganglioma.CONCLUSION: SPECT/CT exploits the synergism between the functional information from radiopharmaceutical imaging and anatomy from CT, translating to improved diagnostic accuracy and meaningful impact on patient care.

Anesthetic management of bilateral pheochromocytoma resection in Von Hippel-Lindau syndrome:A case report

BACKGROUND Von Hippel-Lindau disease(also known as VHL syndrome),is an autosomal dominant inherited disease.We describe a sporadic case of VHL syndrome where bilateral pheochromocytomas were unexpectedly identified.The patient underwent selective laparoscopic resections of the pheochromocytomas,and the anesthetic management during surgery was complex and challenging.CASE SUMMARY A 22-year-old man presented to our hospital to seek medical advice for infertility without any other complaints.The results of computed tomography and catecholamine levels in blood and urine demonstrated adrenal gland masses which were diagnosed as pheochromocytomas.Further examination confirmed that the patient also had VHL syndrome.After thorough preparation,the patient underwent selective laparoscopic resection of the pheochromocytomas and was discharged 10 d after surgery.We describe the process of perioperative anesthesia management in this patient undergoing pheochromocytoma resection.CONCLUSION This case summaries specific clinical traits and considerations in perioperative anesthesia management for VHL syndrome patients undergoing bilateral pheochromocytoma resection.

Mesenteric paraganglioma: Report of a case

We report a rare case of paraganglioma that developed in the mesentery of terminal ileum. A 78-year-old woman complained of right-sided abdominal pain. Abdominal computed tomography revealed a solid heterogeneously enhanced mass in the right lower abdomen. The tumor was laparoscopically excised. The mesenteric tumor was well circumscribed, ovoid, and encapsulated and measured 3 cm × 1.5 cm × 1.5 cm. Histological examination showed a cellular neoplasm comprised of nests and groups of tumor cells separated by fibrovascular connective tissue, giving a characteristic nested Zellballen pattern. Immunohistochemically, the tumor cells were positive for chromogranin, synaptophysin, CD56, and vimentin and negative for cytokeratins, SMA, CD34, CD117/c-kit and S100. On the basis of histologic and immunohistochemical features, a diagnosis of mesenteric paraganglioma was made. The operative and postoperative courses were unremarkable, and the patient was discharged on postoperative day 7. She was doing well 1 year after the surgery with no signs of recurrence. Extra-adrenal paragangliomas most commonly develop adjacent to the aorta, particularly the area corresponding to the organ of Zuckerkandl. Mesenteric paraganglioma, as in our case, is extremely rare; only 11 cases have been reported in the literature. We herein discuss the clinical findings of these cases.

Endocrine hypertension:An overview on the current etiopathogenesis and management options

Endocrine causes of secondary hypertension include primary aldosteronism,pheochromocytoma,cushing's syndrome,hyperparathyroidism and hypo-and hyperthyroidism.They comprise 5%-10% of the causes of secondary hypertension.Primary hyperaldosteronism,the most common of the endocrine cause of hypertension often presents with resistant or difficult to control hypertension associated with either normo-or hypokalemia.Pheochromocytoma,a great mimicker of many conditions,is associated with high morbidity and mortality if left untreated.A complete history including pertinent family history,physical examination along with a high index of suspicion with focused biochemical and radiological evaluation is important to diagnose and effectively treat these conditions.The cost effective targeted genetic screening for current known mutations associated with pheochromocytoma are important for early diagnosis and management in family members.The current review focuses on the most recent evidence regarding causes,clinical features,methods of diagnosis,and management of these conditions.A multidisciplinary approach involving internists,endocrinologists and surgeons is recommended in optimal management of these conditions.

Management of bladder pheochromocytoma by transurethral resection

Bladder pheochromocytoma is the most common extra-adrenal genitourinary tumor.Endoscopic management is feared due to the risk of intra-operative hypertensive crisis.We described a case of successful endoscopic management of a bladder pheochromocytoma and discussed its technical aspects.

Pheochromocytoma and stress cardiomyopathy:Insight into pathogenesis

AIM To investigate the occurrence of cardiomyopathy(CMP)in a cohort of patients with histologically proven pheochromocytoma(pheo),and to determine if catecholamine excess was causative of the left ventricular(LV)dysfunction.METHODS A retrospective chart review spanning years 1998through 2014 was undertaken and patients with a diagnosis of pheo confirmed with histopathologic examination were included.Presenting electrocardiograms and cardiac imaging studies were reviewed.Transthoracic echocardiography(TTE),ventriculography or single positron emission computed tomography imaging was evaluated and if significant abnormalities[left ventricular hypertrophy(LVH)or LV dysfunction]were noted in the pre operative period a follow up post-operative study was also analyzed.Multivariate analysis using logistic regression was used to investigate independent predictors for outcomes of interest,LV dysfunction and LVH.RESULTS We identified 18 patients with diagnosis of pheo confirmed on pathology.Mean age was 54.3±19.3years and 11(61.1%)patients were females.50%of such patients had either resistant hypertension or labile blood pressures during hospitalization,which had raised suspicion for a pheo.Cardiac imaging studies were available for 12(66.7%)patients at the time of inclusion into study and preceding the adrenalectomy.7(58.3%)patients with a TTE available for review had mild or more severe LVH while 3(25%)patients had LV dysfunction of presumably acute onset.In a multivariate analysis,elevated catecholamine levels as assessed by urinary excretion of metabolites was not an independent predictor of development of LV systolic dysfunction or of presence of LVH on TTE.Two female patients with a preceding history of hypertension had marked LV hypertrophy and systolic anterior motion of the mitral valve.Prolongation of the QTc interval was noted in 5(27.8%)patients but no acute arrhythmias were observed in any patient.CONCLUSION This study adds to the growing body of literature on the predilection of patients with pheochromocytomas to develop non-ischemic CMP.Degree of catecholamine excess as measured by urinary secretion of metabolites did not predict the development of CMP but 2 of 3patients developed CMP in the setting of significant acute physiologic stress.Our findings provide support to the proposed etiologic role of elevated catecholamines in TC and other stress induced forms of CMP,however,activation of a brain-neural-cardiac axis from acute stress and local release of catecholamines but not chronic catecholamine elevations are likely to be responsible in pheo related CMP.

Robot-Assisted Laparoscopic Resection of Large-Volume Pheochromocytoma through the Surface of the Kidney

Objective: To investigate the clinical application of robot-assisted laparoscopic surgery on the treatment of large-volume pheochromocytoma. Methods: A retrospective analysis of 31 patients with pheochromocytoma disease admitted to the Department of Urology, Affiliated Hospital of Hebei University from May 2020 to August 2021. According to clinical data, the tumor volume was 62.4 ± 29.5 mm, including 16 males and 15 females, aged (35.6 ± 16.1) years old;17 cases on the left side and 14 cases on the right side. All patients underwent anatomical resection through the renal superficial approach, and underwent pheochromocytoma resection through the retroperitoneal approach. The operation time, blood loss, postoperative complications, retention time of drainage tube and postoperative follow-up were observed. Results: All the 31 operations were successful, and there were no obvious postoperative complications. The average operation time, blood loss, and drainage tube retention time were 71 min, 80 mL, and (1.2 ± 0.6) days, respectively. Postoperative pathology was confirmed to be pheochromocytoma. There was no tumor recurrence in the follow-up for 1 - 15 months. Conclusion: Robot-assisted laparoscopic anatomical resection of large-volume pheochromocytoma through the renal surface of the abdominal cavity can provide a larger operating space during the operation, with clear anatomical landmarks of “lipocrasis”, less bleeding, less trauma, intraoperative and postoperative. The advantages of fewer complications, procedural operation, and shorter learning curve can be promoted in clinical practice.

Multivessel coronary artery ectasia and severe calcification in a patient with pheochromocytoma:a case report

Multivessel coronary artery ectasia with severe calcification is rare among patients with coronary artery disease. A 74-year-old Chinese woman suffered from acute myocardial infarction on a background of 50 years of poorly controlled hypertension secondary to pheochromocytoma, which was surgically removed in June 2012 prior to the presentation. Coronary angiography revealed total occlusion of the proximal left anterior descending artery, and multiple ectasias with severe calcification in the left main, circumflex and right coronary artery. After an aspiration thrombectomy and balloon angioplasty, grade 3 coronary flow was restored in the left descending coronary artery. No cardiac events were found in the 12-month follow-up. We conclude that multivessel coronary artery ectasia and severe calcification may be present in patients with a long-standing history of hypertension secondary to pheochromocytoma.

Thoracotomy of an asymptomatic, functional, posterior mediastinal paraganglioma: A case report

BACKGROUND Paragangliomas in the mediastinum are rare, accounting for only 1%-2% of all paragangliomas and < 0.3% of all mediastinal tumors. Most paragangliomas are nonfunctional, therefore, asymptomatic functional paragangliomas in the left posterior mediastinum are extremely rare. Perioperative management including preoperative preparation, careful intraoperative procedures, and strict postoperative care is important, and one-stage surgical resection should be performed only after appropriate perioperative measures are undertaken. Because those tumors are rare, it is necessary to report known cases to raise awareness regarding them. CASE SUMMARY We report the case of a 47-year-old male who was admitted to our hospital with the chief complaints of intermittent tearing pain on the left side of the chest and back for more than 10 mo. A chest contrast-enhanced computed tomography scan revealed a round, solid mass in the left posterior mediastinum, with low-density cystic lesions in the middle, and no enlarged lymph nodes in the hilum or mediastinum (Figure 1). After the diagnosis of paraganglioma, the patient was preoperatively given an oral adrenoceptor blocking drug (phenoxybenzamine), and intravenous fluid resuscitation for two weeks, subsequently the patient underwent a one-stage resection of lesions via left thoracotomy. The patient’s blood pressure increased to 220/120 mmHg when the tumor was touched, which could be relieved by symptomatic treatment such as accelerating liquid transfusion or other intervention to lower blood pressure. The patient recovered uneventfully after surgery, with no abnormal blood pressure or recurrence during one year of follow-up visits.CONCLUSION Surgical resection is the preferred treatment for asymptomatic functional paragangliomas.

Surgical treatment of large pheochromocytoma(>6 cm):A 10-year single-center experience

Objective:Clinical practice guidelines recommend open adrenalectomy(OA)for large pheochromocytoma(LPCC)>6 cm in size.Although laparoscopic adrenalectomy(LA)for the treatment of LPCC has been reported,its role remains unclear.This study aimed to compare the effectiveness of LA and OA,and summary the surgical treatment experience.Methods:Data concerning LPCC,from January 2010 to June 2019 of a single institution,were retrospectively reviewed.Altogether 82 patients with a tumor larger than 6 cm were included(52 patients in LA group and 30 patients in OA group).Groups were balanced by propensity score matching(PSM)into 15 pairs.Patients’demographics,preoperative characteristics,and prognosis were analyzed.Results:Before PSM,the OA group had larger tumor sizes(median[interquartile range,IQR]:8.9[7.3-10.3]vs.7.2[6.7-8.0]cm;p=0.000)and higher vanillylmandelic acid level(median[IQR]:114.3[67.8-326.4]vs.66.6[37.8-145.8]μmol/24 h;p=0.004)and needed a higher cumulative dose of prazosin(median[IQR]:83.5[37.0-154.0]vs.38.0[21.0-81.0]mg;p=0.028).After PSM,the baseline data showed no significant differences between both groups.The LA group had relatively more stable blood pressure in surgery,with a lower fluctuation of systolic blood pressure(mean±standard deviation[SD]:70.9±25.1 vs.107.4±46.2 mmHg,p=0.012)and a lower percentage of hemodynamic instability(46.7%vs.86.7%,p=0.020).The LA group had shorter postoperative hospital stays(mean±SD:6.4±2.7 vs.10.1±3.4 days;p=0.003)than the OA group.Differences regarding metastasis rate(6.7%vs.0,p=1.000)were not statistically significant between LA and OA groups.The median(IQR)follow-up time of 82 patients was 72.5(47.0-103.5)months.Binary logistic regression showed that right-side tumors or those>8 cm in size were independent risk factors of OA.Conclusion:LA is a safe,minimally invasive procedure for LPCC and has relatively better perioperative characteristics in large medical centers.Patients with tumors on the right side or larger than 8 cm are more likely to undergo OA initially.