Role of preoperative endoscopic ultrasound-guided fine-needle tattooing of a pancreatic head insulinoma

Although insulinomas are rare, they are the most com-mon pancreatic neuroendocrine tumor, with an inci-dence of four cases per million population. Insulinomas are generally benign indolent intrapancreatic tumors. Surgical resection remains the main option for treat-ment. However, up to 67% of a pancreatic head insu-linomas are nonpalpable, thus surgical resection of the nonplapable insulinoma in this area could become prob-lematic resulting in prolonged surgical time, increased risk of pancreatic duct injury and need for pancreati-coduodenectomy. Endoscopic ultrasound-guided fine- needle tattooing(EUS-FNT), has been shown to have a crucial role for localization of pancreatic body and tail lesions, facilitating laparoscopic distal pancreatectomyand helping surgeons identify the location of the tumor. EUS-FNT might have a role for preoperative localiza-tion of pancreatic head insulinomas which are likely to be nonpalpable. We report a case of preoperative EUS-FNT for localization of a nonplapable pancreatic head insulinoma. This report demonstrates that EUS-FNT of pancreatic head insulinomas may facilitate surgical resection, reduce operative time and decrease surgical complications.     

Endoscopic ultrasound is highly accurate and directs management in patients with neuroendocrine tumors of the pancreas

Preoperative localization of pancreatic neuroendocrine tumors with traditional imaging fails in 40-60% of patients. Endoscopic ultrasound (EUS) is highly sensitive in the detection of these tumors. Previous reports included relatively few patients or required the collaboration of multiple centers. We report the results of EUS evaluation of 82 patients with pancreatic neuroendocrine tumors. METHODS: We prospectively used EUS early in the diagnostic evaluation of patients with biochemical or clinical evidence of neuroendocrine tumors. Patients had surgical confirmation of tumor localization or clinical follow-up of >1 yr. RESULTS: Eighty-two patients underwent 91 examinations (cases). Thirty patients had multiple endocrine neoplasia syndrome type 1. One hundred pancreatic tumors were visualized by EUS in 54 different patients. The remaining 28 patients had no pancreatic tumor or an extrapancreatic tumor. Surgical/pathological confirmation was obtained in 75 patients. The mean tumor diameter was 1.51 cm and 71% of the tumors were < or =2.0 cm in diameter. Of the 54 explorations with surgical confirmation of a pancreatic tumor, EUS correctly localized the tumor in 50 patients (93%). Twenty-nine insulinomas, 18 gastrinomas, as well as one glucagonoma, one carcinoid tumor, and one somatostatinoma were localized. The most common site for tumor localization was the pancreatic head (46 patients). Most tumors were hypoechoic, homogenous, and had distinct margins. EUS of the pancreas was correctly negative in 20 of 21 patients (specificity, 95%). EUS was more accurate than angiography with or without stimulation testing (secretin for gastrinoma, calcium for insulinoma), transcutaneous ultrasound, and CT in those patients undergoing further imaging procedures. EUS was not reliable in localizing extrapancreatic tumors. CONCLUSIONS: In this series, the largest single center experience reported to date, EUS had an overall sensitivity and accuracy of 93% for pancreatic neuroendocrine tumors. Our results support the use of EUS as a primary diagnostic modality in the evaluation and management of patients with neuroendocrine tumors of the pancreas.     

Endoscopic ultrasonography for preoperative diagnosis and localization of insulinomas

BACKGROUND: Endoscopic ultrasonography (EUS) is generally accepted as a sensitive method for the detection of small pancreatic tumors. We report our experience with EUS for preoperative imaging of insulinomas. METHODS: Nine patients with clinical and biochemical signs of insulinoma were examined by EUS using a 7.5/12 MHz radial-scanning ultrasound endoscope prior to surgery. EUS outcome was evaluated on the basis of surgery (open or laparoscopic) and examination of the resected specimens. RESULTS: Two EUS-negative patients appeared, by reassessment of clinical and biochemical data, not to have an insulinoma and were not operated on. EUS correctly imaged and localized five of seven insulinomas that were surgically removed. One isoechoic tumor in the pancreatic head and one pedunculated tumor connected to the caudal side of the pancreatic body were missed by EUS. EUS could demonstrate the size and shape of the imaged tumors, as well as their relationship to adjacent structures, such as the pancreatic duct, bile duct, and large vessels. CONCLUSIONS: Our experience with seven insulinomas accords with previous reports claiming EUS to be the method of choice for preoperative imaging and localization of pancreatic islet cell tumors.     

Endoscopic Ultrasonography for Preoperative Diagnosis and Localization of Insulinomas

Background: Endoscopic ultrasonography (EUS) is generally accepted as a sensitive method for the detection of small pancreatic tumors. We report our experience with EUS for preoperative imaging of insulinomas. Methods: Nine patients with clinical and biochemical signs of insulinoma were examined by EUS using a 7.5/12 MHz radial-scanning ultrasound endoscope prior to surgery. EUS outcome was evaluated on the basis of surgery (open or laparoscopic) and examination of the resected specimens. Results: Two EUS-negative patients appeared, by reassessment of clinical and biochemical data, not to have an insulinoma and were not operated on. EUS correctly imaged and localized five of seven insulinomas that were surgically removed. One isoechoic tumor in the pancreatic head and one pedunculated tumor connected to the caudal side of the pancreatic body were missed by EUS. EUS could demonstrate the size and shape of the imaged tumors, as well as their relationship to adjacent structures, such as the pancreatic duct, bile duct, and large vessels. Conclusions: Our experience with seven insulinomas accords with previous reports claiming EUS to be the method of choice for preoperative imaging and localization of pancreatic islet cell tumors.     

Determinants of surgical resection for pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (pNETs) include functioning and non‐functional tumors. Functioning tumors consist of tumors that produce a variety of hormones and their clinical effects. Therefore, determinants of resection of pNETs should be discussed for each group of tumors. Less than 10% of insulinomas are malignant, therefore more than 90% of the cases can be cured by surgical resection. Lymphadenectomy is generally not necessary in insulinoma operation. If preoperative localization of the insulinoma is completed, enucleation from the pancreatic body or tail, and distal pancreatectomy can be performed safely by laparoscopy. When preoperative localization of a sporadic insulinoma is not confirmed, surgical exploration is needed. Intraoperative localization of a tumor, intraoperative insulin sampling and frozen section are required. The crucial purpose of surgical resection is to control inappropriate insulin secretion by removing all insulinomas. Gastrinomas are usually located in the duodenum or pancreas, which secrete gastrin and cause Zollinger‐Ellison syndrome (ZES). Duodenal gastrinomas are usually small, therefore they are not seen on preoperative imaging studies or endoscopic ultrasound, and can be found only at surgery if a duodenotomy is performed. In addition, lymph node metastasis is found in 40–60% of cases. Therefore, the experienced surgeons should direct operation for gastrinomas. Surgical exploration with duodenotomy should be performed at a laparotomy. Other functioning pNETs can occur in the pancreas or in other locations. Curative resection is always recommended whenever possible after optimal symptomatic control of the clinical syndrome by medical treatment. Indications for surgery depend on clinical symptom control, tumor size, location, extent, malignancy and presence of metastasis. A lot of non‐functioning pNETs are found incidentally according to the quality improvement of imaging techniques. Localized, small, malignant non‐functioning pNETs should be operated on aggressively, while in possibly benign tumors smaller than 2 cm the surgical risk‐benefit ratio should be carefully weighted. Surgical liver resection is generally proposed in curative intent to all patients with operable metastases from G1 or G2 pNET. The benefits of surgical resection of liver metastases have been demonstrated in terms of overall survival and quality of life. Complete resection is associated with better long‐term survival.     

Fluorine-18-L-dihydroxyphenylalanine (18F-DOPA) positron emission tomography as a tool to localize an insulinoma or beta-cell hyperplasia in adult patients

CONTEXT AND OBJECTIVE: Fluorine-18-L-dihydroxyphenylalanine (18F-DOPA) positron emission tomography (PET) is a promising method in localizing neuroendocrine tumors. Recently, it has been shown to differentiate focal forms of congenital hyperinsulinism of infancy. The current study was set up to determine the potential of 18F-DOPA PET in identifying the insulin-secreting tumors or beta-cell hyperplasia of the pancreas in adults. PATIENTS AND METHODS: We prospectively studied 10 patients with confirmed hyperinsulinemic hypoglycemia and presumed insulin-secreting tumor using 18F-DOPA PET. Anatomical imaging was performed with computed tomography (CT) and magnetic resonance imaging (MRI). All patients were operated on, and histological verification was available in each case. Semiquantitative PET findings in the pancreas using standardized uptake values were compared to standardized uptake values of seven consecutive patients with nonpancreatic neuroendocrine tumors. RESULTS: By visual inspection of 18F-DOPA PET images, it was possible in nine of 10 patients to localize the pancreatic lesion, subsequently confirmed by histological analysis. 18F-DOPA uptake was enhanced in six of seven solid insulinomas and in the malignant insulinoma and its hepatic metastasis. Two patients with beta-cell hyperplasia showed increased focal uptake of 18F-DOPA in the affected areas. As compared to CT or MRI, 18F-DOPA PET was more sensitive in localizing diseased pancreatic tissue. CONCLUSION: 18F-DOPA PET was useful in most patients with insulinoma and negative CT, MRI, and ultrasound results. In agreement with previous findings in infants, preoperative 18F-DOPA imaging seems to be a method of choice for the detection of beta-cell hyperplasia in adults. It should be considered for the detection of insulinoma or beta-cell hyperplasia in patients with confirmed hyperinsulinemic hypoglycemias when other diagnostic work-up is negative.     

Intra-operative procedures to localize endocrine tumours of the pancreas and duodenum

Somatostatin receptor scintigraphy is the best imaging method to identify the presence of neuroendocrine gastroenteropancreatic tumours. Nevertheless, a well structured surgical approach incorporating specific intra-operative methods can localize those tumours that cannot be readily detected by this imaging technique. In the case of gastrinoma, standard palpation allows duodenal tumour detection in approximately 60% of cases, endoscopic transillumination, in more than 80%. Furthermore, adding duodenotomy, 95-97% duodenal tumours can be localized. Intraoperative ultrasound, instead, does not add much to standard palpation in duodenal gastrinoma localization. For insulinoma detection, among the intra-operative methods, inspection gives the poorest results, identifying the lesion in only 20% of cases. Palpation offers better results, localizing 60-80% of insulinomas. The introduction of intra-operative ultrasound has revolutionized the ability to find pancreatic insulinoma, allowing the surgeon to identify the insulinoma in nearly every patient.     

Value of endoscopic ultrasonography and somatostatin receptor scintigraphy in the preoperative localization of insulinomas and gastrinomas. Experience of 54 cases

AIM: The classic morphological techniques for the localization of insulinomas and gastrinomas are of limited value. Endoscopic ultrasonography and somatostatin receptor scintigraphy have shown high sensitivity for the detection of gastroenteropancreatic endocrine tumors. The aim of the study was to evaluate the sensitivity of endoscopic ultrasonography and that of somatostatin receptor scintigraphy in the localization of insulinomas and gastrinomas.PATIENTS AND METHODS: This retrospective study concerned 54 patients with insulinoma (n=29) or gastrinoma (n=26) operated on between March 1991 and March 2000 and who had at least one among the two tested examinations. Forty-two patients had scintigraphy (17 with insulinoma, 25 with gastrinoma), 47 had endoscopic ultrasonography (28 with insulinoma, 17 with gastrinoma). One of the ten patients with MEN 1 had both tumors. All diagnosis were confirmed by histologic examination.RESULTS: The sensitivity of scintigraphy for the localization of insulinomas was 47%. There was one false positive. Sensitivity of endoscopic ultrasonography for insulinomas was 85%. The sensitivity of scintigraphy in the detection of gastrinomas was 65% for the tumors in the duodenopancreatic area, 20% for the tumors in the pancreatic tail and 71% for metastasis. The sensitivity of endoscopic ultrasonography was 46% for duodenal tumors, 75% for pancreatic tumors and 57% for lymph node metastasis. The combination of both localization studies increased sensitivity to 94%.CONCLUSION: Endoscopic ultrasonography and somatostatin receptor scintigraphy are the gold standard for localization of gastrinomas. Association of both examinations increases the sensitivity. Scintigraphy for the detection of insulinomas should be performed when endoscopic ultrasonography is negative.     

胰岛素瘤的术前及术中超声定位

目的:探讨术前及术中超声在胰岛素瘤定位诊断中的价值.方法:对4例胰岛素瘤患者的术前B型超声检查B超及术中B超、计算机断层摄影(CT)、核磁共振成像术(MRI)和数字减影血管造影(DSA)定位治疗进行分析.结果:术前B超,CT,MRI和DSA对胰岛素瘤的定位诊断准确率分别为40%,100%,40%,20%和60%,术中超声(IOUS)定位诊断准确率为100%.结论:术中超声对胰岛素瘤的定位诊断率高,并可显示肿瘤的毗邻关系.有助于术中选择合适的手术方式.     

彩色多普勒内镜超声在胰岛细胞瘤术前定位诊断中的作用

目的 探讨彩色内镜超声在胰岛细胞瘤术前定位诊断中的作用。方法 对经内科检查定性诊断为胰岛细胞瘤，并准备手术切除的7例患者，术前进行彩色多普勒内镜超声（ECDUS），经腹B超和胰腺螺旋CT增强扫描检查，并与手术和病理检查结果相对照，比较上述3种影像学检查在术前定位诊断中的作用。结果 7例患者手术和病理检查共发现10个病灶，ECDUS检出8个，胰腺螺旋CT增强扫描检出1个，经腹B超未有检出，病灶部位与手术见一致。ECDUS漏诊的2个病灶，直径均小于或等于0.5cm。检查中无并发症发生。结论 ECDUS对胰岛细胞瘤的术前定位诊断比B超，CT等无创性检查技术，敏感性高，定位准确，但对于直径小于或等于0.5cm的病灶，定位诊断仍有困难。     

Insulinoma: diagnostic strategies and surgical treatment. A 22-year experience.

BACKGROUND/AIMS: The efficacy of preoperative localization methods and the results of the surgical treatment of insulinoma were studied. METHODOLOGY: Fifty-nine patients referred for surgical treatment were studied and the results of the diagnostic tools for tumor localization were compared with findings at surgical intervention. The influence of the type of surgical procedure in the immediate and late postoperative course was also studied. RESULTS: Ultrasonography had a sensitivity of 30%, computed tomography 25%, angiography 54%, portal vein sampling 94%, endoscopic ultrasonography 27% and magnetic resonance 17%. Intraoperative palpation localized 98.2% of the tumors and by the addition of intraoperative echography, all lesions were identified. In 55 patients with benign lesions, 22 enucleations, 25 distal pancreatectomies, 7 pancreatectomies plus enucleation and one duodenopancreatectomy were performed. Malignant tumors were treated by pancreatic resection, postoperative hepatic artery embolization and systemic chemotherapy. There was no postoperative mortality. Pancreatic fistula was the most common complication. Three patients who underwent distal pancreatectomy developed late diabetes (9.3%). CONCLUSIONS: Extensive preoperative investigation, mainly with invasive methods, is not indicated and by combining intraoperative palpation and echography most of the cases can be adequately dealt with. Preservation of pancreatic tissue with enucleation and preservation of the spleen are the best choice for treatment of benign insulinomas.     

胰岛素瘤17例临床诊治分析

目的　探讨胰岛素瘤的诊断和治疗方法。　方法　回顾性地分析我院自 196 6年 ～ 2 0 0 0年收治的 17例胰岛素瘤。　结果　胰腺 B超、腹部 CT、选择性腹腔动脉造影检查准确率分别为 82 .4 %、72 .7%、6 0 %。2例未手术 ,15例肿瘤切除。肿瘤位于胰头钩突 3例 ,胰颈 1例 ,胰体尾 11例 ;80 %肿瘤直径 <3cm;行单纯肿瘤摘除术 8例 ,胰体尾切除术 4例 ,胰体尾加脾脏切除者 2例 ,胰腺节段性切除(捆绑式胰体尾空肠吻合空肠端侧吻合术 ) 1例。　结论　血糖、血胰岛素水平测定结合胰腺 B超、CT检查能有效提高功能性胰岛素瘤的诊断。治疗多为单纯性肿瘤切除 ,恶性肿瘤应行根治性切除 ,腹腔镜微创手术正处于尝试阶段 ,药物治疗仍然在探讨阶段。     

Evaluation of the usefulness of percutaneous transhepatic portal catheterization for preoperatively diagnosing the localization of insulinomas.

INTRODUCTION: The precise intraoperative localization of insulinoma is essential for successful surgical management. AIMS: To assess the usefulness of measuring insulin levels by preoperative percutaneous transhepatic portal catheterization (PTPC) and intraoperative ultrasonography (US). METHODOLOGY: PTPC and other preoperative procedures (enhanced computed tomography [CT], arteriography, and US) were performed in eight patients with insulinoma based on our experience during the past 18 years. Intraoperative US was performed in six of the eight patients. RESULTS: PTPC was undertaken in all eight patients, and increased levels of insulin at the sites corresponding to tumors were observed in all patients. Intraoperative US was performed in six patients, which made it possible to detect insulinomas as hypoechoic masses in all of these patients. All tumors were found to exist as single entities. CONCLUSION: PTPC showed the highest diagnostic accuracy in detecting the number of and accurately localizing the tumors before surgery. Meanwhile, all findings from intraoperative US were identical to those of the resection samples, suggesting that this method is a highly reliable examination technique. We conclude that a combination of PTPC and intraoperative US may be essential for the successful surgical management of insulinomas.     

Role of intraoperative ultrasonography in the surgical management of insulinomas

The findings in 35 surgically treated patients with insulinoma and 43 tumors of these patients were analyzed to confirm the efficacy of diagnostic modalities and surgical interventions. The rate of accurate preoperative tumor localization was 72% by angiography, 53% by computed tomographic scan, 55% by ultrasonography, and 83% by percutaneous transhepatic portal vein sampling. Extensive operative exposure and palpation detected 81% of the tumors and intraoperative ultrasonography demonstrated 96% of the tumors. Intraoperative ultrasonography was significantly better than any other diagnostic procedure and was able to demonstrate the anatomical relationship of the insulinoma to the essential structures of the pancreas. Intraoperative ultrasonography also helped determine the safest route for enucleating the insulinomas. Five patients (14%) in our series had metastatic diseases; 2 of these patients with metastases beyond the lymph nodes died due to the growth of tumors. The other 33 patients were free of insulinoma syndrome after the removal of the insulinomas. Streptozotocin was used in 1 patient with recurrent malignant insulinoma, with encouraging results.     

EUS-guided alcohol ablation of an insulinoma

BACKGROUND: Surgical resection is currently considered to be the criterion standard for treatment of insulinomas. Alternative treatments, despite medication with diazoxide, are lacking. EUS-guided ethanol ablation of endocrine tumors has not been reported before. INTERVENTION: A 78-year-old woman was referred with typical symptoms of an insulinoma. Diagnosis was confirmed by laboratory findings, EUS, and EUS-guided FNA. Because of severe complications during several hypoglycemic episodes, a poor general condition, and strict refusal of surgical resection, the decision was made to ablate the insulinoma by EUS-guided alcohol injection. A total of 8 mL 95% ethanol was injected into the tumor. RESULTS: The patient was discharged and exhibited no further hypoglycemic episodes, and her general condition improved rapidly. Based on clinical, morphologic, and biochemical criteria, we achieved a durable complete remission of the tumor. CONCLUSIONS: EUS-guided ablation may become a minimally invasive alternative for patients with insulinomas in whom surgery is not feasible.     

Laparoscope resection of retroperitoneal ectopic insulinoma: A rare case

Ectopic insulinoma is a very rare and dormant tumor. Here we report the case of a 79-year-old female who presented with repeated episodes of hypoglycemia and was diagnosed with insulinoma based on laboratory and imaging examinations. Computed tomography and positron emission tomography revealed a tumor in the retroperitoneum under and left of the hepatoduodenal ligament, which was resected successfully using a laparoscopic approach. Pathologic results revealed an ectopic insulinoma, which was confirmed immunohistochemically. Ectopic insulinomas are accompanied by hypoglycemia that can be misdiagnosed as drug- or disease-induced. These tumors are difficult to diagnose and locate, particularly in atypical cases or for very small tumors. Synthetic or targeted examinations, including low blood glucose, elevated insulin, proinsulin, and C-peptide levels, 48-h fasting tests, and relevant imaging methods should be considered for suspected cases of insulinoma. Surgery is the treatment of choice for patients with insulinoma, and laparoscopic resection is a feasible and effective method for select ectopic insulinoma cases.     

Preoperative diagnosis of insulinoma: low body mass index, young age, and female gender are associated with negative imaging by endoscopic ultrasound

OBJECTIVE: Endoscopic ultrasound (EUS) is a highly reliable procedure to localize insulinomas preoperatively. It has been considered to be important in planning surgical strategy, especially considering a minimal invasive approach. However, even under ideal conditions experienced examiners miss about 10-20% of insulinomas by EUS imaging. DESIGN AND METHODS: This retrospective study aimed to identify factors associated with negative EUS imaging. Twenty-nine consecutive patients (24 benign and 5 malignant) with sporadic pancreatic insulinomas confirmed by successful surgery and positive histopathology were included. All EUS examinations were performed by one single experienced examiner over a period of one decade. RESULTS: Three of the tumors were not detected by preoperative EUS as they were isoechoic to the surrounding healthy pancreatic tissue; 25 could be detected as hypoechoic lesions, (including all malignant tumors), and one lesion was hyperechoic. Low body mass index (P=0.053) and young age (P=0.037) were associated with negative EUS imaging. All patients with negative imaging were females. The position on the examiner's learning curve, the diameter and location of insulinoma, and endocrine parameters (insulin concentrations and insulin-glucose ratios in the prolonged fasting test) had no influence on the success of EUS imaging. CONCLUSIONS: Some insulinomas are missed by preoperative EUS imaging as they are completely isoechoic. A low body mass index, female gender, and young age might be risk factors for negative imaging.     

Localization of islet cell tumors

In summary, although similar imaging techniques are used for the localization of insulin and gastrin secreting islet cell tumors, the success rates are very different. Fortunately, the best results are obtained in the tumor for which effective medical treatment is less available, namely insulinomas, which can be found and successfully resected in over 90 per cent of patients. Both portal venous sampling and experienced intraoperative ultrasound are critical for successful surgery of small insulin-secreting tumors. Facilities without these resources should not explore patients when the conventional imaging studies are negative. Gastrinomas, on the other hand, will elude detection by even the most experienced surgeons in over 20 per cent of patients with sporadic Zollinger-Ellison syndrome in spite of positive portal venous sampling and intra-arterial secretin studies. The very small size of these tumors and their occurrence in more difficult to explore extrapancreatic sites provides the basis for this difference. However, patients with negative imaging studies and negative surgical explorations have an excellent prognosis on long-term follow-up when gastric acid hypersecretion is controlled. An annual computed tomographic scan is recommended since the appearance of a tumor would mandate surgical resection because of the significant incidence of malignancy in larger tumors. However, progression to imageable tumors has been unusual in our experience with this group of patients. There remains a small group of patients with highly malignant, rapidly metastasizing, gastrin-secreting islet cell carcinomas for whom localization is simple but of little relevance. However, locally invasive gastrinomas may often be resectable and provide prolonged remission and even cure. Aggressive surgery, supported by detailed cross-sectional and angiographic localization, has a role in this small group of patients.     

Hypoglycémie et insulinome

Insulinomas are rare causes of hypoglycemia. After having ruled out non insulinomatous causes of hypoglycemia in a patient in whom Whipple's triad is documented, hyperinsulinism must be demonstrated biochemically, either during a spontaneous hypoglycemic episode or, more often, during a supervised fast which may be prolonged up to 72h. A mixed-meal test may also help to diagnose the very rare cases of postprandial hypoglycemia related to non insulinoma pancreatogenic hypoglycemic syndrome (NIPHS) or to some rare insulinomas.Only when diagnosis of hypoglycemic hyperinsulinism is made, the tumor localization process may be initiated. This may be difficult due to the small size of insulinomas (generally < 1 cm). Multimodal approach is necessary. The association of endoscopic ultrasound and CT-scan or MRI seems optimal. Octreoscan® will be also performed. First results with a very new technique, the GLP-1 receptor imaging, are promising for localizing very small tumors.This localization aims to allow a sparing surgery; enucleation of benign tumors, if possible, allows a pancreatic tissue preservation in patients with quite normal survival.     

Laparoscopic distal pancreatectomy for neuroendocrine tumors of the pancreas

Although neuroendocrine tumors of the pancreas are traditionally managed by laparotomy, these rare neoplasms may be amenable to laparoscopic surgical resection. We present our experience with laparoscopic distal pancreatectomy in two such patients, and discuss the operative technique with emphasis on organ preservation. Two female patients aged 63 and 69 years presented with clinical and biochemical features of an insulinoma and a vasoactive intestinal peptide secreting tumor (VIPoma), and were found on cross-sectional imaging to have 1.2-cm and 4.5-cm solitary tumors in the tail of the pancreas. They underwent laparoscopic distal pancreatectomy with and without preservation of splenic vessels and spleen respectively. Both procedures were completed laparoscopically. The operating time was 180 and 210 minutes respectively. There were no postoperative complications. The postoperative hospital stay was 4 and 14 days respectively. Histology revealed a benign insulinoma and a malignant VIPoma with lymph node metastases respectively. Laparoscopic distal pancreatectomy for neuroendocrine tumors of the pancreas may be accomplished safely, with preservation of the spleen and splenic vessels in benign disease, and with benefits to the patients in terms of postoperative recovery.