Surgical treatment of insulinomas

Insulinoma: a quarter century of dietary control

Summary

Insulinomas are rare pancreatic neuroendocrine neoplasms (NENs) that are typically sporadic and solitary, with the majority being <2 cm in diameter at diagnosis. The median duration of symptoms before diagnosis is variable; however, this is usually in the region of 12-18 months. We report on an insulinoma diagnosed some 25 years following initial symptoms, having by that stage attained a diameter of 4 cm. We present a 50-year-old man who was reported with hypoglycaemic symptoms on his wedding 25 years prior to eventual confirmation of an insulinoma. He had since learned to live with the symptoms by eating frequently to manage his hypoglycaemia. However, over recent months, he reported a substantial deterioration in his symptoms, and indeed, had collapsed on two occasions. He had a fasting glucose of 2.9 mmol/L with grossly inappropriate elevated insulin and C-peptide levels. MRI demonstrated a 4.1 cm lesion at the body of pancreas and an indeterminate 9-mm liver lesion with a negative 68Gallium-DOTATATE PET scan. Accordingly, he was initiated on diazoxide and referred to the surgical team for distal pancreatectomy: histology confirmed a 4.4-cm well-differentiated pancreatic NEN of intermediate grade (NEN G2, Grade 2, 2017 World Health Organization (WHO) pancreatic-NEN classification), with positive immunohistochemistry for insulin. His hypoglycaemia episodes have ceased, and he remains under active surveillance. Our case demonstrates the possibility of dietary control of insulinoma-induced hypoglycaemia, and the likelihood that such a prolonged delay in diagnosis has led to the uncommonly large size of the apparently benign tumour which is usually 'small and indolent'.

Learning points

Most patients with insulinomas have lesions that are 1-2 cm in size, with 96% being less than 3 cm. The mean tumour size of insulinomas found in 3 of the largest reported series was 1.5 cm, with a range of 0.1-7.0 cm. It is not uncommon for patients to have symptoms for several months to years before diagnosis; however, no reported cases had the symptoms such long for 25 years, and the large size of the tumour in this case may reflect the very long history.

Endoscopic ultrasound-guided ethanol and radiofrequency ablation of pancreatic insulinomas: a systematic literature review

BACKGROUND

Insulinoma is the most common neuroendocrine neoplasm of the pancreas, characterised by hypoglycaemic symptoms. Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) and ethanol ablation (EUS-EA) are novel methods for treating insulinoma.We aimed to perform a systematic review to assess the efficacy and safety of EUS-guided ablation techniques for pancreatic insulinomas.

METHODS

We systematically searched for articles detailing EUS-guided ablations of insulinomas. We performed a qualitative analysis and summarised data on the efficacy and safety of EUS-RFA and EUS-EA techniques.

RESULTS

In total, we identified 35 case reports and case series describing 75 patients with insulinomas treatment with EUS-guided ablation. Twenty-seven patients were treated with EUS-RFA, 47 patients with EUS-EA, and 1 patient received EUS-EA and EUS-RFA in the same session. In total, 84 insulinomas were ablated (EUS-RFA: 31, EUS-EA: 53). Most insulinomas were in the head of the pancreas (40%). The clinical success rate for EUS-guided ablation techniques was 98.5%. The median glucose level was 1.95 (Q1-Q3: 1.69-2.13) mmol/L before ablation compared to 6.20 (Q1-Q3: 5.30-7.05) mmol/L after treatment. The median insulin and C-peptide levels before and after RFA/EA were 230 (Q1-Q2: 120-257) pmol/L and 41 (Q1-Q2 35-42) pmol/L; 2077 (Q1-Q2 1644-2459) pmol/L and 819 (Q1-Q2 696-1072) pmol/L, respectively. There were eleven adverse events: seven abdominal pain, two mild acute pancreatitis, one necrotising acute pancreatitis and one local hematoma. All patients recovered, and there were no periprocedural deaths.

CONCLUSIONS

EUS-guided ablation of insulinoma seems to be a safe and effective treatment and is an alternative to surgical resection in selected cases.

Malignant insulinoma hypoglycaemia: complex palliative management

This case presentation describes a 65-year-old woman with metastatic malignant insulinoma who experienced frequent episodes of hypoglycaemia causing significant distress and burden to her quality of life. The report describes how medical management was altered and how the patient was supported in order to alleviate these burdens. In particular, the report highlights the first documented use of flash glucose monitoring in insulinoma, which was beneficial in reducing the discomfort of lancet use and anxiety associated with hypoglycaemic episodes. This case demonstrates the benefits of an individualised approach, collaboration with other specialisms and recommends further evaluation of the use of flash glucose monitoring in palliative care.

Insulinoma: A Recurrent Pancreatic Tumor Amendable to Computed Tomography-Guided Ethanol-Lipiodol Injection

Insulinomas are rare, with an annual incidence of 1–4 people per mission. Insulinomas are the most common functioning endocrine neoplams of the pancreas. Endoscopic ultrasound has both diagnostic and therapeutic yield in undifferentiated pancreatic tumors. We present a case of a recurrent insulinoma, refractory to surgical and medical management diagnosed with endoscopic ultrasound. Our case uniquely conveys a successful, alternative approach to addressing symptomatic insulinomas refractory to surgical or medical management through computed tomography–guided percutaneous ethanol-lipiodol injection.

Descripción de la experiencia en pacientes diagnosticados con insulinoma. Estudio multicéntrico en Medellín, Colombia

Objetivo: describir la experiencia de los pacientes con insulinoma, diagnosticados y tratados entre los años 2002 y 2017 en tres hospitales de la ciudad de Medellín, Colombia. Métodos: estudio descriptivo y retrospectivo de pacientes con criterios bioquímicos para hipoglucemia hiperinsulínica y confirmación histopatológica de insulinoma. Resultados: se estudiaron 19 casos, 10 eran mujeres (52,6 %), la edad media al diagnóstico fue 43 años (D.E 15,5). Hubo cuatro casos de insulinoma multifocal (21,1 %), tres asociados con NEM-1 (15,8 %) y dos malignos (10,6 %). Todos presentaron hipoglucemia en ayunas y 63,2 % posprandial. En la prueba de ayuno, el nadir de glucemia sucedió antes de 48 horas en todos los casos, en promedio 9 horas (D.E 8,0). El diagnóstico bioquímico fue realizado con hipoglucemia e insulina elevada en todos los casos, aunque el péptido C fue reportado en nueve pacientes (47,3 %) y las sulfonilureas en dos (11,1 %). La localización preoperatoria se hizo por imágenes en 12 individuos (68,5 %) y las pruebas invasivas fueron necesarias en seis (31,5 %). Las pruebas diagnósticas fueron positivas en un 83 % para resonancia, 50 % para ecografía endoscópica y prueba de estímulo intraarterial con calcio y 100 % para ecografía intraoperatoria. La cirugía se realizó en 18 casos (94,7 %). La mortalidad (15,8 %) fue derivada de complicaciones en el posoperatorio temprano; la curación se logró en todos los casos. Conclusiones: el insulinoma en nuestro medio tiene características demográficas y clínicas similares a otras series. Existen limitaciones locales para el acceso a los estudios bioquímicos y en el rendimiento diagnóstico de las pruebas de localización.

Radiosynthesis and evaluation of an 18F-labeled silicon containing exendin-4 peptide as a PET probe for imaging insulinoma

Background

Analogues of exendin-4 have been radiolabeled for imaging the glucagon-like peptide type 1 receptors (GLP-1R) which are overexpressed in insulinoma. The aim of this research was to synthesize an ¹⁸F–labeled silicon containing exendin-4 peptide (¹⁸F-2) and to evaluate its in vitro and in vivo behavior in CHL-GLP-1 receptor positive tumor-bearing mice.

¹⁸F–labeled silicon containing exendin-4 peptide (¹⁸F-2) was prepared via one-step nucleophilic substitution of a silane precursor with ¹⁸F–fluoride in the presence of acetic acid and K222. ¹⁸F-2 was then administered to tumor-bearing mice for PET imaging and ex vivo biodistribution experiments.

Results

¹⁸F-2 was produced in a radiochemical yield (decay corrected) of 1.5% and a molar activity of max. 16 GBq/μmol. The GLP-1R positive tumors were clearly visualized by PET imaging. Biodistribution studies showed reduced uptake of ¹⁸F-2 in the kidneys compared to radiometal labeled exendin-4 derivatives. The radiotracer showed specific tumour uptake which remained steady over 2 h.

Conclusions

This exendin-4 analogue, ¹⁸F-2, is a potential probe for imaging GLP-1R positive tumors.

Diagnosis of insulinoma using the ratios of serum concentrations of insulin and C-peptide to glucose during a 5-hour oral glucose tolerance test

The 72-hour fast test is the current standard for the diagnosis of insulinoma. However, to conduct this test patients require hospitalization due to the chance of severe hypoglycemic episodes. Thus, it is costly and stressful for the patient. An out-patient test would serve the patient better and be more economical. Our aim was to evaluate the value of insulin to glucose and C-peptide to glucose ratios during a prolonged 5-hour oral glucose tolerance test (5-hour OGTT) in qualitative diagnosis of insulinoma, and to identify the optimal threshold for clinical screening. Initially, 15 subjects with pathological insulinoma and 12 control subjects with reactive hypoglycemia were enrolled in the study. A further 75 subjects with symptoms of hypoglycemia as a chief complaint at their initial clinic visit were subsequently screened. Serum insulin, C- peptide levels and blood glucose were quantified after a 5-hour OGTT in all participants and the ratios of serum concentrations of insulin and C-peptide to glucose were calculated. Subjects with insulinoma had significantly different insulin-to-glucose and C-peptide-to-glucose ratios from reactive hypoglycemia at the times of fasting, 4-hour post glucose load and 5-hour post glucose load. Higher specificity (73.08%) and sensitivity (82.67%) were achieved with the combined insulin-to-glucose ratio at the 5-hour post load and the C-peptide-to-glucose ratio at fasting. In combination, ratios of insulin and C-peptide release relative to blood glucose levels, measured during a 5-hour OGTT, may have important clinical value in the diagnosis of insulinoma.

Efficacy of laparoscopic ultrasonography in laparoscopic resection of insulinoma

Insulinoma is the most common functioning islet cell tumor of the pancreas, with an annual incidence of 4 cases/1 million individuals. It is treated by surgical methods. Open surgery was once considered the standard approach for the treatment of insulinoma. However, the procedure is traumatic and requires a large incision, which does not satisfy the growing expectations of minimally invasive management of small-sized tumors. Insulinomas are usually benign solitary tumors and mostly occur sporadically, which makes them suitable candidates for laparoscopic management. The potential advantages of laparoscopic management of insulinoma over open surgery include shorter duration of hospitalization, quicker recovery, and better cosmetic effect. However, because of the small tumor size as well as the depth and uncertainty of the location of the tumor, laparoscopic localization of the lesion without tactile sensation is difficult. Laparoscopic ultrasonography can detect about 90% of insulinomas, and its sensitivity is comparable to that of manual palpation along with intraoperative ultrasonography during open surgery; thus, it ensures the feasibility of laparoscopic management of insulinoma and reinforces its advantage as a minimally invasive procedure. Laparoscopic ultrasonography is vital for the localization of insulinomas and characterization of the surrounding pancreatic structure and should, therefore, be considered an integral part of the laparoscopic management of insulinoma.

Clinical Presentation and Diagnosis of Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors are a rare group of neoplasms that arise from multipotent stem cells in the pancreatic ductal epithelium. Although they comprise only 1% to 2% of pancreatic neoplasms, their incidence is increasing. Most pancreatic neuroendocrine tumors are nonfunctioning, but they can secrete various hormones resulting in unique clinical syndromes. Clinicians must be aware of the diverse manifestations of this disease, as the key step to management of these rare tumors is to first suspect the diagnosis.

Long-standing insulinoma: two case reports and review of the literature

Background

Insulinomas are rare pancreatic endocrine tumors. Most are benign and solitary. However, the nonspecific symptoms and small size of these tumors led to difficulties of diagnosis and localization.

Case presentation

We present two Arab patients with pancreatic long-standing insulinoma. Both patients presented episodic hypoglycemic symptoms respectively during 10 and 2 years. Biochemical and morphological workup detected localized pancreatic insulinoma. Open procedure surgery was done for the two patients and insulinomas were successfully removed by enucleation.

Conclusion

Insulinoma remains a diagnostic challenge to practitioners. Diagnosis of suspected cases is easily confirmed by standard endocrine tests, especially the supervised fasting test. Accurate preoperative localization is essential for more effective and safest surgery.

Clinical outcomes of 15 consecutive patients who underwent laparoscopic insulinoma resection: The usefulness of monitoring intraoperative blood insulin during laparoscopic pancreatectomy

BACKGROUND

Insulinoma is a very serious functional tumor. Surgeons should confirm complete resection of insulinomas before completing the operation, even in laparoscopic surgery.

METHODS

Between August 2007 and September 2014, 15 consecutive patients with biochemical evidence of an insulinoma underwent laparoscopic pancreatectomy. Intraoperatively, a peripheral arterial blood sample was taken, and insulin was measured by quick insulin assay. Insulin levels were determined before anesthesia induction, every 30 min thereafter, and every 30 min for at least 1 h after tumor resection to confirm insulin levels did not increase before surgery was completed.

RESULTS

All 15 patients (3 men and 12 women, average age 57.2 years) successfully underwent laparoscopic resection. One patient had two tumors, and the remaining 14 patients had one tumor each (three in the head, five in the body, and eight in the tail of the pancreas). Preoperative localization and regionalization studies identified the tumor correctly through CT (12/15 [80.0%]), MRI (9/12 [75.0%]), angiography (11/13 [84.6%]), endoscopic ultrasonography (7/10 [70.0%]), and selective arterial calcium injection (14/14 [100%]). Intraoperative ultrasonography detected 13 of 15 tumors (86.7%), and intraoperative blood insulin monitoring confirmed the complete resection of 16 of 16 tumors (100%). All patients were discharged with normal insulin levels and have been followed up for 3-88 months. There has been no recurrence of symptoms in any patients and none has died.

CONCLUSION

Complete removal of an insulinoma can be reliably predicted by intraoperative blood insulin monitoring even in laparoscopic pancreatectomies.

Laparoscopic spleen-preserving distal pancreatectomy for insulinoma: experience of a single center

BACKGROUND

Laparoscopic spleen-preserving distal pancreatectomy is gaining acceptance for the treatment of insulinomas of the pancreatic body and tail. The aim of this report is to evaluate the feasibility, safety and outcomes of this procedure in a retrospective series.

METHODS

From May 2004 to November 2013, 9 patients underwent laparoscopic spleen-preserving distal pancreatectomy for benign insulinomas in our department. Tumors were single and sporadic in eight patients, while the remaining patient had insulinomas in the setting of multiple endocrine neoplasia type 1. Tumors were located by preoperative imaging in all cases. Laparoscopic ultrasound was always performed to guide the surgical procedure.

RESULTS

All the operations were carried out laparoscopically with a mean operative time of 110 min (range 90-210 min) and a mean blood loss of 50 ml (range 30-120 ml). One patient (11.1%) died on the 22nd post-operative day for massive intra-abdominal bleeding associated with pancreatitis of the stump. Two patients (22.2%) developed pancreatic fistula that healed conservatively. Mean postoperative hospital stay was 7.1 days (range 5-18 days). All alive patients were free from recurrence after a mean follow-up of 45 months (range 11-72 months).

CONCLUSION

Laparoscopic spleen-preserving distal pancreatectomy is safe and feasible for the management of benign insulinomas. Definition of the tumor with preoperative imaging and laparoscopic ultrasound is essential to achieve high cure rate with minimal conversion.

Management of endocrine disease: a clinical update on tumor-induced hypoglycemia

Tumor-induced hypoglycemia (TIH) is a rare clinical entity that may occur in patients with diverse kinds of tumor lineages and that may be caused by different mechanisms. These pathogenic mechanisms include the eutopic insulin secretion by a pancreatic islet β-cell tumor, and also the ectopic tumor insulin secretion by non-islet-cell tumor, such as bronchial carcinoids and gastrointestinal stromal tumors. Insulinoma is, by far, the most common tumor associated with clinical and biochemical hypoglycemia. Insulinomas are usually single, small, sporadic, and intrapancreatic benign tumors. Only 5-10% of insulinomas are malignant. Insulinoma may be associated with the multiple endocrine neoplasia type 1 in 4-6% of patients. Medical therapy with diazoxide or somatostatin analogs has been used to control hypoglycemic symptoms in patients with insulinoma, but only surgical excision by enucleation or partial pancreatectomy is curative. Other mechanisms that may, more uncommonly, account for tumor-associated hypoglycemia without excess insulin secretion are the tumor secretion of peptides capable of causing glucose consumption by different mechanisms. These are the cases of tumors producing IGF2 precursors, IGF1, somatostatin, and glucagon-like peptide 1. Tumor autoimmune hypoglycemia occurs due to the production of insulin by tumor cells or insulin receptor autoantibodies. Lastly, massive tumor burden with glucose consumption, massive tumor liver infiltration, and pituitary or adrenal glands destruction by tumor are other mechanisms for TIH in cases of large and aggressive neoplasias.

Application of biochemical markers CA 19-9, CEA and C-reactive protein in diagnosis of malicious and benign pancreatic tumors

INTRODUCTION

We would save many lives and spare a lot of suffering if we could only detect and accurately determine the character and TMN staging of pancreatic tumors (PTs). With improved diagnosis, we could offer specific treatment that would result in better treatment outcome. The aim of study was to determine the significance of neoplastic markers CA 19-9 and CEA for prognosis in inflammatory and carcinomatous PTs.

MATERIAL AND METHODS

We based our research upon a group of 170 patients. The patients were treated in our Oncologic Surgery Department from January 2007 to December 2010 for PTs. The patients were divided into four groups depending on the character of the tumor and underwent the following treatments: group 1 - 34 patients with carcinoma of the ampulla of Vater, group 2 - 64 patients with PTs at different stages (1, 2, 3) according to TMN classification, group 3 - 62 patients with PTs at stage 4 on the TMN scale (unresectable tumors), group 4 - 28 patients with inflammatory PTs.

RESULTS

The results of Ca 19-9 in group 2 were 736.00 (25-75% 220.40-4285.00) ng/ml before surgery, 53.00 (25-75% 12.60-84.00) ng/ml in the 7 days after surgery, 29.4 (25-75% 7.90-113.00) ng/ml at day 30, and 119.00 (25-75% 96.30-621.00) ng/ml 3 months after the operation. These results were significantly higher than the control group but were significantly lower than the results for group 3 (unresectable tumors). The highest average concentration and median for CA 19-9 and CEA were noted in patients with unresectable PTs (the 3(rd) group). The average concentration for CEA was lowest in group 4, but much higher than the lab limits.

CONCLUSIONS

The sensitivity of the CA 19-9 marker may be as high as 88%. Values of CA 19-9 above 852 U/ml may indicate TNM stage 4, consistent with an unresectable PT. In the cases where CA 19-9 is within normal limits but C-reactive protein is above normal limits (often thirty times the upper limit), in comparison to the control group and to patients with pancreatic neoplasms, strong consideration should be given towards the inflammatory characteristics of the pancreatic changes and conservative treatment should be applied.

Is laparoscopic approach for pancreatic insulinomas safe? Results of a systematic review and meta-analysis

BACKGROUND

No consensus exists as to whether laparoscopic treatment for pancreatic insulinomas (PIs) is safe and feasible. The aim of this meta-analysis was to assess the feasibility, safety, and potential benefits of laparoscopic approach (LA) for PIs. The abovementioned approach is also compared with open surgery.

METHODS

A systematic literature search (MEDLINE, EMBASE, Cochrane Library, Science Citation Index, and Ovid journals) was performed to identify relevant articles. Articles that compare the use of LA and open approach to treat PI published on or before April 30, 2013, were included in the meta-analysis. The evaluated end points were operative outcomes, postoperative recovery, and postoperative complications.

RESULTS

Seven observational clinical studies that recruited a total of 452 patients were included. The rates of conversion from LA to open surgery ranged from 0%-41.3%. The meta-analysis revealed that LA for PIs is associated with reduced length of hospital stay (weighted mean difference, -5.64; 95% confidence interval [CI], -7.11 to -4.16; P < 0.00001). No significant difference was observed between LA and open surgery in terms of operation time (weighted mean difference, 2.57; 95% CI, -10.91 to 16.05; P = 0.71), postoperative mortality, overall morbidity (odds ratio [OR], 0.64; 95% CI, 0.35-1.17; P = 0.14], incidence of pancreatic fistula (OR, 0.86; 95% CI, 0.51-1.44; P = 0.56), and recurrence of hyperglycemia (OR, 1.81; 95% CI, 0.41-7.95; P = 0.43).

CONCLUSIONS

Laparoscopic treatment for PIs is a safe and feasible approach associated with reduction in length of hospital stay and comparable rates of postoperative complications in relation with open surgery.

Type 2 diabetes mellitus in a patient with malignant insulinoma manifesting following surgery

BACKGROUND

Insulinomas, although they are rare, are the most common of pancreatic islet cell tumours. The incidence is estimated at only four per million person-years and only 5-12% of reported cases are malignant. Distinction between malignant and benign tumours can only be made by the presence of metastasis, as there are no specific morphologic, biochemical or genetic features distinguishing them. Most patients with malignant insulinoma have lymph node or liver metastases and, rarely, bone involvement. The coincidence of insulinoma and diabetes mellitus is an extremely rare condition and reported only in a few cases.

CASE REPORT

We report a 45-year-old woman who was diagnosed with insulinoma on the basis of clinical and laboratory findings and endoscopic examination. Histopathological diagnosis revealed well-differentiated endocrine carcinoma of the pancreas with lymph node metastases. The case was accepted as malignant insulinoma and the patient underwent surgery. Interestingly, hyperglycaemia occurred after the removal of the insulinoma, with the requirement for insulin in the post-operative 3 weeks, which was changed to oral anti-diabetic agents as a permanent treatment. The patient is still being treated with oral anti-diabetic agents. We think that the patient might have had diabetes mellitus, because of insulin resistance that developed with a high-caloric intake stimulated by hypoglycaemia, and which had been masked for many years, but manifested overtly after removal of the tumour.

CONCLUSIONS

Although this is a rare condition, clinicians should bear in mind that insulinomas may exist together with diabetes mellitus, and it is important to have this suspicion when considering the perioperative approach and for the prevention of morbidities.

Neuroendocrine pancreatic tumors: guidelines for management and update

Pancreatic neuroendocrine tumors (PanNETs) are a diverse group of rare neoplasms. Commonly referred to as islet cell tumors, PanNETs are classified as functional or nonfunctional depending on their production of specific pancreatic endocrine hormones (e.g. insulin, gastrin, glucagon, and others) and association with the resultant clinical syndromes. While most PanNETs are sporadic, syndromic patients, in particular those with multiple endocrine neoplasia type 1 (MEN-1) and von Hippel Lindau (VHL), are at increased risk of developing these tumors. Recent investigations of patients with sporadic and syndromic PanNETs have elucidated critical pathways in tumor development, such as mammalian target of rapamycin (mTOR) signaling and its downstream growth factors such as vascular endothelial growth factor (VEGF). Prognosis ranges from favorable for localized, low-grade neoplasms to poor for advanced, high-grade tumors. Regardless of the stage at presentation, surgery is the first-line therapy for patients with disease amenable to surgical resection. We favor formal pancreatectomy with conventional lymph node sampling for the vast majority of patients, either through open or laparoscopic techniques. Those with insulinomas, however, may be candidates for enucleation. Cytoreductive surgery is also recommended for patients with locoregional recurrences or hepatic metastases. Regional adjuvants such as radiofrequency ablation (RFA), transarterial chemoembolization (TACE), and others are often employed in an attempt to palliate symptoms and prolong survival. Unfortunately, cytotoxic chemotherapy has been largely ineffective in treating patients with PanNETs. The somatostatin analogue octreotide, however, has been effective in palliating symptoms and slowing the progression of disease. Other promising systemic agents, including sunitinib and everolimus, have targeted critical PanNET signaling pathways. In summary, surgery remains the principal therapeutic strategy for patients with PanNETs, but continued research may identify more robust systemic therapies for those with advanced disease.

Tratamento cirúrgico dos insulinomas do pâncreas

RACIONAL - O insulinoma do pâncreas é neoplasia neuroendócrina proveniente das células beta das ilhotas pancreáticas. Apesar de rara, é a neoplasia endócrina pancreática mais comum, com cerca de quatro casos por milhão de pessoas. O tratamento preferencial dos insulinomas é cirúrgico. OBJETIVO - Analisar as características clínicas, epidemiológicas, cirúrgicas e anatomopatológicas dos pacientes tratados na última década em dois serviços. MÉTODOS - Foram revisados retrospectivamente os prontuários dos pacientes submetidos à cirurgia para tratamento de insulinoma no período de 1999 a 2011. Dados demográficos, tipo e duração dos sintomas, associação ou não à síndrome endócrina e exames diagnósticos foram obtidos dos registros de prontuários. Analisaram-se, também, o método cirúrgico, achados intra-operatórios e complicações imediatas e tardias. RESULTADOS - Dezesseis pacientes com diagnóstico de insulinoma foram submetidos ao tratamento cirúrgico. Foram excluídos dois por falta de registros completos no prontuário. Do total, 68,7% eram mulheres. A idade variou de 20 a 60 anos, com média de 39 anos. Apenas um caso era associado à síndrome de neoplasia endócrina múltipla tipo 1. Sintomas neuropsiquiátricos, principalmente a síncope, foram os mais comuns. A duração média das manifestações clínicas até o diagnóstico foi de um ano e meio. Exames de imagem foram utilizados em todos os pacientes com 68,7% de localização pré-operatória do tumor. Todas as operações foram realizadas de forma convencional (aberta), sem uso da laparoscopia. As lesões foram identificadas em todas as porções do pâncreas sendo a maioria na cabeça pancreática. O alívio dos sintomas só não foi obtido em um paciente. Não houve óbito entre os pacientes analisados. CONCLUSÃO - O diagnóstico de insulinoma é frequentemente estabelecido após vários meses do início das manifestações clínicas e o tratamento cirúrgico é curativo na quase totalidade dos pacientes.

Surgical treatment of pancreatic insulinomas

BACKGROUND

Insulinoma is a pancreatic neuroendocrine tumor originated from pancreatic islet beta cells. Although rare, is the most common pancreatic endocrine tumor, with about four cases per million people. The preferential treatment of insulinoma is surgical.

AIM

To analyze the epidemiological, pathological, clinical and surgical patients treated in the last decade in two surgical services.

METHODS

Were retrospectively reviewed the medical records of patients undergoing surgical treatment of insulinoma in the period of 1999 to 2011. Demographic data, type and duration of symptoms, associated or not with endocrine syndrome and diagnostic tests were obtained from medical records. Were analyzed the method of surgery, intraoperative findings and immediate and late complications.

RESULTS

Sixteen patients with insulinoma underwent surgical treatment, 68,7% were women. The age ranged from 20 to 60 years, with a mean age of 39 years. Only one case was associated with multiple endocrine neoplasia type 1. Neuropsychiatric manifestations, mainly syncope, were the most prevalent. The average duration of clinical manifestations until the diagnosis was one year and a half. Imaging tests were used in all patients with 68.7% of preoperative tumor localization. All operations were performed in a conventional (open) manner, without use of laparoscopy. The lesions were identified in all portions of the pancreas with the majority in the pancreatic head. Relief of symptoms was not obtained only in one patient. There were no deaths among the patients.

CONCLUSION

The diagnosis of insulinoma is often established after several months of the onset of clinical manifestations and surgical treatment is curative in almost all patients.

Laparoscopic versus open treatment for benign pancreatic insulinomas: an analysis of 89 cases

BACKGROUND

The use of a laparoscopic approach in the treatment of insulinomas is increasing. This retrospective study aimed to evaluate the authors' experience with laparoscopic surgery for benign pancreatic insulinomas and to compare the results for a laparoscopic approach versus an open approach.

METHODS

From January 2000 to December 2009, data were collected retrospectively from 89 patients who underwent resection of pancreatic insulinoma via either laparoscopy (n = 43) or laparotomy (n = 46). Clinical data, tumor features, and intra- and postoperative characteristics were analyzed.

RESULTS

The operation time, blood loss, and complication rate did not differ significantly between the laparoscopic and open approach groups. In the laparoscopic group, the time required to achieve recovery of gastrointestinal function and postoperative oral intake was significantly shorter in the laparotomy group, as was the hospital stay. By the end of the follow-up period, 85 (95.5%) of the 89 patients were symptom free.

CONCLUSIONS

Laparoscopic surgery is a safe procedure for patients with benign insulinomas. The complication rates are comparable with those for laparotomy procedures. Relative to open operations, laparoscopic pancreas operations are associated with a more rapid postoperative recovery.

Pancreatic endocrine tumors

Pancreatic endocrine tumors have been steadily growing in incidence and prevalence during the last two decades, showing an incidence of 4-5/1,000,000 population. They represent a heterogeneous group with very varying tumor biology and prognosis. About half of the patients present clinical symptoms and syndromes related to substances released from the tumors (Zollinger-Ellison syndrome, insulinoma, glucagonoma, etc) and the other half are so-called nonfunctioning tumors mainly presenting with symptoms such as obstruction, jaundice, bleeding, and abdominal mass. Ten percent to 15% of the pancreatic endocrine tumors are part of an inherited syndrome such as multiple endocrine neoplasia type 1 (MEN-1), von Hippel-Lindau (VHL), neurofibromatosis, or tuberousclerosis. The diagnosis is based on histopathology demonstrating neuroendocrine features such as positive staining for chromogranin A and specific hormones such as gastrin, proinsulin, and glucagon. Moreover, the biochemical diagnosis includes measurement of chromogranins A and B or specific hormones such as gastrin, insulin, glucagon, and vasoactive intestinal polypeptide (VIP) in the circulation. In addition to standard localization procedures, radiology (computed tomography [CT] scan, magnetic resonance imaging [MRI], ultrasound [US]), somatostatin receptor scintigraphy, and most recently positron emission tomography with specific isotopes such as (11)C-5 hydroxytryptamin ((11)C-5-HTP), fluorodopa and (68)Ga-1,4,7,10-tetra-azacyclododecane-N,N',N″,N‴-tetra-acetic acid (DOTA)-octreotate are performed. Surgery is still one of the cornerstones in the management of pancreatic endocrine tumors, but curative surgery is rarely obtained in most cases because of metastatic disease. Debulking and other cytoreductive procedures might facilitate systemic treatment. Cytotoxic drugs, biological agents, such as somatostatin analogs, alpha interferons, mammalian target of rapamycin (mTOR) inhibitors and tyrosine kinase inhibitors are routinely used. Tumor-targeted radioactive treatment is available in many centres in Europe and is effective in patients with tumors that express high content of somatostatin receptors type 2 and 5. In the future, treatment will be based on tumor biology and molecular genetics with the aim of so-called personalized medicine.

Surgical management of patients with insulinomas: Result of 292 cases in a single institution

BACKGROUND

Insulinoma is rare tumor with an incidence of approximately four cases per million per year. There are few large sample, single-center series that focus on the surgical management strategy of insulinomas.

PATIENTS AND METHODS

Medical records of patients diagnosed as insulinoma from 1990 to 2010 in Peking Union Medical College Hospital were reviewed retrospectively. Clinical data were collected and statistically analyzed.

RESULTS

A total of 328 patients were diagnosed with insulinomas; 292 of them underwent 320 operations, which included 46 laparoscopic surgeries. Tumor enucleation was the most common operative procedure. Multiple tumors were found in 30 cases; 17 cases were multiple endocrine neoplasia-1 syndrome. Thirteen patients with malignant insulinomas underwent tumor resection. Pancreatic fistula (PF) was the most frequent complication, and the incidence of clinical PFs (Grades B and C) was 14.4%. There was no significant statistical difference between open and laparoscopic surgery in blood loss, operative time, and complications. Metachronous tumors were noted in 11 patients.

CONCLUSION

Surgery is the best treatment of choice for insulinoma patients. Surgical approach depends on tumor size, location, and its pathological characters. Laparoscopic management of insulinomas is feasible and safe for tumors located in the body or tail of the pancreas. Open surgery combined with intraoperative ultrasonography is recommended to avoid omission of lesions in patients with multiple insulinomas. An aggressive surgical approach is indicated for malignant insulinoma patients.

Assessment of contrast-enhanced ultrasonography in diagnosis and preoperative localization of insulinoma

OBJECTIVE

This study was to evaluate the value of contrast-enhanced ultrasonography (CEUS) in the diagnosis and preoperative localization of insulinoma and explore the enhancement patterns of the tumors.

METHODS

Unenhanced and contrast-enhanced ultrasonographic examinations of 31 patients who underwent resection of insulinomas were retrospectively reviewed. The diagnosis sensitivity and localization specificity of CEUS for insulinomas were determined. Results of unenhanced ultrasonography and CEUS were compared by Chi-square test.

RESULTS

Unenhanced ultrasonography could display 9 of 37 (24.3%) surgically verified insulinomas in 31 patients, while the diagnosis sensitivity and localization specificity of preoperative CEUS was 33 (89.2%) and 32 (86.5%) of the 37 tumors, respectively. In contrast to the unenhanced ultrasonography, the improvement of CEUS in the diagnosis and preoperative localization of insulinomas was significant (p<0.0001). The enhancement pattern of insulinoma on CEUS was fast wash-in and slow wash-out. All the tumors were homogeneous hypervascularity in the earlier arterial phase, while the tumors still displayed hyperenhancing pattern in the late phase.

CONCLUSION

Our study demonstrates the great potential of CEUS in the diagnosis and preoperative localization of insulinomas. Since CEUS is a convenient, inexpensive, effective and non-invasive modality, the study supports the use of CEUS as a primary tool in the evaluation of patients with insulinomas.

Clinical profile of insulinoma: analysis from a tertiary care referral center in India

OBJECTIVE

To describe the clinical presentation, localization techniques, surgical procedures and outcome in patients with insulinoma.

METHODS

Retrospective analysis of case records of patients diagnosed with insulinoma between January 1993 and June 2009 at a tertiary-care hospital was done. Seventeen patients underwent diagnostic 72-h fast. The sensitivity of computed tomography (CT) of pancreas was judged using intraoperative findings as the gold standard.

RESULTS

Twenty-six patients (19 women) with mean age 42.2 years (median age 39.5 years) with biochemical/imaging evidence of insulinoma were included. All patients who underwent 72-h fast developed symptomatic hypoglycemia within 48 h. The sensitivity and positive predictive value (PPV) of CT of pancreas was 68.4% and 92.8%, respectively. Twenty patients underwent surgery, of whom four were operated on without preoperative localization. Four patients had recurrence of symptoms. Of the six patients who were not operated upon, the lesion was localized in four.

CONCLUSION

This audit shows that all patients with insulinoma develop hypoglycemia within 48 h of fasting. CT of pancreas localizes the lesion in two thirds of cases and would be a useful initial investigation in patients with suspected insulinoma.

Insulinoma: pathophysiology, localization and management

Insulinoma is a rare neuroendocrine tumor that causes oversecretion of insulin and, as a result, patients present with symptoms of hypoglycemia. Fortunately, insulinomas are usually benign and solitary, and surgical cure rates are highly favorable. Most of these tumors occur sporadically, but they can also be associated with multiple endocrine neoplasia type-1 syndrome. The diagnosis is confirmed by a supervised fast, and early detection is important. Several preoperative and intraoperative techniques with various success rates have been employed in order to localize the lesion. When technically feasible, tumor enucleation is the procedure of choice; however, a more formal resection may be necessary for certain tumors. In the age of laparoscopy, the role of laparoscopic surgery in the management of insulinomas is continuing to attract attention. This review will discuss the historical background, pathogenesis, diagnosis, localization and management of insulinomas.

Multiple proinsulin-secreting tumors of the pancreas treated by laparoscopic distal pancreatectomy and splenectomy

BACKGROUND

Patients with pancreatic tumors that induce hypoglycemia present with a myriad of symptoms. Laboratory testing can frequently result in data challenging to the clinician to confirm the biochemical diagnosis. Proinsulin, in addition to insulin levels, may be essential in evaluating and diagnosing an insulinoma.

METHODS

The objective of this case report is to demonstrate the potential importance of proinsulin levels in the evaluation of tumor-induced hypoglycemia. We report a 49-year-old woman with an unusual clinical presentation. Unlike many patients with tumor-induced hypoglycemia, her fasting glucose levels were fairly unimpressive, her insulin levels were undetectable during a prolonged fast, and she had elevated proinsulin levels.

RESULTS

The inpatient fast was remarkable for levels of serum glucose 53 mg/dl or higher, a serum insulin <2 uIU/ml, C-peptide 0.7-1.1 (nl 0.8-3.1 ng/ml), and proinsulin 29.2-36.8 pmol/l (nl < or = 18.8 pmol/l). CT scanning of the abdomen revealed multiple pancreatic lesions. A laparoscopic distal pancreatectomy led to the removal of multiple neuroendocrine tumors, which stained only for proinsulin and not for other pancreatic tumor markers. Postoperatively, she normalized her biochemical serum studies and has remained symptom-free 2 years later.

CONCLUSIONS

The measurement of proinsulin plays an important part in the diagnostic workup of neuroendocrine tumors causing hypoglycemia. These potentially malignant tumors can be treated adequately with minimally invasive surgery.

Pancreatic insulinoma: a surgical experience

BACKGROUND

Small size, high benignity rate, and sporadic nature make insulinomas suitable for laparoscopic resection. On the other hand, occult location or multicentricity mandate open surgery. This study was designed to analyze a series of patients who had pancreatic insulinomas and underwent initial treatment at our institution.

METHODS

Clinical records of the 34 patients with pancreatic insulinomas who underwent surgical resection between 1995 and 2007 were reviewed. Main variables for analysis were cure of the disease and surgical complications.

RESULTS

There were 20 women and 14 men with a mean age of 40 +/- 13 years. Mean size of the tumors was 2.2 +/- 1 cm. Laparoscopic resection was completed in 14 of 21 patients. Most tumors that were resected by laparoscopy were solitary, benign, and located in the body and tail of the pancreas. Open surgery was selected for 13 patients, including 7 sporadic (5 in the head), 4 related to the MEN syndrome, and 2 malignant tumors. Surgical morbidity occurred in 23 patients. The most common complication was pancreatic fistula (3/13 in open, 4/14 in laparoscopic, and 6/7 in conversions). One patient in the open group died 15 days after surgery from massive PTE. Postoperative normoglycemia was achieved in all patients and persisted for a follow-up period of 4 +/- 3.7 years.

CONCLUSIONS

Most insulinomas in our series were small and benign. Tumors that were located in the body and tail were more often amenable for laparoscopic resection. The cure rate was very high. Pancreatic fistula was the most frequent complication.

Insulinoma

Insulinoma is a rare neuroendocrine tumor with an incidence of 4 per 1 million persons per year, which may occur as a unifocal sporadic event in patients without an inherited syndrome or as a part of multiple endocrine neoplasia type 1. Key neuroglycopenic and hypoglycemic symptoms in conjunction with biochemical proof establish the diagnosis. Once the diagnosis is established, the insulinoma is preoperatively localized within the pancreas with the goal of surgical excision for cure. This review discusses the historical background, diagnosis, and management of sporadic insulinoma.

Radiofrequency ablation of solitary pancreatic insulinoma in a patient with episodes of severe hypoglycemia

Insulinomas are rare neuroendocrine tumors of the pancreas. Therapy of first choice is the surgical resection or enucleation. In cases of metastases or in patients with high surgical risk, medical therapy with diazoxide or octreotide is an alternative. In this case, we describe the successful use of computed tomography (CT)-guided radiofrequency ablation (RFA) of an insulinoma in an 80-year-old female patient. The patient suffered from episodes of severe nightly hypoglycemia with a minimal glucose concentration of 1.95 mmol/l (36 mg/dl). An insulinoma measuring 1.5 cm in diameter was localized by endoscopic ultrasound and CT scan in the tail of the pancreas. Owing to a high surgical risk caused by the patient's comorbidities and poor physical condition, the resection of the tumor was not considered. The medical treatment with diazoxide failed to control the symptoms of hypoglycemia sufficiently. Using CT-guided percutaneous RFA, the insulinoma was successfully ablated. No postinterventional complications occurred. During a 5-week follow-up, episodes of hypoglycemia were absent. A control-CT, 5 weeks after RFA, revealed no residual tumor. In conclusion, we found RFA suitable for the treatment of pancreatic insulinomas. Until more data concerning efficacy and complication rates have been collected; the procedure should be reserved for the treatment of patients who are no candidates for surgical therapy and in whom symptoms cannot be controlled by the medical therapy.

Laparoscopic surgery for pancreatic insulinomas: a single-institution experience of 29 cases

BACKGROUND

Laparoscopic approach has been increasingly used in the treatment of pancreatic benign diseases. This report evaluates our experience with laparoscopic surgery for pancreatic insulinomas.

METHODS

Between July 2000 and December 2007, laparoscopic pancreatectomy was attempted in 29 consecutive patients with insulinomas. The localization of tumors, operating characteristics, and clinical outcomes were analyzed.

RESULTS

Tumors were precisely localized in 28 of 29 (96.6%) patients by a combination of preoperative imaging techniques and intraoperative ultrasonography. Laparoscopic pancreatectomy was successfully performed in 26 patients, including enucleation (n = 14), hand-assisted enucleation (n = 2), and distal pancreatectomy with (n = 9) or without (n = 1) spleen preservation. Two conversions to open procedure were required because of unfavorable locations of the tumors. The pancreatic fistula occurred in four patients who underwent tumor enucleation. The median hospital stay was 5.5 days (range, 3-18 days) after laparoscopic procedure. Twenty-eight patients with pancreatic resection were free of symptoms and remained normoglycemic after a median follow-up period of 19 months (range, 10-36 months).

CONCLUSION

Laparoscopic pancreatic resection is a feasible and safe procedure for patients with insulinomas. Further studies are required to evaluate the potential application of the hand-assisted approach for tumors located at anatomically unfavorable positions.

Overtly manifested diabetes mellitus after resection of insulinoma

Insulinoma is the most common cause of endogenous hyperinsulinemic hypoglycemia in adults. However, the coincidence of insulinoma and diabetes is extremely uncommon. We describe a rare, but very interesting case of diabetes mellitus which was masked by insulinoma and was overtly manifest after the removal of the insulinoma.

Hypoglycemia associated with the production of insulin-like growth factor II in a pancreatic islet cell tumor: a case report

An insulinoma is characterized by endogenous hyperinsulinemia and hypoglycemia. However, it has been reported that insulinomas with normal levels of plasma insulin and a normal insulin to glucose ratio occur in patients with hypoglycemia. Although overproduction of Insulin-like growth factor II (IGF-II) by non-islet cell tumors such as large mesenchymal tumors, can cause hypoglycemia, no cases of circulating plasma IGF-II from an islet cell tumor contributing to hypoglycemia have been reported. We report here a rare case of a pancreatic islet tumor in a patient with hypoglycemia that was associated with increased plasma IGF-II, which returned to normal after tumor resection.

Improved contemporary surgical management of insulinomas: a 25-year experience at the Massachusetts General Hospital

OBJECTIVE

To determine changes in the management strategy of patients with insulinomas and identify critical factors in patient outcome.

BACKGROUND

Pancreatic insulinomas are rare neoplasms that are present in various ways. The optimal approach to localization, operative management, and follow-up of insulinomas is undetermined.

METHODS

Sixty-one patients with a diagnosis of insulinoma requiring surgery at a tertiary care center between 1983 and 2007 were reviewed. Demographic details, mode of presentation, preoperative localization, operative procedures, and pathology data were assessed. The effect of different factors on survival was determined.

RESULTS

Seven of 61 (11%) patients had a diagnosis of multiple endocrine neoplasia-type 1 (MEN-1). Multiple insulinomas were noted in 8% of cases and were more common in MEN-1 patients. The overall rate of malignancy was 8%. Confusion (67%), visual disturbances (42%), and diaphoresis (30%) were the most common presenting symptoms. Weight gain was noted in 44% of patients. The median duration of symptoms before diagnosis was 18 (1-240) months. The sensitivity of preoperative imaging of tumors before 1994 was 75%, compared with 98% after this period, which included use of endoscopic ultrasound scanning (P = 0.012). A combination of palpation and intraoperative ultrasound detected 92% of tumors. Distal pancreatectomy (40%), enucleation (34%), and pancreaticoduodenectomy (16%) were the most common procedures and pancreatic fistula occurred in 18% of patients. Three patients underwent noncurative distal pancreatectomy in the early period. The 10-year disease-specific and disease-free survival was 100% and 90% respectively. There were 5 patients with disease recurrence. Lymph node metastases (P < 0.001), lymphovascular invasion (P < 0.001), and the presence of MEN-1 (P = 0.035) were prognostically significant adverse factors in disease-free survival. Lymphovascular invasion was the only significant factor on multivariate analysis (P = 0.002).

CONCLUSION

Pancreatic insulinomas can be readily localized preoperatively with modern imaging to avoid unsuccessful blind pancreatic resection. Surgical resection is associated with low morbidity and mortality and achieves long-term disease-free survival in the absence of lymphovascular invasion.

Occult sporadic insulinoma: Localization and surgical strategy

Insulinomas continue to pose a diagnostic challenge to physicians, surgeons and radiologists alike. Most are intrapancreatic, benign and solitary. Biochemical diagnosis is obtained and imaging techniques to localize lesions continue to evolve. Surgical resection is the treatment of choice. Despite all efforts, an occult insulinoma (occult insulinoma refers to a biochemically proven tumor with indeterminate anatomical site before operation) may still be encountered. New localization preoperative techniques decreases occult cases and the knowledge of the site of the mass before surgery allows to determine whether enucleation of the tumor or pancreatic resection is likely to be required and whether the tumor is amenable to removal via a laparoscopic approach. In absence of preoperative localization and intraoperative detection of an insulinoma, blind pancreatic resection is not recommended.

[Laparoscopic surgical treatment of insulinomas with the use of intraoperative ultrasonography]

BACKGROUND

Insulinoma are insulin productive tumors originated from the pancreatic beta cells with an incidence of 4/1 million persons. It is more prevalent between the 5th and 6th decade, in women (2:1) and from the endocrine pancreatic tumor is the more frequent (50% to 60%). Insulinoma behave as a benign tumor when the diameter is inferior to 2 cm. The diagnosis is mainly clinical and laboratorial. Surgery is the unique treatment with potential cure.

AIM

The present observation reports the use of simultaneous laparoscopic resection associated to intraoperative ultrasonography.

METHODS

Five patients were studied (3 man and 2 women) with age from 20 to 53 years old, clinically diagnosed with insulinoma. After image work out it was proposed nuclear resection of the insulinoma by laparoscopic technique associated to intraoperative ultrasonography.

RESULTS

The patients had a complete remission of tumor related hypoglycemia and one patient developed a pancreatic fistula and other a pancreatic pseudocist with good postoperative resolution.

CONCLUSIONS

The videolaparoscopic approach for the surgical treatment of insulinoma is feasible. The intraoperative ultrasonography helps to identify the lesions and check their complete resection with low complication rate.

Laparoscopic treatment of benign insulinomas localized in the body and tail of the pancreas: a single-center experience

BACKGROUND

The increasingly widespread use of minimally invasive surgery has allowed surgeons to exploit this approach for complex procedures, such as pancreatic resections, though its actual role outside simple operations remains debated.

METHODS

This is a study of 12 consecutive patients, 5 men and 7 women, with pancreatic insulinoma who were treated at our institution from 2000 to September 2005. All patients presented with typical symptoms and laboratory findings of hyperinsulinism and were good candidates for laparoscopic surgery. Preoperative diagnostic work-up, operating time, postoperative complication rate, length of hospital stayd and clinical outcome were assessed.

RESULTS

Successful laparoscopic resection was performed in 11 out of 12 patients: 4 had tumor enucleation, and 7 had distal pancreatectomy; among these latter 5 had spleen-preserving distal pancreatectomy. In 1 case conversion to open surgery was necessary. Mean operative time was 170 minutes. The median tumor size was 18 mm, and all the insulinomas were benign. Four complications were observed in this group, and the median hospital stay was 8 days.

CONCLUSIONS

The laparoscopic approach proved to be feasible and safe, although the average operative time was longer and demanded good surgical skills as well as precise localization of the tumor and definition of its nature. Tumors located in the body or tail of the pancreas that are benign in nature can better benefit of laparoscopic approach.

Laparoscopic versus open approach for solitary insulinoma

BACKGROUND

In recent years, advances in laparoscopic techniques have allowed surgeons to treat pancreatic lesions laparoscopically. Insulinoma, the most prevalent pancreatic endocrine tumor, is mostly benign and curable with surgical resection. This study aimed to assess the results from laparoscopic resection (LG) of insulinomas and to compare them with the results from open surgery (OG).

METHODS

From September 1999 to December 2005, 56 laparoscopic pancreatic resections were performed for selected patients, including 12 laparoscopic resections of insulinomas. The results were compared with those of patients who underwent open resection of insulinomas selected from the authors' pancreatic database.

RESULTS

Three conversions to the open approach were required because of inability to identify the tumor. There were no deaths in either group, and the morbidity rates were 25% (3/12) for LG and 55% (5/9) for OG (nonsignificant difference). The pancreatic fistula rate after laparoscopic enucleation was statistically lower than after open enucleation (14% vs 100%; p = 0.015). The mean postoperative hospital stay was 13 +/- 5.9 days for LG and 17.6 +/- 7.5 days for OG (nonsignificant difference). After exclusion of the patients who underwent conversion to laparotomy, the mean postoperative hospital stay was 11.5 +/- 5.8 days for LG and 17.6 +/- 7.5 days for OG (p = 0.04).

CONCLUSION

This study demonstrates the feasibility and safety of laparoscopic resection of insulinomas. The laparoscopic approach was associated with a decrease in hospital stay and pancreatic fistula after enucleation. Preoperative localization tests and laparoscopic ultrasonography seem necessary to prevent conversion.

[Pancreatic insulinomas]

Insulinoma is the most frequent neuroendocrine pancreatic tumor. In the present study, the clinical and immunohistochemical results of 20 patients who underwent surgery between January 1986 and December 2004 were evaluated. Clinical presentation, laboratory data, imaging studies, aspects of the surgical technique, complication rates and medium- and long-term follow-up were analyzed. Surgical treatment was recommended in all patients based on presenting symptoms and laboratory signs of hypoglycemia and hyperinsulinemia. In 15 patients, the lesion was identified preoperatively. In the 5 remaining patients, intraoperative palpation and ultrasonography were used to locate the lesion. The most frequently performed surgical procedures were pancreatic resection in 10 patients and laparotomic enucleation in the remaining 10. Laparoscopy was used in two patients. Two patients developed diabetes mellitus. The most frequent surgical complication was pancreatic fistula. No mortality was observed in the present series. Symptom reversion, characterized by disappearance of Whipple's triad and normal or increased glycemia values compared with preoperative values, was observed in all patients.

The management of insulinoma

BACKGROUND

Insulinomas are rare tumours. Their clinical presentation, localization techniques and operative management were reviewed.

METHODS

An electronic search of the Medline, Embase and Cochrane databases was undertaken for articles published between January 1966 and June 2005 on the history, presentation, clinical evaluation, use of imaging techniques for tumour localization and operative management of insulinoma.

RESULTS AND CONCLUSION

Most insulinomas are intrapancreatic, benign and solitary. Biochemical diagnosis is obtained during a supervised 72-h fast. Non-invasive preoperative imaging techniques to localize lesions continue to evolve. Intraoperative ultrasonography can be combined with other preoperative imaging modalities to improve tumour detection. Surgical resection is the treatment of choice. In the absence of preoperative localization and intraoperative detection of an insulinoma, blind pancreatic resection is not recommended.

A prospective evaluation of laparoscopic exploration with intraoperative ultrasound as a technique for localizing sporadic insulinomas

BACKGROUND

Preoperative imaging studies localize insulinomas in less than 50% of patients. Arteriography with calcium stimulation and venous sampling (ASVS) regionalizes greater than 90% of insulinomas but requires specialized expertise and an invasive procedure. This prospective study evaluated laparoscopic exploration with IOUS compared with the other localization procedures in patients with a sporadic insulinoma.

METHODS

Between March 2001 and October 2004, 14 patients (7 women and 7 men; mean age, 53) with an insulinoma were enrolled in an IRB-approved protocol. Computed tomography, magnetic resonance imaging, ultrasound scan, and arteriography with calcium stimulation and venous sampling were performed preoperatively. A surgeon, blinded to the results of the localizing studies, performed a laparoscopic exploration with intraoperative ultrasound (IOUS). At the completion of the exploration, the success of laparoscopy for localization was scored, and the tumor was resected.

RESULTS

Twelve of 14 tumors were localized successfully before laparoscopy (noninvasive, 7 of 14; invasive, 11 of 14). Laparoscopic IOUS localized successfully 12 of 14 tumors. All lesions were resected, and all patients were cured (median follow-up, 36 months).

CONCLUSION

Laparoscopic IOUS identified 86% of tumors. The authors consider laparoscopic IOUS to be equivalent to ASVS in localizing insulinomas. Further study is therefore warranted to determine the role of laparoscopy with IOUS in the localization and treatment algorithm for patients with sporadic insulinoma.

Insulinoma

Although rare, insulinomas are the most common functioning islet cell tumour of the pancreas. Recognition of the key neuroglycopenic symptoms should trigger the initial investigation. Biochemical proof of endogenous hyperinsulinemic hypoglycemia establishes the diagnosis. Several options are available for imaging and localizing these tumours including ultrasonography, computed tomography, and intra-arterial calcium stimulation with venous sampling. The tumours are usually small, single, benign, well-circumscribed, and evenly distributed throughout the pancreas. This tumour may be a part of the multiple endocrine neoplasia type 1 (MEN-1) syndrome, in which case the tumours are almost always multiple. Surgical treatment is the only curative method, traditionally accomplished with enucleation or partial pancreatic resection. Patients are almost invariably cured lifelong with complete excision of a benign insulinoma. The most recent developments in this area are the recognition of noninsulinoma pancreatogenous hypoglycemia syndrome as a cause of organic hypoglycemia, and the development of laparoscopic techniques to excise these tumours.

[Surgical treatment of gastric, enteric, and pancreatic endocrine tumors Part 1. Treatment of primary endocrine tumors]

Endocrine tumors (ET) of the digestive tract (formerly called neuroendocrine tumors) are rare. They are classified into two principal types: gastrointestinal ET's (formerly called carcinoid tumors) which are the most common, and pancreaticoduodenal ET's. Functioning ET's secrete polypeptide hormones which cause characteristic hormonal syndromes. The management of ET is multidisciplinary. Poorly-differentiated ET's have a poor prognosis and are treated by chemotherapy. Surgical excision is the only curative treatment of well-differentiated ET's. The surgical goals are to: 1. prolong survival by resecting the primary tumor and any nodal or hepatic metastases, 2. control the symptoms related to hormonal secretion, 3. prevent or treat local complications. The most common sites of gastrointestinal ET's ( carcinoids) are the appendix and the rectum; these are often small (<1 cm), benign, and discovered fortuitously at the time of appendectomy or colonoscopic removal. Ileal ET's, even if small, are malignant, frequently multiple, and complicated in 30-50% of cases by bowel obstruction, mesenteric invasion, or bleeding. The carcinoid syndrome (consisting of abdominal pain, flushing, diarrhea, hypertension, bronchospasm, and right sided cardiac vegetations) is caused by the hypersecretion of serotonin into the systemic circulation; it occurs in 10% of cases and is usually associated with hepatic metastases. More than half of the cases of pancreatic ET are non-functional. They are usually malignant and of advanced stage at diagnosis presenting as a palpable or obstructing mass or as liver metastases. Insulinoma and gastrinoma (cause of the Zollinger-Ellison syndrome) are the most common functional ET's. 80% are sporadic; in these cases, tumor size, location, and malignant potential determine the type of resection which may vary from a simple enucleation to a formal pancreatectomy. In 10-20% of cases, pancreaticoduodenal ET presents in the setting of multiple endocrine neoplasia (NEM type I), an autosomal-dominant genetic disease with multifocal endocrine involvement of the pituitary, parathyroid, pancreas, and adrenal glands. For insulinoma with NEM-I, enucleation of lesions in the pancreatic head plus a caudal pancreatectomy is the most appropriate procedure. For gastrinoma with NEM-I, the benefit of surgical resection for tumors less than 2-3 cm in size is not clear. The lesions are frequently small, multiple, and widespread and recurrence is frequent after excision. The long-term prognosis is nevertheless fairly good. But the eventual development of liver metastases which are the most common cause of mortality still argues for an aggressive surgical approach in the early stages of the disease.

Symptomatic control of hypoglycaemia with prednisone in refractory metastatic pancreatic insulinoma

A 55-year-old female presented with recurring episodes of loss or decline in the quality of consciousness due to hypoglycaemia caused by insulin overproduction in hormonally active metastatic pancreatic insulinoma. All standard anticancer treatment modalities including chemotherapy, radiation, interferon alpha 2b, and lanreotide failed to achieve symptomatic control. The patient became dependent on continuous intravenous glucose supply. Based on anecdotal reports in literature, prednisone therapy was started in order to increase insulin resistance, reduce glucose utilization, increase hepatic glucose production, and impair insulin secretion. After 10 days of therapy, the patient was released from continuous intravenous glucose infusion. After several weeks, administration of prednisone was lowered to a daily maintenance dose of 2.5 mg with excellent symptomatic effects. In conclusion, prednisone therapy may be considered as a valid option to achieve symptomatic control in hormonally active therapeutically resistant insulinomas.