Intraoperative ultrasound with palpation is still superior to intra-arterial calcium stimulation test in localising insulinoma

Insulinoma in pregnancy (a case presentation and systematic review of the literature)

Insulinomas are rare, benign and functional tumors that coincidentally may become overt during pregnancy or in the post-partum period. As the general symptoms of a pregnancy might cover the clinical presentation, diagnosing remains challenging. We present one additional case of a post-partum insulinoma, combined with a systematic review of the literature to sum up relevant details in diagnosis and treatment. A systematic request of Pubmed/Medline was conducted using the following terms: "insulinoma AND pregnancy" and "insulinoma" for a second request of ClinicalTrials.gov. All publications concerning pregnant or post-partum women with insulinoma were included. Thirty-six cases could be identified for analysis. Each publication was reviewed for demographic, diagnostic and therapeutic data. The most frequent clinical signs were unconsciousness and neurological symptoms. 64.9% were diagnosed during early pregnancy and 35.1% post-partum. 91.9% underwent surgery with a third resected during pregnancy without severe influence on fetal or maternal outcome. Three patients died of metastatic disease or misdiagnosing, two of them miscarried. Insulinoma in pregnancy is rare but should be considered in case of unclear hyperinsulinemic hypoglycemia. Surgery can be performed during the second trimester or post-partum with promising outcome.

Essentials of Insulinoma Localization with Selective Arterial Calcium Stimulation and Hepatic Venous Sampling

Insulinomas are the most common functional pancreatic neuroendocrine tumor. Most insulinomas can be localized non-invasively with cross-sectional and nuclear imaging. Selective arterial calcium stimulation and hepatic venous sampling is an effective and safe minimally-invasive procedure for insulinoma localization that may be utilized when non-invasive techniques are inconclusive. The procedure’s technical success and proper interpretation of its results is dependent on the interventional radiologist’s knowledge of normal and variant pancreatic arterial perfusion. Accurate pre-operative localization aids in successful surgical resection. Technical and anatomic considerations of insulinoma localization with selective arterial calcium stimulation and hepatic venous sampling are reviewed.

Surgical Management of Neuroendocrine Tumours of the Pancreas

Neuroendocrine tumours of the pancreas (pNET) are rare, accounting for 1-2% of all pancreatic neoplasms. They develop from pancreatic islet cells and cover a wide range of heterogeneous neoplasms. While most pNETs are sporadic, some are associated with genetic syndromes. Furthermore, some pNETs are 'functioning' when there is clinical hypersecretion of metabolically active peptides, whereas others are 'non-functioning'. pNET can be diagnosed at a localised stage or a more advanced stage, including regional or distant metastasis (in 50% of cases) mainly located in the liver. While surgical resection is the cornerstone of the curative treatment of those patients, pNET management requires a multidisciplinary discussion between the oncologist, radiologist, pathologist, and surgeon. However, the scarcity of pNET patients constrains centralised management in high-volume centres to provide the best patient-tailored approach. Nonetheless, no treatment should be initiated without precise diagnosis and staging. In this review, the steps from the essential comprehensive preoperative evaluation of the best surgical approach (open versus laparoscopic, standard versus sparing parenchymal pancreatectomy, lymphadenectomy) according to pNET staging are analysed. Strategies to enhance the short- and long-term benefit/risk ratio in these particular patients are discussed.

The functioning side of the pancreas: a review on insulinomas

PURPOSE

Insulinomas are a rare type of neuroendocrine tumors, originating in the pancreas, difficult to diagnose and to treat. Due to its rarity, insulinomas are a not well-known pathological entity; thus, the diagnostic process is frequently a medical challenge with many possible differential diagnoses. The diagnostic process varies between non-invasive procedures, such as the fasting test or imaging techniques, and invasive ones. Insulinomas are rarely malignant, but the glycemic imbalance correlated with this tumor can frequently alter the quality of life of the patients and the consequent hypoglycemia can be extremely dangerous. Moreover, insulinomas can be associated with different genetic syndromes, such as Multiple Endocrine Neoplasia 1, accompanied by other specific symptoms. There are many different treatment strategies, depending on the need to control symptoms or control diseases progression, the only curative one being surgery.

METHODS AND RESULTS

We reviewed the evidences present in the literature on insulinomas and reported its main clinical characteristics and management strategies.

CONCLUSION

The aim of this review of the literature is to present the current knowledge on insulinomas, exploring the main clinical characteristics, the diagnostic tools, and the therapeutic strategies.

Surgical management of pancreatic neuroendocrine tumors: an introduction

Introduction: Neuroendocrine tumors of the pancreas (pNETs) represent only 1% to 2% of all pancreatic neoplasms. These tumors can be classified as functional or nonfunctional tumors; as sporadic or from a genetic origin; as neuroendocrine neoplasms or carcinoma. Over the last decade, diagnosis of pNETs has increased significantly mainly due to the widespread use of cross-sectional imaging. Those tumors are usually associated with a good prognosis. Surgery, the only curative option for those patients, should always be discussed, ideally in a multidisciplinary team setting.Areas covered: We discuss i), the preoperative management of pNETs and the importance of accurate diagnosis, localization, grading and staging with computed tomography, magnetic resonance imaging, endoscopic ultrasound, and nuclear medicine imaging; ii), surgical indications and iii), the surgical approach (standard pancreatectomy vs pancreatic-sparing surgery).Expert opinion: The treatment option of all patients presenting with pNETs should be discussed in a multidisciplinary team setting with surgeon's experienced in both pancreatic surgery and neuroendocrine tumor management. A complete preoperative imaging assessment - morphological and functional - must be performed. Surgery is usually recommended for functional pNETs, nonfunctional pNETs >2 cm (nf-pNETs) or for symptomatic nf-pNETs.

Pre- and intraoperative diagnostic requirements, benefits and risks of minimally invasive and robotic surgery for neuroendocrine tumors of the pancreas

Pancreatic neuroendocrine tumours (PanNET) are rare tumours, accounting for 1%-2% of all pancreatic neoplasms. These tumors are classified as functioning neuroendocrine tumours (F-PanNETs) or non-functioning (NF-PanNETs) depends on whether the tumour is associated with clinical hormonal hypersecretion syndrome or not. In the last decades, diagnosis of PanNETs has increased significantly due to the widespread of cross-sectional imaging. Whenever possible, surgery is the cornerstone of PanNETs management and the only curative option for these patients. Indeed, after R0 resection, the 5-year overall survival rate is around 90-100% for low grade lesions but significantly drops after incomplete resections. Compared to standard resections, pancreatic sparing surgery, i.e. enucleation and central pancreatectomy, significantly decreased the risk of pancreatic insufficiency. It should be performed in patients with good general condition and normal pancreatic function to limit the operative risk and enhance the benefit of surgery. Nowadays, due to many known advantages of minimally invasive surgery, there is an ongoing trend towards laparoscopic and robotic pancreatic surgery. The aim of this study is to describe the pre- and intraoperative diagnostic requirements for the management of PanNETs and the benefits and risks of minimally invasive surgery including laparoscopic and robotic approach in view of the recent literature.

Gamma Emitters in Pancreatic Endocrine Tumors Imaging in the PET Era: Is there a Clinical Space for 99mTc-peptides?

Background:

Pancreatic Neuroendocrine Tumors (PNETs) are rare neoplasms, sporadic or familial, even being part of a syndrome. Their diagnosis is based on symptoms, hormonal disorders or may be fortuitous. The role of Nuclear Medicine is important, mainly because of the possibility of a theranostic strategy. This approach is allowed by the availability of biochemical agents, which may be labeled with radionuclides suitable for diagnostic or therapeutic purposes, showing almost identical pharmacokinetics. The major role for radiopharmaceuticals is connected with radiolabeled Somatostatin Analogues (SSA), since somatostatin receptors are highly expressed on some of the neoplastic cell types.

Discussion:

Nowadays, in the category of radiolabeled SSA, although 111In-pentetreotide, firstly commercially proposed, is still used, the best choice for diagnosis is related to the so called DOTAPET radiotracers labeled with 68-Gallium (Ga), such as 68Ga-DOTATATE, 68Ga-DOTANOC, and 68Ga-DOTATOC. More recently, labeling with 64-Copper (Cu) (64Cu-DOTATATE) has also been proposed. In this review, we discuss the clinical interest of a SAA (Tektrotyd©) radiolabeled with 99mTc, a gamma emitter with better characteristics, with respect to 111Indium, radiolabeling Octreoscan ©. By comparing both pharmacokinetics and pharmacodynamics of Octreoscan©, Tektrotyd© and PET DOTA-peptides, on the basis of literature data and of our own experience, we tried to highlight these topics to stimulate further studies, individuating actual clinical indications for all of these radiotracers.

Conclusion:

In our opinion, Tektrotyd© could already find its applicative dimension in the daily practice of NETs, either pancreatic or not, at least in centers without a PET/CT or a 68Ga generator. Because of wider availability, a lower cost, and a longer decay, compared with respect to peptides labeled with 68Ga, it could be also proposed, in a theranostic context, for a dosimetry evaluation of patients undergoing Peptide Receptor Radionuclide Therapy (PRRT), and for non-oncologic indications of radiolabelled SSA. In this direction, and for a more rigorous cost/effective evaluation, more precisely individuating its clinical role, further studies are needed.

Cross sectional and nuclear medicine imaging of pancreatic insulinomas

Insulinomas are rare neuroendocrine tumors which occur predominantly in the pancreas. Although majority of the insulinomas are benign, over-secretion of insulin by the tumor leads to debilitating hypoglycemic symptoms. The diagnosis is based on clinical and biochemical findings. After the diagnosis is made, the principal challenge lies in locating the tumor because most tumors are solitary and small in size. Locating the tumor is of paramount importance as complete surgical excision is the only curative treatment, and incomplete resection leads to persistence of symptoms. Different preoperative and intraoperative imaging techniques have been used with varying success rates for the insulinoma imaging. Besides localizing the tumor, imaging also helps to guide biopsy, detect metastatic lesions, and perform image-guided therapeutic procedures. This review will discuss the role of different Cross sectional and nuclear medicine imaging modalities in insulinomas.

Preoperative localization of an insulinoma: selective arterial calcium stimulation test performance

PURPOSE

Preoperative localization of an insulinoma is recommended to improve the cure rate, but non-invasive procedures can fail to detect the tumour. The objective of the study was to assess the performance of a selective arterial calcium stimulation test in the preoperative localization of insulinomas that were not detected by conventional imaging procedures.

METHODS

We conducted a monocenter retrospective case review of 13 patients who had endogenous hyperinsulinism and were treated between 1994 and 2013. Patients were selected on the basis of negative or doubtful non-invasive preoperative imaging. A selective arterial calcium stimulation test was performed by pancreatic and hepatic arteriography with selective intra-arterial calcium stimulation and hepatic venous sampling in order to obtain the plasma insulin measurement. We evaluated the efficacy of the test by comparing the results with an endoscopic ultrasound.

RESULTS

Twelve of the 13 patients underwent surgery, and the presence of an insulinoma was proven in 11 patients by pathological analysis of the tumour. An endoscopic ultrasound was consistent with surgery in 71.4 % of cases, while selective arterial calcium stimulation was consistent with surgery in 90.9 % and allowed detection of an insulinoma in two additional patients with a negative endoscopic ultrasound. One false-negative and one false-positive arterial calcium test were observed. No adverse events were recorded except transient skin flush following calcium injection in one patient.

CONCLUSION

The selective arterial calcium stimulation test is a sensitive diagnostic procedure for localizing insulinomas and may be considered when non-invasive radiological imaging does not allow the detection of an occult insulinoma.

Impact of variant pancreatic arterial anatomy and overlap in regional perfusion on the interpretation of selective arterial calcium stimulation with hepatic venous sampling for preoperative localization of occult insulinoma

BACKGROUND

To determine the impact of variant pancreatic arterial anatomy and overlap in regional perfusion on the interpretation of selective arterial calcium stimulation (SACST) with hepatic venous sampling for preoperative localization of occult insulinoma.

METHODS

An institutional review board-approved retrospective review was undertaken of 42 patients with surgically confirmed, occult insulinoma who underwent SACST from January 1996 to March 2014. Location of the insulinoma was predicted initially based on the biochemical results of SACST alone according to Doppman's criteria. Pancreatic arteriograms were reviewed blinded to the biochemical results and the regional perfusion of each artery assessed. The anatomic and perfusion data were combined with the biochemical results to make a second prediction and compared with the surgical findings.

RESULTS

The biochemical results were positive in 1, 2, and 3 arterial distributions in 73.8%, 21.4%, and 4.8% of patients, respectively. The celiac trunk and superior mesenteric artery (SMA) anatomy were aberrant in 38.1% and 35.7% of patients, respectively. Clinically significant variations included dorsal pancreatic artery replaced to SMA (21.4%) and celiac stenosis (4.8%). Significant variation and overlap in regional pancreatic perfusion was observed, particularly for the SMA. Sensitivity for insulinoma localization was 54.8% (diagnostic arteriography), 73.8% (biochemical data), 88.1% (biochemical, anatomic, perfusion data), and 92.8% (arteriographic, biochemical, anatomic, perfusion data).

CONCLUSION

Careful review of the pancreatic arterial anatomy and regional perfusion is critical for correct interpretation of the biochemical results of SACST and improves the sensitivity of localization for occult insulinoma, particularly in the presence of pancreatic arterial variants or overlap in regional perfusion.

Endoscopic diagnosis and treatment of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PNETs) are rare pancreatic neoplasms comprising only 1% to 2% of all pancreatic tumors. In recent years, the number of incidentally discovered PNETs has greatly increased given the widespread use of axial imaging. However, a significant proportion of PNETs may not be visualized on conventional imaging such as computed tomography, magnetic resonance imaging, and somatostatin receptor scintigraphy. Endoscopic ultrasound (EUS) has become an integral part of the diagnosis of PNETs because of its high sensitivity for detecting, localizing, and diagnosing PNETs. EUS-guided tissue acquisition provides histologic and immunologic confirmation, and may also allow prognostication about tumor behavior. In addition to preoperative assessment of these tumors, EUS has also been shown to have an important role in nonoperative management of small nonfunctional PNETs. Finally, recent developments suggest that interventional EUS may be used to aid intraoperative localization of PNETs and to deliver therapeutic agents for the treatment of PNETs. This review will discuss the endoscopic diagnosis and treatment of PNETs, with focus on recent advances in the utility of EUS in the clinical management of these tumors.

Update on surgical treatment of pancreatic neuroendocrine neoplasms

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

Endoscopic ultrasound (EUS)-guided fiducial placement allows localization of small neuroendocrine tumors during parenchymal-sparing pancreatic surgery

BACKGROUND

Parenchymal-sparing pancreatic surgery is ideal for lesions such as small pancreatic neuroendocrine tumors (PanNET). However, precise localization of these small tumors at surgery can be difficult. The placement of fiducials under endoscopic ultrasound (EUS) guidance (EUS-F) has been used to direct stereotactic radiation therapy for pancreatic adenocarcinoma. This report describes two cases in which placement of fiducials was used to guide surgical resection. This study aimed to assess the feasibility, safety, and efficacy of using EUS-F for intraoperative localization of small PanNETs.

METHODS

A retrospective study analyzed two consecutive patients with small PanNETs who underwent EUS-F followed by enucleation in a tertiary-care referral hospital. The following features were examined: technical success and complication rates of EUS-F, visibility of the fiducial at the time of surgery, and fiducial migration.

RESULTS

In the study, EUS-F was performed for two female patients with a 7-mm and a 9-mm PanNET respectively in the uncinate process and neck of the pancreas. In both patients, EUS-F was feasible with two Visicoil fiducials (Core Oncology, Santa Barbara, CA, USA) placed either within or adjacent to the tumors using a 22-gauge Cook Echotip needle. At surgery, the fiducials were clearly visible on intraoperative ultrasound, and both the tumor and the fiducials were successfully enucleated in both cases. No complications were associated with EUS-F, and no evidence of pancreatitis was shown either clinically or on surgical pathology. This investigation had the limitations of a small single-center study.

CONCLUSIONS

For patients undergoing enucleation, EUS-F is technically feasible and safe and aids intraoperative localization of small PanNETs.

Diagnosis and management of insulinoma

Insulinomas, the most common cause of hypoglycemia related to endogenous hyperinsulinism, occur in 1-4 people per million of the general population. Common autonomic symptoms of insulinoma include diaphroresis, tremor, and palpitations, whereas neuroglycopenenic symptoms include confusion, behavioural changes, personality changes, visual disturbances, seizure, and coma. Diagnosis of suspected cases is based on standard endocrine tests, especially the prolonged fasting test. Non-invasive imaging procedures, such as computed tomography and magnetic resonance imaging, are used when a diagnosis of insulinoma has been made to localize the source of pathological insulin secretion. Invasive modalities, such as endoscopic ultrasonography and arterial stimulation venous sampling, are highly accurate in the preoperative localization of insulinomas and have frequently been shown to be superior to non-invasive localization techniques. The range of techniques available for the localization of insulinomas means that blind resection can be avoided. Intraoperative manual palpation of the pancreas by an experienced surgeon and intraoperative ultrasonography are both sensitive methods with which to finalize the location of insulinomas. A high proportion of patients with insulinomas can be cured with surgery. In patients with malignant insulinomas, an aggressive medical approach, including extended pancreatic resection, liver resection, liver transplantation, chemoembolization, or radiofrequency ablation, is recommended to improve both survival and quality of life. In patients with unresectable or uncontrollable insulinomas, such as malignant insulinoma of the pancreas, several techniques should be considered, including administration of ocreotide and/or continuous glucose monitoring, to prevent hypoglycemic episodes and to improve quality of life.

Enucleation and limited pancreatic resection provide long-term cure for insulinoma in multiple endocrine neoplasia type 1

AIM

To assess the characteristics and long-term outcome after surgery in patients with multiple endocrine neoplasia type 1 (MEN1)-associated insulinoma.

METHODS

Retrospective analysis of prospectively collected data of MEN1 patients with organic hyperinsulinism at a tertiary referral center.

RESULTS

Thirteen (17%) of 74 patients with MEN1 had organic hyperinsulinism. The median age at diagnosis was 27 (range 9-48) years. In 7 patients insulinoma was the first manifestation of the syndrome. All patients had at least one pancreatic neuroendocrine neoplasm (pNEN) upon imaging, including CT, MRI or endoscopic ultrasonography. Seven patients had solitary lesions upon imaging, 4 patients had one dominant tumor with coexisting multiple small pNENs, and 2 patients had multiple lesions without dominance. Eight patients had limited resections (1 segmental resection, 7 enucleations), 4 subtotal distal pancreatectomies, and 1 patient a partial duodenopancreatectomy. There was no postoperative mortality. Six patients experienced complications, including pancreatic fistula in 5 patients. Pathological examination revealed median three (range 1-14) macro-pNENs sized between 6 and 40 mm, and a total of 14 potentially benign insulinomas were detected in the 13 patients. After median follow-up of 156 months, only 1 patient developed recurrent hyperinsulinism after initial enucleation. Twelve patients developed new pNENs in the pancreatic remnant and 4 patients underwent reoperations (3 for metastatic ZES, 1 for recurrent hyperinsulinism). One of 5 patients with an initial extended pancreatic resection developed insulin-dependent diabetes mellitus.

CONCLUSION

Enucleation and limited resection provide long-term cure for MEN1 insulinoma in patients with solitary or dominant tumors. Subtotal distal pancreatectomy should thus be preserved for patients with multiple pNENs without dominance given the risk of exocrine and endocrine pancreas insufficiency in the mostly young patients.

Pancreatic neuroendocrine tumors: biology, diagnosis,and treatment

Pancreatic neuroendocrine tumors (PNETs), a group of endocrine tumors arising in the pancreas, are among the most common neuroendocrine tumors. The genetic causes of familial and sporadic PNETs are somewhat understood, but their molecular pathogenesis remains unknown. Most PNETs are indolent but have malignant potential. The biological behavior of an individual PNET is unpredictable; higher tumor grade, lymph node and liver metastasis, and larger tumor size generally indicate a less favorable prognosis. Endocrine testing, imaging, and histological evidence are necessary to accurately diagnose PNETs. A 4-pronged aggressive treatment approach consisting of surgery, locoregional therapy, systemic therapy, and complication control has become popular in academic centers around the world. The optimal application of the multiple systemic therapeutic modalities is under development; efficacy, safety, availability, and cost should be considered when treating a specific patient. The clinical presentation, diagnosis, and treatment of specific types of PNETs and familial PNET syndromes, including the novel Mahvash disease, are summarized.

Gastroenteropancreatic neuroendocrine tumors in multiple endocrine neoplasia type 1

We reviewed the literature about entero-pancreatic neuroendocrine tumors in Multiple Endocrine Neoplasia type 1 syndrome (MEN1) to clarify their demographic features, localization imaging, practice, and appropriate therapeutical strategies, analyzing the current approach to entero-pancreatic neuroendocrine tumors in MEN1. Despite the fact that hyperparathyroidism is usually the first manifestation of MEN1, the penetrance of these tumors is similar. They are characterized by multiplicity of lesions, variable expression of the tumors, and propensity for malignant degeneration. Both the histological type and the size of MEN1 neuroendocrine tumors correlate with malignancy. Monitoring of pancreatic peptides and use of imaging exams allow early diagnosis and prompt surgical treatment, resulting in prevention of metastatic disease and improvement of long-term survival. Surgery is often the treatment of choice for MEN1-neuroendocrine tumors. The rationale for surgical approach is to curtail malignant progression of the disease, and to cure the associated biochemical syndrome, should it be present.

Pancreatic endocrine tumors in multiple endocrine neoplasia type 1 syndrome: review of literature

OBJECTIVE

To analyze the surgical approach to multiple endocrine neoplasia type 1 (MEN 1)-related pancreatic endocrine tumors (PETs).

METHODS

We reviewed selected publications and our personal experience with MEN 1-associated PETs to delineate their general characteristics, current practice and controversies, preoperative imaging and intraoperative assessment, and appropriate therapeutic strategies including radical surgical procedures.

RESULTS

The penetrance of PETs in the setting of MEN 1 is similar to that of parathyroid tumors, even though hyperparathyroidism is usually the first manifestation of MEN 1 syndrome. In contrast with the sporadic counterparts, MEN 1-related PETs are characterized by an early onset, multiplicity of lesions, variable expression of the tumors, and propensity for malignant degeneration. Both the histologic type and the size of these tumors correlate with malignant potential.

CONCLUSION

The rationale for surgical considerations for these tumors is to curtail the malignant progression of the disease and to cure or aid in management of the associated biochemical syndromes. A surgical procedure is often the treatment of choice for PETs in patients with MEN 1. Monitoring of pancreatic peptides and use of diagnostic imaging allow an early pancreatic resection, in conjunction with prevention of metastatic PETs and improvement of long-term survival. Hepatic metastatic lesions can be successfully treated by surgical resection.

The role of interventional venous sampling in localising neuroendocrine tumours

PURPOSE OF REVIEW

This review focuses on the role of interventional venous sampling in the diagnosis and localization of neuroendocrine tumours (NETs), and its role in relation to conventional and novel imaging techniques.

RECENT FINDINGS

Imaging of NETs has evolved together with advances in imaging technology. Imaging localization plays an important role in the subsequent management of these tumours. This article provides an overview of the application of venous sampling in the localization of NETs, presented with current evidence to support its continued role in the diagnostic work-up of pituitary, parathyroid, pancreatic, adrenal and ovarian endocrine disease.

SUMMARY

Interventional venous sampling continues to be a highly sensitive modality in the localization of NETs. Although significant advances in noninvasive anatomic and functional imaging modalities have reduced the reliance of this well established technique, the latest literature continues to support its important role in the diagnostic armament of these unique and rare tumours.

Intraoperative ultrasound of the pancreas

Intraoperative ultrasound provides spatial resolution of the pancreas superior to computed tomography, magnetic resonance imaging, and transabdominal sonography. This pictorial essay will review common benign and malignant pancreatic processes including the following: pancreatic ductal adenocarcinoma, pancreatitis, endocrine tumors, mucinous cystic neoplasm, intraductal papillary mucinous neoplasm, serous cystadenoma, and solid pseudopapillary tumor. The use of intraoperative ultrasound in specific surgical situations will be discussed, which include the following: (1) identification of insulinoma(s) which are not detectable preoperatively, (2) identification of the pancreatic duct to determine dissection planes for chronic pancreatitis surgery (eg, Puestow procedure) and for tumor resection, and (3) staging purposes for malignant disease.

Surgical approach and perioperative complications determine short-term outcomes in patients with insulinoma: results of a bi-institutional study

BACKGROUND

Despite advancements in radiologic imaging and minimally invasive surgery, the evaluation and management of insulinomas is institution and surgeon dependent. Therefore, the reported surgical outcomes are highly variable. We compared the surgical management and outcomes of insulinomas between two international tertiary-care surgical units to better identify the best management as determined by short-term outcomes.

METHODS

We performed a retrospective review of patients who underwent surgery for insulinomas over a 117-month period at UT Southwestern Medical Center in Dallas (UTSW) and Queen Mary Hospital in Hong Kong (QMHK). Data collected included imaging studies, operative procedure, complications, and outcomes.

RESULTS

Thirty-seven patients were identified. Preoperative localization by computed tomography (CT) scan was successful in 21 patients (63.9%). In Hong Kong, 16 patients underwent selective arterial cannulation and calcium stimulation (SACST) with a success rate of 87.5%. Surgical management consisted of enucleation in 24 patients and distal pancreatectomy in 13 patients. Thirty patients underwent a concurrent intraoperative ultrasound, with localization in 96.7%. Laparoscopic procedures were accomplished in 20 patients. Nine postoperative complications were identified, four occurring in the laparoscopic group. Patients undergoing laparoscopic procedures had a decreased length-of-stay (LOS) compared with patients undergoing an open procedure and patients who had uncomplicated surgery had a trend toward decreased LOS.

CONCLUSION

Though the accuracy of CT scans for localizing insulinomas is only 64%, the addition of SACST or intraoperative ultrasound and pancreatic palpation increases accuracy to 97.1%. Compared with open procedures, laparoscopic resection is associated with comparable complication rates and shorter hospital length of stay.

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.