Well-differentiated pancreatic tumor/carcinoma: insulinoma

68Ga-NODAGA-Exendin-4 PET/CT Findings in a Case of Metastatic Insulinoma With Refractory Hypoglycemia Controlled by 90Y Transarterial Radioembolization

ABSTRACT

Metastatic insulinomas can cause recurrent hypoglycemia requiring continuous IV glucose infusion. Various medical and chemotherapeutic treatment options are used to reduce the patient's risk of death due to hypoglycemia. Treatment-resistant hepatic metastatic insulinomas may benefit clinically from 90Y transarterial radioembolization therapy. In this case, we present a case of liver metastatic insulinoma that achieved clinical improvement after 2 cycles of 90Y microspheres transarterial radioembolization, and the presence of active metastases was demonstrated with 68Ga-NODAGA-exendin-4 PET/CT imaging.

Stereotactic Body Radiation Therapy for Symptomatic Pancreatic Insulinoma: Two-Case Report and Literature Review

Insulinoma is the most common functional neuroendocrine tumor of the pancreas, with the main clinical symptom being hypoglycemia. The standard treatment is surgery, but some patients are not eligible for surgery, while in those operated on, the risk of perioperative complications is up to 30%. Diazoxide treatment to prevent hypoglycemia is effective only in 50% of patients. To prevent tumor growth and hormonal excess, stereotactic radiotherapy may be an alternative to surgical treatment. In our paper, we present two cases of patients with insulinoma treated successfully with stereotactic body radiation therapy (SBRT).

Outcomes of endoscopic ultrasound-guided ablation and minimally invasive surgery in the treatment of pancreatic insulinoma: a systematic review and meta-analysis

Background and aims

Most pancreatic insulinomas can be treated by minimally invasive modalities. The aim of this meta-analysis was to assess the clinical outcomes of endoscopic ultrasound (EUS)-guided ablation and minimally invasive surgery (MIS) in the treatment of pancreatic insulinoma.

Materials and methods

Online databases were searched for relevant studies. The primary aim was to compare the rates of adverse events (AEs) and the secondary aims were to compare the clinical and technical success rates, length of hospital stays, and symptom recurrence rates between EUS and MIS approaches.

Results

Eight studies with 150 patients were identified that reported EUS-guided ablation outcomes, forming the EUS group, and 9 studies with 236 patients reported MIS outcomes, forming the MIS group. The pooled median age of the included patients in the EUS group was greater than that of the MIS group (64.06 vs. 44.98 years old, p < 0.001). Also, the technical success rate was significantly higher in the EUS group (100% vs. 96.6%, p = 0.025), while the clinical success was significantly higher (6%) in the MIS group (94% vs. 98.7%, p = 0.021). The AE rates (18.7% vs. 31.1%, p = 0.012) and severe AE rates (1.3% vs. 7.9%, p = 0.011) were significantly lower in the EUS group. The median length of hospital stay in the EUS group (2.68 days, 95% CI: 1.88-3.48, I2 = 60.3%) was significantly shorter than in the MIS group (7.40 days, 95% CI: 6.22-8.58, I2 = 42.2%, p < 0.001). The recurrence rate was significantly higher in the EUS group (15.3% vs. 1.3%, p < 0.001).

Conclusions

EUS-guided ablation is associated with a lower AE rate and a shorter length of hospital stay, but a higher recurrence rate for the treatment of insulinoma compared with MIS. The EUS approach may be an alternative, even first-line, treatment for poor surgery candidates.

Preoperative pancreatic stent placement before the enucleation of insulinoma located in the head and neck of the pancreas in proximity to the main pancreatic duct: study protocol for a multicentre randomised clinical trial in Chinese tertiary medical centres

INTRODUCTION

The surgical intervention approach to insulinomas in proximity to the main pancreatic duct remains controversial. Standard pancreatic resection is recommended by several guidelines; however, enucleation (EN) still attracts surgeons with less risk of late exocrine/endocrine insufficiency, despite a higher postoperative pancreatic fistula (POPF) rate. Recently, the efficacy and safety of preoperative pancreatic stent placement before the EN have been demonstrated. Thus, a multicentre open-label study is being conducted to evaluate the efficacy and safety of stent placement in improving the outcome of EN of insulinomas in proximity to the main pancreatic duct.

METHODS AND ANALYSIS

This is a prospective, randomised, open-label, superiority clinical trial conducted at multiple tertiary centres in China. The major eligibility criterion is the presence of insulinoma located in the head and neck of the pancreas in proximity (≤2 mm) to the main pancreatic duct. Blocked randomisation will be performed to allocate patients into the stent EN group and the direct EN group. Patients in the stent EN group will go through stent placement by the endoscopist within 24 hours before the EN surgery, whereas other patients will receive EN surgery directly. The primary outcome is the assessment of the superiority of stent placement in reducing POPF rate measured by the International Study Group of Pancreatic Surgery standard. Both interventions will be performed in an inpatient setting and regular follow-up will be performed. The primary outcome (POPF rate) will be tested for superiority with the Χ2 test. The difference in secondary outcomes between the two groups will be analysed using appropriate tests.

ETHICS AND DISSEMINATION

The study has been approved by the Peking Union Medical College Hospital Institutional Review Board (K23C0195), Ruijin Hospital Ethics Committee (2023-314), Peking University First Hospital Ethics Committee (2024033-001), Institutional Review Board of Xuanwu Hospital of Capital Medical University (2023223-002), Ethics Committee of the First Affiliated Hospital of Xi'an Jiaotong University (XJTU1AF2023LSK-473), Institutional Review Board of Tongji Medical College Tongji Hospital (TJ-IRB202402059), Ethics Committee of Tongji Medical College Union Hospital (2023-0929) and Shanghai Cancer Center Institutional Review Board (2309282-16). The results of the study will be published in an international peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT05523778.

Diabetes management in cancer patients. An Italian Association of Medical Oncology, Italian Association of Medical Diabetologists, Italian Society of Diabetology, Italian Society of Endocrinology and Italian Society of Pharmacology multidisciplinary consensus position paper

Cancer management has significantly evolved in recent years, focusing on a multidisciplinary team approach to provide the best possible patient care and address the various comorbidities, toxicities, and complications that may arise during the patient's treatment journey. The co-occurrence of diabetes and cancer presents a significant challenge for health care professionals worldwide. Management of these conditions requires a holistic approach to improve patients' overall health, treatment outcomes, and quality of life, preventing diabetes complications and cancer treatment side-effects. In this article, a multidisciplinary panel of experts from different Italian scientific societies provide a critical overview of the co-management of cancer and diabetes, with an increasing focus on identifying a novel specialty field, 'diabeto-oncology', and suggest new co-management models of cancer patients with diabetes to improve their care. To better support cancer patients with diabetes and ensure high levels of coordinated care between oncologists and diabetologists, 'diabeto-oncology' could represent a new specialized field that combines specific expertise, skills, and training.

Not Just an Accident: A Case of Insulinoma

Insulinomas are a rare cause of recurrent hypoglycemia in non-diabetic patients. Diagnosis requires hypoglycemia (plasma glucose <50 mg/dL), neuroglycopenic symptoms, and prompt relief of symptoms following the administration of glucose, known as Whipple's triad. The gold standard diagnostic tests are measuring insulin, C-peptide, and glucose during a 72-hour fast. In the preoperative period and in patients with unresectable or metastatic tumors, medical management with diazoxide and octreotide can be considered for recurrent hypoglycemia. We present a case of insulinoma in a 37-year-old woman who initially presented after a seizure-related motor vehicle accident. Upon admission, her initial glucose level was 32 mg/dL, indicating a likely hypoglycemic seizure. During her hospitalization, she had recurrent episodes of fasting and postprandial hypoglycemia, ranging from 32-70 mg/dL. She exhibited the characteristics of Whipple's triad when values dropped below 50 mg/dL. These episodes necessitated continuous infusions of 10% dextrose. Tests for insulin autoantibodies, sulfonylurea screens, and thyroid function yielded unremarkable results. A 72-hour fasting test was initiated to investigate potential endogenous causes of excessive insulin production. Laboratory results from a venous glucose level of 46 mg/dL indicated a notable rise in C peptide and insulin levels, alongside beta hydroxybutyrate suppression, all of which fulfilled the diagnostic criteria for insulinoma. An abdominal magnetic resonance imaging (MRI) unveiled a 1.3 cm mass in the pancreatic tail. This case emphasizes the importance of employing a focused approach when evaluating non-diabetic individuals displaying hypoglycemia with positive Whipple's triad. This targeted method not only enables early detection of this rare condition but also assists in eliminating other common causes of recurrent hypoglycemia in non-diabetic individuals. Moreover, in addition to this diagnosis being rare, it is important to note that patients with insulinomas typically do not exhibit a glucose level low enough to induce seizures during their initial presentation.

Endoscopic Ultrasound-guided Radiofrequency Ablation Versus Surgical Resection for Treatment of Pancreatic Insulinoma

BACKGROUND & AIMS

Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) is emerging as a safe and effective treatment for pancreatic neuroendocrine tumors. We aimed to compare EUS-RFA and surgical resection for the treatment of pancreatic insulinoma (PI).

METHODS

Patients with sporadic PI who underwent EUS-RFA at 23 centers or surgical resection at 8 high-volume pancreatic surgery institutions between 2014 and 2022 were retrospectively identified and outcomes compared using a propensity-matching analysis. Primary outcome was safety. Secondary outcomes were clinical efficacy, hospital stay, and recurrence rate after EUS-RFA.

RESULTS

Using propensity score matching, 89 patients were allocated in each group (1:1), and were evenly distributed in terms of age, sex, Charlson comorbidity index, American Society of Anesthesiologists score, body mass index, distance between lesion and main pancreatic duct, lesion site, size, and grade. Adverse event (AE) rate was 18.0% and 61.8% after EUS-RFA and surgery, respectively (P < .001). No severe AEs were observed in the EUS-RFA group compared with 15.7% after surgery (P < .0001). Clinical efficacy was 100% after surgery and 95.5% after EUS-RFA (P = .160). However, the mean duration of follow-up time was shorter in the EUS-RFA group (median, 23 months; interquartile range, 14-31 months vs 37 months; interquartile range, 17.5-67 months in the surgical group; P < .0001). Hospital stay was significantly longer in the surgical group (11.1 ± 9.7 vs 3.0 ± 2.5 days in the EUS-RFA group; P < .0001). Fifteen lesions (16.9%) recurred after EUS-RFA and underwent a successful repeat EUS-RFA (11 patients) or surgical resection (4 patients).

CONCLUSION

EUS-RFA is safer than surgery and highly effective for the treatment of PI. If confirmed in a randomized study, EUS-RFA treatment can become first-line therapy for sporadic PI.

Study protocol for a multicenter randomized controlled trial to compare radiofrequency ablation with surgical resection for treatment of pancreatic insulinoma

BACKGROUND

Insulinoma is the most common functional pancreatic neuroendocrine tumor and treatment is required to address symptoms associated with insulin hypersecretion. Surgical resection is effective but burdened by high rate of adverse events (AEs). Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) demonstrated encouraging results in terms of safety and efficacy for the management of these tumors. However, studies comparing surgery and EUS-RFA are lacking.

AIMS

The primary aim is to compare EUS-RFA with surgery in term of safety (overall rate of AEs). Secondary endpoints include: (a) severe AEs rate; (b) clinical effectiveness; (c) patient's quality of life; (d) length of hospital stay; (e) rate of local/distance recurrence; (f) need of reintervention; (g) rate of endocrine and exocrine pancreatic insufficiency; (h) factors associated with EUS-RFA related AEs and clinical effectiveness.

METHODS

ERASIN-RCT is an international randomized superiority ongoing trial in four countries. Sixty patients will be randomized in two arms (EUS-RFA vs surgery) and outcomes compared. Two EUS-RFA sessions will be allowed to achieve symptoms resolution. Randomization and data collection will be performed online.

DISCUSSION

This study will ascertain if EUS-RFA can become the first-line therapy for management of small, sporadic, pancreatic insulinoma and be included in a step-up approach in case of clinical failure.

Safety and efficacy of endoscopic ultrasound-guided radiofrequency ablation for pancreatic insulinoma: A single-center experience

BACKGROUND/OBJECTIVES

Insulinomas are rare, functioning pancreatic neuroendocrine neoplasms (pNEN), whose gold standard therapy is surgical resection. Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) is a recent technique that has emerged as a minimally invasive therapeutic option for patients with pancreatic lesions not eligible for surgery. In this study, we aimed to describe a series of patients with unresectable pancreatic insulinoma treated with EUS-RFA.

METHODS

This is a single-center, retrospective study including all consecutive patients with functioning pancreatic insulinoma undergoing EUS-RFA for surgical unfitness or surgery refusal, between March 2017 and September 2021. Technical success (i.e., complete mass ablation), adverse event rate and severity, clinical and radiologic outcomes (i.e., symptom remission with a normal concentration of blood glucose, and the presence of intralesional necrosis), and post-procedural follow-up were assessed.

RESULTS

A total of 10 patients (mean age: 67.1 ± 10.1years; F:M 7:3) were included. The mean size of insulinoma was 11.9 ± 3.3 mm. Technical success and clinical remission were achieved in 100% of patients. Only one (10%) patient was successfully treated with two RFA sessions. Two procedure-related early adverse events occurred, including two (20%) cases of mild abdominal pain. No major complications were observed. The complete radiologic response within 3 months after EUS-RFA was observed in all patients (100%). After a median follow-up of 19.5 (range12-59) months, symptom remission and persistent euglycemia were assessed in all the patients.

CONCLUSIONS

Data from this case series suggest that EUS-RFA is a feasible and safe therapeutic approach for pancreatic insulinomas in patients unwilling or unable to undergo surgery with medium-term efficacy.

Diagnosis, Management and Theragnostic Approach of Gastro-Entero-Pancreatic Neuroendocrine Neoplasms

Gastro-entero-pancreatic neuroendocrine neoplasms (GEP-NENs) constitute an ideal target for radiolabeled somatostatin analogs. The theragnostic approach is able to combine diagnosis and therapy by the identification of a molecular target that can be diagnosed and treated with the same radiolabeled compound. During the last years, advances in functional imaging with the introduction of somatostatin analogs and peptide receptor radionuclide therapy, have improved the diagnosis and treatment of GEP-NENs. Moreover, PET/CT imaging with ¹⁸F-FDG represents a complementary tool for prognostic evaluation of patients with GEP-NENs. In the field of personalized medicine, the theragnostic approach has emerged as a promising tool in diagnosis and management of patients with GEP-NENs. The aim of this review is to summarize the current evidence on diagnosis and management of patients with GEP-NENs, focusing on the theragnostic approach.

Metastatic insulinoma: exploration from clinicopathological signatures and genetic characteristics

Background

Insulinoma is a rare type of pancreatic neuroendocrine tumor with low incidence and low-malignant features. While very few insulinomas present with malignant behaviours, such as lymph node and liver metastasis, only a few studies have focused on this field owing to the limitation of samples. Existing evidence suggests that metastatic insulinoma largely derive from non-functional pancreatic neuroendocrine tumor. However, we found a portion of metastatic insulinomas may derive from non-metastatic insulinomas and explored their clinicopathological signatures and genetic characteristics.

Methods

Four metastatic insulinoma patients with synchronous liver metastasis or lymph node metastasis at the Peking Union Medical College Hospital between October 2016 and December 2018 were enrolled, and whole exon and genome sequencing were performed on fresh frozen tissues and peripheral blood samples. Clinicopathological information and genomic sequencing results were collected and matched to explore the characteristics of the metastatic insulinomas.

Results

These four metastatic insulinoma patients underwent surgery or interventional therapy, and their blood glucose levels immediately increased and maintained within standard range after treatment. For these four patients, the proinsulin/insulin molar ratio <1 and primary tumors were all present as PDX1+, ARX-, and insulin+, which were similar to non-metastatic insulinomas. However, the liver metastasis showed PDX1+ and ARX+, insulin+. Meanwhile, genomic sequencing data showed no recurrently mutations and typical CNV patterns. However, one patient harboured the YY1 T372R mutation, a recurrently mutated gene in non-metastatic insulinomas.

Conclusions

A portion of metastatic insulinomas were largely derived from non-metastatic insulinomas in hormone secretion and ARX/PDX1 expression patterns. Meanwhile, the accumulation of ARX expression may be involved in the progression of metastatic insulinomas.

68Ga-DOTA-Exendin-4 PET/CT Demonstrated a Higher Detection Efficacy for Double-Primary Insulinomas Than MRI: A Case Report

ABSTRACT

We presented a 20-year-old woman with gradually increasing lethargy and multiple episodes of dizziness for 5 months. The laboratory examination revealed decreasing level of blood glucose and elevated levels of fasting plasma insulin and C-peptide. The MRI identified a focal nodule in the tail of the pancreas. 68Ga-DOTA-exendin-4 PET/CT revealed 2 intense focal tracer uptakes in the tail of the pancreas, one of which corresponded to the lesion revealed on MRI. The immunohistochemical results of resected samples confirmed the diagnosis of double-primary insulinomas. 68Ga-DOTA-exendin-4 PET/CT demonstrated excellent localization and characterization for double-primary insulinomas in the tail of the pancreas.

Insulinoma in childhood: a retrospective review of 22 patients from one referral centre

Background

Insulinomas are very rare in childhood with sparse knowledge on the clinical aspects and the presence of Multiple Endocrine Neoplasia type 1 (MEN1).

Methods

We conducted a retrospective review of patients diagnosed with insulinoma between 1995 and 2021, presenting to one referral centre in Russia. Clinical, biochemical, genetic, imaging and histological data were collected. In addition, follow-up and family data were obtained.

Results

A total of twenty-two children aged 5 to 16 years were identified. The median (range) gap between the first hypoglycaemia symptoms and diagnosis was 10 (1-46) months. Twelve children (55%) were misdiagnosed to have epilepsy and were treated with anticonvulsants before hypoglycemia was revealed. Contrast enhanced MRI and/or CT were accurate to localize the lesion in 82% (n=18). Five patients (23%) had multiple pancreatic lesions. All children underwent surgical treatment. The median (range) diameter of removed tumors was 1.5 (0.3-6) cm. Histopathological studies confirmed the presence of insulinoma in all cases. Immunohistochemical studies revealed G2 differentiation grade in 10 out of 17 cases. Two patients were diagnosed with metastatic insulinoma. One of them had metastases at the time of insulinoma diagnosis, while the other was diagnosed with liver metastases eight years after the surgery. Eight children (36%) were found to carry MEN1 mutations, inherited n=5, de novo n=1, no data, n=2. Children with MEN1 had significantly higher number of pancreatic tumors compared to sporadic cases. All of them developed additional MEN1 symptoms during the following 2-13 years. In the five patients with inherited MEN1, seven family members had hitherto undiscovered MEN1 manifestations.

Conclusions

In this large cohort of children with rare pediatric insulinomas, MEN1 syndrome and G2 tumors were frequent, as well as hitherto undiscovered MEN1 manifestations in family members. Our data emphasize the need of genetic testing in all children with insulinoma and their relatives, even in the absence of any other features, as well as the importance of a prolonged follow-up observation.

Case presentation of 8-year follow up of recurrent malignant duodenal Insulinoma and lymph node metastases and literature review of malignant Insulinoma management

BACKGROUND

Insulinoma is an uncommon insulin-secreting neuroendocrine tumor that presents with severe recurrent hypoglycemia. Although cases of extrapancreatic insulinomas have been reported, the majority of insulinomas occur in the pancreas. The number of reported cases of ectopic insulinomas with follow-up assessments is limited and they do not report disease recurrence. The current report presents the first documented case of recurrent extrapancreatic insulinoma with 8 years of follow-up, provides relevant literature review, and proposes surveillance and treatment strategies.

CASE PRESENTATION

We describe an insulinoma localized in the duodenal wall of a 36-year-old female who presented in 2013 with weight gain and Whipple's triad and was successfully managed with duodenotomy and enucleation. She presented again in 2017 with recurrent Whipple's triad and was found to have metastatic disease localized exclusively to peripancreatic lymph nodes. Primary pancreatic insulinoma was not evident and her hypoglycemia resolved following lymph node dissection. Eight years after initial presentation continuous glucose monitoring (CGM) showed a trend for euglycemia, and PET-CT Gallium 68 DOTATATE scan evaluation indicated absence of recurrent disease.

CONCLUSION

Insulinomas are rare clinical entities and extrapancreatic insulinomas are particularly uncommon. Follow-up evaluation and treatment strategies for ectopic insulinoma recurrence presents a significant clinical challenge as the condition has hitherto remained undescribed in the literature. Available evidence in the literature indicates that lymph node metastases of intrapancreatic insulinomas likely do not change prognosis. Given the absence of long-term data informing the management and monitoring of patients with extrapancreatic insulinoma, we suggest patient education for hypoglycemic symptoms, monitoring for hypoglycemia with CGM, annual imaging, and a discussion with patients regarding treatment with octreotide or alternative somatostatin receptor analog therapies.

Case report - Selective internal radiation therapy (SIRT) in a patient with hyperinsulinemic hypoglycemia due to a metastatic insulinoma with late onset of endocrine activity

Insulinomas are the most common functioning pancreatic neuroendocrine tumors (NET), which can lead to hyperinsulinemic hypoglycemia. In advanced metastatic stages of the disease, the prognosis is poor. Patients with hormonally active insulinomas primarily present with features of neuroglycopenia. Transformation from a nonfunctional to a functional NET is rare. Here, we present a case of a 59-year-old male adult with a metastatic insulinoma and late onset of endocrine activity. Besides medical treatment with Diazoxide and small frequent feedings, continuous intravenous glucose application was eventually required to avoid hypoglycemia. Furthermore, we show that selective internal radiation therapy (SIRT) can be an effective therapeutic approach for symptom reduction in advanced metastatic disease.

A novel diagnostic model for insulinoma

The aim is to describe a simple and feasible model for the diagnosis of insulinoma. This retrospective study enrolled 37 patients with insulinoma and 44 patients with hypoglycemia not due to insulinoma at the First Affiliated Hospital of Guangxi Medical University. General demographic and clinical characteristics; hemoglobin A1c (HbA1c), insulin and C-peptide concentrations; and the results of 2-h oral glucose tolerance tests (OGTT) were recorded, and a logistic regression model predictive of insulinoma was determined. Body mass index (BMI), HbA1c concentration, 0-h C-peptide concentration, and 0-h and 1-h plasma glucose concentrations (P < 0.05 each) were independently associated with insulinoma. A regression prediction model was established through multivariate logistics regression analysis: Logit p = 7.399+(0.310 × BMI) - (1.851 × HbA1c) - (1.467 × 0-h plasma glucose) + (1.963 × 0-h C-peptide) - (0.612 × 1-h plasma glucose). Using this index to draw a receiver operating characteristic (ROC) curve, the area under the curve (AUC) was found to be 0.957. The optimal cut-off value was - 0.17, which had a sensitivity of 89.2% and a specificity of 86.4%. Logit P ≥ - 0.17 can be used as a diagnostic marker for predicting insulinoma in patients with hypoglycemia.

Is the Size of Insulinoma Predictive for its Endocrine Behavior? An Endoscopic Ultrasound Study

OBJECTIVE

Insulinoma is a rare tumor of the pancreas that can lead to spontaneous hypoglycemia due to excessive insulin secretion. Seventy-two-hour fast is the gold standard for finding the correct diagnosis. Endoscopic ultrasound (EUS) is an established examination method to identify the suspicious lesion. Previous studies correlate the measured size of insulinoma and their endocrine behavior. This study was designed to find a relation between these variables.

METHODS

We took the data of patients who had a histologically confirmed insulinoma after receiving an endoscopic ultrasound in our department. Size and echogenicity were correlated with the endpoint of the 72-hour fast and hormone levels.

RESULTS

A total of 45 patients were identified. Most insulinomas were small with a volume of<2 cm³ (median 1.15 cm³). There was no correlation between the duration of fasting, hormone levels, and the size of the insulinoma. In addition, in a subgroup analysis, no connection could be established between the size of the insulinoma and the amount of insulin released after oral glucose exposure. We found that homogeneous tumors were significantly smaller and had a lower Ki-67 index. Furthermore, there was a tendency towards a shorter duration for the 72-hour fast for the small tumors.

DISCUSSION

This data suggests that the measured size of insulinoma by EUS is not related to the time until termination of the 72-hour fast and measured hormone levels. The echogenicity seems more important, showing that homogenous tumors are an indicator of a higher differentiation, which can result in a shorter duration of the fasting period. The differences in the secretion behavior of the insulinomas could complicate the correlation of size and the 72-hour fast period.

Pancreatic neuroendocrine tumour-insulinoma masquerading as a psychiatric illness

A female patient in her early sixties had problems of recurrent syncopal attacks and panic attacks over the last 5 years. She had been initially managed for an anxiety disorder with psychiatric medications. During one of those episodes, she was brought to our hospital in an unconscious state with a low blood sugar level of 43 mg/dL. She was suspected to have a neuroendocrine tumour and diagnosis was established by supervised fasting up to 72 hours and imaging. Her recorded blood sugar during fasting was 37 mg/dL. She underwent surgery and presently remains asymptomatic. Physicians should have a high suspicion of insulinoma in patients presenting with repeated episodes of hypoglycaemic symptoms in the absence of any cognizable cause.

Insulinoma: an uncommon cause of delirium

We present the case of an 83-year-old woman with recurrent episodes of delirium occurring overnight, associated with hypoglycaemia. Other causes for delirium were excluded. Laboratory findings were in keeping with endogenous insulin production. Computerised tomography imaging revealed a small mass in the pancreas supporting a presumed diagnosis of an insulinoma. Given the patient's frailty and cognitive impairment, a conservative management approach was taken. Diazoxide was commenced with resolution of episodes of delirium. This case highlights hypoglycaemia, and insulinoma, as a rare, but treatable cause of delirium. It demonstrates the importance of blood sugar screening in delirium. It emphasises the holistic modifications to management, which must be taken to ensure patient-centred care when caring for an older adult living with frailty, who may have cognitive impairment.

Diagnostic performance of noninvasive imaging modalities for localization of insulinoma: A meta-analysis

BACKGROUND

Insulinoma is the most common functional neuroendocrine tumor found only in the pancreas. The early detection of insulinoma is of importance. Studies comparing the performance of noninvasive modalities were limited by sample size and heterogeneity between studies. The aim of this meta-analysis was to evaluate the diagnostic performance of PET/CT, SPECT/CT, CT and MRI for the localization of insulinoma, and to provide evidence for clinical practice.

METHODS

PubMed, Embase, Cochrane Library, Wanfang Data and China National Knowledge Infrastructure were searched from inception to May 31, 2021. Pooled sensitivity, specificity, positive Likelihood Ratio (+LR) and negative Likelihood Ratio (-LR), diagnostic odds ratio (DOR), and concordance rate were calculated.

RESULTS

A total of 19 studies including 708 patients of insulinoma reached the inclusion criteria. PET/CT imaging demonstrated a pooled sensitivity of 0.79 (95% CI: 0.54-0.92) and a pooled specificity of 0.84 (95% CI: 0.20-0.99). The pooled sensitivity and specificity of SPECT/CT were 0.77 (95% CI: 0.46-0.93) and 0.45 (95% CI: 0.22-0.70). CT showed an overall sensitivity of 0.54 (95% CI: 0.35-0.72) and specificity of 0.75 (95% CI: 0.54-0.88). The pooled sensitivity and specificity for MRI were 0.54 (95% CI: 0.31-0.75) and 0.65 (95% CI: 0.39-0.84), respectively. The concordance rates of PET, SPECT, CT, and MRI were 78% (95% CI: 66-90%), 74% (95% CI: 52-97%), 56% (95% CI: 41-72%), and 53% (95% CI: 33-73%), respectively.

CONCLUSION

Results of this study indicate that PET/CT demonstrated superior performance than SPECT/CT, CT and MRI for the localization of insulinoma. GLP-1R based PET/CT manifested better diagnostic performance in comparison with SSTR based PET/CT imaging modality.

Diagnostic and Interventional Role of Endoscopic Ultrasonography for the Management of Pancreatic Neuroendocrine Neoplasms

Pancreatic neuroendocrine neoplasms (PanNENs) are relatively rare, but their incidence has increased significantly in the last decades. Precise diagnosis and prognostic stratification are crucial for proper patient management. Endoscopic ultrasound (EUS) is the modality of choice for diagnosis of solid pancreatic tumors, showing a higher tumor detection rate than other imaging modalities, especially for small size lesions. EUS also serves as a guide for preoperative sampling and other interventions. EUS-tissue acquisition is a safe and highly accurate technique for cyto/histological diagnosis of PanNENs with a well-demonstrated correlation between Ki-67 proliferation index values and tumor grading on EUS and surgical specimens according to the WHO 2017 classification. Furthermore, the possibility of a preoperative EUS-guided fine needle tattooing or fiducial markers placement may help the surgeon to locate small and deep tumors, thus avoiding formal pancreatic resections in favor of parenchymal-sparing surgery. Finally, locoregional ablative treatments using either ethanol injection or radiofrequency ablation have been proposed in recent studies with promising results in order to control symptoms or reduce tumor burden in selected patients unfit for surgery with functioning or non-functioning PanNENs. This article review highlights the current role of EUS in PanNENs management, focusing on the present and future applications of EUS-guided interventions.

Carcinoid Syndrome and Hyperinsulinemic Hypoglycemia Associated with Neuroendocrine Neoplasms: A Critical Review on Clinical and Pharmacological Management

The carcinoid syndrome (CS) and hyperinsulinemic hypoglycemia (HH) represent two of the most common clinical syndromes associated with neuroendocrine neoplasms (NENs). The former is mainly related to the serotonin secretion by a small bowel NEN, whereas the latter depends on an insulin hypersecretion by a pancreatic insulinoma. Both syndromes/conditions can affect prognosis and quality of life of patients with NENs. They are often diagnosed late when patients become strongly symptomatic. Therefore, their early detection and management are a critical step in the clinical management of NEN patients. A dedicated and experienced multidisciplinary team with appropriate therapeutic strategies is needed and should be encouraged to optimize clinical outcomes. This review aims to critically analyze clinical features, evidence and treatment options of CS and HH and therefore to improve their management.

Multiple endocrine neoplasia type 1 (MEN-1) and neuroendocrine neoplasms (NENs)

Neuroendocrine neoplasms (NENs) are relatively rare neoplasms with 6.4-times increasing age-adjusted annual incidence during the last four decades. NENs arise from neuroendocrine cells, which release hormones in response to neuronal stimuli and they are distributed into organs and tissues. The presentation and biological behaviour of the NENs are highly heterogeneous, depending on the organ. The increased incidence is mainly due to increased awareness and improved detection methods both in the majority of sporadic NENs (non-inherited), but also the inherited groups of neoplasms appearing in at least ten genetic syndromes. The most important one is multiple endocrine neoplasia type 1 (MEN-1), caused by mutations in the tumour suppressor gene MEN1. MEN-1 has been associated with different tumour manifestations of NENs e.g. pancreas, gastrointestinal tract, lungs, thymus and pituitary. Pancreatic NENs tend to be less aggressive when arising in the setting of MEN-1 compared to sporadic pancreatic NENs. There have been very important improvements over the past years in both genotyping, genetic counselling and family screening, introduction and validation of various relevant biomarkers, as well as newer imaging modalities. Alongside this development, both medical, surgical and radionuclide treatments have also advanced and improved morbidity, quality of life and mortality in many of these patients. Despite this progress, there is still space for improving insight into the genetic and epigenetic factors in relation to the biological mechanisms determining NENs as part of MEN-1. This review gives a comprehensive update of current evidence for co-occurrence, diagnosis and treatment of MEN-1 and neuroendocrine neoplasms and highlight the important progress now finding its way to international guidelines in order to improve the global management of these patients.

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.

Multiple Endocrine Neoplasia Type 1 and the Pancreas: Diagnosis and Treatment of Functioning and Non-Functioning Pancreatic and Duodenal Neuroendocrine Neoplasia within the MEN1 Syndrome - An International Consensus Statement

The better understanding of the biological behavior of multiple endocrine neoplasia type 1 (MEN1) organ manifestations and the increase in clinical experience warrant a revision of previously published guidelines. Duodenopancreatic neuroendocrine neoplasias (DP-NENs) are still the second most common manifestation in MEN1 and, besides NENs of the thymus, remain a leading cause of death. DP-NENs are thus of main interest in the effort to reevaluate recommendations for their diagnosis and treatment. Especially over the last 2 years, more clinical experience has documented the follow-up of treated and untreated (natural-course) DP-NENs. It was the aim of the international consortium of experts in endocrinology, genetics, radiology, surgery, gastroenterology, and oncology to systematically review the literature and to present a consensus statement based on the highest levels of evidence. Reviewing the literature published over the past decade, the focus was on the diagnosis of F- and NF-DP-NENs within the MEN1 syndrome in an effort to further standardize and improve treatment and follow-up, as well as to establish a "logbook" for the diagnosis and treatment of DP-NENs. This shall help further reduce complications and improve long-term treatment results in these rare tumors. The following international consensus statement builds upon the previously published guidelines of 2001 and 2012 and attempts to supplement the recommendations issued by various national and international societies.

Insulinoma presenting with postprandial hypoglycemia and a low body mass index: A case report

BACKGROUND

Insulinomas are the most common type of functioning endocrine neoplasms of the pancreas presenting hypoglycemic symptoms. Patients characteristically develop symptoms while fasting, but some patients have reported symptoms only in the postprandial state. Repeated and prolonged hypoglycemic episodes can reduce the awareness of adrenergic symptoms, and patients may have amnesia, which delays diagnosis.

CASE SUMMARY

We describe a case of a 24-year-old underweight patient who showed hypoglycemic symptoms for almost 6 years. Although patients with insulinoma characteristically develop symptoms while fasting, this young man had hypoglycemic symptoms up to one hour postprandially, especially after high-sugar meals and after physical activity. The fasting tests and imaging methods performed at local hospitals were evaluated as negative for abnormal results. However, brown adipose tissue exhibited increased metabolic activity, and some muscle groups had histological changes as indicated by positron emission tomography with 2-deoxy-2-[fluorine-18]fluoro-D-glucose integrated with computed tomography. Glycogen deficiency was also histologically confirmed. The patient’s symptoms progressed over the years and occurred more frequently, i.e., several times a month, and the patient had reduced awareness of adrenergic symptoms. The follow-up fasting test was positive, and the imaging results showed a tumor in the head of the pancreas. The patient underwent laparotomy with enucleation of the insulinoma.

CONCLUSION

Weight gain and fasting hypoglycemia are not necessarily characteristics of insulinoma. In prolonged cases, adrenergic symptoms can be suppressed.

[Intermittent disturbances of perception during fasting in a 46-year-old female patient]

BACKGROUND

We report the case of a 46-year-old female patient who presented in the emergency department with intermittent disturbances of perception when fasting.

DIAGNOSTICS

In the diagnostic fasting test, a hyperinsulinemic hypoglycemia already occurred after 7h. A sonographic examination was inconspicuous, therefore, a Ga 68-HA-DOTATATE positron emission tomography computed tomography (PET-CT) was carried out. The results were indicative of a neuroendocrine neoplasm, which gave rise to the suspicion of an insulinoma.

CLINICAL COURSE

For surgical treatment the patient was transferred to an external hospital. Following surgery, the patient was free of symptoms.

CONCLUSION

If multiple symptoms of hypoglycemia are present, an insulinoma as the cause must be considered in the differential diagnostics.

Surgical management of insulinomas at the Azerbaijan Medical University: a retrospective study of 21 cases over a 10-year period

Background/aim

This study represents the first report that evaluates the experience gathered from diagnosis, surgical treatment and outcome of insulinoma patients from Azerbaijan.

Materials and methods

We retrospectively review of insulinoma patients for a 10-year period. Collected data included patient demographics, laboratory and imaging tests, detailed surgical reports, histopathological examination of resected specimens, and clinical follow-up.

Results

Twenty-one insulinoma patients were identified. Male patients comprised 52.4%; mean age was 44 years. Mean time to diagnosis was 14 months; 61% patients had ≥3 medical referrals due to hypoglycemia-related symptoms. Diagnosis sensitivity of CT, MRI and US was 85%, 80%, and 55%, respectively. The mean glucose, insulin, C-peptide levels were 35.7 ± 9.5 mg/dL, 33.5 ± 21.9 µU/mL, and 3.74 ± 1.88 ng/mL, respectively. Pancreatic head and tail were the most frequent tumor locations; mean tumor size was 1.5 ± 0.7 cm. No statistical association was found between the tumor size and preoperative glucose, C-peptide and insulin levels. Distal pancreatectomy and enucleation were the most common surgical procedures. Local tumor recurrence rate was 14%. There was no mortality.

Conclusions

To prevent delayed diagnoses, physicians should be familiar with the typical symptoms of these rare tumors.

Functionality is not an independent prognostic factor for pancreatic neuroendocrine tumors

BACKGROUND

Pancreatic neuroendocrine neoplasms (pNENs) that produce hormones leading to symptoms are classified as functional tumors, while others are classified as nonfunctional tumors. The traditional view is that functionality is a factor that affects the prognosis of pNEN patients. However, as the sample sizes of studies have increased, researches in recent years have proposed new viewpoints.

AIM

To assess whether functionality is an independent factor for predicting the prognosis of pNEN patients.

METHODS

From January 2004 to December 2016, data of patients who underwent surgery at the primary site for the treatment of pNENs from the Surveillance, Epidemiology, and End Results (SEER) database and West China Hospital database were retrospectively analyzed.

RESULTS

Contemporaneous data from the two databases were analyzed separately as two cohorts and then merged as the third cohort to create a large sample that was suitable for multivariate analysis. From the SEER database, age (P = 0.006) and T stage (P < 0.001) were independent risk factors affecting the survival. From the West China Hospital database, independent prognostic factors were age (P = 0.034), sex (P = 0.032), and grade (P = 0.039). The result of the cohort consisting of the combined populations from the two databases showed that race (P = 0.015), age (P = 0.002), sex (P = 0.032) and T stage (P < 0.001) were independent prognostic factors. In the West China Hospital database and in the total population, nonfunctional pNETs and other functional pNETs tended to have poorer prognoses than insulinoma. However, functionality was not associated with the survival time of patients with pNETs in the multivariate analysis.

CONCLUSION

Functionality is not associated with prognosis. Race, age, sex, and T stage are independent factors for predicting the survival of patients with pNETs.

Progesteron receptor expression in insulin producing cells of neuroendocrine neoplasms

Progesterone receptor (PgR) inhibits cell proliferation in pancreatic neuroendocrine neoplasms (PanNEN). In non-neoplastic pancreas, loss of PgR induces β-cell proliferation and insulin production. However, detailed association between PgR and insulin producing PanNENs is poorly understood. Insulin, proinsulin, and PgR were immunolocalized in 82 PanNENs (54 non-functioning PanNENs: NF-PanNENs and 28 insulinomas). The status of immunoreactivity was compared to the clinicopathological factors of the patients. Immunoreactivity was also confirmed by employing the double-immunohistochemistry. These results were also compared with those in non-neoplastic Langerhans islets. PgR immunoreactivity was significantly higher in insulinomas than that in NF-PanNENs (p < 0.001). Insulin and proinsulin immunoreactivity was also detected in 20 (37 %) of (single cell) insulin positive NFs (Ins^pos-NF-PanNEN), in which PgR expression was higher than in insulin negative NF-PanNENs (Ins^neg-NF-PanNEN, p = 0.03). The ratio of PgR-insulin double positive cells to overall insulin positive cells, as well as PgR-proinsulin double positive cells to proinsulin positive cells, was detected to the same degree in insulinoma (PgR-insulin 70 %, PgR-proinsulin 66 %), Ins^pos-NF-PanNENs (PgR-insulin 65 %, PgR-proinsulin 68 %) and normal islet (PgR-insulin 80 %, PgR-proinsulin 72 %). PgR and insulin expressing cells colocalize in tumor cells of the PanNENs regardless of the hormone-related symptoms of the patients. Inhibitory effect of PgR on tumor cells might be associated with the favourable clinical outcome of insulinoma patients.

Biomarkers for Pancreatic Neuroendocrine Neoplasms (PanNENs) Management-An Updated Review

Pancreatic neuroendocrine tumors (PanNENs) are rare sporadic cancers or develop as part of hereditary syndromes. PanNENs can be both functioning and non-functioning based on whether they produce bioactive peptides. Some PanNENs are well differentiated while others-poorly. Symptoms, thus, depend on both oncological and hormonal causes. PanNEN diagnosis and treatment benefit from and in some instances are guided by biomarker monitoring. However, plasmatic monoanalytes are only suggestive of PanNEN pathological status and their positivity is typically followed by deepen diagnostic analyses through imaging techniques. There is a strong need for new biomarkers and follow-up modalities aimed to improve the outcome of PanNEN patients. Liquid biopsy follow-up, i.e., sequential analysis on tumor biomarkers in body fluids offers a great potential, that need to be substantiated by additional studies focusing on the specific markers and the timing of the analyses. This review provides the most updated panorama on PanNEN biomarkers.

Advances in the Diagnosis and Management of Well-Differentiated Neuroendocrine Neoplasms

Neuroendocrine neoplasms constitute a diverse group of tumors that derive from the sensory and secretory neuroendocrine cells and predominantly arise within the pulmonary and gastrointestinal tracts. The majority of these neoplasms have a well-differentiated grade and are termed neuroendocrine tumors (NETs). This subgroup is characterized by limited proliferation and patients affected by these tumors carry a good to moderate prognosis. A substantial subset of patients presenting with a NET suffer from the consequences of endocrine syndromes as a result of the excessive secretion of amines or peptide hormones, which can impair their quality of life and prognosis. Over the past 15 years, critical developments in tumor grading, diagnostic biomarkers, radionuclide imaging, randomized controlled drug trials, evidence-based guidelines, and superior prognostic outcomes have substantially altered the field of NET care. Here, we review the relevant advances to clinical practice that have significantly upgraded our approach to NET patients, both in diagnostic and in therapeutic options.

Long-standing Sporadic Pancreatic Insulinoma: Report of a Rare Case

Insulinomas are rare, functional pancreatic neuroendocrine tumors arising from the pancreatic multipotent stem cells or neuroendocrine islet, occurring with a higher proportion in females. Majority of insulinomas have a sporadic etiology; however, only 5%-10% develop as a part of multiple endocrine neoplasm type 1 syndrome. They usually present with symptoms of hypoglycemia including disturbance in orientation, tremors, diaphoresis, altered mental state, seizures and visual changes among others. The diagnosis is based on appreciation of the classic Whipple triad, i.e. neuroglycopenic symptoms and sympathetic drive along with low serum glucose levels (<50 mg/dL) and a complete reversibility of these symptoms with prompt administration of glucose. The gold standard treatment for insulinoma involves complete surgical excision (i.e. enucleation), which is curative in 90% of the patients. Health care physicians should have a high index of suspicion for this tumor in patients presenting with neurological and sympathetic symptoms, particularly if they are resolved after eating. Here, we report the case of a 48-year-old female with the history of multiple episodes of hypoglycemic symptoms for the past two years which improved on glucose intake. Furthermore, we also summarized the discussion regarding diagnosis and management of pancreatic insulinoma.

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.

Targeted Systemic Treatment of Neuroendocrine Tumors: Current Options and Future Perspectives

Neuroendocrine tumors (NETs) originate from the neuroendocrine cell system in the bronchial and gastrointestinal tract and can produce hormones leading to distinct clinical syndromes. Systemic treatment of patients with unresectable NETs aims to control symptoms related to hormonal overproduction and tumor growth. In the last decades prognosis has improved as a result of increased detection of early stage disease and the introduction of somatostatin analogs (SSAs) as well as several new therapeutic options. SSAs are the first-line medical treatment of NETs and can control hormonal production and tumor growth. The development of next-generation multireceptor targeted and radiolabelled somatostatin analogs, as well as target-directed therapies (as second-line treatment options) further improve progression-free survival in NET patients. To date, however, a significant prolongation of overall survival with systemic treatment in NET has not been convincingly demonstrated. Several new medical options and treatment combinations will become available in the upcoming years, and although preliminary results of preclinical and clinical trials are encouraging, large, preferrably randomized clinical studies are required to provide definitive evidence of their effect on survival and symptom control.

Early detection of cognitive impairment in patients with insulinoma

PURPOSE

Long-standing hypoglycemia can cause cognitive impairment, and whether recurrent severe hypoglycemia impacts cognitive function in patients with insulinoma has not been studied. This study focused on exploring the cognitive function in patients with insulinoma.

METHODS

A prospective study was conducted to assess cognitive function in patients with insulinoma by administering the Montreal Cognitive Assessment (MoCA) questionnaire between January 2016 and July 2017, and patients with cognitive impairment were followed up to undergo the MoCA test 1 year after surgery. The MoCA scores after surgery were compared with the scores before surgery, and the associations between cognitive impairment and relevant factors were further evaluated by multiple linear regression analysis.

RESULTS

Eighteen out of thirty-four patients (53%) with insulinoma were screened positive for cognitive impairment as defined by a MoCA score <26. Performance in certain cognitive domains, including visuospatial and executive functions, delayed memory, attention, language, and abstraction, was significantly worse in patients with cognitive impairment. Multivariate analysis indicated that MoCA scores correlated significantly with tumor grade and years of education. Eight patients with cognitive impairment were lost to follow-up. The remaining ten patients with cognitive impairment showed improvements 1 year postoperatively, and seven patients recovered to normal cognitive function.

CONCLUSIONS

Cognitive impairment was found in patients with insulinoma and was reversible in some patients 1 year after surgery. More studies are needed to explore the underlying mechanisms of the existence and reversibility of cognitive impairment in patients with insulinoma.

[Choice of surgical approach to insulin-producing pancreatic tumors]

AIM

To determine the optimal surgical approach to insulin-producing pancreatic tumors via an analysis of early postoperative results.

MATERIAL AND METHODS

There were 134 patients with insulin-producing pancreatic tumors followed by organic hyperinsulinism who have undergone surgery in the faculty-based surgical clinic of the Sechenov First Moscow State Medical University for the period 1990-2017. Patients were divided into three groups depending on type of surgical intervention. Surgical procedure was determined after comprehensive preoperative and intraoperative examination including intraoperative ultrasound.

RESULTS

Incidence of postoperative complications was 32.8%. Ten (7.5%) patients required redo surgical interventions. Overall postoperative mortality was 4.5%. The best immediate results were observed in patients undergoing distal pancreatectomy. There was a correlation between incidence of early postoperative complications and tumor location depth in the enucleation group.

CONCLUSION

Enucleation is advisable for insulinoma of pancreatic head or uncinated process, as well as superficial tumors of the left half of the pancreas. Distal pancreatectomy is indicated for deep tumors of the left half of the pancreas. Indications for pancreatoduodenectomy are individual.

68Ga-DOTA-Exendin PET-MRI Fusion Imaging in a Case of Insulinoma

Persistent hyperinsulinemic hypoglycemia in adults is most commonly caused by insulinomas, which pose a diagnostic challenge to physicians, surgeons, and radiologists and require multimodality imaging for precise localization and staging. PET tracers such as F-FDOPA and glucagon-like peptide 1 receptor analogs have been used for imaging insulinomas. Glucagon-like peptide 1 receptor analogs have recently shown promising results in preoperative localization of these tumors, as all insulinomas express glucagon-like peptide 1 receptors. Ga-DOTA-Exendin PET and MRI done in the present case helped in precise localization and management of the culprit lesion, whereas contrast-enhanced CT and F-FDOPA PET failed to do so.

Specific and Non-Specific Biomarkers in Neuroendocrine Gastroenteropancreatic Tumors

The diagnosis of neuroendocrine tumors (NETs) is a challenging task: Symptoms are rarely specific, and clinical manifestations are often evident only when metastases are already present. However, several bioactive substances secreted by NETs can be included for diagnostic, prognostic, and predictive purposes. Expression of these substances differs between different NETs according to the tumor hormone production. Gastroenteropancreatic (GEP) NETs originate from the diffuse neuroendocrine system of the gastrointestinal tract and pancreatic islets cells: These tumors may produce many non-specific and specific substances, such as chromogranin A, insulin, gastrin, glucagon, and serotonin, which shape the clinical manifestations of the NETs. To provide an up-to-date reference concerning the different biomarkers, as well as their main limitations, we reviewed and summarized existing literature.

Comparison of the diagnostic accuracy of the current guidelines for detecting insulinoma

Objective Insulinomas are rare pancreatic endocrine tumors characterized by hypoglycemia. Guidelines by the Endocrine Society (ES), the European (ENETS) and the North American (NANETS) Neuroendocrine Tumor Societies provide divergent diagnostic criteria. This study compared the diagnostic accuracy of these different criteria during the 72-h fasting test. Design Retrospective cohort study. Methods From 2000 to 2014, 64 patients with a suspected insulinoma underwent a 72-h fasting test and were included in the analysis. This study assessed the diagnostic sensitivity, specificity and accuracy based on venous blood glucose and corresponding insulin levels measured by electrochemiluminescence immunoassay (ECLIA). Results Based on 64 individuals (18 with, 46 without insulinoma), the ES criteria provided a diagnostic sensitivity of 0.94 (0.73-1.00), specificity of 0.89 (0.76-0.96) and accuracy of 0.91 (0.81-0.96). ENETS/NANETS criteria reached a diagnostic sensitivity of 0.78 (0.52-0.94), specificity of 1.00 (0.92-1.00) and accuracy of 0.94 (0.85-0.98). Conclusions These results point to a higher diagnostic sensitivity with less specificity for diagnosing insulinoma using ES criteria and a higher specificity at lower sensitivity by using ENETS/NANETS criteria. Before considering these results when applying the different criteria in clinical practice, the results should be confirmed in further studies comprising larger cohorts.

Clinical remission of an inoperable malignant insulinoma by the combination treatment with octreotide and everolimus

We report a 52-year-old woman with inoperable malignant insulinoma with multiple liver metastases. Histological examination of biopsy specimens from the pancreatic and hepatic lesions revealed pancreatic neuroendocrine tumor (pNET), G2. The tumor cells were positive for somatostatin receptor (SSTR) 2, 5, and the mammalian target of rapamycin (mTOR). Monthly intramuscular administration of octreotide LAR and once-daily oral administration of everolimus combination treatment markedly reduced the sizes of liver metastases, and hypoglycemia was well controlled. Combination treatment with somatostatin analog and mTOR inhibitor may be another effective approach in inoperable metastatic malignant insulinoma.

Distinct clinicopathological and prognostic features of insulinoma with synchronous distant metastasis

BACKGROUND

The clinicopathological and prognostic features of insulinoma with synchronous metastases are unclear. This study aimed to verify the distinct clinicopathological and prognostic features of insulinoma with synchronous distant metastasis.

METHODS

Patients with pancreatic neuroendocrine tumor (PanNET) were retrospectively enrolled and divided into cohort 1 (Fudan University Shanghai Cancer Center) and cohort 2 (Surveillance, Epidemiology, and End Results Program database). Both cohorts were further divided into three subgroups: insulinoma, nonfunctioning pancreatic neuroendocrine tumor (NF-PanNET), and non-insulinoma functioning pancreatic neuroendocrine tumor (NiF-PanNET).

RESULTS

Cohorts 1 and 2 comprised 505 and 2761 patients (1566 M0 patients and 1195 M1 patients), respectively. In cohort 1 and cohort 2 M0 subgroup, insulinoma showed longer disease-free survival, overall survival (OS), and disease-specific survival (DSS) than NiF-PanNET and NF-PanNET (not reached vs. 48 and 60months, p < 0.001; 183months vs. 87 and 109months, p < 0.001; 247months vs. 121 and 140months, p = 0.002). However, in cohort 2 M1, the mDSS for metastatic insulinoma was shorter than that for NiF-PanNET (31months vs. 61months, p = 0.045), while the mDSS and mOS were similar to those for NF-PanNET. The percentage of T1 and N0 patients was similar between the metastatic insulinoma subgroup and NiF-PanNET and NF-PanNET subgroups. The Ki-67 index and recurrence had a positive linear relationship only for NiF-PanNET and NF-PanNET (p = 0.009).

CONCLUSIONS

Insulinoma with synchronous metastasis showed clinicopathological and prognostic characteristics similar to those of NF-PanNET. Metastatic insulinoma had worse prognosis than non-insulinoma F-PanNET. These findings may help in the clinical management of metastatic insulinoma.

Pancreatic Cancer: An Emphasis on Current Perspectives in Immunotherapy

Pancreatic cancer affects both male and female individuals with higher incidences and death rates among the male population. Detection of this malignancy is delayed due to the lack of symptoms in the early-stage cancer, which makes it extremely difficult to treat. Identifying effective strategies has been a challenge for improving the survival rates in pancreatic cancer patients. Resistance to chemotherapy is often developed in pancreatic cancer treatment. Although many strategies are under clinical trials to target certain markers associated with cancer, immunotherapeutic approaches are currently gaining importance. Immunotherapy for pancreatic cancer is in the limelight after preclinical research showed some promise. Immunotherapy approaches were tested along with other treatment options to enhance the treatment effect. Adoptive cell transfer and immune checkpoint inhibitors are currently in clinical trials. The Food and Drug Administration approved pembrolizumab in a fast-tracked review for advanced pancreatic cancer patients. Pembrolizumab blocks the checkpoint protein, programmed cell death protein 1 (PD-1), on T cells to boost the response of the immune system against cancer cells, thereby shrinking tumors. The recent developments in immunotherapy and the early success in other cancers are encouraging to further test immunotherapy in pancreatic cancer. The combination of pembrolizumab and pelareorep, an isolate of human reovirus, is in phase II clinical study in metastatic disease. Depending on the results of current clinical trials and testing, the strategies in the pipeline are expected to increase the use of immunotherapy in the clinical testing setting. Success in immunotherapy is urgently needed to address the side-effects, treating patients with advanced disease and reducing metastasis for increasing the survival rate in pancreatic cancer patients.

Molecular Imaging to the Surgeons Rescue: Gallium-68 DOTA-Exendin-4 Positron Emission Tomography-Computed Tomography in Pre-operative Localization of Insulinomas

Background

Insulinoma is an islet-cell neoplasm that secretes insulin. It is usually localized to the pancreas and is often the most common cause of endogenous hyperinsulinemic hypoglycaemia in non-diabetic adult patients. Surgical excision with a curative intent is the standard modality of treatment, and it requires precise localization of tumor tissue. Ga-68 DOTA-exendin-4 PET/CT scan is a clinically reasonable and sensitive scan for the identification of insulinoma. The aim of this prospective cohort study was to determine the overall accuracy of Ga-68 DOTA-exendin-4 PET/CT scan in the detection of insulinoma.

Materials and Methods

Eight patients with fasting hyperinsulinemic hypoglycaemia with neuroglycopenic symptoms were enrolled in this study which was conducted during October 2016 to October 2017. Whole body PET/CT scan was performed on a Philips time of flight PET/CT scanner, 60 minutes after injection of Ga-68 DOTA-exendin-4 (and also Ga-68 DOTANOC). The imaging findings were compared to the histopathological diagnosis in six out of eight patients and to subsequent follow up in the remaining two patients who did not undergo surgery.

Results

The sensitivity of Ga-68 DOTA-Exendin-4 PET/CT scan in insulinoma detection was found to be 75%.

Conclusion

Ga-68 DOTA-Exendin-4 PET/CT scan is highly sensitive for identification and exact localization of insulinoma which can guide better surgical exploration. However, randomised controlled trials are needed to assess the accuracy of Ga-68 DOTA-Exendin PET/CT scan in localization of insulinoma.

68Ga DOTA-Exendin PET/CT for Detection of Insulinoma in a Patient With Persistent Hyperinsulinemic Hypoglycemia

Insulinomas are the most common functioning pancreatic neuroendocrine tumors and the leading cause of persistent hypoglycemia with hyperinsulinemia in adults. Glucagon-like-peptide-1 (GLP) receptor analogs are the latest agents being used in the detection of insulinomas, with initial reports suggesting high sensitivity due to universal GLP1 receptor expression on these tumors. PET/CT imaging in this patient using Ga DOTA-Exendin, a GLP receptor analog, proved useful for accurate localization of the culprit lesion, aiding in the definitive management of the patient.

An observational analysis of insulinoma from a single institution

BACKGROUND

Insulinoma is the commonest functioning pancreatic neuroendocrine tumor causing hyperinsulinemic hypoglycemia.

AIM

This study is aimed to evaluate the clinical features, preoperative laboratory and imaging diagnosis and pathologic findings of insulinoma.

METHODS

Data of the patients from 2001 to 2016 diagnosed as insulinoma in Tongji Hospital, China were retrospectively extracted and analyzed.

RESULTS

A total of 40 patients were diagnosed as insulinoma with a male/female ratio of 0.68:1. The median onset age was 46.5 years. Nearly all the included patients presented neurological symptoms and 60% presented autonomic symptoms. More than 95% of the patients met the functional European Neuroendocrine Tumor Society criteria including glucose, insulin and C-peptide levels. The preoperative detection rates of ultrasonography, enhanced computed tomography, magnetic resonance imaging, and endoscopic ultrasonography were 60.50%, 84.95%, 80% and 83.3% respectively. The joint imaging examinations can markedly increase the detection rate. The mean tumor size was 1.89 ± 0.72 cm. Ki-67 index by histopathological diagnosis were all less than 20%. The positive rates of insulin, synaptophysin and chromogranin A were close to 100%.

CONCLUSION

Laboratory tests of glucose, insulin and C-peptide are reliable for preoperative diagnosis. Combination of the imaging examinations can improve the diagnosis.