Diagnosis and management of insulinoma

Variables associated with endogenous hyperinsulinism in hypoglycemia diagnosis. Could the 72-hour fasting test be shortened in low-risk patients?

Background

The 72-hour fasting test remains the standard for the diagnosis of endogenous hyperinsulinism. We investigated which variables could identify patients at low risk for endogenous hyperinsulinism, in whom a shortening of the 72-hour fasting test could be considered.

Methods

This multicenter, retrospective study included 64 individuals (46 women, median age 45 years) without diabetes who underwent 72-hour fasting tests for the etiologic diagnosis of hypoglycemia. Pre- and intra-test variables were collected, including point-of-care glucose trajectories during the test. Testing was stopped before 72 h if symptomatic serum glucose <55 mg/dL or asymptomatic serum glucose ≤45 mg/dL occurred. Endogenous hyperinsulinism was diagnosed in individuals who had serum glucose <55 mg/dL, serum insulin ≥3.0 μU/mL, and serum C-peptide ≥0.6 ng/mL.

Results

Patients with endogenous hyperinsulinism (n = 10) had steeper descending point-of-care glucose trajectories (p < 0.001) than those without it. Older age and lower minimum pre-test serum glucose concentrations were independently associated with endogenous hyperinsulinism. A calculator for probability prediction of endogenous hyperinsulinism was developed including these variables and sex (AUC = 0.94). Older age, female sex, lower body mass index, and lower minimum point-of-care glucose during the first 24 h of fasting were independently associated with serum glucose <55 mg/dL after the first 24 h of fasting. A calculator for predicting probability of serum glucose <55 mg/dL after the first 24 h of fasting was developed including these variables (AUC = 0.84).

Conclusions

Pre- and intra-test variables can identify individuals at low risk for endogenous hyperinsulinism, in whom shortening the 72-hour fasting test could be considered.

Multicenter Study on the Clinical Characteristics, Diagnosis, and Treatment Outcomes of Insulinoma: Insights From 15 Medical Centres

OBJECTIVE

This study aimed to evaluate the clinical characteristics, diagnostic approaches, and treatment outcomes of insulinoma patients from diverse regions across the country. We conducted a retrospective analysis of medical records from 76 adult patients diagnosed with insulinoma between 2018 and 2023 at 15 medical centres. Data collected included demographics, presenting symptoms, laboratory and imaging results, surgical reports, pathology findings, and clinical follow-up information.

DESIGN

Multi-centre retrospective study.

METHODS

The study revealed that key factors such as age, BMI, symptom duration, tumour size, and follow-up period were similar across genders. The majority of patients experienced neuroglycopenic symptoms, particularly during fasting. Insulinoma was typically diagnosed either during fasting or spontaneously, with no significant gender differences in glucose and insulin levels during hypoglycemia. However, men exhibited higher C-peptide levels (p < 0.05). Common comorbidities included hypertension, hypothyroidism, and cardiovascular conditions, and some patients had been using antiepileptics or antidepressants before their diagnosis.

RESULTS

Preoperative tumour diagnoses were largely accurate, with endoscopic ultrasound (EUS) being the most effective method. Most tumours were small ( < 2 cm) and located in the pancreas body, with the majority being solitary. Surgical treatments primarily involved enucleation or distal pancreatectomy. Follow-up data indicated high remission rates, with low rates of nonremission and mortality.

CONCLUSION

This study emphasises that early diagnosis and intervention, particularly in patients with a history of neurological or psychiatric issues, postprandial symptoms, or rapid symptom improvement after treatment, can lead to significantly better outcomes.

Studies on Treatment Within the Scope of Medical Biotechnology for Pancreatic Diseases

The pancreas is made of two compartments: the exocrine pancreas, a source of digestive enzymes, and the endocrine islets which produce vital hormones. Distinct diseases could arise in the pancreas such as diabetes, neuroendocrine tumors, pancreatitis, and pancreatic cancers. Various treatment methods are being researched against these diseases. Treatment with recombinant proteins, therapeutic antibodies, vaccination, gene therapy, tissue engineering, and stem cell treatment are treatment methods. Furthermore, biomarkers are important for both treatment and diagnosis. However, some of the treatment methods mentioned above have not yet been applied to some pancreatic diseases. This review provides insights into the latest advancements in diagnosis and treatment for pancreatic diseases within the scope of medical biotechnology. In addition, some methods that are not yet used for treatment purposes for pancreatic diseases but are used in other diseases that occur in different organs due to similar reasons have been investigated. In this context, possible diagnosis and treatment methods for pancreatic diseases are interpreted. The first aim of this review is to bring together and present the current diagnosis and treatment methods for pancreatic diseases. The second aim is to highlight methods that may have treatment potential by comparing pancreatic diseases that cannot be treated with similar diseases.

Practical application of melatonin for pancreas disorders: protective roles against inflammation, malignancy, and dysfunctions

Melatonin, a hormone primarily produced by the pineal gland, exhibits a range of physiological functions that extend beyond its well-known role in regulating circadian rhythms. This hormone influences energy metabolism, modulates insulin sensitivity, and plays a significant role in controlling sleep patterns and food intake. Notably, melatonin is also synthesized in various peripheral organs, including the gastrointestinal system and pancreas, suggesting its function as a local hormone. The presence of melatonin receptors in the pancreas underscores its relevance in pancreatic physiology. Pancreatic disorders, such as diabetes mellitus (DM), pancreatitis, and pancreatic cancer, often stem from inflammatory processes. The majority of these conditions are characterized by dysregulated immune responses and oxidative stress. Melatonin's anti-inflammatory properties are mediated through the inhibition of pro-inflammatory cytokines and the activation of antioxidant enzymes, which help to mitigate cellular damage. Furthermore, melatonin has demonstrated pro-apoptotic effects on cancer cells, promoting cell death in malignant tissues while preserving healthy cells. Thus, melatonin emerges as a multifaceted agent with significant therapeutic potential for pancreatic disorders. Its ability to reduce inflammation and oxidative stress positions it as a promising adjunct therapy for conditions such as diabetes mellitus, pancreatitis, and pancreatic cancer. By modulating immune responses and enhancing cellular resilience through antioxidant mechanisms, melatonin not only addresses the symptoms but also targets the underlying pathophysiological processes associated with these disorders. This review aims to categorize and summarize the impacts of melatonin on pancreatic functions and disorders, emphasizing its potential as a therapeutic agent for managing pancreatic dysfunctions. Future research should focus on elucidating the precise mechanisms by which melatonin exerts its protective effects on pancreatic tissues and exploring optimal dosing strategies for clinical applications. The integration of melatonin into treatment regimens may enhance existing therapies and offer new hope for individuals suffering from pancreatic dysfunctions.

A Five-Year Journey to Diagnosis: Resolving Persistent Hypoglycemia Through Successful Insulinoma Resection-A Case Report

Insulinoma is a rare functional pancreatic neuroendocrine tumor with an annual prevalence of 0.5-5 cases per million. It is characterized by excessive insulin secretion, leading to recurrent hypoglycemia, often diagnosed through Whipple's triad: hypoglycemic symptoms, documented low plasma glucose, and symptom resolution after glucose administration. Approximately 90% of insulinomas are sporadic, while 10% are associated with multiple endocrine neoplasia type 1. Diagnosis is frequently delayed due to nonspecific symptoms and misattributions to neurological or psychiatric conditions. Biochemical confirmation through a supervised fasting test and advanced imaging modalities, including CT, MRI, and endoscopic ultrasound (EUS), is essential for identifying and localizing the tumor. We report the case of a 52-year-old male who presented with a 5-year history of recurrent fasting and postprandial hypoglycemic episodes, including adrenergic and neuroglycopenic symptoms such as palpitations, diaphoresis, dizziness, and episodes of altered sensorium. Initial evaluations misattributed his symptoms to neurological and cardiac disorders, delaying diagnosis. Upon presentation, Whipple's triad was confirmed, and biochemical testing revealed hyperinsulinemic hypoglycemia (plasma glucose: 27 mg/dL, serum insulin: 45.83 mIU/L, C-peptide: 7.03 ng/mL). Imaging identified a 3 × 3 cm hypervascular lesion in the pancreatic tail. The patient underwent distal pancreatectomy, and histopathological analysis confirmed a grade 1 neuroendocrine tumor. Postoperative outcomes were favorable, with complete resolution of symptoms and normalization of glucose and insulin levels. Follow-up showed no recurrence of hypoglycemia. This case underscores the challenges in diagnosing insulinoma due to nonspecific symptoms and highlights the importance of Whipple's triad, biochemical tests, and imaging in timely diagnosis. Surgical resection remains the definitive treatment, with excellent long-term outcomes when performed promptly.

Metastatic Insulinoma Managed With Continuous Glucose Monitoring in a Young Female Patient

Insulinomas are rare neuroendocrine neoplasms and causes of hypoglycemia. They present with neuroglycopenic symptoms, including confusion and seizures. Suspected diagnosis must be confirmed through bloodwork and imaging. The majority of insulinomas are benign and cured surgically; less than 10% of insulinomas are malignant. Malignant insulinomas present a unique and rare challenge in managing persistent hypoglycemia and tumor burden. We present a case of a young woman who presented with Whipple triad and high-grade masses in her pancreas, liver, and distant lymph node metastases on imaging. Insulinoma was diagnosed. Hypoglycemia was managed with continuous dextrose infusion, diazoxide, and lanreotide. She was discharged on medical management and a continuous glucose monitor. Her metastatic disease is being treated with a capecitabine and temozolomide (CAPTEM) regimen showing 30% reduction in tumor burden. In conjunction with the National Institutes of Health, she is undergoing evaluation with numerous neuroendocrine tumor surgeons for cytoreductive surgery.

The Occult Insulinoma Was Localized Using Endoscopic Ultrasound Guidance: A Case Report

Insulinomas are the primary etiology of endogenous hyperinsulinemic hypoglycemia, which often manifest with Whipple's triad and neuroglycopenic symptoms. Given the diverse clinical manifestation and subtle onset of insulinomas generally in a small size, detecting a minority of these generally small tumors can be challenging. We reported a case of a 44-year-old female patient with recurrent hypoglycemia accompanied by hyperinsulinemia, and the conventional imaging revealed no abnormality. With the aid of endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB), the insulinoma was precisely diagnosed and localized, and successfully excised via operation. The patient's hyperinsulinemia and hypoglycemic episodes were relieved significantly after surgery. The application of EUS-FNAB notably enhances the diagnostic accuracy for occult insulinomas, thereby informing appropriate surgical management. Herein, we advocate for invasive EUS examination in patients exhibiting strong clinical and laboratory indicators of insulinoma, even when conventional imaging results are negative.

Pancreatic Neuroendocrine Tumors-Diagnostic Pitfalls of Non-Diabetic Severe Hypoglycemia: Literature Review and Case Report

Background: Hypoglycemia in the case of persons without diabetes is a rare event, being usually, initially misinterpreted based on the symptoms that can mimic various diseases, especially of a neuro-psychiatric nature. In the case of the identification of insulin-mediated hypoglycemia, the evaluation of pancreatic neuroendocrine tumors, which represent the most common and worrisome causes of non-diabetic insulin-mediated hypoglycemia, must be considered. Case Report: We present the case of a 57-year-old patient, hospitalized for a history of approximately one month of recurrent episodes of symptoms suggestive for severe hypoglycemia. The biological evaluation performed during an episode of hypoglycemia showed a plasma glucose value of 44 mg/dL, insulinemia 16.3 µU/mL, C peptide 3.72 ng/mL, HbA1c 4.99%, absence of urinary ketone bodies and anti-insulin antibodies <0.03 U/mL. The CT and MRI examination showed a 15.3/15 mm rounded tumor in the pancreatic corporeo-caudal region. The pancreatic tumor formation was enucleated and the histopathological and immunohistochemical analysis confirmed the diagnosis of the pancreatic neuroendocrine tumor with a positive reaction for chromogranin A, synaptophysin and insulin, without malignancy features (Ki 67 positive in 1% of the tumor cells). The postoperative evolution was favorable, without episodes of hypoglycemia, the fasting insulinemia one day after surgery being 4.1 µU/mL and HbA1c at three weeks postoperatively being 5.51%. Conclusions: The management of patients with hyperinsulinemic hypoglycemia secondary to insulinoma involves multidisciplinary collaboration with an important role in recognizing symptoms suggestive of hypoglycemia in a person without diabetes, initiating biological and imaging evaluation, establishing the optimal therapeutic option and histopathological confirmation.

Diagnosis and management of benign secreting pancreatic insulinoma: What's new? 4 case report

Introduction and importance: Even though insulinoma is the most frequent neuroendocrine tumor, it represents only 2% of pancreatic 2% of all pancreatic neoplasms. Diagnosis is relatively simple, and surgery after accurate determination of the tumors location within the pancreas is the cornerstone of its treatment. Case presentation: We herein report 4 patients undergoing various surgeries for benign secreting insulinomas, after extensive radiological and endoscopic exploration. Clinical discussion: Diagnosis is relatively simple relying on clinical and biological criteria, it must be followed by an extensive and accurate preoperative determination of the tumors localization. The laparoscopic tumoral enucleation is the treatment of choice for small isolated tumors, but open surgery still has its indications. Conclusion: Pancreatic insulinoma is a rare neuroendocrine tumor that can be life-threatening due to hypoglycemic manifestations. The diagnosis is based on clinical and biological criteria. echo endoscopy and to a lesser extent radiological exploration can precisely determine the tumors location. Laparoscopic surgical enucleation of the tumor remains the preferred curative treatment.

Complete Resolution of Frequent, Non-Specific Hypoglycemia Symptoms After Surgical Removal in a Patient With Pancreatic Tail Insulinoma: A Case Report

Insulinoma, the most common functional pancreatic neuroendocrine tumor, is a rare and typically benign tumor. However, excessive insulin secretion can result in life-threatening hypoglycemia, which is often misdiagnosed due to its nonspecific early symptoms, leading to a delayed diagnosis. Rigorous evaluation is required once insulinoma is suspected since the tumor might also be challenging to detect through imaging techniques. This case study explores insulinoma's diagnostic, localization, and management challenges. We present the case of a 41-year-old female patient who had multiple episodes of severe hypoglycemia for the past four years. A combination of biochemical and morphological examinations led to the identification of a localized pancreatic insulinoma. Subsequently, an open surgical procedure was performed, resulting in a successful removal of the insulinomas through enucleation and remarkable post-operative result. It is essential to consider insulinoma as a potential underlying cause of recurrent hypoglycemia in non-diabetic individuals. High awareness might significantly reduce the risk of delayed diagnosis of the disease, and successful surgical removal of the insulinoma not only alleviates hypoglycemic symptoms but also leads to a complete resolution of the condition, preventing life-threatening complications associated with untreated hypoglycemia.

Insulin-Related Suicides-3 Cases

Insulin is a pancreas-produced hormone, which is essential for normal life. In persons with diabetes, who lack sufficient production of endogenous insulin, the availability of exogenously-produced and administered insulin represents an extremely valuable, life-preserving medical advancement. Unfortunately, as with many other medications, overdosage with insulin can and does occur, sometimes in an intentional suicidal manner. Another possible insulin-related suicidal action involves the intentional cessation of insulin therapy by someone who relies on insulin for survival. In this case series, we present 3 cases of insulin-related suicides, including two related to intentional insulin overdose and one where a known diabetic purposefully stopped taking insulin in order to commit suicide.

Percutaneous Ultrasound-Guided Radiofrequency Ablation as a Therapeutic Approach for the Management of Insulinomas and Associated Metastases in Dogs

Insulinomas are the most common neoplasms of the endocrine pancreas in dogs, leading to persistent hypoglycemia due to inappropriate insulin secretion. The standard treatment is surgical resection, but it carries significant risks, including pancreatitis and diabetes mellitus. This study investigates the efficacy and safety of percutaneous ultrasound-guided radiofrequency ablation (RFA) as an alternative to surgery. A total of 29 dogs diagnosed with insulinoma were treated with RFA, targeting both primary pancreatic tumors and metastases in regional lymph nodes or the liver. Blood glucose levels and tumor size were monitored before and after the procedure. RFA led to a significant increase in blood glucose levels and a reduction in tumor size in all patients, with minimal postoperative complications. The results suggest that RFA is a feasible and effective treatment option for insulinomas in dogs.

Insulinoma in Patients with Diabetes- A Systematic Review of Previously Reported Cases

Introduction

Paradoxical co-existence of insulinoma and diabetes is extremely rare. Although a few case reports addressed this association, a comprehensive study elucidating this relationship has been lacking. We performed a systematic review of published cases of insulinoma in diabetes.

Methods

We conducted a literature search using PubMed and Google Scholar, employing various combinations of the following terms: 'insulinoma', 'diabetes', 'nesidioblastosis', 'endogenous hyperinsulinism', 'hypoglycaemia', and 'hyperglycaemia' (from January 1900 to January 30, 2024). Exclusion criteria included non-English publications, duplicate articles, reports lacking sufficient data, cases of endogenous hyperinsulinemic hypoglycaemia other than insulinoma, and inaccessible articles. Statistical analysis was performed using appropriate methods.

Results

Sixty patients were considered for the final analysis. Mean age was 61 ± 15 years (range: 17-96 years) with a slight female preponderance; 88.3% had type-2 diabetes with a median duration of 8 years. The median delay in diagnosis of insulinoma was 6 months. Median blood glucose varied from 30.5 mg/dL to 235 mg/dL, with a mean HbA1c of 5.6 ± 1.3% (range: 2.9%-8.2%). Critical sampling data were available in 75% of cases. The median size of the insulinoma was 2 cm. Furthermore, 5.2% of insulinomas were extra-pancreatic. Among pancreatic insulinomas, 14.5% were multi-focal. One-third of cases were malignant. Surgical resection was done in 70.9% of cases, while 40% received drug therapy and 12.7% received both, with 20.7% overall mortality. Malignant insulinoma (P = 0.007), micro-angiopathic (P = 0.018) and macro-angiopathic complications (P = 0.039), and other co-morbidities (P = 0.009) were associated with unfavourable prognosis, while being overweight and obese (P = 0.020) at presentation was associated with favourable prognosis.

Conclusion

This first systematic review provides insights into the uniqueness of insulinoma in diabetes.

Small Insulinoma Followed-up as an Indolent Pancreatic Tumor

A woman in her 60s presented with a small pancreatic head tumor. Imaging studies revealed a 13-mm well-defined pancreatic head tumor. A neuroendocrine neoplasm was suspected, and the patient opted for observation at that time. After 8 months, the patient began experiencing sweating while fasting, and blood tests during regular follow-up visits showed hypoglycemia. Hypoglycemia was induced during fasting test. The tumor exhibited clear features of an insulinoma during follow-up observation. While small neuroendocrine neoplasms are often managed through observation, caution should be exercised regarding their transformation into functional neuroendocrine tumors.

Insulinoma: Unraveling the Mystery of a Stealthy Culprit

Insulinoma, a rare pancreatic neuroendocrine tumor, stealthily lurks within the pancreas, often evading detection until its distinctive symptom, recurrent hypoglycemia, comes to the surface. This case report aims to highlight the significance of a multidisciplinary approach in the management of this uncommon neuroendocrine tumor by discussing the diagnostic, therapeutic, and follow-up difficulties encountered in an older adult presenting with atypical symptoms of insulinoma.

A Long Way to Find a Small Tumor: The Hunt for an Insulinoma

We report a case of a 35-year-old woman with recurrent episodes of hypoglycemia. Biochemical investigation was suggestive of hyperinsulinemic hypoglycemia, and hence a provisional diagnosis of insulinoma was made. Despite extensive investigation using magnetic resonance imaging, endoscopic ultrasound, and 68Ga-DOTATATE positron emission tomography/computed tomography (PET/CT) scanning, the tumor could not be localized. Long-distance travel allowed her to undergo a 68Ga-Exendin-4 PET/CT scan that identified a lesion in the uncinate process of the pancreas, subsequently confirmed by intraoperative ultrasound. Enucleation of the 1.5-cm lesion was performed, and histopathology confirmed a well-differentiated pancreatic neuroendocrine tumor. Postoperatively, the patient has remained free of hypoglycemic episodes and has shown normalization of glucose levels. This case underscores the efficacy of 68Ga-Exendin-4 PET/CT in the localization of an occult insulinoma, facilitating timely and curative surgical intervention, and the importance of patients having access to such a facility when not locally available.

Pancreatic insulinomas: Our 15-year surgical experience

BACKGROUND

Insulinomas are rare endocrine tumors of the pancreas. The majority are benign, sporadic, and solitary. Surgery is the only curative treatment. In this study, we present our experiences with the perioperative management of sporadic and benign pancreatic insulinomas.

METHODS

Patients who underwent surgery for pancreatic insulinoma in our clinic between 2008 and 2023 were retrospectively reviewed. Demographic data, preferred radiological methods, surgical procedures, and morbidity and mortality data were evaluated. Patients with malignant, invasive, or familial multiple endocrine neoplasia mutations were excluded from the study.

RESULTS

Nineteen patients underwent surgery, with a median age of 49 years (range: 33-85). Symptoms related to hypoglycemia were the most commonly observed. The tumor location was identified preoperatively in 74% of cases using computed tomography. Palpation and intraoperative ultrasound identified the tumor location in 88% of patients. Enucleation (53%) were the most common surgical procedures. Pancreatic fistula occurred in three patients (17%). While serious morbidity was lower in patients who underwent enucleation, the rate of fistula formation was higher.

CONCLUSION

The accurate localization of insulinomas plays a crucial role in determining the appropriate surgical procedure. With high success rates and lower morbidity, enucleation is the recommended procedure for suitable patients.

Hypovascular insulinoma with reduced microvessel density on histopathology: a case report

Pancreatic neuroendocrine tumors (PanNETs) are generally hypervascular and readily detectable on imaging tests. However, hypovascular PanNETs are clinically problematic, requiring multiple imaging tests and tissue analyses to differentiate them from pancreatic ductal cancers. A 41 year-old man presented with Whipple's triad; 72 h fasting test followed by glucagon challenge test suggested insulinoma. However, contrast-enhanced computed tomography image showed a 17 mm tumor with poor enhancement and unclear borders in the tail of the pancreas. Abdominal magnetic resonance imaging and contrast-enhanced endoscopic ultrasonography (EUS) indicated cystic degeneration and necrosis at the same site; EUS-guided fine-needle aspiration cytology indicated a PanNET Grade 1 tumor. Although the imaging was inconclusive, diazoxide treatment ameliorated the hypoglycemia-related symptoms and insulinoma was deemed likely; following tail pancreatectomy and splenectomy, the symptoms disappeared. Pathological examination revealed a tumor positive for insulin and classed as PanNET Grade 1 according to the 2019 WHO classification. The microvessel density (MVD) of the tumor was found to be as low as 3.9%, which may partly account for the inconclusive images. The present case was difficult to diagnose preoperatively due to hypovascularity on imaging because of reduced MVD. It is clinically important to evaluate MVD in cases of hypovascular PanNETs by multiple preoperative imaging studies to differentiate them from pancreatic cancers and to validate the findings by postoperative pathological analysis.

Computed tomography features in prediction of histological differentiation of pancreatic neuroendocrine neoplasms - a single-centre retrospective cohort study

Purpose

The aim of our study was to analyse the histological differentiation and computed tomography imaging features of pancreatic neuroendocrine neoplasms (PNENs).

Material and methods

We performed a retrospective single-centre cohort study of 157 patients with histologically confirmed PNEN. We compared the results of the preoperative biopsy from the tumour with reports of the multi-slice computed tomography performed by a radiologist with 30 years of clinical practice.

Results

Specific computed tomography (CT) features are associated with histological differentiation, such as enhancement in the arterial phase (p = 0.032), Wirsung's duct dilatation (p = 0.001), other organ infiltration (p < 0.001), distant metastases (p < 0.001), and enlarged regional lymph nodes (p = 0.018). When there is an organ infiltration, the likelihood of the tumour having histological malignancy grades G2 or G3 triples (95% CI: 1.21-8.06). Likewise, the existence of distant metastases increases the risk almost fourfold (95% CI: 1.44-10.61), and a tumour size of 2 cm or larger is linked to a nearly threefold rise in the risk of histological malignancy grades G2 or G3 (95% CI: 1.21-6.24).

Conclusions

Certain CT characteristics: enhancement during the arterial phase, Wirsung's duct dilatation, organ infiltration, distant metastases, and the enlargement of regional lymph nodes are linked to histological differentiation.

Risk of Esophageal and Gastric Cancer in Patients with Type 2 Diabetes Receiving Glucagon-like Peptide-1 Receptor Agonists (GLP-1 RAs): A National Analysis

INTRODUCTION

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are becoming more popular in managing type 2 diabetes mellitus (T2DM). Concerns linger over potential links to malignancies like pancreatic and thyroid cancers, requiring more research to clarify their safety profiles. Additionally, evidence suggests GLP-1 RAs may lower colorectal and pancreatic cancer risk, especially in obese and overweight individuals, indicating a protective effect beyond weight loss. Current studies leave a gap in comprehensively understanding cancer risks associated with GLP-1 RAs, which prompts further research to enhance our understanding of their overall safety.

METHODS

We queried the US Collaborative Network (63 health care organizations) of the TriNetX research database. Patients with T2DM were identified and divided into two cohorts: patients on GLP-1 RAs and patients not on GLP-1 RAs. We excluded tobacco use and alcohol use disorders, obese patients with a body mass index (BMI) of >25 kg/m2, and those with a family history of gastrointestinal malignancy, infectious mononucleosis, chronic gastritis, pernicious anemia, helicobacter pylori infection, or gastroesophageal reflux disease (GERD). We used a 1:1 propensity score matching (PSM) model using patients' baseline characteristics, medications, labs, and genetics. We compared the rate of gastric cancer and esophageal cancer at the seven-year mark.

RESULTS

A total of 2,748,431 patients with T2DM were identified. Of those, 6% (n = 167,077) were on a GLP-1 RA and 94% (n = 2,581,354) were not on a GLP-1 RA. After PSM, both cohorts included 146,277 patients. Patients with T2DM who were on a GLP-1 RA, compared to those who were not, had a statistically significant lower risk of both gastric cancer (0.05% vs. 0.13%, p < 0.0001) and esophageal cancer (0.04% vs. 0.13%, p < 0.0001) at the seven-year mark.

CONCLUSION

The use of GLP-1 RAs in patients with T2DM does not significantly increase the risk of gastric or esophageal cancer. This finding supports the continued use of GLP-1 analogues as a therapeutic option in managing T2DM, considering their well-established benefits and low risk of complications. Based on the study results, these medications may even have a protective effect against these malignancies.

[18F]FB(ePEG12)12-exendin-4 noninvasive imaging of insulinoma negative for insulin immunostaining on specimen from endoscopic ultrasonography-guided fine needle aspiration: a case report with review of literature

Insulinomas are the most common functional pancreatic neuroendocrine neoplasm; when treatment is delayed, they induce hyperinsulinemic hypoglycemia, which is life-threatening. As surgical resection is the only curative treatment for insulinoma, preoperative localization is crucial; however, localization based on conventional imaging modalities such as computed tomography (CT) and magnetic resonance imaging is often inconclusive. Somatostatin receptor-targeted imaging is another option for detecting pancreatic neuroendocrine neoplasms but has low sensitivity and is not specific for insulinoma. The clinical application of other localizing approaches such as selective arterial calcium stimulation and endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) is limited by their being invasive and/or technically complex. Moreover, an EUS-FNA specimen of an insulinoma may be negative on insulin immunostaining. Thus, a noninvasive and clinically practical insulinoma-specific diagnostic tool to discriminate insulinomas with high accuracy is anticipated. Glucagon-like peptide-1 receptor (GLP-1R)-targeted imaging has emerged in the effort to fulfill this need. We recently developed the novel fluorine-18-labeled exendin-4-based probe conjugated with polyethylene glycol, [18F]FB(ePEG12)12-exendin-4 (18F-exendin-4) for positron emission tomography (PET) imaging and reported its clinical benefit in a case of insulinoma in the pancreatic tail. We report here a case of insulinoma in the pancreatic head in which an EUS-FNA specimen was negative on insulin immunostaining while precise preoperative localization and conclusive evidence for curative enucleation was provided by 18F-exendin-4 PET/CT (Japan Registry of Clinical Trials; jRCTs051200156).

Hyperinsulinemic Hypoglycemia Due to an Insulinoma in a 2-Year-Old Child

Insulinomas are rare insulin-secreting tumors that most commonly affect adults. A 26-month-old child presented to her local emergency department with severe hypoglycemia. Initial workup was consistent with hyperinsulinemic hypoglycemia. Over the course of 10 months, multiple therapies for hyperinsulinism (HI) were trialed without significant benefit. Genetic testing for genes associated with HI was negative. At age 35 months, the patient was transferred to our center for further treatment. She underwent several imaging tests that revealed a lesion on her pancreas concerning for an insulinoma. The patient underwent surgical intervention to enucleate the lesion. Histopathological review of the specimen confirmed a benign, well-circumscribed insulinoma. A postoperative fasting test proved the patient was cured and she was discharged without the need for further glucose monitoring.

Implications of noncoding regulatory functions in the development of insulinomas

Insulinomas are rare neuroendocrine tumors arising from pancreatic β cells, characterized by aberrant proliferation and altered insulin secretion, leading to glucose homeostasis failure. With the aim of uncovering the role of noncoding regulatory regions and their aberrations in the development of these tumors, we coupled epigenetic and transcriptome profiling with whole-genome sequencing. As a result, we unraveled somatic mutations associated with changes in regulatory functions. Critically, these regions impact insulin secretion, tumor development, and epigenetic modifying genes, including polycomb complex components. Chromatin remodeling is apparent in insulinoma-selective domains shared across patients, containing a specific set of regulatory sequences dominated by the SOX17 binding motif. Moreover, many of these regions are H3K27me3 repressed in β cells, suggesting that tumoral transition involves derepression of polycomb-targeted domains. Our work provides a compendium of aberrant cis-regulatory elements affecting the function and fate of β cells in their progression to insulinomas and a framework to identify coding and noncoding driver mutations.

Neuroendocrine Tumors of Unknown Primary in the Setting of Cytoreductive Hepatectomy

BACKGROUND

Surgical cytoreduction for neuroendocrine tumor liver metastasis (NETLM) consistently shows positive long-term outcomes. Despite reservations in guidelines for surgery when the primary tumor is unidentified (UP-NET), this study compared the surgical and oncologic long-term outcomes between patients with these rare cases undergoing cytoreductive surgery and patients who had liver resection for known primaries.

METHODS

The study identified 32 unknown primary liver metastases (UP-NETLM) in 522 retrospectively evaluated patients who underwent resection of well-differentiated NETLM between January 2000 and December 2020. Tumor and patient characteristics were compared with those in 490 cases of liver metastasis from small intestinal (SI-NETLM) or pancreatic (pNETLM) primaries. Survival analysis was performed to highlight long-term outcome differences. Surgical outcomes were compared between liver resections alone and simultaneous primary resections to assess surgical risk distinctions.

RESULTS

The UP-NET patients had fewer NETLMs (p = 0.004), which on the average were larger than SI-NETLMs or pNETLMs (p = 0.002). Expression of Ki-67 was balanced among the groups. Major hepatectomy was performed more often in the UP-NETLM group (p = 0.017). The 10-year survival rate of 53% for UP-NETLM was comparable with that for SI-NETML (58%; p = 0.463) and pNETLMs (47%; p = 0.497). The median hepatic progression-free survival was 26 months for the UP-NETLM patients and 25 months for the SI-NETLM patients compared to 12 months for the pNETLM patients (p < 0.001). Perioperative mortality was lower than 2%, and severe postoperative morbidity occurred in 21%, similarly distributed among all the groups.

CONCLUSION

The surgical risk and long-term outcomes for the UP-NETLM patients were comparable with those for other NETLM cases, affirming the validity of equally aggressive surgical cytoreduction as a therapeutic option in carefully selected cases.

Robotic versus laparoscopic surgery for sporadic benign insulinoma: Short- and long-term outcomes

BACKGROUND

Minimally invasive surgery is the optimal treatment for insulinoma. The present study aimed to compare short- and long-term outcomes of laparoscopic and robotic surgery for sporadic benign insulinoma.

METHODS

A retrospective analysis of patients who underwent laparoscopic or robotic surgery for insulinoma at our center between September 2007 and December 2019 was conducted. The demographic, perioperative and postoperative follow-up results were compared between the laparoscopic and robotic groups.

RESULTS

A total of 85 patients were enrolled, including 36 with laparoscopic approach and 49 with robotic approach. Enucleation was the preferred surgical procedure. Fifty-nine patients (69.4%) underwent enucleation; among them, 26 and 33 patients underwent laparoscopic and robotic surgery, respectively. Robotic enucleation had a lower conversion rate to laparotomy (0 vs. 19.2%, P = 0.013), shorter operative time (102.0 vs. 145.5 min, P = 0.008) and shorter postoperative hospital stay (6.0 vs. 8.5 d, P = 0.002) than laparoscopic enucleation. There were no differences between the groups in terms of intraoperative blood loss, the rates of postoperative pancreatic fistula and complications. After a median follow-up of 65 months, two patients in the laparoscopic group developed a functional recurrence and none of the patients in the robotic group had a recurrence.

CONCLUSIONS

Robotic enucleation can reduce the conversion rate to laparotomy and shorten operative time, which might lead to a reduction in postoperative hospital stay.

Why do patients with cancer die?

Cancer is a major cause of global mortality, both in affluent countries and increasingly in developing nations. Many patients with cancer experience reduced life expectancy and have metastatic disease at the time of death. However, the more precise causes of mortality and patient deterioration before death remain poorly understood. This scarcity of information, particularly the lack of mechanistic insights, presents a challenge for the development of novel treatment strategies to improve the quality of, and potentially extend, life for patients with late-stage cancer. In addition, earlier deployment of existing strategies to prolong quality of life is highly desirable. In this Roadmap, we review the proximal causes of mortality in patients with cancer and discuss current knowledge about the interconnections between mechanisms that contribute to mortality, before finally proposing new and improved avenues for data collection, research and the development of treatment strategies that may improve quality of life for patients.

Endoscopic loco-regional treatment in controlling pancreatic neuroendocrine tumors (PNETs) behavior: a case series and literature review

Pancreatic neuroendocrine tumors (PNETs) are considered rare pancreatic neoplasms, and it is a challenging disease entity due to its indolent behavior and is difficult to manage. Diagnostic challenge is usually found in the imaging-based approach, such as transabdominal ultrasound, abdominal CT scan, and abdominal MRI. Surgery is still the main key player in controlling the disease. The main problems in clinical practice are the early detection of small PNETs lesion and non-functional PNET (NF-PNET) cases. Most cases usually come with large tumor size or metastatic disease. Endoscopic ultrasound (EUS) has been well-known as the most sensitive tool for early detection of pancreatic malignancy. It has now also been developed for managing pancreatic cancer, such as tumor ablation therapy. We presented four variety of PNETs cases (one patient with non-functioning PNETs and three patients with functioning PNETs) who have been successfully treated with EUS-guided radiofrequency ablation (RFA) with good control of tumor growth during follow-up. One patient with a large-size insulinoma could have the tumor controlled gradually after several EUS-RFA sessions. No adverse events or major complications were observed during and after the EUS-RFA procedure. EUS has been shown as a promising tool not only for more accurate diagnosis but also for tumor growth control. However, it would need further comparison studies between EUS and surgical approaches to make a better treatment strategy.

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).

Spontaneous Hypoglycemia in a Non-diabetic Patient: A Diagnostic and Therapeutic Conundrum

Hypoglycaemia is a medical emergency requiring an immediate intervention to prevent neuroglycopenic symptoms such as confusion, seizures, and coma. While evaluating for the cause of hypoglycemia, after excluding common causes like insulin use or sepsis, other causes involving endogenous hypoglycemia need to be evaluated. A cause to be considered is nesidioblastosis. This rare entity is also known as non-insulinoma pancreatogenous hypoglycemia syndrome. There have been instances where this disorder has been mistaken as insulinoma due to the characteristics shared by the two. Here, we present a case of a non-diabetic male experiencing symptoms of giddiness and palpitations for the past two years who had been extensively evaluated to rule out insulinoma and was diagnosed with nesidioblastosis.

A Case Report: Hypoglycaemic Unawareness Associated With Insulinoma

Hypoglycaemic unawareness (HU) is more frequently described in relation to diabetics in the literature. We have noted that there is also an increasing reporting of HU in insulinoma cases. We report a hospital presentation for an incidental finding of hypoglycaemic unawareness in a gentleman in his fifties who was eventually diagnosed with insulinoma following biochemical studies, radiologic evaluation and histologic evaluation of an excised lesion between the pancreas and the spleen. We have reviewed existing literature evidence regarding the possible aetiologies and management options for this occurrence. More research studies to identify the epidemiology of this association and the determination of a protocol for increased detection of patients with insulinoma who display HU will need to be done.

A Rare Case of Malignant Insulinoma Associated With Gastrointestinal Bleed

A gastrointestinal bleed (GIB) in the setting of metastatic insulinoma is a rare phenomenon. It appears that cases of metastatic insulinoma causing GIB are rare, often influenced by the tumor's location. Our case involves an 82-year-old male with dementia and a history of recurrent hypoglycemia, presenting with an episode of altered mental status. The patient exhibited hypoglycemia alongside a melena episode and anemia. Diagnostic criteria, including Whipple's triad, confirmed endogenous insulin production. Computed tomography (CT) showed a left paraaortic/retroperitoneal mass. Esophagogastroduodenoscopy (EGD) visualized an extrinsic mass at the gastric body, which caused an ulcerated surface that was treated with clipping and hemostasis. The patient's recurrent hypoglycemic episodes were treated with glucose, while his GIB was managed with hemostasis and clipping. However, the patient was not a surgical candidate, and further medical treatment was ceased by the family.

Imaging Update for Hereditary Abdominopelvic Neuroendocrine Neoplasms

ABSTRACT

Neuroendocrine neoplasms have shown a linear increase in incidence and prevalence in recent decades, primarily due to improved cross-sectional imaging, expanded use of endoscopic procedures, and advanced genetic analysis. However, diagnosis of hereditary neuroendocrine tumors is still challenging because of heterogeneity in their presentation, the variety of tumor locations, and multiple associated syndromes. Radiologists should be familiar with the spectrum of these tumors and associated hereditary syndromes. Furthermore, as the assessment of multiple tumor elements such as morphology, biochemical markers, and presence of metastatic disease are essential for the treatment plan, conventional anatomic and functional imaging methods are fundamental in managing and surveilling these cases. Our article illustrates the role of different cross-sectional imaging modalities in diagnosing and managing various hereditary abdominopelvic neuroendocrine tumors.

Recurrent Hypoglycemia After Total Gastrectomy: A Case Report and Literature Analysis

BACKGROUND Hypoglycemia is a common complication following total gastrectomy, primarily caused by dumping syndrome and severe malnutrition, with late dumping syndrome being particularly significant. However, for recurrent fasting hypoglycemia, the possibility of insulinoma should be considered. Hypoglycemia caused by insulinoma can lead to severe consequences, including seizures and even death. Thus, it is crucial to differentially diagnose hypoglycemia occurring after total gastrectomy. CASE REPORT In this report, we present the case of a 36-year-old Chinese woman who underwent total gastrectomy for gastric cancer and subsequently received chemotherapy. Four months after surgery, she began experiencing recurrent seizures, and multiple tests confirmed hypoglycemia. A series of laboratory and imaging examinations ultimately led to a diagnosis of insulinoma. After surgical resection of the tumor, the patient's hypoglycemic symptoms resolved, and pathology results confirmed an insulinoma. CONCLUSIONS This case report highlights the rapid weight loss and severe hypoglycemia observed in a patient only 4 months after total gastrectomy for gastric cancer. Although dumping syndrome was initially suspected based on the clinical course, the final diagnosis turned out to be insulinoma. The case underscores the importance of comprehensive evaluation and appropriate diagnostic investigations for patients experiencing hypoglycemia after total gastrectomy. Furthermore, the case suggests that the increased levels of enteroglucagon following changes in the gastrointestinal tract resulting from total gastrectomy may promote the development of insulinomas. This case report also contributes to the existing literature regarding atypical presentations of insulinomas and their association with gastric resection.

Short fasting test as a reliable and effective tool to diagnose insulinoma

PURPOSE

The diagnosis of insulinoma can be challenging, requiring documentation of hypoglycaemia associated with non-suppressed insulin and C-peptide, often achieved during a prolonged 72 h fast performed in inpatient setting. Our goal is to predict weather a shorter outpatient fasting test initiated overnight and prolonged up until 24 h could be a sensitive method for diagnosing insulinoma.

METHODS

We conducted a retrospective monocentric study on subjects admitted to our Unit of Endocrinology from 2019 to 2022 for clinical suspicion of insulinoma and underwent the short fasting test. A comparison between the short test group and the group of subjects who underwent the standard prolonged fasting test (from 2003 to 2018) has also been performed. The short fasting test was initiated by the patient overnight at home and proceeded the following day in outpatient setting (Day Hospital). As in the standard protocol, symptoms and capillary blood glucose (CBG) were strictly monitored. Venous blood was drawn for glycaemia, insulin and C-peptide at admission and at established intervals, in case of symptoms of hypoglycaemia or if CBG ≤ 45 mg/dl, when the fast would be suspended.

RESULTS

The final sample consisted of 37 patients, with mean age of 44.5 ± 12.6 years (17-74). Short and standard tests were performed in 15 and 22 subjects, respectively. Diagnostic values for insulinoma were observed in 12 patients: in 5/15 who underwent the short fasting test, in 6/22 who underwent the prolonged test and in 1 patient who was initially negative on the short test and subsequently showed diagnostic values during the prolonged test. The diagnosis of insulinoma was achieved in 11/12 cases within 24 h of the beginning of the fast (91.7%).

CONCLUSIONS

A short fasting test could be a valid, sensitive and reliable first-line workup in diagnosing insulinoma.

Sweet Saboteur: Insulinoma Presenting As Recurrent Hypoglycemic Seizures

Insulinoma, a rare neuroendocrine tumor of the pancreas, often presents diagnostic challenges due to its diverse clinical manifestations. We present the case of a 25-year-old female with recurrent hypoglycemic seizures and neuroglycopenic symptoms, ultimately diagnosed with insulinoma. Despite an initial asymptomatic period, the patient experienced progressively worsening symptoms over three years, culminating in eight episodes of generalized tonic-clonic seizures per week. Biochemical investigations during hypoglycemic episodes revealed elevated C-peptide and insulin levels, consistent with endogenous hyperinsulinemia. Imaging studies, including contrast-enhanced computed tomography (CECT) and Ga-DOTATATE scan, confirmed a hyper-enhancing lesion in the distal body of the pancreas, indicative of insulinoma. Histopathological examination (HPE) further corroborated the diagnosis. Prompt recognition and surgical excision led to the complete resolution of symptoms and improved long-term prognosis. This case underscores the importance of considering insulinoma in young individuals presenting with recurrent hypoglycemic episodes and highlights the significance of early diagnosis and intervention in preventing morbidity and mortality associated with this condition.

Polymeric Microneedles for Health Care Monitoring: An Emerging Trend

Bioanalyte collection by blood draw is a painful process, prone to needle phobia and injuries. Microneedles can be engineered to penetrate the epidermal skin barrier and collect analytes from the interstitial fluid, arising as a safe, painless, and effective alternative to hypodermic needles. Although there are plenty of reviews on the various types of microneedles and their use as drug delivery systems, there is a lack of systematization on the application of polymeric microneedles for diagnosis. In this review, we focus on the current state of the art of this field, while providing information on safety, preclinical and clinical trials, and market distribution, to outline what we believe will be the future of health monitoring.

Diagnostic Modalities, Management Considerations, and Outcomes of Insulinoma: A Case Series from a Tertiary Care Centre

Introduction

Insulinomas are rare, usually sporadic, and typically benign pancreatic neuroendocrine tumours. Pre-operative localization is challenging and evidence on comparative analysis of anatomic and scintigraphic modalities for pre-operative tumour localization is limited, even in contemporary series.

Methods

The current study was designed to study the clinical features and management challenges of insulinomas managed at a tertiary care centre. Clinical features, diagnosis, imaging techniques, surgical procedures, and outcomes details were collated. Pre-operative imaging techniques (CT/MRI, nuclear scintigraphy) were compared with intraoperative and histopathological findings to assess their accuracy of localization.

Results

Thirty-seven patients (15 females [42%]; median age 36 years [IQR 28-49]) were included in the study. In four patients (10.8%), the tumour occurred in the setting of multiple endocrine neoplasia type 1 (MEN 1) while the remaining were sporadic. The sensitivity of pre-operative localization was 61.5% (multiphasic CT), 66.6% (multiphasic MRI), 100% (68Ga Exendin-4 PET-CT), and 91.6% (EUS). Three patients with normal multiphasic CT had localization on 68Ga Exendin-4 PET-CT. The positive predictive value (PPV) of both Exendin-PET-CT and EUS was similar at 91.6% and 91.6%, respectively. All patients (except one with nesidioblastosis), who underwent enucleation or partial pancreatic resection, were cured.

Conclusion

68Ga Exendin-4 PET-CT based is a non-invasive imaging modality that has high sensitivity and PPV and can be used as a first-line imaging modality. The overall prognosis of these tumours is good with high cure rates attained following surgical resection.

Recurrent Non-islet Cell Tumor Hypoglycemia Secondary to Hepatocellular Carcinoma: Case Report and Literature Review

RATIONALE

Non-islet cell tumor hypoglycemia (NICTH) is a paraneoplastic syndrome caused by tumors other than insulinoma that is primarily due to excessive production of insulin-like growth factor-II (IGF-II). The prevalence of NICTH is likely underestimated because of a lack of clinical recognition.

PATIENT CONCERNS

A 41-year-old male with massive malignant liver tumors presented with recurrent severe hypoglycemia, weight loss, and liver cirrhosis.

DIAGNOSIS

NICTH related to IGF-II produced by hepatocellular carcinoma was diagnosed based on clinical symptoms, biochemical tests, and elevated IGF-II/IGF-I ratio.

INTERVENTION

Initial treatment with intravenous glucose and parenteral nutrition showed limited efficacy. Glucocorticoids and recombinant human growth hormone led to progressive improvement in blood glucose levels.

OUTCOME

Due to extensive tumor burden and liver failure, surgical resection was not feasible, and the patient ultimately succumbed to refractory hypoglycemia and passed away in two weeks.

LESSONS

Early recognition and diagnosis of NICTH are crucial in patients with recurrent hypoglycemia and large tumors. Surgical resection is the preferred treatment option, but supportive care and pharmacological interventions, such as glucocorticoids and growth hormone, can help manage refractory hypoglycemia. Further research is needed to explore novel treatment options, including anti-IGF-I and -IGF-II neutralizing antibodies.

Pancreatic Insulinoma Masquerading as Neurological Disease: Diagnosis and Treatment of a Rare Tumor

Insulinomas are rare functional pancreatic neuroendocrine tumors that typically manifest with classic hypoglycemic symptoms, such as diaphoresis, palpitations, and tremors. Although infrequent, neuroglycopenic symptoms associated with insulinomas have been reported, often leading to delayed diagnoses. Here, we present the case of a 31-year-old male with pancreatic insulinoma who experienced recurrent episodes of seizures and confusion preceded by diaphoresis, tremors, and palpitations. During these episodes, he was found to be hypoglycemic. Comprehensive evaluations, including brain and abdominal imaging, as well as biochemical and serological testing, were conducted. The findings confirmed a diagnosis of pancreatic insulinoma. The patient underwent surgical resection of the tumor, and a biopsy confirmed the insulinoma diagnosis. He remained asymptomatic during subsequent follow-ups.

How should we differentiate hypoglycaemia in non-diabetic patients?

Hypoglycaemic syndromes are rare in apparently healthy individuals and their diagnosis can be a difficult challenge for clinicians as there are no shared guidelines that suggest how to approach patients with a suspect hypoglycaemic disorder. Since hypoglycaemia symptoms are common and nonspecific, it's necessary to document the Whipple Triad (signs and/or symptoms compatible with hypoglycaemia; relief of symptoms following glucose administration; low plasma glucose levels) before starting any procedure. Once the triad is documented, a meticulous anamnesis and laboratory tests (blood glucose, insulin, proinsulin, C-peptide, β-hydroxybutyrate and anti-insulin antibodies) should be performed. Results can guide the physician towards further specific tests, concerning the suspected disease. In this review, we consider all current causes of hypoglycaemia, including rare diseases such as nesidioblastosis and Hirata's syndrome, describe appropriate tests for diagnosis and suggest strategies to differentiate hypoglycaemia aetiology.

Contemporary Approaches to the Surgical Management of Pancreatic Neuroendocrine Tumors

The incidence of pancreatic neuroendocrine tumors (PNETs) is on the rise primarily due to the increasing use of cross-sectional imaging. Most of these incidentally detected lesions are non-functional PNETs with a small proportion of lesions being hormone-secreting, functional neoplasms. With recent advances in surgical approaches and systemic therapies, the management of PNETs have undergone a paradigm shift towards a more individualized approach. In this manuscript, we review the histologic classification and diagnostic approaches to both functional and non-functional PNETs. Additionally, we detail multidisciplinary approaches and surgical considerations tailored to the tumor's biology, location, and functionality based on recent evidence. We also discuss the complexities of metastatic disease, exploring liver-directed therapies and the evolving landscape of minimally invasive surgical techniques.

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.

Long-term Survival in a Child with Malignant Insulinoma After Liver Transplantation

Insulinoma is one of the pancreatic neuroendocrine tumors (PanNET) and is exceptionally rare in children. The tumor leads to severe hypoglycemia caused by excessive insulin release. We report a pediatric patient with malignant insulinoma who underwent liver transplantation (LT) due to liver metastases of the insulinoma. A 13-year-old girl presented with symptoms of hypoglycemia due to hyperinsulinism. On computed tomography (CT), a polycystic lesion in the head of the pancreas and enlarged lymph nodes were revealed. A modified Whipple’s operation was performed, and histological examination confirmed PanNET. CT also showed an enlarged liver with numerous metastases. Allogeneic LT was carried out successfully. Positron emission tomography-CT using 68Ga-DOTA-labeled somatostatin analogs (SSAs) at the age of 22 years confirmed complete metabolic remission. The patient currently remains under immunosuppressive and anti-proliferative treatment. Multiple surgical interventions, LT combined with SSAs, and immunosuppressive medication proved effective in this case of metastatic malignant insulinoma.

[Current views on the treatment of insulinoma]

RELEVANCE

Insulinoma is the most common hormonally active neuroendocrine tumor (NET) of the pancreas. In recent years, there has been a trend towards an increase in the incidence of NET especially insulinoma.

AIM

Summarizing and analyzing current data on various approaches to the treatment of insulinoma. Our review includes a comprehensive assessment of the advantages and disadvantages of currently available insulinoma treatment methods in comparison with past experience, as well as a review of promising methods that are not currently widely used.

MATERIALS AND METHODS

Analysis of literature from such databases as scientific electronic library elibrary.ru, Pubmed, Google Scholar, MedLine, Scopus and Web of Science.

RESULTS

The most common treatment for insulinoma is surgery. For patients with high operative risk, alternative methods such as alcohol ablation, radiofrequency ablation, and tumor embolization may be used. Medications include the use of somatostatin analogues, diazoxide. The literature describes the potential benefit of the use of beta-blockers, phenytoin, glucagon, however, in clinical trials, these drugs have not demonstrated a significant effect. For the treatment of malignant and metastatically advanced insulinoma, targeted therapy (primarily Everolimus), chemotherapy, as well as embolization (including chemoembolization, radioembolization), radiofrequency ablation (RFA), microwave ablation and cryoablation, ultrasound ablation (HIFU), laser ablation, brachytherapy, irreversible electroporation are used.

CONCLUSION

The study of new drugs is an important task for scientists, among medications the most promising are new generations of somatostatin analogues, targeted drugs and chemotherapy drugs. The rare frequency of insulinoma makes it difficult to conduct randomized controlled trials and prospective studies. That is why physicians and scientists need to maintain close contacts with each other and take into account the experience of treating each patient with such disease, which will help develop effective treatment algorithms in the future.

Homeostasis Model Assessment of β-Cell Function for Diagnosis of Insulinoma

CONTEXT

Diagnosis of insulinoma is based on different criteria from the 72-hour fasting test according to current guidelines (Endocrine Society [ES], European [ENETS], and North American [NANETS] Neuroendocrine Tumor Societies), including assessment of β-cell function by glucagon stimulation test.

OBJECTIVE

This study tested whether the homeostasis model assessment of insulin secretion, including assessment of β-cell function, (HOMA-B) at the end of the fasting test provides comparable efficacy for insulinoma diagnosis.

METHODS

In 104 patients with suspected insulinoma, 72-hour fasting tests were performed with frequent assessment of glucose, insulin, and C-peptide in venous blood. HOMA-B values using insulin and C-peptide were calculated at the end of the fasting test, as defined by the lowest glucose concentration from each participant.

RESULTS

HOMA-B was more than 6.5-fold higher in patients with (n = 23) than in those without (n = 81) insulinoma (insulin and C-peptide; both P < .001). HOMA-B (cutoff using insulin >253 a.u. and C-peptide >270 a.u.) had a sensitivity of 0.96, 0.78 to 1.00, and a specificity of 0.96 or greater (≥0.89-0.99) for insulinoma diagnosis. ES and ENETS/NANETS criteria reached a diagnostic sensitivity of less than or equal to 0.96 (≤0.78-1.00) and ≤0.83 (≤0.61-0.95) as well as specificity of ≤0.85 (≤0.76-0.92) and less than or equal to 1.00 (≤0.96-1.00) for insulin, and C-peptide, respectively. Using insulin for HOMA-B, sensitivity tended to be higher compared to ENETS/NANETS criteria (P = .063) and specificity was higher compared to ES criteria using insulin and C-peptide (both P < .005).

CONCLUSION

HOMA-B, as calculated at the end of the fasting test employing defined cutoffs for insulin and C-peptide, provides excellent diagnostic efficacy, suggesting that it might represent an alternative and precise tool to diagnose insulinoma.

A Systematic Review of the Accuracy of Insulin and C-peptide Secretion Ratios During the Oral Glucose Tolerance Test to Diagnose Insulinoma

Background

Insulinoma is one of the causes of recurrent hypoglycemia, one of the chief complaints for emergency department admission. The gold standard in diagnosing insulinoma is a 72-hour fasting test which is inconvenient and inefficient as it requires hospitalization. Research has found that measurement of insulin and C-peptide during OGTT may help diagnose insulinoma. We aimed to assess the diagnostic value of OGTT in diagnosing insulinoma.

Methodology

The literature search was conducted on 19 August 2022 using several databases (MEDLINE, Scopus, Embase, and ScienceDirect). All studies that measured OGTT as diagnostic tools in diagnosing insulinoma and 72-hour fasting test as reference standard were included. The quality assessment of the selected studies was based on the Centre of Evidence-Based Medicine University of Oxford and the Quality Assessment of Diagnostic Accuracy-2 tool (QUADAS-2). Analysis of the included studies was performed qualitatively. This study was registered on PROSPERO (CRD42022360205).

Results

A total of two case-control studies (106 patients) were included, which were at risk of bias and low concern of applicability. Both studies demonstrated that the combination of insulin and C-peptide levels measured during OGTT had high specificity, sensitivity, positive predictive value, and negative predictive value in diagnosing insulinoma compared to the reference standard. A logistic regression model of 8.305 - (0.441 × insulin 2-h/0-h) - (1.679 × C-peptide 1-h/0-h) >0.351 has the highest diagnostic value in one study (AUC 0.97, Sensitivity 86.5%, Specificity 95.2%, PPV 94.1, NPV 88.9).

Conclusion

The measurement of 0-h and 2-h insulin and C-peptide levels during 2-h OGTT was found in two small case-control studies with a total of 106 patients to have good sensitivity and specificity. However, due to these limitations, future research is still needed to validate the potential use of OGTT for the diagnosis of insulinoma.

Insulinoma: Metastatic Recurrence 38 Years Following Initial Diagnosis in Pregnancy

A case of recurrent insulinoma spanning 4 decades is described. Following a delayed diagnosis, hyperinsulinemic hypoglycemia was confirmed in a 24-year-old woman during early pregnancy. Initial surgery, culminating in subtotal pancreatectomy, was noncurative. A 1-cm insulinoma was subsequently resected from the head of the pancreas postpartum, with postoperative resolution of hypoglycemia. However, 32 years later, the patient experienced a recurrence of hypoglycemic symptoms. Eventually, a subcentimeter extrapancreatic lesion was identified anterior to the pancreatic head on gallium-68 DOTA-Exendin-4 positron emission tomography/computed tomography. In 2022, a third operation was performed, with excision of a 4 × 3 mm tumor adjacent to the pancreatic head, and histology confirming insulinoma. She was again cured of symptoms.

Peptide Receptor Radionuclide Therapy Is Effective for Clinical Control of Symptomatic Metastatic Insulinoma: A Long-Term Retrospective Analysis

Metastatic insulinoma is a rare malignant neuroendocrine tumor characterized by inappropriate insulin secretion, resulting in life-threatening hypoglycemia, which is often difficult to treat. There is currently very limited information about the efficacy of peptide receptor radionuclide therapy (PRRT) for clinical control of hypoglycemia. The aim of this long-term retrospective study was to evaluate the therapeutic efficacy of PRRT for improving hypoglycemia, to evaluate the change of medication after PRRT, and to calculate progression-free survival (PFS) and overall survival (OS). Methods: Inclusion criteria were histologically proven somatostatin receptor-positive metastatic malignant insulinoma and at least 2 cycles of [90Y]Y-DOTATOC or [177Lu]Lu-DOTATOC therapy from early 2000 to early 2022. A semiquantitative scoring system was used to quantify the severity and frequency of hypoglycemic episodes under background antihypoglycemic therapy (somatostatin analog, diazoxide, everolimus, corticosteroids): score 0, no hypoglycemic episodes; score 1, hypoglycemic events requiring additional conservative treatment with optimization of nutrition; score 2, severe hypoglycemia necessitating hospitalization and combined medication or history of hypoglycemic coma. Hypoglycemic score before and after PRRT was analyzed. Time of benefit was defined as a time range of fewer hypoglycemic episodes in the observation period than at baseline. Information on antihypoglycemic medication before and after therapy, PFS, and OS was recorded. Results: Twenty-six of 32 patients with a total of 106 [90Y]Y-DOTATOC/[177Lu]Lu-DOTATOC cycles were included. The average observation period was 21.5 mo (range, 2.3-107.4 mo). Before therapy, 81% (n = 21) of the patients had a hypoglycemia score of 2 and 19% (n = 5) had a score of 1. After PRRT, 81% of patients (n = 21) had a decreased score, and the remaining 5 patients showed a stable situation. There was temporary worsening of hypoglycemia just after injection of [90Y]Y-DOTATOC/[177Lu]Lu-DOTATOC in 19% of patients. The average time of benefit in the observation period was 17.2 mo (range, 0-70.2 mo). Antihypoglycemic medication reduction was achieved in 58% (n = 15) of patients. The median OS and PFS after the start of PRRT were 19.7 mo (95% CI, 6.5-32.9 mo) and 11.7 mo (95% CI, 4.9-18.5 mo), respectively. Conclusion: To our knowledge, our study included the largest cohort of patients with malignant insulinoma to be evaluated. Long-lasting symptom control and reduction of antihypoglycemic medications were shown in most patients after late-line PRRT.

Insulinoma Presenting as Seizures: Challenges of Managing a Rare Disease in a Resource-challenged Setting

Insulinomas are functioning pancreatic neuroendocrine tumors (NETs). They secrete insulin, and hence, present with hypoglycemia. We report a case of insulinoma in a 16-year-old girl presenting as seizures. She was initially managed at a private clinic and later commenced on carbamazepine when convulsion persisted. Convulsions were generalized, associated with dizziness and altered sensorium, often preceded by hunger and physical exertion, but relieved by the intake of carbonated drinks and fruit juice. She was referred to the neurology clinic when seizures persisted, despite the use of anticonvulsant. She was later referred to the endocrine clinic on suspicion of insulinoma when her random blood glucose (BG) was found to be low during an episode of convulsion. She was moderately obese but other examination findings were normal. She had a 72-hour prolonged fast, which was terminated when hypoglycemia (BG = 2.2 mmol/L) ensued after 12 hours, with elevated serum insulin and C-peptide. Abdominal magnetic resonance imaging scan showed a pancreatic tumor suggestive of insulinoma. She subsequently had distal pancreatectomy performed with complete resolution of symptoms. Unusual presentation of insulinoma may delay diagnosis, resulting in wastage of resources with increased morbidities and mortality.